Field of the invention
[0001] The invention relates generally to an artificial turf, and, more particularly, to
an artificial turf infill comprising olive pit material, to an artificial turf using
said artificial turf infill, and a method of making said artificial turf infill.
Background
[0002] Use of artificial turf for the surface of sport fields, natural lawn replacement
for back yards and public squares, etc. is increasing rather rapidly due to the convenience
and economic efficiency of maintenance compared to natural turf.
[0003] One of the problems associated with existing artificial turf designs is the use of
synthetic materials like rubber and elastic particles as infill which can find their
way into various waterways and water reservoirs.
[0004] Heretofore some efforts have been made for the development of an infill that uses
organic materials rather than elastic synthetic materials. See, for example,
EP2917413B1 ("EP'413"),
US10822751B2 ("US'751"), and
US 10822752B2 ("US'752") proposing various bio-based materials. The EP'413 and the US'751 patents
describe the use of vegetable material comprising the rachis of cereal ear as infill,
while the US'752 patent describes an infill which uses cellulosic fiber material from
pine wood.
[0005] EP3868955A1 patent application describes using olive pit particles as infill for artificial turf
which are produced by crushing naturally occurring pits in a grinder, granulator,
or cracker mill. The general concept of using olive pit particles is rather known
since at least 2010 by the publication of
US2010/055461 patent application which describes an artificial turf having organic particles of
a group consisting of, coconut shells, ground pecan shells, ground peanut shells,
ground corn cobs, and ground olive stones. See also the
US2018/0080183,
US6,632,527,
US2002/0048676,
US2006/0121236,
US2008/0176010, and
US2015/0252537 patent references which describe various bio-based material infills for artificial
turfs.
[0006] The article "Sustainable infill from natural olive pits," published in the Kompendium
Sportplatz journal 3
rd Edition 2022, p. 107, describes grinding olive pits and using the generated olive
particles as infill for an artificial turf.
[0007] Despite the above rather limited attempts to produce an artificial turf infill purely
or predominantly comprising organic materials that has satisfactory performance characteristics
in varying weather conditions over an extended period of time, to date there is no
practical solution that can satisfy these requirements. Improved solutions are needed
that employ organic infill that protects the environment, provides proper foot traction,
reduced biodegradation and enhanced resistance to microbial infestations in moist
and wet conditions.
Summary of the Invention
[0008] The present invention provides an artificial turf infill, an artificial turf employing
the artificial turf infill, and a method of forming the artificial turf infill in
the independent claims. Various embodiments of the present invention are given in
the dependent claims. Embodiments of the present invention provide new, improved solutions
to the above problems associated with the prior art.
[0009] According to an aspect of the present invention an artificial turf infill is provided
comprising an olive pit material, and microporous zeolite particles.
[0010] The olive pit material may comprise rounded and thermally treated olive pit fragments
having a size of 0.5 mm or greater, in particular 0.5 mm to 4.0 mm, more in particular
0.5 mm to 2.5 mm, and most in particular 0.5 mm to 2.0 mm, in an amount of at least
80.0 wt%, in particular 90.0 wt% to 99.0 wt%, more in particular 95.0 wt% to 99.0
wt%, and most in particular 98.0 wt% to 99.0 wt% of the total weight of the total
olive pit material in the infill. The olive pit material may further comprise olive
pit particles having a size of less than 63 µm in an amount of at least 0.5 wt%, in
particular 1.0 wt% to 20.0 wt%, more in particular 1.0 wt% to 10.0 wt %, and most
in particular 1.0 wt% to 2.0 wt% of the total olive pit material in the infill.
[0011] The olive pit material may have a bimodal size distribution with a major mode and
a minor mode, wherein the major mode comprises the rounded, thermally treated olive
pit fragments and has a peak between 0.5 mm to 4.0 mm, more in particular 0.5 mm to
2.5 mm, and most in particular 0.5 mm to 2.0 mm, and wherein the minor mode comprises
the olive pit particles and has a peak at less than 63 µm.
[0012] The olive pit material may be thermally treated at a temperature of 80 °C to 250
°C.
[0013] The rounded, and thermally treated olive pit fragments may be obtained by a tumbling
treatment of fractured olive pits together with the microporous zeolite particles.
The olive pit fragments may be formed by fracturing in an olive oil extraction process
during a compression operation of the olives for extracting oil from the olives and
have sharp edges due to the fracturing. The thermo-tumbling process smoothens the
sharp edges by attrition by rubbing the olive pit particles against each other and
against the microporous zeolite particles to form the rounded, thermally treated olive
pit fragments.
[0014] The microporous zeolite particles may be added in the infill in an amount of 1.0
to 30.0 wt%, in particular 5.0 to 25.0 wt%, and more in particular 10.0 to 20.0 wt%
of the total amount of the infill.
[0015] The microporous zeolite particles may have a grain size between 0.1 mm and 1.5 mm,
in particular between 0.4 mm to 1.2 mm, and more in particular between 0.9 mm and
1.2 mm, and a maximum surface specific surface area of 21 m
2/g.
[0016] The microporous zeolite particles may have a porosity between 15% and 20% volume
parts.
[0017] In some embodiments, the microporous zeolite particles may have a grain size distribution
wherein 70% to 90% of the grains by weight have a size in the range of 0.4 mm to 1.5
mm and 10% to 30% of the grains by weight have a size smaller than 0.4 mm.
[0018] The microporous zeolite particles may have a hardness between 3.5 and 5.5 on the
Mohs scale and a moisture level smaller than 6 wt% as measured by the wet method,
i.e., based on the total weight of the zeolite solids and moisture.
[0019] The artificial turf infill may further comprise at least one further bio-based material
including pit fragments of at least one other stone-containing fruit, wherein the
pit fragments of the further bio-based material have a different elasticity than the
rounded, and thermally treated olive pit fragments, and wherein the at least one further
bio-based material comprises cork particles, rounded cherry pit fragments, and combinations
thereof.
[0020] The artificial turf infill may comprise only bio-based materials and being free of
any rubber, elastomeric, or polymer-based infill, and, in particular also free of
any sand.
[0021] Another aspect of the present invention is directed to an artificial turf comprising
the artificial turf infill as described above and in any of the claims 1-12.
[0022] The artificial turf may further comprise:
a stabilization layer comprising or consisting of at least one of sand, the olive
pit particles, and at least a portion of the microporous zeolite particles; and
a performance layer positioned on the stabilizing layer, wherein the performance layer
comprises or consists of the artificial turf infill of any of the preceding claims
or comprises or consists of the rounded and thermally treated olive pit fragments
and is basically free of the olive pit particles.
[0023] Yet another aspect of the present invention is directed to a method of creating an
artificial turf, the method comprising:
installing an artificial turf,
applying the artificial turf infill of any one of claims 1-14 on the installed artificial
turf, wherein the infill comprises at least a mixture of the rounded, olive pit fragments,
the olive pit particles and the microporous zeolite particles, wherein the applying
the artificial turf infill on the installed artificial turf is performed in a single
step,
allowing the olive pit particles in the applied infill to automatically trickle down
into the voids between the fragments, thereby automatically forming a stabilizing
layer consisting essentially of the trickled-down particles, and a performance layer
containing the rounded olive pit fragments,
wherein at least a portion of the microporous zeolite particles trickles down and
settles into the stabilizing layer.
Yet another aspect of the present invention is directed to a kit for manufacturing
an artificial turf, the kit comprising the artificial turf infill of any of the claims
1 to 16 and at least one other component for making the artificial turf.
[0024] Unlike the prior art, where olive pits are crushed into sharp, and comparatively
very small infill particles using an extra crushing step, the present invention uses
larger size olive pit fragments from olive oil extraction processes without applying
an additional crushing step. The sharp edges of the olive pit particles may make them
uncomfortable to the skin of the artificial turf users and may even injure the skin
of the artificial turf users.
[0025] Unlike the prior art, the present invention further treats the olive pit fragments
for rounding their edges, make them smoother before using them as infill.
[0026] Unlike the prior art, the present invention olive pit fragments are thermally treated
for removing the residual odor from the olives, increasing their surface hardness
and tenacity, and making them antimicrobially resistant, and attrition resistant.
[0027] Unlike the prior art, the method of the present invention is free of a step which
crushes or grinds the not-yet rounded olive pit fragments or the rounded olive-pit
fragments.
[0028] These and other features and advantages of the present invention will become better
understood from the following detailed description of the invention in conjunction
with the accompanying drawings.
Brief Description of the Drawings
[0029] In the following, embodiments of the invention are explained in greater detail, by
way of example only, making reference to the drawings in which:
Figure 1 shows an artificial turf having an infill from rounded and thermally treated
olive pit fragments according to some embodiments of the present invention;
Figure 2A is a simplified schematic of an olive extraction process according to some
embodiments of the present invention;
Figure 2B is a simplified schematic of a thermo-tumbling process according to some
embodiments of the present invention followed by a sieving operation;
Figure 3 shows a further embodiment of an artificial turf with an infill comprising
a stabilization layer and a performance layer;
Figures 4A and 4B illustrate a single step application of an infill mixture on the
artificial turf and its subsequent self-segregation into a stabilizing and a performance
layer;
Figure 5 is a simplified flow chart of a method of making an infill according to some
embodiments of the present invention; and
Figures 6A to 6E shows rounded and thermally treated olive pit fragments produced
by the thermo-tumbling process at different magnifications in an infill layer formation.
Detailed Description of the Invention
[0030] Like numbered elements in these figures are either equivalent elements or perform
the same function. Elements which have been discussed previously may not necessarily
be discussed in later figures.
[0031] According to its broadest aspects the present invention provides a bio-based infill
that exhibits improved performance characteristics in varying weather conditions over
an extended period of time. The bio-based infill includes an olive pit material and,
in some embodiments, at least one other bio-based infill. In some embodiments the
bio-based material includes microporous zeolite particles. The present invention further
provides a method for making the artificial turf infillartificial turf infillinfill.
[0032] In some embodiments, the olive pit material is prepared using olive pit fragments
generated in an oil extraction process which uses compression for extracting the olive
oil. For example, the oil extraction process may employ an olive press. The olive
pit fragments may have sharp edges which are created when the olive pits break under
the compression force in the olive press. In some embodiments, the present invention
uses a tumbling treatment of the olive pit fragments to smoothen their sharp edges,
and provide rounded olive pit fragments which are substantially free of any sharp
edges. The same tumbling process may also be used for any additional bio-based material.
In some embodiments, the additional bio-based material may be tumbled together with
the olive pit fragments to enhance the effectiveness of the tumbling process in rounding
the sharp edges of the olive pit fragments. In some embodiments, the artificial turf
infill comprises the rounded olive pit fragments prepared by the tumbling treatment
process.
[0033] Rounded as this term is used here, means that the fragments do not have sharp edges
which can cause skin injury to the users of the artificial turf.
[0034] According to embodiments, rounded fragments are fragments generated in an abrasive
process, in particular by tumbling. As a consequence of tumbling, traces of tumbling
may be visible on the surface of the fragments.
[0035] The tumbling of the olive pit fragments generates an olive pit material having bimodal
size distribution with a major mode comprising rounded olive pit fragments having
a size greater than 0.5 mm, in particular 0.5 mm to 4.0 mm, more in particular 0.5
mm to 2.5 mm, and most in particular 0.5 mm to 2.0 mm. A minor mode of the bimodal
distribution comprises olive pit particles having a size of less than 63 µm.
[0036] According to embodiments, the tumbling is controlled to generate the olive pit particles
having a size less than 63 µm in an amount of at least 0.5 wt%, in particular 1.0
wt% to 20.0 wt%, more in particular 1.0 wt% to 10.0 wt %, and most in particular 1.0
wt% to 2.0 wt% of a total olive pit material generated by the tumbling. Controlling
the tumbling includes controlling the tumbling intensity and the duration of the tumbling
among other things. Other parameters may include the presence or absence of other
materials and the design characteristics of the tumbling apparatus such as internal
design, size, and the presence of any baffles.
[0037] In some embodiments, the olive pit material comprising the olive pit fragments is
thermally treated. The thermal treatment may be performed simultaneously with the
tumbling treatment or separately from the tumbling treatment.
[0038] The conditions of the thermal treatment may be modified to adjust its effects on
the moisture and chemical composition of the olive pit material which in turn affect
the properties of the olive pit fragments.
[0039] The tumbling and/or thermal treatments allow adjusting the properties of the infill
to improve the overall design of an artificial turf. For example, depending on turf
blade length, density and other characteristics of an artificial turf, the infill
may be modified as may be needed by changing the size, roundness, surface hardness,
tenacity, moisture content and even chemical composition of the olive pit fragments.
These adjustments can be done by changing the time, and intensity of the tumbling
and/or of the thermal treatments.
[0040] The removal of the sharp edges via the tumbling process in combination with the thermal
treatment of the olive pit fragments results in an olive pit material that when added
as infill in an artificial turf exhibits an exceptional balance of traction, energy
absorption, stable foot and energy restitution characteristics which can meet the
standards for professional sport fields artificial turfs, including soccer, rugby,
American football and the like. In this regard, it is believed, without wishing to
be bound by theory, that the rounded surface hardened fragments allow a controlled
rolling movement against each other, thus preventing excessive friction with the shoes
of the athletes using the turf. At the same time the rounded surface hardened fragments
provide sufficient support and stable footing.
[0041] The olive pit material of the invention can be used as infill for artificial turfs
for professional sport fields, however, it can also be used in other applications
such as, for example, artificial turfs in parks and private gardens.
[0042] According to some embodiments of the present invention, an artificial turf infill
is provided comprising rounded and thermally treated olive pit fragments.
[0043] According to some embodiments, the infill comprises rounded and thermally treated
olive pit fragments and optionally whole olive pits. The whole pits are olive pits
which did not break during the oil extraction process or during the thermo-tumbling
treatment.
[0044] According to some embodiments, the infill comprises rounded and thermally treated
olive pit fragments, olive pit particles and optionally also some whole olive pits.
[0045] It is noted that the size of the fragments can be adjusted within the aforementioned
ranges to meet the specific design requirements of an artificial turf which may also
depend on the length of the turf fibers and the density of the turf fibers. One of
the advantages of the present invention is that the size, surface hardness, and degree
of smoothness (or roughness) of the fragments, can be customized to meet the requirements
of any particular artificial turf design by adjusting the processing conditions of
the tumbling and thermal treatments.
[0046] According to some embodiments, an "olive pit particle" is a piece of olive pit material
with a size of less than 63 µm in size (larger dimension or diameter). It is noted
that having the olive pit particles in the infill is generally advantageous because
they tend to settle and form a lower stabilization layer which can eliminate the need
for a stabilization layer of sand which is used conventionally in existing artificial
turf infill systems. An infill without sand is desirable because sand tends to stick
very tightly to the other artificial turf material (especially to the backing of the
artificial turf) and can damage the shredders used to shred the artificial turf material
when the artificial turf is recycled at the end of its useful life. Also, the process
of installing the artificial turf is simplified because a step of adding a sand layer
can be eliminated.
[0047] According to some embodiments, the total amount of olive pit material in the infill
comprises at least 80.0 wt%, in particular 90.0 wt% to 99.0 wt%, more in particular
95.0 wt% to 99.0 wt%, and most in particular 98.0 wt% to 99.0 wt% of the rounded and
thermally treated olive pit fragments. Also, the olive pit particles may be in an
amount of at least 0.5 wt%, in particular 1.0 wt% to 20.0 wt%, more in particular
1.0 wt% to 10.0 wt%, and most in particular about 1.0 wt% to 2.0 wt% of the total
weight of the olive pit material.
[0048] According to some embodiments, the total amount of olive pit material in the infill
comprises 95.0 wt% to 99 wt% of the rounded and thermally treated olive pit fragments
having a size of 0.5 mm to 2.0 mm and olive pit particles having a size of less than
63 µm, in an amount of 1.0 wt% to 2.0 wt% of the total weight of the olive pit material.
[0049] According to some embodiments, the total amount of olive pit material in the infill
comprises 98.0 wt% to 99.0 wt% of the rounded and thermally treated olive pit fragments
having a size of 0.5 mm to 2.0 mm and olive pit particles having a size of less than
63 µm, in an amount of 1.0 wt% to 2.0 wt % of the total weight of the olive pit material.
[0050] According to some embodiments, the rounded and thermally treated olive pit fragments
are obtained by a thermo-tumbling treatment of olive pit fragments. The olive pit
fragments are formed in an olive oil extraction process which employs a compression
operation of the olives for extracting oil from the olives. The compression oil extraction
process causes the olive pits to break creating the olive pit fragments which generally
may have sharp edges. The olive pit fragments are separated from the other products
of the olive oil extraction process, i.e., the extracted olive oil, the pulp and the
skin of the olives and are subjected to the thermo-tumbling treatment. The thermo-tumbling
treatment smoothens the sharp edges of the fragments. Olive pit particles having a
size of less than 63 µm may be generated during the tumbling treatment. According
to some embodiments, the thermo-tumbler product including the rounded olive pit fragments
and the olive pit particles obtained from the thermo-tumbling treatment are sieved
to remove at least partially some of the olive pit particles.
[0051] According to some embodiments, an artificial turf infill is provided which comprises,
in addition to the rounded and thermally treated olive pit fragments, at least one
further biobased material including pit fragments of at least one other stone-containing
fruit (i.e., other than olives), wherein the pit fragments of the further bio-based
material have a different elasticity than the rounded and thermally treated olive
pit fragments.
[0052] According to some embodiments, the at least one further bio-based material comprises
cork particles, cherry pit fragments and combinations thereof. The cork and cherry
pit fragments may be subjected to the same tumbling and thermal treatments as the
olive pit fragments. The cork and cherry pit fragments may be subjected to the same
tumbling and thermal treatments as the olive pit fragments, for example, by adding
them in the same thermo-tumbler apparatus together with the olive pit fragments. According
to some embodiments, the infill fragments made of the further bio-based material may
be larger than the rounded and thermally treated olive pit fragments. According to
some embodiments, the infill fragments made of the further bio-based material may
have a size (largest dimension or diameter) of 0.5 to 4.0 mm, in particular 0.5 to
3.0 mm.
[0053] According to an aspect of the present invention, an artificial turf is provided using
the inventive artificial turf infill. According to some embodiments, the artificial
turf may comprise a stabilization layer comprising or consisting of the olive pit
particles. In some embodiments, the stabilization layer may also include particles
of the at least one other bio-based material. The olive pit particles and when used
the particles of the at least one other bio-based material may be obtained from the
thermo-tumbling treatment. The artificial turf may also comprise a performance infill
layer positioned over the stabilization infill layer. The rounded and thermally treated
olive pit fragments may form the performance infill layer. The performance infill
layer may cover the stabilization layer. In some embodiments, the performance infill
layer may also include fragments of the at least one other bio-based material in addition
to the rounded and thermally treated olive pit fragments. The rounded and thermally
treated olive pit fragments and the fragments of the other bio-based material may
be obtained from the same tumbling and thermal treatments.
[0054] According to some other embodiments the artificial turf may comprise an infill layer
made of the rounded and thermally treated olive pit fragments. In yet some other embodiments
the artificial turf may comprise an infill layer made of the rounded and thermally
treated olive pit fragments and fragments of the at least one other bio-based material.
[0055] Preferably, the artificial turf comprises an infill which consists entirely of bio-based
materials.
[0056] A "bio-based material" as used herein is a material wholly or partly derived from
materials of biological origin, excluding materials embedded in geological formations
and/or fossilized materials. In particular, bio-based materials can be materials which
predominantly (> 50 wt%) comprise or consist of biodegradable and/or compostable materials,
and, in some embodiments, materials only consisting of compostable materials.
[0057] Hence, unlike typical artificial turf infill, the present invention infill can be
made totally free of any sand, or of any non-bio-based, synthetic infill like the
rubber, elastomeric, or polymer-based materials used in infills of the state of the
art.
[0058] According to another aspect of the present invention, zeolite particles may be added
in the infill of the artificial turf. Preferably, the zeolite particles are added
in the stabilization layer. Preferably, the zeolite particles may be microporous zeolite
particles. These microporous zeolite particles provide a cooling effect via storing
water in their pores during rainy weather conditions or when the turf is watered,
and slowly releasing via evaporation of the stored water during hot days.
[0059] In some embodiments, an infill is provided which is made of biodegradable material,
and is essentially free of any synthetic, non-biodegradable material. Essentially
free means that less than 1 wt%, preferably less than 0.5 wt% of the infill may be
synthetic, non-biodegradable material. Other natural materials such as zeolite and
sand may be added in the infill.
[0060] In some embodiments, an infill is provided which is made of compostable material,
and is essentially free of any synthetic, non-biodegradable material. Essentially
free means that less than 1 wt%, preferably less than 0.5 wt% of the infill may be
synthetic, non-biodegradable material. Other natural materials such as zeolite and
sand may be added in the infill.
[0061] According to yet another aspect of the present invention, the rounded and thermally
treated olive pit fragments are made accordingly to a method comprising providing
olive pit fragments from an oil extraction process employing compressing the olives
for extracting the olive oil, and tumbling the olive pit fragments to smoothen sharp
edges of the olive pit fragments to produce rounded olive pit fragments. For example,
the method may include feeding the olive pit fragments in a tumbler, and tumbling
them at an effective tumbling intensity and for an effective amount of time to smooth
out substantially all sharp edges of the olive pit fragments and produce rounded and
thermally treated olive pit fragments.
[0062] According to some embodiments, the tumbling intensity may be adjusted to effectively
remove all sharp edges of the olive pit fragments. The tumbling is performed at an
effective tumbling intensity and for an effective amount of time inside the tumbler
apparatus to generate rounded olive pit fragments which are substantially free of
any sharp edges. As a result of the smoothening of the sharp edges the very small
size olive pit particles are formed.
[0063] The tumbling generates an olive pit material having a bimodal size distribution.
[0064] In some embodiments, the method may further comprise thermally treating the olive
pit fragments. According to some embodiments, thermal treatment involves heating to
a temperature of 80 °C to 130 °C, in particular 100 °C to 130 °C, and more in particular
110 °C to 130 °C.
[0065] Thermal treatment in this temperature range between 80 °C and 130 °C may remove any
residual natural smell of the olive pits and may also reduce the amount of equilibrium
moisture in the olive pit material.
[0066] In some embodiments, heat treatment means that the olive pit fragments are heated
to a sufficiently high temperature, that the heat treatment not only reduces the equilibrium
moisture of the olive pit material and eliminates any residual olive odor, but also
modifies their chemical structure. Chemical modification of the olive pit structure
may be measured by X-ray photoelectron analysis (XPS) of the oxygen to carbon ratio
of the material. In some embodiments, thermally treated olive pit material means that
the olive pit material has been sufficiently heated to show at least a 3%, preferably
at least 5%, and more preferably 5% to 10 % reduction in the oxygen to carbon ratio
compared to thermally untreated olive pit material as measured by XPS analysis. It
has been found that such higher temperature thermal treatment transforms the olive
pit material to become (like tropical wood) more durable and resistant to decay in
a moist/humid environment. It has been found that heating above a temperature of 130
°C, and preferably 150 °C is needed for this chemical modification to occur.
[0067] Thermal treatment at higher temperatures than 150 °C, in particular 160 °C to 250
°C, and more in particular of 180 °C to 250 °C has the advantage that the antimicrobial
resistance of the olive pit fragments is increased, and their hygroscopicity is reduced
significantly. Also, the surface hardness and tenacity of the treated material is
increased. The olive pit fragments become more durable, more resistant to biodegradation
in moist and humid conditions and also more resistant to additional fracturing or
attrition when used as infill in an artificial turf.
[0068] In some embodiments, the thermal treatment heats the olive pit material to a temperature
higher than 150 °C, in particular 160 °C to 250 °C, and more in particular 180 °C
to 250 °C.
[0069] Thermal treatment at these higher temperatures has the benefit of increasing the
resistance of the olive pit fragments against moisture-induced biodegradation, which
is particularly beneficial in humid regions or when the artificial turf infill comprises
a zeolite which is irrigated frequently before and during a game to cool the sports
field and the players.
[0070] Although not wishing to be bound by any particular theory, it is believed that heat
treatment at the elevated temperature above 130 °C and in particular at a temperature
of 150 °C to 250 °C not only removes any residual moisture or odors but, more importantly,
also changes the chemical structure/composition of the hemicellulose, cellulose and
lignin components of the olive pit fragments which results in substantially reduced
hygroscopicity or effectively almost zero hygroscopicity for the thermally treated
olive pit material at such temperatures. As a result, the olive pit material becomes
resistant to natural biodegradation and is also much less likely to suffer from microbial
infestations. These properties make the thermally treated artificial turf infill of
the present invention particularly suitable to be used with microporous zeolite particles
that can be used to store water during watering of the turf and release it gradually
thereafter, thus, cooling the turf and the athletes (or users) of the turf without
reducing the useful lifespan of the infill (and of the turf) due to the increased
moisture conditions. Thus, the artificial turf infill and artificial turf using the
artificial turf infill of the present invention can be watered more frequently and
also last longer than existing turfs.
[0071] Heating for the thermal treatment may be performed with any suitable means. In some
embodiments, hot air, steam or superheated steam may be fed inside a tumbling apparatus
and the heat treatment may be performed simultaneously with the tumbling treatment.
In some other embodiments the heat treatment may be performed separately and independently
of any tumbling treatment, for example in an oven. The temperature and duration of
the thermal treatment may be adjusted as may be needed for adjusting the effects of
the heat treatment on the properties of the olive pit material.
[0072] In some embodiments the duration of the tumbling treatment of the olive pit fragments
may range for a period of 1 minute to 8 minutes, and in particular for a period of
2 minutes to 6 minutes. For example, the tumbling treatment may in some embodiments
last for a period of 2.5 minutes to 3 minutes. However, these time periods are provided
only as examples, and longer periods may be used without departing from the scope
of the present invention. For example, generally, the tumbling and/or thermal treatment
may last from a few minutes to a few hours.
[0073] According to some embodiments, the method comprises sieving the thermo-tumbler product
to remove at least some of the thermo-tumbler product olive pit particles having a
size of less than 63 µm. The removed olive pit particles may be used for forming a
stabilization layer for the infill.
[0074] In a preferred embodiment, the product from the thermo-tumbler is used without separation
or sieving to form an infill layer for an artificial turf. According to some embodiments,
the method further comprises mixing together with the olive pit fragments, or the
rounded olive pit fragments or the rounded and thermally treated olive pit fragments,
at least one other bio-based material including cork particles, and cherry pits whole,
fragments, or mixtures thereof.
[0075] For example, fragments of at least one other bio-based material may also be fed in
a thermo-tumbler and mixed together with the olive pit fragments.
[0076] According to some embodiments, at least one of sand, and zeolite, preferably just
zeolite and, in particular, microporous zeolite particles, may be mixed together with
the olive pit fragments, or the rounded olive pit fragments or the rounded and thermally
treated olive pit fragments and the at least one other bio-based material.
[0077] The microporous zeolite particles are added in an amount of 1.0 to 30.0 wt%, in particular
5.0 to 25.0 wt%, and more in particular 10.0 to 20.0 wt% of the total amount of the
infill. The zeolite is added for providing a cooling effect in the infill because
the zeolite microporous material absorbs water in rainy, wet conditions and releases
by evaporation in hot sunny days to cool down the infill and the turf. The zeolite
may also improve the overall shaping of the olive pit fragments and of any additional
bio-based additional stones by providing added abrasion during the tumbling process.
[0078] According to some embodiments, the infill comprises only bio-based materials and
is free of any rubber, elastomeric, or polymer-based infill, and is preferably also
free of any sand.
[0079] The method for making the artificial turf infill according to the present invention
does not include any step of crushing or grinding the not-yet rounded olive pit fragments
or the rounded olive-pit fragments.
[0080] According to another aspect of the present invention, a method of use of the artificial
turf infillartificial turf infillinfill is provided wherein the artificial turf infill
can be used to form the infill of an artificial turf.
[0081] According to some embodiments, a method for forming an infill for an artificial turf
is provided, the method comprising:
providing an infill mixture comprising:
component a including the rounded and thermally treated olive pit fragments and optionally
fragments of at least one additional bio-based material,
component b comprising microporous zeolite particles, and
component c comprising olive pit particles, and
applying the infill mixture of components, a, b and c in a single-step on an installed
artificial turf system comprising a plurality of turf fibers secured to a backing
material,
wherein within a period of time of one month or less, preferably 1week or less, and
more preferably 1 day or less the components a, b, and c separate into at least a
stabilization layer, and a performance layer which forms over the stabilization layer,
wherein the stabilization layer comprises the thermo-tumbler product olive pit particles,
and the microporous zeolite particles, and
wherein the performance layer comprises the rounded and thermally treated olive pit
fragments and when used the particles of the at least one other biobased material.
According to some embodiments, sand may be used as part of the component b and may
settle to become part of the stabilization layer, however, such embodiment is less
preferred.
[0082] Via the thermo-tumbling treatment, the olive pits and olive pit fragments obtain
a rounded shape which is designed to protect the skin of the players from injury,
improves the packing density of the infill, reduces undesired water splashing in rainy
conditions, and minimizes infill migration into the environment. In addition, the
rounded and thermally treated olive pit material has no residual olive odor, has antimicrobial
resistance, enhanced surface hardness and tenacity.
[0083] The thermo-tumbler product may be used directly or after subsequent post-processing
removal of the olive pit particles as artificial turf infill.
[0084] The thermo-tumbler product comprises olive pit particles (dust-like particles generated
by abrasion). According to some embodiments, the method of preparing the infill, further
comprises a sieving operation of the thermo-tumbler product to reduce the amount of
the olive pit particles having a size of less than 63 µm to an amount of 2.0 % or
less of the thermo-tumbler product, preferably to an amount of 1.0 to 2.0 % by weight
of the thermo-tumbler product. Keeping this level of olive pit particles has been
found to be beneficial because the olive pit particles allow for a higher packing
density of the infill. According to some embodiments, further sieving is possible
to reduce the amount of olive pit particles to less than 1.0 wt %.
[0085] The removed olive pit particles from the thermo-tumbler product can be used as infill
for a stabilization layer either alone or together with sand and/or zeolite, preferably
with zeolite only.
[0086] When zeolite and/or sand are used, they are also preferably added in the thermo-tumbler
to increase the abrasive effect/rounding effect of the thermo-tumbler treatment step.
[0087] According to some embodiments, a sand, zeolite, and rounded olive pit fragment mixture
is used in particular as the stabilization layer. The zeolite has the additional advantage
of cooling the artificial turf. In another embodiment, a zeolite and rounded olive
pit fragment mixture is used in particular as the stabilization layer.
[0088] According to some embodiments, a method of creating an artificial turf, comprises
installing an artificial turf, and applying the artificial turf infill on the artificial
turf. The infill comprises at least a mixture of the rounded and thermally treated
olive pit fragments and of the olive pit particles, whereby the application is performed
in a single step. The method further comprises allowing the olive pit particles in
the applied infill to automatically trickle down into the voids between the fragments,
thereby automatically forming a stabilization layer consisting essentially of the
trickled-down particles, and a performance layer containing the rounded olive pit
fragments. The infill mixture may further include zeolite which may also settle and
become art of the stabilization layer. The infill mixture may also comprise at least
one other bio-based material which can form the performance layer. It has been found,
rather unexpectedly that the tumbling treatment of the olive pit fragments helps this
segregation and trickle-down effect, possibly because in addition to the large difference
in the relative size of the fragments and the particles their enhanced round shape
obtained by the tumbling helps the movement of the small size particles through the
much larger fragments. Referring now to figure 1, an artificial turf 10 is provided
which comprises an infill 12 comprised of rounded and thermally treated olive pit
fragments 24 obtained by a thermo-tumbling treatment of olive pit fragments. The infill
12 further contains olive pit particles 26 also obtained from the thermo-tumbling
process. The olive pit particles 26 are smaller in size than the rounded and thermally
treated olive pit fragments 24. The olive pit particles 26 have a size of less than
63 µm.In the illustrated embodiment, the olive pit particles 26 may be in an amount
of 0.5 wt% to 2.0 wt% and the rounded and thermally treated fragments 24 may be in
an amount of 98.0 wt% or greater of the total olive pit material. The olive pit particles
26 may eventually settle to a lower part of the infill 12. In FIG. 1, an enlarged
image of the rounded, and thermally treated olive pit fragments are shown from a section
of the infill. More images of the olive pit infill in different magnifications are
shown in figures 6A to 6E.
[0089] Referring now to figure 2A, the olive pit fragments 6 are formed in an olive oil
extraction process 2, for example, during a compression operation of olives 1 for
the extraction of the olive oil 3 from the olives. Olive oil extraction processes
using compression of the olives are well known and, therefore, are not described here
in detail. It should also be understood that the olive pit fragments 6 may contain
some whole pits, i.e., non-fractured pits.
[0090] As illustrated in Figure 2A, the olive pit fragments 6 are separated from the other
products, i.e., the extracted olive oil 3, and the olive pulp and skin 4. As shown
in FIG. 2B, the olive pit fragments 6 are fed to a thermo-tumbler 21 to be subjected
to a thermo-tumbling treatment.
[0091] In a preferred embodiment, the infill 12 of figure 1 consists of a single layer of
infill formed of only rounded and thermally treated olive pit fragments 24 and olive
pit particles 26 from the thermo-tumbling process, without any rubber-based infill,
or polymer-based infill and, more preferably, without any non-bio-based material including
any sand.
[0092] In a variation of the embodiment of figure 1, the olive pit particles 26 in the infill
12 may be reduced or totally removed by subjecting the thermo-tumbler product 29 to
at least one sieving operation to remove some or all of the olive pit particles 26.
[0093] The artificial turf 10 comprises a plurality of the artificial turf fibers 16 securely
attached to the backing 11. The fibers 16 may be texturized with a non-straight shape
such as curly, wavy, or folded shape. The texturization can be produced mechanically
or chemically using well-known methods during the fiber manufacturing. The artificial
turf fibers may have a density (number of fibers per artificial turf area) and/or
degree of texturization that under a bird's eye perspective, at least 60%, more preferentially
at least 70% of the size of the area covered by the artificial turf consists of the
fibers and the rest consists of the carrier mesh or the backing or the infill.
[0094] The turf fibers 16 may be made of synthetic polymer material such as, for example,
polyethylene ("PE"), polypropylene ("PP"), polyamide ("PA"), or combinations thereof.
The fibers 16 may be mono filament, slit film, fibrillated, texturized, or combinations
thereof. The backing 11 may be made of any suitable material. For example, the backing
11 may comprise a thermoset polymer material. According to some embodiments, the backing
11 may comprise a polyurethane resin. However, it is noted that the invention is not
limited in any particular turf fiber or backing materials and other suitable turf
fiber and backing materials may be used.
[0095] The pile height of the artificial turf may vary by design and may be, for example,
between about 10.0 mm to about 100.0 mm, preferably between 15.0 mm to 70.0 mm. The
pile height is the distance measured from the bottom surface of the turf backing 11
to the tip of the fibers 16. The fibers 16 can be attached to the turf backing 11
by any suitable method including, for example, tufting, weaving, knitting, needle
punching, or a combination thereof.
[0096] The height of the infill 12 may vary by design and also the pile height. A typical
infill height is from about 10.0 mm to 50.0 mm. The infill height is designed to provide
adequate weight of the infill per square area of the infill to prevent movement and
wrinkles on the artificial turf surface.
[0097] Referring to figure 2B, the thermo-tumbling treatment of the olive pit fragments
24 comprises placing them inside a rotating thermo-tumbler 21 and tumbling them while
at the same time flowing hot air through the thermo-tumbler 21 to obtain a mixture
of rounded and thermally treated olive pit fragments, and olive pit particles. The
olive pit articles may also be referred to as olive pit dust and are basically created
in the thermo-tumbler through the abrasion of the sharp edges of the fragments. The
intensity and duration of the tumbling can be adjusted to avoid excessive formation
of olive pit particles 26. Typically, the intensity, and duration of the tumbling
are controlled to keep the amount of olive pit particles to less than 5.0 wt%, and,
more preferably, to less than 2.0 wt% of the total olive pit material.
[0098] According to some embodiments, hot air or steam may be used for thermally treating
the olive pit fragments. The olive pit particles are olive pit fragments of less than
63 µm. The thermo-tumbling treatment may be a batch or a continuous process. Preferably,
the thermo-tumbling treatment is a continuous process. Any suitable thermo-tumbling
apparatus may be used.
[0099] Although, the tumbling and the thermal treatment in the described embodiments are
performed simultaneously and in the same apparatus, it is to be understood, that this
is just an example of a preferred embodiment and that these treatments could also
be performed separately without departing from the scope of the present invention.
[0100] According to some embodiments, following the treatment in the thermo-tumbler 21,
the thermo-tumbler product 29 is sieved via a sieve 31 to remove the thermo-tumbler
product olive pit particles 26. The rounded and thermally treated olive pit fragments
24 are used as infill for an artificial turf. The removed olive pit particles may
be used for a stabilization layer of the infill. The rounded and thermally treated
olive pit fragments 24 are used for the performance layer of the infill. For example,
referring to figure 3, the rounded and thermally treated olive pit fragments 24 free
of the olive pit particles 26 can be used in a performance layer 38 for an artificial
turf 30 either alone or together with a second biobased material, such as, for example,
cork particles and/or cherry pits 25. When a second bio-based material such as the
cork particles and/or the cherry pits 25 are used in the infill, they are preferably
added in the thermo-tumbler 21 together with the olive pit fragments. In some embodiments,
zeolite in the form of microporous zeolite particles is also added in the thermo-tumbler
21. As shown in figure 2B, the rounded and thermally treated olive pit fragments,
when used the second bio-based material fragments 25 and the microporous zeolite particles
can be separated from the olive pit particles 26 using the sieve 31. The use of cherry
pits may further improve the infill shock absorption and force reduction.
[0101] The use of the cork particles and/or cherry pits 25 as a second bio-based material
is advantageous because they may allow better packing of the infill and better customization
of the overall elasticity of the infill (i.e., the mixture of olive pit fragments
cork particles and/or cherry pits) by adjusting the weight ratio of each of the rounded
and thermally treated olive pit fragments and of the at least one other bio-based
material in the infill to obtain the desired overall elasticity for the infill. The
cork particles and/or the cherry pits may be subjected to the same thermo-tumbling
process as the olive pit fragments by adding them into the thermo-tumbler 21. The
cherry pits may be whole pits or fragmented pits before fed into the thermo-tumbler
21. The cherry pits may be the remnants of cherry pit commercial processes for making
cherry juice, and the like. In a preferred embodiment, the olive pit fragments 24
and the cherry pits 25 are mixed together within the thermo-tumbler 21 which may further
enhance the rounding of the olive pit fragments 24.
[0102] According to the embodiment of figure 3, the separated olive pit particles 26 using
a sieving process (see figure 2B) are used as infill for a stabilization layer 35
preferably alone or together with any particles (of less than 63 µm size) of another
bio-based material, while the rounded and thermally treated olive pit fragments 24
free of the olive pit particles 26 are used to form the performance layer 38 either
alone or together with a second biobased material fragments (of a size of 0.5 mm or
greater) such as, cork particles and cherry pits 25. According to this embodiment,
the artificial turf 30 comprises the stabilization layer 35 formed on the baking 11
of the artificial turf 30 exclusively with the olive pit olive pit particles or in
a mixture with a second stabilizing bio-based material, and the performance layer
38 formed on the stabilization layer 35 formed exclusively with the rounded and thermally
treated olive pit fragments 24 or with a mixture of the rounded and thermally treated
olive pit fragments 24 and a second bio-based material particles, such as, preferably
the cork particles and/or the cherry pit particles. Preferably, the performance layer
38 comprises the rounded olive pit fragments 24 and second bio-based material of the
cork fragments and/or cherry pit fragments 25 in a mixture prepared, for example,
in the thermo-tumbler 21 and sieving the thermo-tumbler product to separate the olive
pit particles 26 which are used for forming the stabilization layer 35. The stabilization
layer 35 may optionally include sand which is currently widely used in state of the
art infills, however, the present invention allows completely eliminating the need
for using sand in the stabilization layer. Eliminating the sand is advantageous because
it is non-bio-based material and creates problems in the shredders used in the recycling
of the artificial turf at the end of the useful life of the artificial turf.
[0103] According to some embodiments, microporous zeolite particles may be added in the
infill for providing a cooling effect for the artificial turf. Optionally particles
of a reflective material may also be added. The grain size of the microporous zeolite
particles is determined such that the resulting specific surface area of the particles
is smaller than a maximum specific surface area. The maximum specific surface area
of the microporous zeolite particles is the specific surface area that enables the
water in the particles to release, under an ambient temperature, at a predefined minimum
rate. A progressive release of the water by the microporous zeolite particles and
avoidance of rapid evaporation of the water after the surface has been watered is
desirable in order to allow a lower temperature to be maintained at the level of the
field surface compared to the ambient temperature. In other words, the controlled
release of absorbed water causes progressive cooling under evaporation for some time.
Thus, the amount of watering usually necessary to refresh a field surface can be reduced.
[0104] The grain structure of the microporous zeolite particles enables the formation of
bound water surrounding particles surfaces and maintained by weak force of van der
Waals force. This renders the release or desorption of the water easier in particular
under ambient temperature (e.g., the solar energy is enough to desorb the water).
Naturally, the specific surface area of the microporous zeolite particles varies with
its structure. For example, the finer the particles are, the larger the specific surface
area is (i.e., the smaller the grain size is, the larger the specific surface area
is). For example, the specific surface area of the microporous zeolite particles may
not exceed a minimum specific surface area. The minimum specific surface area may
be the smallest possible specific surface area. In this case, the determined grain
size may be the lower limit of a range of sizes, wherein the upper limit of the range
may be determined using the minimum specific surface area. The microporous zeolite
particles may for example have a grain size between 0.1 mm and 1.5 mm, in particular
between 0.4 mm to 1.2 mm, more in particular between 0.9 mm and 1.2 mm, and a maximum
surface specific surface area of 21m
2/g. For example, a selected specific surface area may be 20 m
2/g.
[0105] According to some embodiments, the artificial turf infillartificial turf infillinfill
comprises microporous zeolite particles having a selected grain size smaller than
1.5 mm and a porosity between 15% and 20% volume parts. In an embodiment, the microporous
zeolite particles may have a grain size distribution wherein 70% to 90% of the grains
by weight have a size in the range of 0.4 mm to 1.5 mm and 10.0% to 30% of the grains
by weight have a size smaller than 0.4 mm.
[0106] According to some embodiments, 0.6 wt% of the zeolite particles at most is not retainable
on a 10-mesh screen. Preferably, the microporous zeolite particles have a hardness
between 3.5 and 5.5 on the Mohs scale. Preferably, the moisture level in the microporous
zeolite particles is smaller than 6 wt%.
[0107] The microporous zeolite particles allow a lower temperature to be maintained at the
level of the field surface compared to the ambient temperature by the controlled release
of water via evaporation. Thus, the amount of watering usually necessary to refresh
a field surface may be reduced.
[0108] According to some embodiments, the mixture of rounded and thermally treated olive
pit fragments obtained from the thermo-tumbler is not sieved at all and is applied
as obtained from the thermo-tumbler once the thermo-tumbling treatment is completed,
on the backing of the artificial turf. It has been found that in a relative short
time, the olive pit particles and the fragments separate with the olive pit particles
settling at the bottom of the infill layer forming a stabilization layer and the larger
rounded and thermally treated olive pit fragments form a performance layer over the
stabilization layer with the olive pit particles. It should be understood that the
transition from the olive pit particles layer to the rounded and thermally treated
olive pit fragments layer may be gradual and that there may be an intermediate layer
between the olive pit particles layer and the rounded olive pit particles comprising
the two different particle size groups. In some embodiments, a zeolite and optionally
sand, preferably of zeolite may also be added.
[0109] Hence, according to some embodiments, the following mixture is generated and applied
on the artificial turf:
- a) rounded and thermally treated olive pit fragments 24,
- b) zeolite 28 (medium sized) (sand may also be added in the component b as optional)
and
- c) olive pit particles 26.
[0110] Referring to figure 4, after having applied the whole mixture including the components
a, b, and c on the artificial turf, the components a, b and c will automatically separate
into different stabilizing and performance layers 45 and 48, respectively, with the
olive pit particles 26 moving downward next to the carrier/backing 11 of the artificial
turf because of their small particle size which makes them fall down filling the cavities
between the larger objects and eventually make it all the way down shifting the larger
particles upwards. It is noted that the artificial turf fibers are not shown in figure
3 for simplicity of presentation. Also, the various components are presented in a
simplified schematic manner and not according to their actual shapes, and sizes.
[0111] This embodiment, (with or without the component 'b') is advantageous because the
mixture is applied on the carrier or backing 11 of the artificial turf 40 in a single
step and within a short period of use it separates by itself in a stabilization layer
45 comprising primarily olive pit particles 26 and when used the microporous zeolite
particles 28, and a performance layer 45 comprising primarily of the rounded and thermally
treated olive pit fragments 24.
[0112] The microporous zeolite particles 28 of the component b, when used, they separate
also with the main bulk of it settling primarily within the stabilization layer 45.
The microporous zeolite particles 28 provide a cooling effect in the infill of the
artificial turf 40 and can also help the artificial turf stay drier in a rainy day
because of their ability to soak water (through absorption) due to their microporous
structure. The result is an artificial turf with less variable performance characteristic
between warm, sunny days and cooler rainy days. Thus, the proposed infill comprising
components a, b and c is advantageous because:
- 1) it is made through a simplified manufacturing mixing process,
- 2) it is applied through a "single-step" application on the backing of the artificial
turf,
- 3) it self-separates into a stabilization layer and a performance layer, and
- 4) it reduces performance variability in different weather conditions.
Thus, unlike many state of the art artificial turf types which require separate formation
of a stabilization layer and a performance layer, according to a preferred embodiment
of the present invention these layers are formed automatically by a single-step application
of the above-mentioned mixture comprising only components 'a' and 'c,' or a mixture
comprising 'a', 'b' and 'c' and self-separation into the stabilizing and performance
layers based on object size and specific gravity will achieve at least similar mechanical
properties like a conventional two-layer artificial turf system with a stabilizing
and performance layer. The infill mixture may include at least one other bio-based
material such as cork particles and/or cherry pits 25 which after an initial settling
period form part of the performance layer 48.
[0113] The infill of the present invention comprises thermally treated bio-based materials
including rounded olive pit fragments and exhibits excellent antimicrobial resistance,
and attrition resistance. It also has no remaining olive odor or other odors from
any additional bio-based materials used. Finally, because of the rounded larger size
fragments obtained by the thermo-tumbling process the infill is less likely to cause
any skin injuries or foot injuries to the users of the artificial turf.
[0114] The infill may further include any other suitable components such as an antimicrobial
agent used for preventing the growth of bacteria, fungi, mold, or other microorganisms.
Any suitable antimicrobial agent may be used and, according to some embodiments, the
antimicrobial agent may also be added in the turf backing and/or turf fibers.
[0115] The artificial turf may further include other components such as a reflective agent.
The reflective agent may be added in the infill and/or in the polymer mixture for
making the artificial turf fibers 16, for further preventing overheating of the fiber
in warm and sunny conditions. The reflective agent may reduce the heat on the artificial
turf field. Suitable reflective agents include titanium dioxide, zinc sulfide, tin
oxide, aluminum oxide, zinc oxide, calcium sulfate, barium sulfate, calcium carbonate,
antimony oxide, sodium silicate, aluminum silicate, silica, mica, clay, and the like.
[0116] In a preferred embodiment an infrared (IR) reflective agent is a mixed metal oxide
type chosen from the group of the rutile (MeO2), hematite (Me2O3), or spinel (Me3O4)
type with metals comprising cobalt, iron, trivalent chrome, tin, antimony, titanium,
manganese and aluminum.
[0117] For example, the reflective agent may be used in an amount from 0.01 wt% to 8.0 wt%,
preferably from 0.3 wt% to 5.0 wt%, more preferably from 0.3 wt% to 3.0 wt% based
on the total fiber weight.
[0118] Referring to figure 5, a method of fabricating an infill for an artificial turf is
provided, the method comprising, providing olive pit fragments separated from an olive
extraction process compressing olives to extract olive oil from the olives (S50),
feeding the olive pit fragments in a thermo-tumbler (S52), feeding hot air or steam
through the thermo-tumbler (S54), tumbling the olive pit fragments (S56), and producing
rounded and thermally treated olive pit fragments including olive pit particles (S58).
[0119] According to some embodiments, the rounded and thermally treated olive pit fragments
including the olive pit particles are used to form an infill for an artificial turf.
[0120] According to some embodiments, the olive pit particles are separated from the thermo-tumbler
product using sieving to remove all olive pit particles having a size of less than
63 µm.
[0121] According to some embodiments, cherry pits whole, fragments, or mixtures thereof
are also fed in the thermo-tumbler and are mixed together with the olive pit fragments.
[0122] According to some embodiments, in addition to the olive pit fragments (with or without
the cherry pits), at least one of sand, and zeolite are added as a second component
in the thermo-tumbler and mixed together with the olive pit fragments an/or the cherry
pits.
[0123] In a preferred embodiment, the product from the thermo-tumbler includes rounded and
thermally treated olive pit fragments and/or cherry pits (component a, bio-based material),
at least one of sand and zeolite, preferably zeolite only or zeolite and sand (component
b) and the olive pit particles (component c), and this mixture of components a, b
and c is applied in a single-step on the backing of the artificial turf, wherein within
a short period time separate into at least a stabilization layer which forms over
the backing, and a performance layer which forms adjacent the stabilization layer.
The stabilization layer comprises the olive pit particles and the sand when sand is
used as at least one part of the component b. The performance layer includes the larger
size bio-based material, i.e., the rounded olive fragments and when used also the
cherry pits and when used also the zeolite particles. It should be understood that
the thermo-tumbler process may also generate olive pit particles not only from the
olive pits but also from the other components when used, i.e., the cherry pits, and
the zeolites, and all these olive pit particles will settle at to form the stabilization
layer, together with the most part or all of the sand used.
[0124] Typically, incorporating the turf fiber into the carrier includes positioning the
fiber so that a first fraction of the fiber is located at the back side of a carrier,
a second fraction of the fiber is protruding to the front side of the carrier and
a third fraction of the fiber is inside the carrier (referred to also as the middle
fraction of the fiber or the carrier portion of the fiber).
[0125] According to some embodiments, the artificial turf fibers are integrated into the
backing and have a density (number of fibers per artificial turf area) and/or degree
of texturization that under a bird's eye perspective, at least 60%, more preferentially
at least 70% of the size of the area covered by the artificial turf consists of the
fibers and the rest consists of the backing or the infill.
[0126] The backing of the artificial turf is made of a thermoset polymer material, however
the invention is not limited in this way and other suitable backing materials may
be used. The thermoset material may include, for example, a polyurethane resin.
[0127] The term "tufting" as used herein refers to a method of incorporating a fiber into
an existing carrier. Short U-shaped loops of fibers are introduced through the carrier
from one side so that their ends point outside of the carrier in the other direction.
Usually, the tuft yarns form a regular array of "dots" on the other side. On the one
side of the carrier where the U-shaped loops are located, the tuft fibers may be tied
for security, although they need not be. The ends of the tuft yarns can then optionally
be frayed or otherwise processed, so that they will subsequently create a dense layer
of fibers protruding from the carrier.
[0128] The term "weaving" as used herein is a method of incorporating an artificial turf
fiber (which can be a monofilament or a bundle of monofilaments) into an existing
carrier, whereby the artificial turf fiber and the fiber(s) that built the carrier
are interlaced. The interlaced fibers and the mesh form a fabric like or cloth like
structure. When an artificial tuft fiber is incorporated by weaving, the fiber interlaces
a series of mesh fibers at least three times. Thus, when a fiber is incorporated by
weaving rather than tufting, a higher fraction of the artificial turf fiber is interlaced
in the carrier material. This may increase the resistance to wear and tear of the
artificial turf.
[0129] According to some embodiments, incorporating the artificial turf fiber into the carrier
comprises tufting the artificial turf fiber into the carrier. According to alternative
embodiments, incorporating the artificial turf fiber into the carrier comprises weaving
the artificial turf fiber into the carrier.
[0130] The formation of the artificial turf may be made using any suitable manufacturing
process. For example, a polymer mixture comprising at least one polymer such as a
polyethylene, and various additives including, for example, a friction control additive,
a reflective agent, an antioxidant, a coloring agent and the like is made by putting
all these components that make it up together and is thoroughly mixed in a mixer device.
The desired distribution of the components can be achieved by using the proper rate
or amount of mixing. The generated mixture is then forwarded to a one-screw feed or
a two-screw feed to be extruded into a monofilament. The monofilament is quenched
or rapidly cooled down, then reheated and oriented by stretching it into an artificial
turf fiber is bundled with additional monofilaments into an artificial turf fiber.
[0131] Next the artificial turf fiber is incorporated into an artificial turf backing. The
incorporation may comprise arranging a plurality of the artificial turf fibers on
a carrier so that first parts of the monofilaments are exposed to a bottom side of
the carrier and second parts of said monofilaments are exposed to a top side of the
carrier. The arranging could be accomplished by tufting or weaving the artificial
turf fiber into the carrier, but other methods of arranging the fibers within the
carrier are also possible. Then a resin reaction fluid mixture is added on the bottom
side of the carrier such that least the first parts become embedded in the fluid.
Finally, the fluid mixture is caused to solidify into a film and surround and thereby
mechanically fix the fibers on the backing.
Examples
Examples 1
[0132] Figures 6A to 6E are images at different magnifications of an infill layer formed
of rounded and thermally treated olive pit material comprising rounded and thermally
treated olive pit fragments having a size of 0.5 to 2.0 mm in an amount of 99.0 wt%
of the total olive pit material, and olive pit particles of a size of less than 63
µm in an amount of 1 wt% of the total olive pit material. The olive material is obtained
after a thermo-tumbling simultaneous treatment in a thermo-tumbler of olive pit fragments
from an olive extraction process for a period of 2.7 minutes at a temperature of 120
°C. These images show that the thermo-tumbling treatment smoothens the rough edges
of the olive pit fragments and provides more rounded olive pit fragments without sharp
edges. Moreover, the infill is free of any remaining olive odor, and is less likely
to cause skin or foot injuries to the users of the artificial turf compared to an
artificial turf using the untreated olive pit fragments. The olive pit material is
applied in a single step over the thermoset polyurethane backing of an artificial
turf comprising turf fibers of polyethylene having a pile height of 70 mm to form
an infill having a height of 30 mm. The artificial turf made with the infill of the
thermo-tumbled olive pit material shows a substantially improved balance of traction,
energy absorption, stable foot and energy restitution characteristics compared to
same artificial turf made with the untreated olive pit material. Untreated olive pit
material refers to the olive pit material prior to the thermo-tumbling process.
Example 2
[0133] The same processes as in Example 1 are repeated except that microporous zeolite particles
are added in an amount of 10.0 wt% of the total infill. The microporous zeolite particles
have a grain size_distribution wherein 80.0 wt% of the grains have a size in the range
of 0.4 mm to 1.5 mm and 20 wt% of the grains have a size smaller than 0.4 mm. The
infill mixture of the olive pit material and the microporous zeolite particles are
processed together in the thermo-tumbler under the same conditions as in example 1
and the thermo-tumbler product without any sieving is applied on the thermoset polyurethane
backing as in example 1. The infills of examples 1 and 2 are watered and their temperatures
are measured at a center point of the infills under the same ambient temperatures
2 and 4 hours later after the watering of the infill whereas the infill of example
2 demonstrates consistently lower temperature than example 1.
Example 3, 4 and 5
[0134] An olive pit material is obtained after a thermo-tumbling simultaneous treatment
in a thermo-tumbler of olive pit fragments from an olive extraction process as in
example 1 except for a period of 60 minutes, and that the olive pit material is heated
to a temperature of 160 °C (for example 3), 180 °C (for example 4) and 200 °C (for
example 5). The olive pit materials from examples 3-5 are substantially free of any
sharp edges and any remaining olive odor and like the olive pit material of Example
1 are less likely to cause skin or foot injuries to the users of the artificial turf
compared to an artificial turf using the untreated olive pit material.
[0135] In addition, the olive pit materials of examples 3-5, compared to the olive pit material
of Example 1, exhibit substantially improved antimicrobial resistance, enhanced abrasion
resistance, and reduced hygroscopicity. The olive pit material of example 3 has significantly
reduced hygroscopicity when compared to the olive pit material of example 1 while
the olive pit materials of examples 4 and 5 exhibit almost no hygroscopicity at all.
Because of the aforementioned significantly improved characteristics and in particular
the reduced hygroscopicity, the olive pit material of example 3 is expected to exhibit
significantly improved resistance to biodegradability and prolonged lifespan compared
to the olive pit material of example 1. Likewise, the olive pit materials of examples
4, and 5 because of their substantially zero hygroscopicity, are expected to exhibit
exceptional resistance to biodegradation in moist and humid conditions making particularly
suitable for artificial turfs used in applications where frequent watering is needed.
XPS analysis shows that examples 3, 4, 5 have substantially reduced O/C (oxygen/carbon)
ratio compared to the O/C ratio of example 1. NMR analysis showed that examples 3,
4, 5 have substantially higher levels of crystalline cellulose measured at 89 ppm
compared to the crystalline levels example 1. The olive pit materials are applied
in a single step over the thermoset polyurethane backing of an artificial turf comprising
turf fibers of polyethylene having a pile height of 70 mm to form an infill having
a height of 30 mm. The artificial turf made with the infill of the thermo-tumbled
olive pit material of examples 3, 4, and 5 show a substantially improved balance of
traction, energy absorption, stable foot and energy restitution characteristics compared
to same artificial turf made with the untreated olive pit material.
Example 6, 7, and 8
[0136] Microporous zeolite particles are added in an amount of 10.0 wt% of the total infill
which employs the olive pit materials from examples 3, 4, and 5, respectively. The
microporous zeolite particles have a grain size_distribution wherein 80.0 wt% of the
grains have a size in the range of 0.4 mm to 1.5 mm and 20 wt% of the grains have
a size smaller than 0.4 mm. The infill mixture of the olive pit material and the microporous
zeolite particles are processed together in the thermo-tumbler under the same conditions
as in example 1 and the thermo-tumbler product without any sieving is applied on the
thermoset polyurethane backing as in example 1. The infills of 6, 7, and 8 are watered
and their temperatures are measured at a center point of the infills under the same
ambient temperatures 2 and 4 hours later after the watering of the infill whereas
the infill of examples 6, 7 and 8 demonstrate consistently lower temperatures than
example 1.
[0137] Although the invention has been described in reference to specific embodiments, it
should be understood that the invention is not limited to these examples only and
that many variations of these embodiments may be readily envisioned by the skilled
person after having read the present disclosure. The invention may thus further be
described without limitation and by way of example only by the following embodiments.
The following embodiments may contain preferred embodiments. Accordingly, the term
"clause" as used therein may refer to such a "preferred embodiment".
[0138] Clause 1. An artificial turf infill comprising: an olive pit material; and microporous
zeolite particles.
[0139] Clause 2. The artificial turf infill of clause 1, wherein the olive pit material
comprises olive pit fragments having a size of 0.5 mm or greater, in particular 0.5
mm to 4.0 mm, more in particular 0.5 mm to 2.5 mm, and most in particular 0.5 mm to
2.0 mm, in an amount of at least 80.0 wt%, in particular 90.0 wt% to 99.0 wt%, more
in particular 95.0 wt% to 99.0 wt%, and most in particular 98.0 wt% to 99.0 wt% of
the total weight of the total olive pit material in the infill.
[0140] Cause 3. The artificial turf infill of clauses 1 or 2, wherein the olive pit material
comprises olive pit particles having a size of less than 63 µm in an amount of at
least 0.5 wt%, in particular 1.0 wt% to 20.0 wt%, more in particular 1.0 wt% to 10.0
wt %, and most in particular 1.0 wt% to 2.0 wt% of the total olive pit material in
the infill.
[0141] Clause 4. The artificial turf infill of any of the preceding claims, wherein the
olive pit material has a bimodal size distribution with a major mode and a minor mode,
wherein the major mode comprises the rounded, thermally treated olive pit fragments
and has a peak between 0.5 mm to 4.0 mm, more in particular 0.5 mm to 2.5 mm, and
most in particular 0.5 mm to 2.0 mm, and wherein the minor mode comprises the olive
pit particles and has a peak at less than 63 µm.
[0142] Clause 5. The artificial turf infill of any of the preceding clauses, wherein the
olive pit material is thermally treated.
[0143] Clause 6. The artificial turf infill of clause 5, the thermally treating can be performed
at a temperature of 80 °C to 130 °C, in particular 100 °C to 130°C, and more in particular
110 °C to 130 °C.
[0144] Clause 7. The artificial turf infill of clause 5, wherein the olive pit material
is thermally treated at a temperature of 150 °C to 250 °C, in particular 160 °C to
250 °C, and more in particular 180 °C to 250 °C.
[0145] Clause 8. The artificial turf infill of any one of the preceding clauses, wherein
the infill comprises rounded olive pit fragments, in particular olive pit fragments
having been rounded in a tumbler.
[0146] Clause 9. The artificial turf infill of the preceding clauses, wherein the rounded,
and thermally treated olive pit fragments are obtained by a thermo-tumbling treatment
of fractured olive pits together with the microporous zeolite particles, wherein the
olive pit fragments are formed by fracturing in an olive oil extraction process during
a compression operation of the olives for extracting oil from the olives and have
sharp edges due to the fracturing, and wherein the thermo-tumbling process smoothens
the sharp edges by attrition by rubbing the olive pit particles against each other
and against the microporous zeolite particles to form the rounded, thermally treated
olive pit fragments.
[0147] Clause 10. The artificial turf infill of any one of the preceding clauses, wherein
the artificial turf infill is free of olive pit particles having a size less than
63 µm.
[0148] Clause 11. The artificial turf infill of any of the preceding clauses, wherein the
artificial turf infill comprises the microporous zeolite particles in an amount of
1.0 to 30.0 wt%, in particular 5.0 to 25.0 wt%, and more in particular 10.0 to 20.0
wt% of the total amount of the infill.
[0149] Clause 12. The artificial turf infill of any of the preceding clauses, wherein the
microporous zeolite particles have a grain size between 0.1 mm and 1.5 mm, in particular
between 0.4 mm to 1.2 mm, more in particular between 0.9 mm and 1.2 mm, and a maximum
surface specific surface area of 21 m
2/g.
[0150] Clause 13. The artificial turf infill of any of the preceding clauses, wherein the
microporous zeolite particles have a porosity between 15% and 20% volume parts.
[0151] Clause 14. The artificial turf infill of any of the preceding clauses, wherein the
microporous zeolite particles have a grain size distribution wherein 70% to 90% of
the grains by weight have a size in the range of 0.4 mm to 1.5 mm and 10% to 30% of
the grains by weight have a size smaller than 0.4 mm.
[0152] Clause 15. The artificial turf infill of any of the preceding clauses, wherein the
microporous zeolite particles have a hardness between 3.5 and 5.5 on the Mohs scale
and a moisture level smaller than 6 wt%.
[0153] Clause 16. The artificial turf infill of any of the preceding clauses,
further comprising at least one further bio-based material including pit fragments
of at least one other stone-containing fruit, and
wherein the pit fragments of the further bio-based material have a different elasticity
than the rounded, and thermally treated olive pit fragments.
[0154] Clause 17. The artificial turf infill of clause 16, wherein the at least one further
bio-based material comprises cork particles, rounded cherry pit fragments, and combinations
thereof.
[0155] Clause 18. The artificial turf infill of any of the preceding clauses, comprising
only bio-based materials and being free of any rubber, elastomeric, or polymer-based
infill, and, in particular also free of any sand.
[0156] Clause 19. An artificial turf comprising the artificial turf infill of any of the
clauses 1-18.
[0157] Clause 20. The artificial turf of clause 19, further comprising:
a stabilization layer comprising or consisting of at least one of sand, the olive
pit particles of clause 3, and at least a portion of the microporous zeolite particles;
and
a performance layer positioned on the stabilizing layer,
wherein the performance layer comprises or consists of the artificial turf infill
of any of the preceding clauses or comprises or consists of the rounded and thermally
treated olive pit fragments and is basically free of the olive pit particles.
[0158] Clause 21. The artificial turf of clauses 19 or 20, wherein the artificial turf infill
is substantially free of any rubber, elastomeric, or polymer-based infill, and, in
particular, also free of any sand.
[0159] Clause 22. A method of creating an artificial turf, comprising: installing an artificial
turf and applying the artificial turf infill of any one of clauses 1-18 on the installed
artificial turf.
[0160] Clause 23. The method of clause 22,
wherein the infill comprises at least a mixture of the rounded, olive pit fragments,
the olive pit particles and the microporous zeolite particles,
wherein the applying the artificial turf infill on the installed artificial turf is
performed in a single step, and wherein the method further comprises: allowing the
olive pit particles in the applied infill to automatically trickle down into the voids
between the fragments, thereby automatically forming a stabilizing layer consisting
essentially of the trickled-down particles, and a performance layer containing the
rounded olive pit fragments.
[0161] Clause 24. The method of clause 23, wherein at least a portion of the microporous
zeolite particles trickles down and settles into the stabilizing layer.
[0162] Clause 25. A kit for manufacturing an artificial turf, the kit comprising the artificial
turf infill of any of the clauses 1 to 19 and at least one other component for making
the artificial turf.
[0163] Clause 26: Clause 1. Use of a mixture comprising olive pit material and microporous
zeolite particles as an artificial turf infill.
[0164] By way of example, embodiments of the invention comprise the following features:
- 1. An artificial turf infill comprising:
- an olive pit material (24, 26); and
- microporous zeolite particles (28).
- 2. The artificial turf infill of claim 1,
wherein the olive pit material (24, 26) comprises olive pit fragments (24) having
a size of 0.5 mm or greater, in particular 0.5 mm to 4.0 mm, more in particular 0.5
mm to 2.5 mm, and most in particular 0.5 mm to 2.0 mm, in an amount of at least 80.0
wt%, in particular 90.0 wt% to 99.0 wt%, more in particular 95.0 wt% to 99.0 wt%,
and most in particular 98.0 wt% to 99.0 wt% of the total weight of the total olive
pit material in the infill.
- 3. The artificial turf infill of any of the preceding claims, wherein the olive pit
material has a bimodal size distribution with a major mode and a minor mode,
wherein the major mode comprises rounded, thermally treated olive pit fragments (24)
and has a peak between 0.5 mm to 4.0 mm, more in particular 0.5 mm to 2.5 mm, and
most in particular 0.5 mm to 2.0 mm, and
wherein the minor mode comprises olive pit particles (26) of less than 63 µm in an
amount of at least 0.5 wt% and has a peak at less than 63 µm.
- 4. The artificial turf infill of any of the preceding claims, wherein the olive pit
material is thermally treated (S54), in particular at a temperature of 80 °C to 250
°C.
- 5. The artificial turf infill of any of the preceding claims, wherein the olive pit
material comprises abrasively rounded olive pit fragments (24), in particular rounded
olive pit fragments rounded in a tumbler.
- 6. The artificial turf infill of claims 2-5,
wherein the rounded, and thermally treated olive pit fragments (24) are obtained by
a thermo-tumbling treatment of fractured olive pits together with the microporous
zeolite particles (28),
wherein the olive pit fragments (6) are formed by fracturing in an olive oil extraction
process (2) during a compression operation of the olives (1) for extracting oil (3)
from the olives and have sharp edges due to the fracturing, and
wherein the thermo-tumbling process smoothens the sharp edges by attrition by rubbing
the olive pit fragments (6) against each other and against the microporous zeolite
particles (28) to form the rounded, thermally treated olive pit fragments (24).
- 7. The artificial turf infill of any of the claims 1-6, wherein the microporous zeolite
particles (28) are added in the infill in an amount of 1.0 to 30.0 wt%, in particular
5.0 to 25.0 wt%, and more in particular 10.0 to 20.0 wt% of the total amount of the
infill (12).
- 8. The artificial turf infill of any of the claims 1-7, wherein the microporous zeolite
particles (28) have a grain size between 0.1 mm and 1.5 mm, in particular between
0.4 mm to 1.2 mm, more in particular between 0.9 mm and 1.2 mm, and a maximum surface
specific surface area of 21m2/g.
- 9. The artificial turf infill of any of the claims 1-8, wherein the microporous zeolite
particles (28) have a porosity between 15% and 20% volume parts.
- 10. The artificial turf infill of any of the claims 1-9, wherein the microporous zeolite
particles (28) have a grain size distribution wherein 70% to 90% of the grains by
weight have a size in the range of 0.4 mm to 1.5 mm and 10% to 30% of the grains by
weight have a size smaller than 0.4 mm.
- 11. The artificial turf infill of any of the claims 1-10, wherein at least 10%, in
particular at least 50%, in particular at least 70%, or at least 90% by weight of
the infill consists of olive pit material.
- 12. The artificial turf infill of any of the claims 1-11, wherein the microporous
zeolite particles (28) have a hardness between 3.5 and 5.5 on the Mohs scale and a
moisture level smaller than 6 wt%.
- 13. The artificial turf infill of any of the claims 1-12,
- further comprising at least one further bio-based material (25) including pit fragments
of at least one other stone-containing fruit,
wherein the pit fragments of the further bio-based material (25) have a different
elasticity than the rounded, and thermally treated olive pit fragments, and
wherein in particular the at least one further bio-based material (25) is selected
from a group comprising cork particles, rounded cherry pit fragments, and combinations
thereof.
- 14. The artificial turf infill of any of the claims 1-11, comprising only bio-based
materials (25) and being free of any rubber, elastomeric, or polymer-based infill,
and, in particular also free of any sand.
- 15. An artificial turf or artificial turf kit comprising the artificial turf infill
of any of the claims 1-14.
- 16. The artificial turf of claim 15, further comprising:
- a stabilization layer (35, 45) comprising or consisting of at least one of sand, the
olive pit particles (26) of claim 2, and at least a portion of the microporous zeolite
particles (28);
- a performance layer (38, 48) positioned on the stabilizing layer,
wherein the performance layer (38, 48) comprises or consists of the artificial turf
infill of any of the preceding claims or comprises or consists of the rounded and
thermally treated olive pit fragments (24) and is basically free of the olive pit
particles (26).
- 17. A method of creating an artificial turf, comprising:
- installing an artificial turf comprising a plurality of artificial turf fibers attached
on a carrier;
- applying the artificial turf infill of any one of claims 1-13 on the installed artificial
turf between the turf fibers, wherein the infill comprises at least a mixture of the
rounded, and thermally treated olive pit fragments (24), the olive pit particles (26)
and the microporous zeolite particles (28), wherein the applying the artificial turf
infill on the installed artificial turf is performed in a single step, and
- allowing the olive pit particles (26) in the applied infill to automatically trickle
down into voids between the olive pit fragments (24), thereby automatically forming
a stabilizing layer (35, 45) consisting essentially of the trickled-down particles,
and a performance layer (38, 48) containing the rounded olive pit fragments (24),
wherein at least a portion of the microporous zeolite particles (28) trickles down
and settles into the stabilizing layer (35, 45).
List of reference numerals
[0165]
- 1
- olives
- 2
- olive oil extraction process
- 3
- olive oil
- 4
- olive pulp and skin
- 6
- olive pit fragments
- 10, 30, 40
- artificial turf (AT)
- 11
- backing of AT
- 12
- infill layer
- 24
- rounded and thermally treated olive pit fragments
- 35, 45
- stabilization layer
- 38, 48
- performance layer
- 26
- olive pit particles
- 25
- at least one other bio-based material
- 21
- thermo-tumbler
- 23
- air flowing in the thermo-tumbler
- 32
- air flowing out the thermo-tumbler
- 28
- microporous zeolite particles
- 29
- thermo-tumbler product
- 31
- sieve for olive pit particles