Technical Field
[0001] The present invention relates generally to carpet, and more particularly relates
to an improved carpet with coarse and fine fibers, and a process for making the same.
The carpet, when used as a mat, removes large and small dirt particles from footwear
due to improved grit and particulate gripping and moisture absorbing capabilities.
Background of the Invention
[0002] Many different carpets exist for varied purposes. Carpets are manufactured generally
by feeding yam from spools through needles into a substrate. This process is known
in the art as "tufting." The type of yarn, length of needle, the needle spacing, and
whether the yarn is looped or cut are just a few factors that relate to the final
carpet product-and-its-intended-use. This invention relates to carpet that is manufactured
for use in making mats, such as welcome mats or "track control" mats as they are known
in the industry.
[0003] Typically, track control mats are placed at or near an entrance of a house or other
building to remove dirt, moisture or other matter from the bottom of the shoes, and
conveyances (such as grocery carts and dollies) used by persons entering the building.
The wiping action should occur as the result of normal walking of one or two steps
on the mat before the persons walk through the interior of the building.
[0004] To prevent dirt and moisture from being tracked from outside throughout the interior
of the building, the mats must not only have the ability to remove moisture and-dirt
from footwear, but also to store the dirt and moisture within the body of the mat.
If a mat does not effectively store the dirt and moisture within the mat, and leaves
the dirt and moisture on the surface of the mat, the dirt and moisture will re-attach
or stick to the bottom of footwear of other persons who subsequently walk on the mat.
Dirt and moisture which re-attaches or sticks in this manner will then be tracked
throughout the building, a condition known in the art as "re-tracking".
[0005] Some types of track control mats are made of a combination of coarse and fine fibers
or filaments (hereinafter collectively referred to as "fibers"). These mats have been
widely used in the past for the purpose of removing soil, moisture and other matter
from a person's shoes or outer footwear. The coarse fibers help to remove large particles
of dirt and the fine fibers help to remove the fine particulate and moisture. There
should be sufficient space between fibers to temporarily hold dirt and moisture to
prevent re-tracking.
[0006] The intended use of a mat relates to the manner in which the mat is constructed.
For example, if a mat will be exposed to significant moisture, the mat may be designed
to contain a greater number of fine fibers to absorb and hold the moisture within
its recesses. On the other hand, a mat that may be exposed to a significant amount
of large particles of dirt may need to have a greater number of coarse fibers.
[0007] The degree of coarseness or fineness of a fiber is measured by its denier. The term
"denier" refers to the weight in grams for a 9,000-meter fiber. A coarse fiber or
filament for use in track control mats typically ranges in denier from 100 to 2,000
denier per filament ("dpf"); and fine fibers for the same application typically range
from 15 to 100 dpf.
[0008] Commercial and public buildings receive large volumes of pedestrian traffic. As a
result, the mats in these buildings should be able to remove and store large quantities
of dirt and moisture on a daily basis. For continuously effective dirt removal, most
mats should be cleaned periodically so that the dirt and moisture stored within the
mat are removed. The most effective way to clean mats is to wash them. Some mats cannot
be washed due to the types of materials used and method employed in manufacturing
the mat. Mats that cannot be washed and reused have a limited effectiveness or lifetime.
[0009] Most track control mats are made with a backing that holds the tufts in place relative
to the substrate. The backing is typically a plastic or rubber material that is melted
or vulcanized and applied to the substrate. In this state, the backing bonds the tufts
to the substrate.
[0010] US-A-3 940 522 discloses using latex cured in an oven which is applied to the underside
of the fabric to secure the pile fibers to the backing.
[0011] Because of the desirability for periodic washings, mats should be manufactured in
a manner that will withstand continued exposure to washing and drying. The materials
used to make the mat should be able to withstand elevated temperatures in both the
washing and drying processes. In addition, mats should be constructed so that the
tufts do not separate from the backing during the cleaning process. Adhesion of the
tufts to the carpet backing is known as "tuft lock." Many commercially available track
control mats at present exhibit poor tuft lock and, as a result, are ineffective for
reuse after washing.
[0012] Other types of track control mats already exist. In United States Patent No. 4,045,605
("the '605 patent") issued to
Breens et al., coarse and fine fibers are used to create one type of track control mat.
Breens et al. describes consecutively feeding coarse and fine fibers into the tufting machine
from two separate sources. In addition, according to
Breens et al., the coarse and fine fibers can be alternately fed-to the tufting machine to create
alternating areas of course and fine fibers on the mat. While this type of track control
mat appears to be effective in removing undesirable dirt and other particles from
footwear, it is susceptible to wear out in a short period of time. The concentrated
areas of stiff fibers exhibits poor tuft lock and become dislodged from the track
control mat during use as well as during washing and drying. Moreover, the concentrated
areas of stiff fibers, described in
Breens et al., tend to lie down against the backing. Conversely, if the mat were manufactured
to provide sufficient stability for the coarse fibers, the fine fibers would have
to be so densely tufted to support the coarse fibers inserted therein that the mat
would be completely ineffective in retaining dirt or moisture.
[0013] United States Patent Nos. 4,820,566 ("the '566 patent") and 5,055,333 ("the '333
patent"), both issued to
Heine et al., also describe the use of a mixture of the fine and coarse fibers tufted to form
a track control mat. The '566 and '333 patents teach that the coarse fibers should
be separated from the fine fibers, typically to form a striped or checkerboard arrangement
between the two types of fibers. While this type of track control mat may be effective
at removing and storing dirt and other particles from the bottoms of shoes, the coarse
fibers tend to become dislodged during use or washing of the mat because they are
not adequately secured to the mat backing. The tuft lock for these fibers is poor
because when the coarse fibers are bonded to the backing at separate locations from
the fine fibers, the coarse fibers do not bond well by themselves to the backing.
Thus, when the mat is used and washed, many of the coarse fibers become dislodged
from the backing. This renders the mat less effective in dirt and moisture removal
and storage after a short period of time.
[0014] The '566 patent also describes a mat made with at least some crimped coarse fibers.
Mats manufactured in accordance with the '566 patent are extremely difficult to manufacture
because the crimped fibers kink up as they are fed through the tufting needles which
causes the fibers to eventually break. This requires the entire process to be shut
down, the needles rethreaded and the process restarted. The continuous kinking and
ultimate breakage of the crimped coarse fibers results in a poor quality mat having
many broken coarse fibers and many unattractive knots where the crimped fibers had
to be reknotted or spliced to continue the tufting process. The frequent breakage
of the crimped coarse fibers results in a significant decrease in productivity. In
addition, mats using crimped fibers are also more expensive to manufacture due to
the added process cost of crimping the fiber.
[0015] The '333 patent describes a mat made with at least one looped, uncrimped, coarse
fiber. While mats made in accordance with the '333 patent do not have some of the
above-identified problems associated with crimped fibers, it has been found that looped
pile mats are less effective in dirt removal. The term "pile" refers to the surface
appearance of the carpet or mat. Carpet pile is either cut or looped. Mats having
looped pile are difficult to clean and remove the dirt held therein. Thus, after a
period of time, the mats having looped pile become less effective at dirt removal
and storage.
[0016] Accordingly, there is a need for a washable track control mat made of varied denier
fibers that is effective in removing and storing large and small dirt particles, moisture
and other matter.
[0017] There is a further need for a washable track control mat that exhibits good tuft-lock
so that the tufted fibers do not separate from the backing.
[0018] There is still a further need for a washable track control mat made of varied denier
fibers wherein the coarse, high denier fibers will not separate from the backing after
use or when subjected to commercial washing and drying.
[0019] There is yet a further need for an effective washable track control mat made with
reduced yarn processing costs.
[0020] There is yet a further need for a method of manufacturing a washable track control
mat made of varied denier fibers wherein the mat is effective in removing and storing
large and small dirt particles, moisture and other matter.
[0021] There is a further need for a method of manufacturing a washable track control mat
that exhibits good tuft-lock so that the tufted fibers do not separate from the backing.
[0022] There is still a further need for a method of manufacturing a washable track control
mat made of varied denier fibers wherein the coarse, high denier fibers will not separate
from the backing after use or when subjected to commercial washing and drying.
[0023] There is yet an even further need for a method of manufacturing a washable track
control mat where yarn processing costs are reduced.
Summary of the Invention
[0024] As will be seen, the present invention overcomes these and other disadvantages associated
with prior art track control mats. Stated generally, the present invention provides
a washable track control mat comprising tufts with at least one tuft being made of
a yarn that is made of at least one fine denier fiber and at least one coarse denier
fiber. The yarn is made by twisting together the coarse denier fiber with the fine
denier fiber. The mat includes a substrate for receiving the tufts. The tufts in the
substrate are bonded to a backing.
[0025] The present invention also is directed to a method for manufacturing a washable track
control mat. The method includes twisting together at least one coarse denier fiber
with at least one fine denier fiber to create a yarn. The method also includes tufting
the yarn through a substrate and bonding the tufts to the substrate.
[0026] Thus, it is an object of the present to provide a washable track control mat made
of varied denier fibers that is effective in removing and storing large and small
dirt particles, moisture and other matter.
[0027] It is a further object of the present invention to provide a washable track control
mat that exhibits good tuft-lock so that the tufted fibers do not separate from the
backing.
[0028] It is a further object of the present invention to provide a washable track control
mat made of varied denier fibers wherein the coarse, high denier fibers will not separate
from the backing after use or when subjected to commercial washing and drying.
[0029] It is a further object of the present invention to provide an effective, washable
track control mat with reduced yarn processing costs.
[0030] It is yet a further object of the present invention to provide a method of manufacturing
a washable track control mat made of varied denier fibers wherein the mat is effective
in removing and storing large and small dirt particles, moisture and other matter.
[0031] It is is yet an even further object of the present invention to provide for a method
of manufacturing a washable track control mat that exhibits good tuft-lock so that
the tufted fibers do not separate from the backing.
[0032] It is still a further object of the present invention to provide a method of manufacturing
a washable track control mat made of varied denier fibers wherein the coarse, high
denier fibers will not separate from the backing after use or when subjected to commercial
washing and drying.
[0033] It is yet a further object of the present invention to provide a method of manufacturing
a washable track control mat where yarn processing costs are reduced.
[0034] Other objects, features and advantages of the present invention will be apparent
upon reading the following specification taken in conjunction with the drawings and
appended claims.
Brief Description of the Drawings
[0035]
Fig. 1 is a cross-sectional view of a portion of a washable track control mat of the
present invention made with single yarn tufts; and
Fig. 2 is a perspective view of a double-ply yarn that may be used in the manufacture
of the present invention.
Detailed Description of the Preferred Embodiments
[0036] Referring now to the drawings in which like numerals indicate like elements throughout
the several views, Fig. 1 shows a side view of a portion of a track control mat 10.
The mat 10 is made of a plurality of tufts 12. The tufts 12 each include a yarn 14
made of a plurality of fine fibers 16 and one coarse fiber 18. The coarse fiber 18
is preferably made of nylon or polyester. The tufts 12 are secured to a substrate
20 by means of a backing 22. The backing 22 bonds the tufted yams 14 to the substrate
20. The backing 22 is preferably vulcanized rubber.
[0037] The mat 10 is made by first manufacturing the yarn 14 used in the tufting process.
The yarn 14, as shown in Fig. 2, is made of a plurality of fine fibers 16 twisted
with one or more coarse fibers 18. The denier range for the fine fibers 16 is preferably
between 20 and 24, and the denier range for the coarse fibers 18 is 300-600. It is
preferable that one coarse fiber 18 is used with a plurality of fine fibers 16 in
each yarn 14. The preferred weight ratio of fine fibers 16 to coarse fibers 18 is
20-24% to 76-80%, respectively.
[0038] The fine fibers 16 are twisted with the coarse fiber 18 to form a single-ply yarn
14. The twist of the fine fibers 16 enables the fine fibers to stand up better when
they are tufted into the substrate 20. Moreover, the twist of the fine fibers 16 help
to support the coarse fiber 18 within the body of the yarn 14 so that the coarse fiber
does not lie down when the mat 10 is finished. It is preferred that the yarn 14 be
twisted 5 to 6 turns per 2.54cm (per inch).
[0039] Once the yarn 14 is twisted, it may be heat treated to set the twist in the fine
fibers 16. Some of the preferred fine fibers 16 used in the yarn 14 are made of non-heatset
materials and do not need to be heat treated. Thus, the heat treatment of the yarn
14 after twisting is optional.
[0040] It has been found that a plurality of yarns 14 or "plies" may be used in the manufacture
of the mat 10 of the present invention. Fig.2 shows two single-ply yarns 14 being
twisted together to form a double or two-ply yarn 24. The number of plies affects
the resultant mat product 10, along with other factors discussed in detail below.
[0041] After the yarn 14 is twisted and heat treated, if desired, and twisted with another
yarn, if desired, the yarn is wound on spools and fed into tufting needles of a tufting
machine where the tufts 12 of the mat 10 are formed into the substrate 20, shown in
Fig 1. After-the tufts 12 are formed, the tufting machine cuts the tufts at the desired
length. In the present invention, the tuft length or pile height preferably ranges
from 6.35 to 19.05mm (1/4 to ¾ inches). Moreover, the needles in the tufting machine
may be arranged to alter the density of the mat 10. The distance between needles or
"gauge" should preferably range from 3.97 to 4.76mm (5/32 to 3/16 inches). In addition,
the number of stitches each needle make per 2.54cm (inch) impacts the final product
of the mat 10. It is preferred that the needles make between 5 to 7 stitches per 2.54cm
(inch) for a 3.97mm (5/32 inch) gauge and between 5 to 8 stitches per 2.54cm (inch)
for a 4.76mm (3/16) gauge. The particular dimensions specified herein provides a mat
10 with sufficient numbers of voids 26 between the tufts 12 to receive and store dirt
and moisture in sufficient volumes required of an effective track control mat.
[0042] The resultant mat 10 will vary in weight for a fixed length of carpet as a result
of the different variables discussed above. It is preferred that the resultant mat
10 weigh between 542.5 to 813.75g/m
2 (16 to 24 ounces per square yard) prior to the application of any backing 22.
[0043] Once the yarn 14 has been fed through the tufting needles and into the substrate
20, the mat 10 is moved from the tufting machines to an area where the backing 22
is applied to bond the tufts 12 to the substrate 20. The backing 22 holds the individual
tufts 12 to the substrate 20 and is machine washable. This feature enables the mat
10 to be subjected to commercial washing without degradation of the tufts 12. A backing
22 made of rubber is also skid resistant and prevents the mat 10 from moving around
once it is placed on the floor.
[0044] Applicant has conducted two tests to determine the effectiveness of the tuft-lock
of mats made in accordance with the teachings of the present invention. The first
test involved washing a first mat made in accordance with the present invention and
a second mat made pursuant to the disclosure in the '566 and '333 patents. Both mats
were washed twenty (20) times. A visual comparison was made of the two mats. The mat
made in accordance with the teachings of the present invention showed no significant
loss of coarse or fine fiber. However, the mat made in accordance with the '566 and
'333 patents showed significant loss of coarse fiber. This test demonstrates the capability
of the present invention to achieve effective tuft-lock and maintain such tuft-lock
after many washings.
[0045] The second test was related to analytically determining the effectiveness of the
tuft-lock of the present invention. Applicant compared the fiber loss of mat samples
made in accordance with the present invention (set 1) with those made in accordance
with the '566 and '333 patents (set 2). Both sets of examples were bone dried and
weighed, then soaked with water, hung and allowed to drip dry for five (5) minutes.
Both sets were then abraded for 2,500 cycles on a U.S. Testing Abrasion Tester. After
being abraded, both sets were bone dried and weighed again. Set 1 showed a loss of
0.555 grams. Set 2 showed a loss of 2.094 grams. The significant fiber loss of the
mats made in accordance with the' 566 and '333 patents further demonstrates the effectiveness
of the tuft lock achieved with the mats made pursuant to the present invention.
[0046] It will be appreciated that the embodiments discussed above are the preferred embodiments,
and that various alternative embodiments are contemplated, falling within the scope
of the appended claims. For example, while nylon or polyester may be the preferred
materials for use as the coarse fiber, natural fibers, such as jute may be used.
1. A process of making a machine washable track control mat including the steps of twisting
together at least one coarse denier fibre with at least one fine denier fibre to create
a yarn and tufting the yarn through a substrate to form a plurality of tufts in the
substrate,
characterised by the steps of:
bonding the tufts to the substrate with vulcanised rubber such that the mat is machine
washable without substantial degradation of tufts, the steps of tufting and bonding
carried out so that the tufts are structured and arranged in the substrate such that
the tufts remove and store dirt and moisture in voids between the tufts to control
tracking of dirt and moisture.
2. The process of claim 1 wherein there are a plurality of fine denier fibres.
3. The process of claim 1 or 2 wherein the yarn is tufted through the substrate at a
rate of 3 to 10 stitches per inch (per 2.54cm).
4. The process of any preceding claim wherein the yarn is twisted 5 to 6 turns per inch
(per 2.54cm).
5. The process of any preceding claim further comprising the step of heat treating the
yarn after the yarn is twisted.
6. A machine washable track control mat including a plurality of tufts and a substrate
to receive the tufts, each of the plurality of tufts comprising a yarn made of at
least one fine denier fibre twisted together with at least one coarse denier fibre,
characterised by:
a backing of vulcanized rubber which bonds the tufts to the substrate such that the
mat is machine washable without substantial degradation of tufts and the tufts being
structured and arranged in the substrate such that the tufts remove and store dirt
and moisture in voids between the tufts to control tracking of dirt and moisture.
7. The machine washable track control mat of claim 6 wherein the yarn is heat treated.
8. The machine washable track control mat of claim 6 or 7 wherein the yarn is received
into the substrate at a rate of 3 to 10 stitches per inch (per 2.54cm).
9. The machine washable track control mat of claims 6, 7, or 8 wherein the yarn is twisted
5 - 6 turns per inch (per 2.54cm).
10. The machine washable track control mat of any of claims 6 to 9 herein the mat weighs
between 16 and 24 ounces per square yard (54.25 x 10-2 kg per sqm or 81.37 x 10-2 kg per sqm) without the vulcanised rubber.
11. The machine washable track control mat of any of claims 6 to 10 wherein the weight
ratio range of fine denier to course fibres is between 20-24% to 76-80% respectively.
1. Verfahren zum Fertigen eines maschinenwaschbaren Fußabtreters, enthaltend die Schritte
des Zusammenzwirbelns wenigstens einer Faser von grobem Denier mit wenigstens einer
Faser von feinem Denier, um einen Garn zu erzeugen, und des Tufting des Garns durch
ein Substrat, um eine Vielzahl an Faserbüscheln im Substrat zu bilden,
gekennzeichnet durch die folgenden Schritte:
Binden der Faserbüschel an das Substrat mit vulkanisiertem Gummi derart, dass die
Matte ohne substantielle Zerlegung der Faserbüschel maschinenwaschbar ist, Ausführen
der Schritte des Tufting und Bindens derart, dass die Faserbündel derart strukturiert
und im Substrat angeordnet sind, dass die Faserbündel Schmutz und Feuchtigkeit entfernen
und in Hohlräumen zwischen den Faserbündeln speichern, um das Verschleppen von Schmutz
und Feuchtigkeit zu steuern.
2. Verfahren nach Anspruch 1, wobei eine Vielzahl von Fasern von feinem Denier besteht.
3. Verfahren nach Anspruch 1 oder 2, wobei das Garn mit einer Rate von 3 bis 10 Stichen
pro Zoll (pro 2.54 cm) durch das Substrat getuftet wird.
4. Verfahren nach einem der vorherigen Ansprüche, wobei das Garn 5 bis 6 Umdrehungen
pro Zoll (pro 2.54 cm) verzwirbelt ist.
5. Verfahren nach einem der vorherigen Ansprüche, das des Weiteren den Schritt der Wärmebehandlung
des Garns umfasst, nachdem das Garn verzwirbelt wurde.
6. Maschinenwaschbarer Fußabtreter, enthaltend eine Vielzahl an Faserbündeln und ein
Substrat zur Aufnahme der Faserbündel, wobei jedes Faserbündel aus der Vielzahl an
Faserbündeln einen Garn umfasst, der aus wenigstens einer Faser von feinem Denier
gefertigt ist, die mit wenigstens einer Faser von grobem Denier zusammengezwirbelt
ist,
gekennzeichnet durch:
einen Teppichgrund aus vulkanisiertem Gummi, der die Faserbündel derart an das Substrat
bindet, dass die Matte ohne wesentliche Zerlegung der Faserbündel maschinenwaschbar
ist, und dadurch, dass die Faserbündel derart strukturiert und im Substrat angeordnet sind, dass die
Faserbündel Schmutz und Feuchtigkeit entfernen und in Hohlräumen zwischen den Faserbündeln
speichern, um das Verschleppen von Schmutz und Feuchtigkeit zu steuern.
7. Maschinenwaschbarer Fußabtreter nach Anspruch 6, wobei das Garn wärmebehandelt ist.
8. Maschinenwaschbarer Fußabtreter nach Anspruch 6 oder 7, wobei das Garn mit einer Rate
von 3 bis 10 Stichen pro Zoll (pro 2.54 cm) durch das Substrat getuftet wird.
9. Maschinenwaschbarer Fußabtreter nach Anspruch 6, 7 oder 8, wobei das Garn 5 bis 6
Umdrehungen pro Zoll (pro 2.54 cm) verzwirbelt ist.
10. Maschinenwaschbarer Fußabtreter nach irgendeinem der Ansprüche 6 bis 9, wobei die
Matte zwischen 16 und 24 Unzen pro Quadratyard (54.25×10-2 kg pro m2 bzw. 81.37×10-2 kg pro m2) ohne den vulkanisierten Gummi wiegt.
11. Maschinenwaschbarer Fußabtreter nach irgendeinem der Ansprüche 6 bis 10, wobei der
Bereich des Gewichtsverhältnisses der Fasern von feinem Denier zu den groben Fasern
in dieser Reihenfolge 20 bis 24 % zu 76 bis 80 % beträgt.
1. Procédé de fabrication d'un paillasson anti-traces lavable en machine, comportant
les étapes consistant à torsader ensemble au moins une fibre de denier grossier avec
au moins une fibre de denier fin pour créer un fil et mettre en touffe le fil à travers
un substrat pour former une pluralité de touffes dans le substrat,
caractérisé par les étapes consistant à :
fixer les touffes sur le substrat à l'aide de caoutchouc vulcanisé de telle sorte
que le paillasson puisse être lavé à la machine sans dégradation importante des touffes,
les étapes consistant à mettre en touffe et à fixer étant effectuées d'une manière
telle que les touffes sont structurées et agencées dans le substrat de telle sorte
que les touffes enlèvent et stockent la poussière et l'humidité dans des vides existant
entre les touffes pour maîtriser les traces au sol de poussière et d'humidité.
2. Procédé selon la revendication 1, dans lequel il existe une pluralité de fibres de
denier fin.
3. Procédé selon la revendication 1 ou 2, dans lequel le fil est mis en touffe à travers
le substrat avec un taux de 3 à 10 boucles par pouce (par 2,54 cm).
4. Procédé selon l'une quelconque des revendications précédentes, dans lequel le fil
est torsadé sur 5 à 6 spires par pouce (par 2,54 cm).
5. Procédé selon l'une quelconque des revendications précédentes, comportant de plus
l'étape consistant à traiter thermiquement le fil après que le fil a été torsadé.
6. Paillasson anti-traces lavable en machine, comportant une pluralité de touffes et
un substrat pour recevoir les touffes, chacune de la pluralité de touffes comportant
un fil constitué d'au moins une fibre de denier fin torsadée avec au moins une fibre
de denier grossier,
caractérisé par :
une couche dorsale de caoutchouc vulcanisé qui fixe les touffes sur le substrat de
telle sorte que le paillasson est lavable à la machine sans dégradation importante
des touffes et les touffes sont structurées et agencées dans le substrat de sorte
que les touffes enlèvent et stockent la poussière et l'humidité dans des vides existant
entre les touffes pour maîtriser les traces au sol de poussière et d'humidité.
7. Paillasson anti-traces lavable en machine selon la revendication 6, dans lequel le
fil est traité thermiquement.
8. Paillasson anti-traces lavable en machine selon la revendication 6 ou 7, dans lequel
le fil est reçu dans le substrat avec un taux de 3 à 10 boucles par pouce (par 2,54
cm).
9. Paillasson anti-traces lavable en machine selon la revendication 6, 7 ou 8, dans lequel
le fil est torsadé à raison de 5 à 6 spires par pouce (par 2,54 cm).
10. Paillasson anti-traces lavable en machine selon l'une quelconque des revendications
6 à 9, dans lequel le paillasson pèse entre 16 et 24 onces par yard carré (54,25 ×
10-2 kg/m2 ou 81,37 × 10-2 kg/m2) sans le caoutchouc vulcanisé.
11. Paillasson anti-traces lavable en machine selon l'une quelconque des revendications
6 à 10, dans lequel la plage de rapport en poids de fibre de denier fin sur fibre
de denier grossier est entre 20 à 24 % et 76 à 80 % respectivement.