Technical field
[0001] This invention relates to certain synthetic oriented net materials suitable for use
in furniture, for example, in seats, beds, sofas and chairs. The upholstery support
material of the present invention will be particularly useful in automobile seats
(both bottoms and backs) and in seats used in other forms of ground transportation
(e.g. buses, trains, etc.) and in aircraft, where a combination of comfort, strength,
and especially light weight is important. Typically, the upholstery support material
of the present invention is suitable for use as a flexible support member in seat
bottoms and backs where traditionally, such support members have taken the form of
springs, webs, straps or molded units (e.g. thick foam pads), and materials of construction
for such seating support members have been steel, burlap, canvas, plastic and elastomeric
strapping and synthetic textile materials. Similarly, the upholstery support material
is suitable for use in beds in lieu of box of wire springs, especially in fold-away
and portable beds where compact size and light weight are especially important. Such
upholstery support materials must satisfy certain physical requirements including
high strength, low creep (shape and size retention), high durability, ability to flex
under load, and increasingly in today's marketplace, low weight. Increasing demand
for improvements in one or more of these criteria lay the groundwork for the present
invention.
Background art
[0002] U.S. Patent 2,919,467, granted January 5, 1960 to Mercer, discloses a method and
apparatus for making plastic netting having the general physical configuration of
one embodiment of the netting used in the upholstery support material of the present
invention. Mercer lists a wide variety of materials as being within his definition
of "plastic" and included within his list is polyesters. Mercer does not disclose
the use of the copolyetherester elastomers used in the present invention. In addition,
Mercer lists a wide variety of uses for his plastic netting, and included within his
list is "armouring upholstery" and "furnishing fabrics". However, Mercer does not
disclose that his netting can be used in furniture support material.
[0003] U.S. Patent Nos. 3,651,014; 3,763,109; and 3,766,146, granted March 21,1972, October
2 and October 16,1973, respectively, all to Witsiepe disclose certain copolyetherester
elastomers which can be used alone or in combination with each other as the material
of construction in the net upholstery support material of the present invention.
[0004] British Patent No. 1,458,341, published December 15, 1976 to Brown et al, discloses
an orientation and heat-setting process for treating copolyetherester elastomers,
which process is conveniently and beneficially used to treat the elastomers disclosed
by Witsiepe in U.S. Patents 3,763,109 and 3,766,146. The Brown process can be used
to treat filaments of Witsiepe's copolyetherester elastomers (which can be subsequently
woven into a net-like structure) and to treat net made by the teachings of Mercer
from the Witsiepe copolyetherester elastomers.
[0005] U.S. Patent No. 4,136,715, granted January 30, 1979 to McCormack et al, discloses
composites of different copolyetherester elastomers having melting points differing
from each other by at least 20°C. Such composites are used in one embodiment of the
upholstery support material of the present invention and are conveniently formed as
a "sheath/core" monofilament (as shown in Figure 1 of McCormack et al) where the core
copolyetherester elastomer is the higher melting point material.
Disclosure of the invention
[0006] This invention relates to synthetic oriented net upholstery support material made
from certain orientable thermoplastic elastomers. The net structure used in the upholstery
support material of the present invention can be extruded as a unitary net structure
as described in detail in U.S. Patent No. 2,919,467, the subject matter of which is
hereby incorporated herein by reference. Alternatively, the net structure used in
the upholstery support material of the present invention can be prepared by extrusion
of a plurality of monofilaments, placing the monofilaments into a net-like configuration,
e.g. by weaving and then bonding the monofilaments to each other where ever they intersect.
Standard weaving techniques, e.g. as shown in Fiber to Fabric, M. D. Potter, pages
59-73 (1945), can be used to prepare the woven embodiments of the present invention.
[0007] The orientable thermoplastic elastomer used in the upholstery support material of
the present invention can be a copolyetherester elastomer, a polyurethane elastomer,
or a polyesteramide elastomer. It can be solid, where the material of construction
is the same throughout, or a sheath/core monofilament, where the melting point of
the sheath component is substantially lower than the melting point of the core component.
In any case, the M
20 strength (i.e. the tensile strength at 20% elongation, measured according to ASTM
D-412) of the oriented thermoplastic elastomer monofilament should be 34.5-310.3 MPa
(5,000-45,000 p.s.i.), preferably 103.4-172.4 MPa (15,000-25,000 p.s.i.).
[0008] The preferred material of construction of the upholstery support material of the
present invention is a copolyetherester elastomer, such as disclosed by Witsiepe (U.S.
Patent Nos. 3,651,014; 3,763,109; and 3,766,146) and McCormack (U.S. Patent No. 4,136,715),
which material has been oriented for improved physical properties, such as by the
technique disclosed by Brown et al (British Patent 1,458,341).
[0009] The copolyetherester polymer which can be used in the instant invention consists
essentially of a multiplicity of recurring intralinear long-chain and short-chain
ester units connected head-to-tail through ester linkages, said long-chain ester units
being represented by the following structure:
and said short-chain ester units being represented by the following structure:
wherein:
G is a divalent radical remaining after removal of terminal hydroxyl groups from poly(alkylene
oxide) glycols having a carbon-to-oxygen ratio of about 2.0-4.3 and molecular weight
between about 400 and 6000;
R is a divalent radical remaining after removal of carboxyl groups from a dicarboxylic
acid having a molecular weight less than about 300; and
D is a divalent radical remaining after removal of hydroxyl groups from a low molecular
weight diol having a molecular weight less than about 250.
[0010] The term "long-chain ester units" as applied to units in a polymer chain refers to
the reaction product of a long-chain glycol with a dicarboxylic acid. Such "long-chain
ester units," which are a repeating unit in the copolyetheresters of this invention,
correspond to formula (a) above. The long-chain glycols are polymeric glycols having
terminal (or as nearly terminal as possible) hydroxy groups and a molecular weight
from about 400-6000. The long-chain glycols used to prepare the copolyetheresters
of this invention are poly(alkylene oxide) glycols having a carbon-to-oxygen ratio
of about 2.0-4.3.
[0011] Representative long-chain glycols are poly(ethylene oxide) glycol, poly(1,2- and
1,3-propylene oxide) glycol, poly(tetramethylene oxide) glycol, random or block copolymers
of ethylene oxide and 1,2-propylene oxide, and random or block copolymers of tetrahydrofuran
with minor amounts of a second monomer such as 3-methyltetrahydrofuran (used in proportions
such that the carbon-to-oxygen mole ratio in the glycol does not exceed about 4.3).
Poly(tetramethylene oxide) glycol (PTMEG) is preferred; however, it should be noted
that some or all of the long chain ester units derived from PTMEG (or any of the other
listed long-chain glycols) and terephthalic acid can be replaced by similar long-chain
units derived from a dimer acid (made from an unsaturated fatty acid) and butane diol.
A C
36 dimer acid is commercially available.
[0012] The term "short-chain ester units" as applied to units in a polymer chain refers
to low molecular weight compounds or polymer chain units having molecular weights
less than about 550. They are made by reacting a low molecular weight diol (below
about 250) with a dicarboxylic acid to form ester units represented by formula (b)
above.
[0013] Included among the low molecular weight diols which react to form short-chain ester
units are aliphatic, cycloaliphatic, and aromatic dihydroxy compounds. Preferred are
diols with 2-15 carbon atoms such as ethylene, propylene, tetramethylene, pentamethylene,
2,2-dimethyltrimethylene, hexamethylene, and decamethylene glycols, dihydroxy cyclohexane,
cyclohexane dimethanol, resorcinol, hydroquinone, 1,5-dihydroxy naphthalene, etc.
Especially preferred are aliphatic diols containing 2-8 carbon atoms. While unsaturated
low molecular weight diols are normally not preferred because they may undergo homopolymerization
it is possible to use minor amounts of diols such as 1,4-butene-2-diol in admixture
with saturated diols. Included among the bis-phenols which can be used are bis(p-hydroxy)diphenyl,
bis(p-hydroxyphenyl) methane, and bis(p-hydroxyphenyl) propane. Equivalent ester-forming
derivatives of diols are also useful (e.g., ethylene oxide or ethylene carbonate can
be used in place of ethylene glycol). The term "low molecular weight diols" as used
herein should be construed to include such equivalent ester-forming derivatives; provided,
however that the molecular weight requirement pertains to the diol only and not to
its derivatives.
[0014] Dicarboxylic acids which are reacted with the foregoing long-chain glycols and low
molecular weight diols to produce the copolyesters used in this invention are aliphatic,
cycloaliphatic, or aromatic dicarboxylic acids of a low molecular weight, i.e., having
a molecular weight of less than about 300. The term "dicarboxylic acids" as used herein,
includes equivalents of dicarboxylic acids having two functional carboxyl groups which
perform substantially like dicarboxylic acids in reaction with glycols and diols in
forming copolyester polymers. These equivalents include esters and ester-forming derivatives,
such as acid halides and anhydrides. The molecular weight requirement pertains to
the acid and not to its equivalent ester or ester-forming derivative. Thus, an ester
of a dicarboxylic acid having a molecular weight greater than 300 or an acid equivalent
of a dicarboxylic acid having a molecular weight greater than 300 are included provided
the acid has a molecular weight below about 300. The dicarboxylic acids can contain
any substituent groups or combinations which do not substantially interfere with the
copolyester polymer formation and use of the polymer of this invention.
[0015] Aliphatic dicarboxylic acids, as the term is used herein, refers to carboxylic acids
having two carboxyl groups each attached to a saturated carbon atom. If the carbon
atom to which the carboxyl group is attached is saturated and is in a ring, the acid
is cycloaliphatic. Aliphatic or cycloaliphatic acids having conjugated unsaturation
often cannot be used because of homopolymerization. However, some unsaturated acids,
such as maleic acid, can be used.
[0016] Aromatic dicarboxylic acids, as the term is used herein, are dicarboxylic acids having
two carboxyl groups attached to a carbon atom in an isolated or fused benzene ring.
It is not necessary that both functional carboxyl groups be attached to the same aromatic
ring and where more than one ring is present, they can be joined by aliphatic or aromatic
divalent radicals or divalent radicals such as -0- or ―SO
2―.
[0017] Representative aliphatic and cycloaliphatic acids which can be used for this invention
are sebacic acid, 1,3-cyclohexane dicarboxylic acid, 1,4-cyclohexane dicarboxylic
acid, adipic acid, glutaric acid, succinic acid, carbonic acid, oxalic acid, azelaic
acid, diethylmalonic acid, allylmalonic acid, 4-cyclohexene-1,2-dicarboxylic acid,
2-ethylsuberic acid, 2,2,3,3-tetramethylsuccinic acid, cyclopentanedicarboxylic acid,
decahydro-1,5-naphthalene dicarboxylic acid, 4,4'-bicyclohexyl dicarboxylic acid,
deca- hydro-2,6-naphthalene dicarboxylic acid, 4,4'-methylene bis-(cyclohexane carboxylic
acid), 3,4-furan dicarboxylic acid, and 1,1-cyclobutane dicarboxylic acid. Preferred
aliphatic acids are cyclohexanedicarboxylic acids and adipic acid.
[0018] Representative aromatic dicarboxylic acids which can be used include terephthalic,
phthalic and isophthalic acids, bi-benzoic acid, substituted dicarboxy compounds with
two benzene nuclei such as bis(p-carboxyphenyl) methane, p-oxy(p-carboxyphenyl) benzoic
acid, ethylene-bis(p-oxybenzoic acid), 1,5-naphthalene dicarboxylic acid, 2,6-naphthalene
dicarboxylic acid, 2,7-naphthalene dicarboxylic acid, phenanthrene dicarboxylic acid,
anthracene dicarboxylic acid, 4,4'-sulfonyl dibenzoic acid, and C
1-C
12 alkyl and ring substitution derivatives thereof, such as halo, alkoxy, and aryl derivatives.
Hydroxyl acids such as p-(¡3-hydroxyethoxy) benzoic acid can also be used providing
an aromatic dicarboxylic acid is also present.
[0019] Aromatic dicarboxylic acids are an especially preferred class for preparing the copolyetherester
polymers used in this invention. Among the aromatic acids, those with 8-16 carbon
atoms are preferred, particularly the phenylene dicarboxylic acids, i.e., phthalic,
terephthalic and isophthalic acids and their dimethyl derivatives.
[0020] It is preferred that at least about 70% of the short segments are identical and that
the identical segments form a homopolymer in the fiber-forming molecular weight range
(molecular weight 5000) having a melting point of at least 150°C and preferably greater
than 200°C. Polymers meeting these requirements exhibit a useful level of properties
such as tensile strength and tear strength. Polymer melting points are conveniently
determined by differential scanning calorimetry.
[0021] Other orientable thermoplastic elastomers useful in the upholstery support material
of the present invention include polyesterurethane elastomers, such as disclosed by
Schollenberger (U.S. Patent No. 2,871,218) and polyetherester amide elastomers, such
as disclosed by Foy (U.S. Patent 4,331,786) and Burzin (U.S. Patent 4,207,410).
[0022] Thermoplastic polyesterurethane elastomers which can be used in the instant invention
are prepared by reacting a polyester with a diphenyl diisocyanate in the presence
of a free glycol. The ratio of free glycol to diphenyl diisocyanate is very critical
and the recipe employed must be balanced so that there is essentially no free unreacted
diisocyanate or glycol remaining after the reaction to form the elastomer of this
invention. The amount of glycol employed will depend upon the molecular weight of
the polyester as discussed below.
[0023] The preferred polyester is an essentially linear hydroxyl terminated polyester having
a molecular weight between 600 and 1200 and an acid number less than 10, preferably
the polyester has a molecular weight of from about 700 to 1100 and an acid number
less than 5. More preferably the polyester has a molecular weight of 800 to 1050 and
an acid number less than about 3 in order to obtain a product of optimum physical
properties. The polyester is prepared by an esterification reaction of an aliphatic
dibasic acid or an anhydride thereof with a glycol. Molar ratios of more than 1 mol
of glycol to acid are preferred so as to obtain linear chains containing a preponderance
of terminal hydroxyl groups.
[0024] The basic polyesters include polyesters prepared from the esterification of such
dicarboxylic acids as adipic, succinic, pimelic, suberic, azelaic, sebacic or their
anhydrides. Preferred acids are those dicarboxylic acids of the formula HOOC-R-COOH,
where R is an alkylene radical containing 2 to 8 carbon atoms. More preferred are
those represented by the formula HOOC(CH2).COOH, where x is a number from 2 to 8.
Adipic acid is preferred.
[0025] The glycols utilized in the preparation of the polyester by reaction with the aliphatic
dicarboxylic acid are preferably straight chain glycols containing between 4 and 10
carbon atoms such as butanediol-1,4, hexamethylene-diol-1,6, and octamethylenediol-1,8.
In general the glycol is preferably of the formula HO(CH
2)
XOH, wherein x is 4 to 8 and the preferred glycol is butanediol-1,4.
[0026] A free glycol must also be present in the polyester prior to reaction with the diphenyl
diisocyanate. The units formed by reaction of the free glycol with the diisocyanate
will constitute the short-chain urethane units. Similarly the units formed by reaction
of polyester with diisocyanate constitute the long-chain urethane units. Advantage
may be taken of residual free glycol in the polyester if the amount is determined
by careful analysis. The ratio of free glycol and diphenyl diisocyanate must be balanced
so that the end reaction product is substantially free of excess isocyanate or hydroxyl
groups. The glycol preferred for this purpose is butanediol-1,4. Other glycols which
may be employed include the glycols listed above.
[0027] The specific diisocyanates employed to react with the mixture of polyester and free
glycol are also important. A diphenyl diisocyanate such as diphenyl methane diisocyanate,
p,p'-diphenyl-diisocyanate, dichlorodiphenyl methane diisocyanate, dimethyl diphenyl
methane diisocyanate, dibenzyl diisocyanate, diphenyl ether diisocyanate are preferred.
Most preferred are the diphenyl methane diisocyanates and best results are obtained
from diphenyl methane-p,p'-diisocyanate.
[0028] Thermoplastic polyetherester amide elastomers which can be used in the instant invention
are represented by the following formula
wherein A is a linear saturated aliphatic polyamide sequence formed from a lactam
or amino acid having a hydrocarbon chain containing 4 to 14 carbon atoms or from an
aliphatic C
S-C
12 dicarboxylic acid and a C
e―Cg diamine, in the presence of a chain-limiting aliphatic carboxylic diacid having
4 to 20 carbon atoms; and B is a polyoxyalkylene sequence formed from linear or branched
aliphatic polyoxyalkylene glycols, mixtures thereof or copolyethers derived therefrom,
said polyoxyalkylene glycols having a molecular weight of between 200-6,000. The polyamide
sequence A consists of a plurality of short-chain amide units. The polyoxyalkylene
sequence B represents a long-chain unit. The polyetherester amide block copolymer
is prepared by reacting a dicarboxylic polyamide, the COOH groups of which are located
at the chain ends, with a polyoxyalkylene glycol hydroxylated at the chain ends, in
the presence of a catalyst constituted by a tetraalkylorthotitanate having the general
formula Ti(OR)
4, wherein R is a linear branched aliphatic hydrocarbon radical having 1 to 24 carbon
atoms.
[0029] Approximately equimolar amounts of the dicarboxylic polyamide and the polyoxyalkylene
glycol are used, since it is preferred that an equimolar ratio should exist between
the carboxylic groups and the hydroxyl groups, so that the polycondensation reaction
takes place under optimum conditions for achieving a substantially complete reaction
and obtaining the desired product.
[0030] The polyamides having dicarboxylic chain ends are preferably linear aliphatic polyamides
which are obtained by conventional methods currently used for preparing such polyamides,
such methods comprising, e.g. the polycondensation of a lactam or the polycondensation
of an amino-acid or of a diacid and a diamine, these polycondensation reactions being
carried out in the presence of an excess amount of an organic diacid the carboxylic
groups of which are preferably located at the ends of the hydrocarbon chain; these
carboxylic diacids are fixed during the polycondensation reaction so as to form constituents
of the macromolecular polyamide chain, and they are attached more particularly to
the ends of this chain, which allows an a-co-dicarboxylic polyamide to be obtained.
Furthermore, this diacid acts as a chain limitator. For this reason, an excess amount
of a-w-dicarboxylic diacid is used with respect to the amount necessary for obtaining
the dicarboxylic polyamide, and by conveniently selecting the magnitude of this excess
amount the length of the macromolecular chain and consequently the average molecular
weight of the polyamides may be controlled.
[0031] The polyamide can be obtained starting from lactams or amino-acids, the hydrocarbon
chain of which comprises from 4 to 14 carbon atoms, such as caprolactam, oenantholactam,
dodecalactam, undecanolactam, dodecanolactam, 11-amino-undecanoic acid, or 12-aminododecanoic
acid.
[0032] The polyamide may also be a product of the condensation of a dicarboxylic acid and
diamine, the dicarboxylic acid containing 4 to 14 preferably from about 6 to about
12 carbon atoms in its alkylene chain and a diamine containing 4 to 14 preferably
from about 6 to about 9 carbon atoms in its alkylene chain. Examples of such polyamides
include nylon 6―6, 6-9, 6-10, 6-12 and 9―6, which are products of the condensation
of hexamethylene diamine with adipic acid, azelaic acid, sebacic acid, 1,12-dodecanedioic
acid, and of nonamethylene diamine with adipic acid. Preferred are polyamides based
on nylon 11 or 12.
[0033] The diacids which are used as chain limiters of the polyamide synthesis and which
provide for the carboxyl chain ends of the resulting dicarboxylic polyamide preferably
are aliphatic carboxylic diacids having 4 to 20 carbon atoms, such as succinic acid,
adipic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid and dodecanedioic
acid.
[0034] They are used in excess amounts in the proportion required for obtaining a polyamide
having the desired average molecular weight within the range of between 300 and 15000
in accordance with conventional calculations such as currently used in the field of
polycondensation reactions.
[0035] The polyoxyalkylene glycols having hydroxyl chain ends are linear or branched polyoxyalkylene
glycols having an average molecular weight of no more than 6000 and containing 2 to
about 4 carbon atoms per oxyalkylene unit such as polyoxyethylene glycol, polyoxypropylene
glycol, polyoxytetramethylene glycol or mixtures thereof, or a copolyether derived
from a mixture of alkylene glycols containing 2 to about 4 carbon atoms or cyclic
derivatives thereof, such as ethylene oxide, propylene oxide or tetrahydrofurane.
Polyoxytetramethylene glycol is preferred.
[0036] The average molecular weight of the polyamide sequence in the block copolymer may
vary from about 300 to about 15,000, preferably from about 1000 to about 10,000.
[0037] The average molecular weight of the polyoxyalkylene glycols forming the polyoxyalkylene
sequence suitable is in the range of from about 200 to about 6,000, preferably about
400 to about 3000.
[0038] Other thermoplastic polyetherester amides which can be used in the instant invention
consist of mixtures of one or more polyamide forming compounds, polytetramethyleneether
glycol (PTMEG) and at least one organic dicarboxylic acid, the latter two components
being present in equivalent amounts.
[0039] The polyamide-forming components are omega-aminocarboxylic acids and/or lactams of
at least 10 carbon atoms, especially lauryllactam and/or omega-aminododecanoic acid
or omega-aminoundecanoic acid.
[0040] The diol is PTMEG having an average molecular weight of between about 400 and 3,000.
[0041] Suitable dicarboxylic acids are aliphatic dicarboxylic acids of the general formula
HOOC-(CH
2)
x-COOH, wherein x can have a value of between 4 and 11. Examples of the general formula
are adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid and decanedicarboxylic
acid. Furthermore usable are cycloaliphatic and/or aromatic dicarboxylic acids of
at least eight carbon atoms, e.g. hexahydroterephthalic acid, terephthalic acid, isophthalic
acid, phthalic acid, or naphthalene-dicarboxylic acids.
[0042] In the preparation of the polyetherester amides, conventional catalysts are utilized,
if desired, in the usual quantities, such as, for example, phosphoric acid, zinc acetate,
calcium acetate, triethylamine, or tetraalkyl titanates. Advantageously, phosphoric
acid is used as the catalyst in amounts of between 0.05 and 0.5% by weight.
[0043] The polyetherester amides can also contain additives which are introduced prior to,
during, or after the polycondensation. Examples of such additives are conventional
pigments, flattening agents, auxiliary processing agents, fillers, as well as customary
thermal and UV stabilizers.
[0044] The short-chain ester, urethane and amide units described above will constitute about
50-95% by weight, preferably 60-85% by weight, of the polymer and ergo, the long chain
ester of ether units constitute about 5-50% by weight, preferably 15―40% by weight
of the polymer. Accordingly, the shore D hardness of the polymer should be 45-85,
preferably 55-75 to obtain polymers suited for the production of oriented monofilaments
whose M
20 is in the range of from about 34.5 to about 310.3 MPa (5,000-45,000 p.s.i.), preferably
in the range of from about 103.4 to about 172.4 MPa (15,000-25,000 p.s.i.).
[0045] If the thermoplastic elastomer filaments are sheath/core, it is preferred that the
short-chain ester, urethane or amide units be at least 50 weight percent of the core
elastomer, with a minimum of 60 weight percent short-chain ester, urethane or amide
units being more preferred and a range of 65 to 85 weight percent short-chain ester,
urethane or amide units being most preferred for the core. The sheath thermoplastic
elastomer should have a melting point of at least 20 degrees C lower than the core
elastomer, and accordingly, it will contain either a lower proportion of short-chain
ester, urethane or amide units or a mixture of chemically dissimilar short-chain ester,
urethane or amide units. In any event, the sheath elastomer will contain at least
20 weight percent short-chain ester, urethane or amide units, preferably at least
30 weight percent short-chain units.
[0046] As mentioned above, the thermoplastic elastomer can be formed into a net configuration
in a process and apparatus as described by Mercer. In this embodiment, a net is formed
by extruding the elastomer through a pair of die sets which are relatively displaced
transversely to the direction of extrusion into positions in which the die orifices
of one set are in registration with those of the other set during which extrusion
of the intersection-forming streams occurs through the composite registered die orifices,
and into positions of non-registration of the die orifices of the sets during which
extrusion of the mesh strand-forming streams occurs, which are divided with a shearing
action out of the said intersection-forming streams. It should be noted that extrusion
of relatively low hardness elastomer (i.e., polymer containing relatively low amounts
of short chain ester, urethane or amide units), may produce some processing difficulties,
such as sticking to the surface of the former. This problem can be alleviated by preblending
a small quantity (e.g. 5 weight percent) of polypropylene to increase the lubricity
of the elastomer. Conveniently, the sets of dies are arranged in an annulus and the
relative displacement is rotary. Netting extruded from this type of die-set will be
in a diamond-mesh tubular configuration which is then slit on a bias at a 45° angle
to the axis of the tube. This changes the diamond-mesh tubular net into a square-mesh
flat configuration suitable for orientation to make it useful as a seating support
member. This bias-slitting process is described in detail in U.S.P. 3,557,268, the
subject matter of which is hereby incorporated by reference. Machine-direction orientation
of the flat elastomer square-mesh net is accomplished by stretching of this square-mesh
sheeting along its longitudinal axis by transporting the sheeting over a series of
rolls with the later rolls turning at a rate faster than the earlier rolls. The degree
of stretch imparted to the sheeting is determined by the relative speeds of the respective
rolls. Allowance must be made for the elastic nature of the thermoplastic elastomer.
For example, in a typical embodiment where it is desired to achieve a final stretch
of 3x, it will be necessary to operate the second roll at a speed 4x the speed of
the first roll. Final stretch ratios of 3x to 4x is preferred. Transverse-direction
orientation is then accomplished by advancing the machine-direction stretched netting
into a tenter frame stretching apparatus and stretching the netting in the transverse
direction to a final stretch ratio of about 3x to 4x.
[0047] Alternatively, monofilaments of thermoplastic elastomer, either solid or sheath/core
as described in McCormack et al can be formed into a net pattern, either by merely
laying such filaments across one another or by interweaving the filaments with one
another, and subsequently bonding the filaments to one another at the intersections.
Bonding of the filaments at the intersections can be by use of conventional adhesives
of textile binders. Commercial suspensions of resin in water can be coated onto the
filaments, dried to remove water, and cured at 110° to 150°C for 30 to 150°C for 30
to 200 seconds. The curing crosslinks the resin in the binder and adheres the filaments
to each other at their intersections. Preferably, bonding of the filaments at the
intersections is effected by heating the filaments to their melting point, applying
sufficient pressure for the respective filaments to flow together, and cooling. In
this embodiment, it is preferred that the monofilament be oriented to a final stretch
ratio of 3X to 4X before it is placed in a net configuration. Further it is preferred
that the monofilament be of the sheath/core variety where the core is the higher melting
component. When bonding is effected by heating to the melting point of the elastomer,
orientation is at least partially destroyed; however when the filament is of the sheath/core
variety, bonding is effected by heating only up to the melting point of the sheath
(the core is always higher melting), then only the orientation of the sheath layer
is disturbed. The orientation of the core remains substantially undisturbed, and the
increased physical properties achieved by orientation of the core filament remains
largely undisturbed.
[0048] During heat sealing, the upholstery support material of the present invention is
heated in air at 140° to 180°C in a tenter oven for 20 to 60 seconds. This causes
the sheath of the coextruded monofilament fill to soften and adhere to the monofilament
warp. Upon cooling, the fabric is stable and can be cut, sewn and adhesively sealed
or stapled to form a suspension.
[0049] The desirable properties characteristic of the upholstery support material of the
present invention can be achieved with some variety in the spacing of the elastomer
filaments. Generally the elastomer filaments should be spaced such that the number
of picks per meter is in the range of
where (a) is the cross-sectional area of the filament in mm
2.
[0050] It should be understood that variations from the configurations described above can
be made without deviating from the concepts and principles embodied in the present
invention. For example, while it is preferred that the upholstery support material
of the present invention have a uniform density of fill and of warp, variable density
warp and/or fill can be achieved by varying the picks per inch or by varying the diameter
of the monofilaments.
[0051] The net upholstery support material of the present invention has a unique combination
of properties not found in commercially available upholstery support materials and
not found in experimental upholstery support materials having the same or similar
geometric configuration as the net upholstery support material of the present invention
but made from materials other than oriented thermoplastic elastomer. In particular,
the net upholstery support material of the present invention has a combination of
high tear resistance and low creep (both dead load static creep and dynamic creep).
In addition the support factor and the K-factors, as hereinafter described, of the
net upholstery support material of the present invention are quite low, thus permitting
very light weight upholstery support members.
[0052] Tear resistance is a measure of the energy required to tear a predetermined length
of the netting (or other furniture support material), normalized per unit weight or
areal density (weight per unit area). The quantification of this property is achieved
by preparing a rectangular sample of the upholstery support material 30.6 cm by 10.2
cm. This sample is then slit halfway down the center of the 30.6 cm length. The two
sides are mounted in an Instron tensile tester to pull a standard trouser tear similar
to ASTM D-470, section 4.6. The sample is pulled to destruction at a rate of 5.1 cm/min.
The resultant curve of force v. deflection is integrated to obtain a value for the
total energy required to complete the 15.3 cm tear and the energy is divided by the
areal density (weight per unit area) of the material to normalize the result. A minimum
value of 0.40 joules/meter-gram/meter
2 is considered satisfactory.
[0053] Creep, both dead load static creep and dynamic creep, are measures of the ability
of the upholstery support material to retain its original shape and resilience after
being subjected to loading. This property of the upholstery support material is generally
considered along with the unit weight of the support material. For economy of use
and, in particular, for weight reduction considerations in automotive and aircraft
applications, it is the objective to keep both creep and unit weight at minimum levels.
Generally, creep properties vary directly with the magnitude of the applied forces
and inversely with the unit weights of upholstery support material. Thus one frequently
must choose between very low creep and very low unit weight, or select a material
somewhere in the middle, which has neither very low creep nor very low unit weight.
The materials of the present invention do offer both low creep and low unit weight.
This is best understood by referring to the relationship between creep on the one
hand, and force and unit weight, on the other. This relationship can be represented
by the following equation:
[0054] Creep=CxForce/Unit weight where "C" is a constant for any particular material.
[0055] In all of the creep tests conducted on the upholstery support materials of this invention,
the force was the same so that the numerator of the equation, Cx Force, can be represented
by K which will hereafter be referred to as the "K-factor". As seen from the above
equation, this K-factor is equal to the creep times the unit weight and, again, it
is the industry objective to achieve minimum values for the "K-factor" values of the
various upholstery support materials used in the industry. This objective is achieved
with the materials of the present invention.
[0056] Dead load static creep is a measure of the ability of the upholstery support material
to retain its original shape and resiliance after being subjected to a static load
for an extended period. The quantification of this property is achieved by preparing
a seat bottom having a 0.33 meter by 0.38 meter opening, said seat bottom having been
made of 2.5 cm thick grade AB exterior plywood. The support material to be tested
was stretched approximately 8% (except for samples G and H which were stretched about
17%) in both directions and stapled in place on all four sides. A 334 Newton weight
is placed on a 20.3 cm diameter wooden disc which is in turn placed on the upholstery
support material and left for 112 days. The deflection of the seat bottom is measured
at the beginning and the end of the 112 days, and the percent change in deflection
is calculated according to the following formula:
where Do is the deflection at the beginning of the 112 days, and 0
112 is the deflection at the end of the 112 days. A maximum value of 14.0% is considered
preferred. When extremely light weight materials are desired, some sacrifice in dead
load static creep can frequently be tolerated and values as high as 20.0% are considered
satisfactory.
[0057] While some commercially available competitive materials may offer dead load static
creep values approaching this upper limit, they do so only in materials having a considerably
higher unit weight. This distinction is most easily demonstrated using the dead load
static creep "K-factor", which as described above, equals the actual static creep
times the unit weight. Thus if two materials offer the same creep, but one weighs
four times as much, the K-factor of the less desirable fabric will be four times higher.
Similarly, if they had the same unit weight, but one had four times less creep, the
K-factor of the more desirable fabric would be four times lower. For the purpose of
further defining the present invention, a static creep K-factor of less than 6000
is considered satisfactory with less than 3000 especially preferred.
[0058] Dynamic creep is a measure of the ability of the upholstery support material to retain
its original shape and resiliance after being subjected to repeated flexing under
load. The quantification of this property is achieved by preparing a seat bottom with
a 0.33 meter by 0.38 meter opening, said seat bottom being made out of 2.5 cm thick
grade AB exterior plywood. The support material to be tested was stretched approximately
8% (except for sample G and H which were stretched about 17%) in both directions and
stapled in placed on all four sides. Next a burlap fabric was loosely stapled over
the support material, followed by a 2.5 cm thick layer of open cell 0.047 g/cm
3 density polyurethane foam, which is in turn covered by a 0.045 g/cm
2 upholstery fabric. During the test a 778 Newton weight was placed on a buttock form
to simulate a 778 Newton man, which was in turn, placed on the completed seat bottom.
This weighted buttock form was then raised (so that there was no weight on the seat
bottom) and lowered (so that the seat bottom was supporting the full weight) repeatedly
for 25,000 cycles at a frequency of 1050 cycles/hour.
[0059] The dynamic creep (i.e. % change in deflection) is calculated according to the following
formula:
where Do is the deflection of the uncovered (i.e. no burlap, polyurethane form or
upholstery fabric) seat bottom due to a 334 Newton weight using a 20.3 cm diameter
wooden disc before the test was started, and 0
25,
000 is the deflection of the uncovered seat bottom due to a 334 Newton weight using a
20.3 cm diameter wooden disc after 25,000 cycles. A maximum value of 8.0 is considered
preferred. As with static creep, where extremely light weight materials are desired,
some sacrifice in dynamic creep can frequently be tolerated and values as high as
22.0% are considered satisfactory.
[0060] While some commercially available competitive materials may offer dynamic creep values
which approach or better this upper limit, they do so only in materials having a considerably
higher unit weight. This distinction is most easily demonstrated using the dynamic
creep "K-factor", which as described above, equals the actual dynamic creep times
the unit weight. For the purpose of further defining the present invention, a dynamic
creep K-factor of less than 5000 is considered satisfactory, with less than 2500 especially
preferred.
[0061] Flexibility, or deflection, is a measure of the ability of the upholstery support
material to provide a moderate amount of flex under a moderate load. Too much flex
and the seat will be considered to be soft or saggy. Too little flex and the seat
will be considered too stiff, hard and uncomfortable. The quantification of this property
is achieved by preparing a seat bottom having a 0.33 meter by 0.38 meter opening,
said seat bottom being made of 2.5 cm thick grade AB exterior plywood. The support
material to be tested was stretched approximately 8% (except for samples G and H which
were stretched about 17%) in both directions and stapled in place on all four sides.
A 334 Newton weight is placed on a 20.3 cm diameter wooden disc which is, in turn,
placed on the upholstery support material, the weight and the disc being approximately
centrally located on the upholstery support material. The deflection of the upholstery
support material is measured in centimeters. A value of 1.25-7.50 cm is considered
satisfactory.
[0062] Support factor is a measure of the amount (or mass) of upholstery support material
necessary to provide a predetermined amount of support. This can be considered a measure
of the efficiency of the upholstery support material. The more efficient the upholstery
support material, the lighter the upholstery support material needed to do a particular
job. The quantification of this property is achieved by preparing a seat bottom with
a 0.33 meter by 0.38 meter opening, said seat bottom being made out of 2.5 cm thick
grade AB exterior plywood. The support material to be tested was stretched approximately
8% (except for samples G and H which were stretched about 17%) in both directions
and stapled on all four sides, the seat bottom with the seat support material is covered
as described above in the dynamic creep test and, the force which will give a deflection
of 3.8 cm (using the 20.3 cm diameter wooden disc as above) is measured. The weight
of the upholstery support material necessary to cover the seat bottom (including the
material under the staples) is measured and the support factor is calculated according
to the following formula:
where
Se is the actual mass in grams of upholstery support material, and
Fe is the actual weight (in Newtons) observed at a deflection of 3.8 cm of the furniture
support material.
A maximum value of 55 grams is considered satisfactory.
[0063] In the following examples, there are shown specific embodiments of the present invention
in direct side-by-side comparison with embodiments of commercially available upholstery
support materials and embodiments similar in physical configuration to the embodiments
of the present invention but made from a material of construction other than thermoplastic
elastomers. It will be seen that only the embodiments of the present invention have
the requisite combination of properties-high tear resistance and low creep (both static
and dynamic). In addition, it will be seen that the embodiments of the present invention
have a low support factor and K-factors (high efficiency), particularly as compared
to several of the commercially available furniture support materials.
[0064] All parts and percentages are by weight and all temperatures are in degrees Celsius,
unless otherwise specified. Measurements not originally in SI units have been so converted
and rounded where appropriate.
Example 1
Preparation of high hardness copolyetherester extruded netting
[0065] Netting was made in a two-step process, extrusion of an unoriented netting followed
by orientation. Copolyetherester (prepared substantially as in Example 1-B of U.S.
Patent No. 3,763,109 except that the amount of dimethyl terephthalate was increased
from 40.5 parts to 55.4 parts. The resulting copolyester contained 81.6% butylene
terephthalate short chain ester units and 18.4% long chain ester units derived from
PTMEG-975 (polytetramethylene ether glycol having an average molecular weight of 975)
and terephthalic acid was extruded through a double rotating slotted die as described
in U.S. Patent No. 2,919,467 at a barrel and die temperature of 232°C and at a rate
of 82 kg/hr onto a horizontal circular former. The counter rotation die speed was
adjusted to form a netting with a diamond mesh which was subsequently slit on a 45°
diagonal to the axis of the circular former. This resulted in a webbing 34-40 cm wide
with longitudinal and transverse strands at right angles on a center line spacing
of 0.76-1.3 cm. The longitudinal strands were next oriented in a 8 roll Marshall and
Williams machine direction stretcher using a 0.25 cm gap, and a preheat roll temperature
of 110°C. The machine orientation ratio (i.e. the difference in speed between fast
and slow rolls) was 4.0x. This resulted in a final longitudinal product orientation
of 3.0x. The transverse strands were next oriented on a Marshall and Williams tenter
frame oven. In this oven the webbing was heated in the preheat stage to 175°C and
then stretched at 180°C to a machine orientation ratio of 4.0×. This resulted in a
final product orientation ratio of 3.0x in the transverse direction. The resulting
net had a strand count of approximately 0.33 strands per centimeter and an average
strand cross-section of about 0.13 cm by 0.09 cm. This netting will be identified
hereinafter as Sample A.
Example 2
Preparation of medium hardness copolyetherester extruded netting
[0066] Netting was made from medium hardness copolyetherester substantially as described
in Example 1, above, except as follows:
(a) The copolyetherester was prepared substantially as described in Example 1 of U.S.
Patent No. 3,766,146 except that the amount of dimethyl terephthalate was increased
from 600 to 654 g. This copolyester contained 60.0% butylene terephthalate units and
40.0% long chain units derived from PTMEG-975 and terephthalic acid.
(b) Polypropylene (5 weight percent) was preblended with the copolyetherester elastomer
to improve the processing properties of the polymer.
(c) The barrel and die temperature was 221°C.
(d) The preheat temperature in the tenter frame oven was 170°C and the oven temperature
was 180°C. The resulting net had a strand count and strand cross-section substantially
the same as the net produced in Example 1 above. This netting will be identified hereinafter
as Sample B.
Example 3
Preparation of netting from woven sheath/core monofilaments of copolyetherester elastomer
[0067] Netting was made in a three-step process:
(a) Extrusion and orientation of sheath/core monofilaments.
(b) Weaving of the monofilaments into a fabric.
(c) Heat bonding the woven monofilament fabric in a tenter frame oven.
[0068] Copolyetherester elastomer monofilaments were prepared substantially as described
in U.S. Patents No. 3,992,499 and 4,161,500. The copolyetherester elastomer in the
sheath is as described in Example 1 in U.S. Patent No. 3,651,014. This copolyester
contained 37.6% butylene terephthalate units, 10.9% butylene isophthalate units and
51.5% long chain units derived from PTMEG-1000 and terephthalic and isophthalic acids.
The copolyetherester elastomer in the core is as described in Example 1 above. The
extrusion conditions were as follows:
[0069] After neck down the solidified unoriented filament diameter was 0.10 cm. This filament
was then fed into an 180 cm quench tank with 23°C water, and was then fed to a 14-roll
draw stretcher. The stretching operation consisted of feeding the unoriented filament
through a 7-roll section of slow rolls followed by a tank with 70°C water, and finally
feeding the filament through a 7-roll section of fast rolls. The use of the 7 rolls
in each section was needed to ensure no slippage of the filament during orientation.
The draw ratio of speeds between the fast and slow rolls sections was 4.3x which resulted
in a product orientation ratio of 3.2x. The resultant cross-section diameter of the
monofilament was 0.05 cm. The weaving of this bi-component filament into a fabric
was done in a loom with a warp and fill strand count of 4 strands per centimeter.
[0070] The bonding of this woven fabric was accomplished by passing it through a tenter-frame
oven at a temperature of 170°C, with a residence time of 30 seconds. During the bonding
step it was important to hold the sides of the woven fabric tight so that the bonded
fabric would have acceptable creep properties. This netting will be identified hereinafter
as Sample C.
Example 4
Preparation of netting from woven dissimilar copolyetherester elastomers monofilaments
[0071] Netting was prepared substantially as described in Example 3 above with the following
exceptions:
a. The warp filament comprised a 30% sheath, 70% core monofilament where the sheath
was a copolyetherester elastomer as described in Example in U.S. Patent No. 3,651,014
and the core was a copolyetherester elastomer as described in Example 1 above.
b. The fill monofilament comprised was a 30% sheath, 70% core monofilament where the
sheath was the same as used in the warp filament and the core was a copolyetherester
elastomer as described in Example 1 of U.S. Patent No. 3,766,146. The core of the
fill filament was extruded at an extruder temperature of 235°C.
c. The loom was set for a strand count of 3.0 strands per centimeter.
[0072] This netting will be identified hereinafter as Sample D.
[0073] In the following Tables samples E through I represent commercially available materials
defined as follows:
[0074] Sample E was a "Vexar" plastic netting, available from Amoco Fabrics, Co., Atlanta,
Georgia having the following specifications:
[0075]
Composition-"ProFax" Polypropylene Type 6523
Strand count-0.6 strands per centimeter
Strand cross-section-0.07 cm by 0.03 cm
Orientation ratio-2.9x
[0076] Sample F was a "Vexar" plastic netting available from Amoco Fabrics, Co., of Atlanta,
Georgia having the following specifications:
[0077]
Composition-"Alathon" high density polyethylene resin type 5294
Strand count-0.6 strand per centimeter
Strand cross-section-0.04 cm by 0.08 cm
Orientation ratio-2.9x
[0078] Sample G was a woven natural rubber netting type 1480 ORTHA-WEB manufactured by Mateba
Webbing of Canada, Dunnsville, Ontario, Canada. The construction of this product consisted
of double wrapped natural rubber strands in the warp direction and textured yarn in
the fill direction. Dimensions of the warp and fill components were estimated to be:
Strand count warp-6 strands per centimeter
Strand count fill-3 strands per centimeter
Strand cross-section-warp-0.02 cm diameter
Strand cross-section-fill-0.02 cmx0.01 cm
[0079] Sample H was J. P. Stevens "Flexor" Type K-1692-S available from United Elastic Division,
J. P. Stevens and Company, Inc., Woolwine, Virginia. This product was a knit fabric
made on a Raschel machine with a stable stitch and had the following properties:
Composition-warp 19% Spandex, fill 81% nylon
Strand count-warp 6 strands per cm, fill 18 strands per centimeter
Strand diameter-warp 0.03 cm, fill 0.006 cm
Sample H was tested in double thickness.
[0080] Sample I was a J. P. Stevens "Flexor" Type K-1949-S which was similar to Sample H
above, but had the following physical properties:
Composition warp-30% Spandex, fill 70% nylon
Strand count―warp 6 strands per cm, fill 16 strands per centimeter
Strand diameter warp-0.04 cm, fill 0.006 cm
Example 5
Preparation of woven netting with various sheath/core elastomer monofilament fill
& warp
[0081] Three fabric samples were made using a monofilament fill and warp with the monofilaments
having sheaths of copolyetherester elastomer as described in Example 1 in U.S. Patent
No. 3,651,014. This copolyester contains 37.6% butylene terephthalate units, 10.9%
butylene isophthalate units and 51.5% long chain units derived from PTMEG-1000 and
terephthalic and isophthalic acids. The core of the monofilament fill was a thermoplastic
elastomer as follows:
[0082] The monofilaments were coextruded and oriented to 4x. The sheath/core ratio in each
of the monofilaments was 20/80 and the caliper of each of the monofilaments was 20
mils (0.51 mm). The samples were plain woven and heat sealed in a tenterframe with
a residence time of 30 seconds and an air temperature of 166°C. The samples contained
17,13 and 16 picks/inch (670, 512 and 630 picks/meter) of the monofilament fill, respectively
for each of samples J, K and Land 15, 16 and 16 strands/inch (590, 630 and 630 strands/meter)
of the polyester yarn warp in each of Samples J, K and L, respectively.
[0083] Each of Samples J-L was tested as described above in Example 1 with the following
results:
Industrial applicability
[0084] The oriented thermoplastic elastomer net upholstery support material of the present
invention is useful in the manufacture of seat backs and bottoms intended for use
in automobiles, aircraft and also in conventional household and industrial furniture.
The unique combination of the properties possessed by the upholstery support material
of the present invention, i.e., high tear resistance, good flexibility, low creep
and low support factor render these materials particularly well suited for use in
applications where high performance and low weight are especially desirable, such
as in automotive and aircraft seating.
Best mode
[0085] Although the best mode of the present invention, that is the single most preferred
embodiment of the present invention, will depend upon the particular desired end use
and the specific requisite combination of properties needed for that use; generally,
the most preferred embodiment of the present invention is that described in detail
above as Sample C.
1. Polsterträgermaterial in Netzkonfiguration mit gekreuzten, aus einem orientierten
thermoplastischen Elastomer bestehenden Strängen, wobei die Stränge an ihren Kreuzungspunkten
miteinander verbunden sind und wobei das Polstermaterial einen Reißfestigkeitswert
von wenigstens 0,40 J/m-g/m2 aufweist, einen K-Faktorwert für die statische Standfestigkeit unter Eigengewicht
von weniger als 6000% Änderung der Durchbiegung-g/m2, einen Durchbiegungswert von 1,25-7,50 cm und einen K-Faktorwert für die dynamische
Standfestigkeit von weniger als 5000% Änderung der Durchbiegung-g/m2.
2. Polsterträgermaterial nach Anspruch 1, worin die Garnstränge durch ihr eigenes
Material aneinander gebunden sind.
3. Polsterträgermaterial nach Anspruch 1 oder 2, worin alle einander kreuzenden Garnstränge
aus dem gleichen thermoplastischen Elastomer sind.
4. Polsterträgermaterial nach Anspruch 1, 2 oder 3, worin die Garnstränge eine Hülle/Kern-Konfiguration
aufweisen, worin die Hülle ein thermoplastisches Elastomer ist, dessen Schmelzpunkt
im wesentlichen niedriger als der Schmelzpunkt des thermoplastischen Elastomeren im
Kern ist.
5. Polsterträgermaterial nach einem der Ansprüche 1 bis 4, welches durch Extrusion
von thermoplastischem Elastomer durch ein Paar von Düsensätzen hergestellt worden
ist, die transversal zur Extrusionsrichtung relativ in Positionen versetzt werden,
in welchen, sich die Düsenöffnungen in einem Satz nacheinander in Deckung und in Nicht-Deckung
mit denen des anderen Satzes befinden.
6. Polsterträgermaterial nach einem der Ansprüche 1 bis 5, welches hergestellt worden
ist durch Extrusion von Monofilamenten aus thermoplastischem Elastomer, Orientierung
der Monofilamente, Anordnung der Monofilamente in einer sich kreuzenden Konfiguration
und Aneinanderbinden der Filamente an den Kreuzungspunkten.
7. Polsterträgermaterial nach einem der Ansprüche 1 bis 6, worin das thermoplastische
Elastomer ein Copolyetherester ist und wenigstens 50 Gew.-% kurzkettige Estereinheiten
enthält.
8. Polsterträgermaterial nach Anspruch 7, worin das Copolyetherelastomer etwa 81,6
Gew.-% kurzkettige Butylenterephthalatestereinheiten und etwa 18,4 Gew.-% von PTMEG
und Terephthalsäure abgeleitete langkettige Estereinheiten enthält.
9. Polsterträgermaterial nach Anspruch 7, worin das Copolyetheresterelastomer etwa
60 Gew.-% kurzkettige Butylenterephthalatestereinheiten und etwa 40 Gew.-% von PTMEG
und Terephthalsäure abgeleitete langkettige Estereinheiten enthält.
10. Polsterträgermaterial nach Anspruch 7, worin das Copolyetheresterelastomer ein
Hüllen/Kern-Monofilament ist, worin das Kerncopolyetheresterelastomer wenigstens 50
Gew.-% kurzkettige Estereinheiten enthält und das Hüllencopolyetheresterelastomer
einen Schmelzpunkt hat, der wenigstens 20°C niedriger ist als der Schmelzpunkt des
Kerncopolyetheresterelastomeren.
11. Polsterträgermaterial nach einem der Ansprüche 1 bis 10, worin das Produktorientierungsverhältnis
wenigstens 3,0x beträgt.
12. Polsterträgermäterial nach einem der Ansprüche 1 bis 11, worin der K-Faktorwert
für die statische Standfestigkeit unter Eigengewicht weniger als 3000% Änderung
der Durchbiegung-g/m2 beträgt und der K-Faktor der dynamischen Standfestigkeit weniger als 2500% Änderung
der Durchbiegung-g/m' beträgt.
13. Polsterträgermaterial nach einem der Ansprüche 1 bis 12, worin die statische Standfestigkeit
unter Eigengewicht weniger als 20,0% Änderung in der Durchbiegung beträgt und die
dynamische Standfestigkeit weniger als 22,0% Änderung in der Durchbiegung beträgt.
14. Polsterträgermaterial nach Anspruch 11, worin die statische Standfestigkeit unter
konstanter Belastung weniger als 14,0% Änderung in der Durchbiegung beträgt und die
dynamische Standfestigkeit weniger als 8,0% Änderung in der Durchbiegung beträgt.
15. Polsterträgermaterial nach einem der Ansprüche 1 bis 14, worin das thermoplastische
Elastomer eine M20-Festigkeit von 34 bis 310 MPa aufweist.
16. Polsterträgermaterial nach Anspruch 15, worin das thermoplastische Elastomer eine
M20-Festigkeit von 103 bis 172 MPa aufweist.
17. Polsterträgermaterial nach einem der Ansprüche 1 bis 16, worin das thermoplastische
Elastomer aus der aus Copolyetherestern, Polyurethanen und Polyesteramiden bestehenden
Gruppe ausgewählt ist.
18. Polsterträgermaterial nach einem der Ansprüche 1 bis 17, worin die Elastomer-Stränge
einen solchen Abstand aufweisen, daß die Zahl der Schüsse/m im Bereich von
liegt, worin (a) die Querschnittsfläche des Strangs in mm
2 ist.
19. Polsterträgermaterial nach einem der Ansprüche 1 bis 18, worin
(a) das Elastomer ein Copolyetherester mit einer M20-Festigkeit von 103 bis 172 MPa ist,
(b) der Elastomer-Strang ein Hüllen/Kern-Monofilament ist, worin die Hülle wenigstens
25 Gew.-% kurzkettige Estereinheiten enthält, der Kern wenigstens 50 Gew.-% kurzkettige
Estereinheiten enthält und das Hüllenelastomer einen Schmelzpunkt aufweist, der wenigstens
20°C niederiger ist als der Schmelzpunkt des Hüllenelastomeren, und
(c) die Elastomer-Stränge an ihren Kreuzungspunkten durch partielles Aufschmelzen
des Hüllenelastomeren verbunden sind.
20. Sitzboden, hergestellt aus dem Polsterträgermaterial nach einem der Ansprüche
1 bis 19.
21. Sitzrücken, hergestellt aus dem Polsterträgermaterial nach einem der Ansprüche
1 bis 19.
22. Bettträgersystem, hergestellt aus dem Polsterträgermaterial nach einem der Ansprüche
1 bis 19.
1. Un matériau de support de tapisserie à configuration de filet comprenant des fils
croisés d'élastomère thermoplastique orienté liés entre eux aux points où ils se croisent,
ledit matériau de tapisserie ayant une valeur de résistance au déchirement d'au moins
0,40 joule/mètre-gramme/mètre carré, une valeur de facteur K de fluage statique sous
charge morte de moins de 6000 pour cent de variation de fléchissement-grammes/mètre
carré, une valeur de fléchissement de 1,25 à 7,50 cm et une valeur de facteur K de
fluage dynamique de moins de 5000 pour cent de variation de fléchissement-grammes/mètre
carré.
2. Le matériau de support de tapisserie de la revendication 1, dans lequel les fils
sont liés entre eux par leur propre substance.
3. Le matériau de support de tapisserie de la revendication 1 ou 2 dans lequel tous
les fils croisés sont formés du même élastomère thermoplastique.
4. Le matériau de support de tapisserie de la revendication 1, 2 ou 3 dans lequel
les fils sont d'une configuration du type gaine/coeur dans laquelle la gaine est un
élastomère thermoplastique dont le point de fusion est sensiblement inférieur au point
de fusion de l'élastomère thermoplastique du coeur.
5. Le matériau de support de tapisserie de l'une quelconque des revendications 1 à
4 qui a été obtenu par extrusion d'élastomère thermoplastique à travers une paire
d'ensembles de filières qui sont déplacés relativement transversalement à la direction
d'extrusion pour venir en des positions où les orifices de filière de l'un des ensembles
sont successivement en coïncidence et en non-coïncidence avec ceux de l'autre ensemble.
6. Le matériau de support de tapisserie de l'une quelconque des revendications 1 à
5 qui a été obtenu par extrusion de monofilaments d'élastomère thermoplastique, orientation
des monofilaments, arrangement des monofilaments en une configuration croisée, et
solidarisation des filaments entre eux aux points où ils se croisent.
7. Le matériau de support de tapisserie de l'une quelconque des revendications 1 à
6 dans lequel l'élastomère thermoplastique est un copolyétherester et contient au
moins 50 pour cent en poids de motifs ester à chaîne courte.
8. Le matériau de support de tapisserie de la revendication 7 dans lequel l'élastomère
de copolyéther contient environ 81,6 pour cent en poids de motifs ester à chaîne courte
téréphtalate de butylène et environ 18,4 pour cent en poids de motifs ester à chaîne
longue dérivés de PTMEG et d'acide téréphtalique.
9. Le matériau de support de tapisserie de la revendication 7, dans lequel l'élastomère
de copolyétherester contient environ 60 pour cent en poids de motifs ester à chaîne
courte téréphtalate de butylène et environ 40 pour cent en poids de motifs ester à
chaîne longue dérivés de PTMEG et d'acide téréphtalique.
10. Le matériau de support de tapisserie de la revendication 7, dans lequel l'élastomère
de copolyétherester est un monofilament du type gaine/coeur dans lequel l'élastomère
de copolyétherester de coeur contient au moins 50 pour cent en poids de motifs ester
à chaîne courte et l'élastomère de copolyétherester de gaine présente un point de
fusion inférieur d'au moins 20°C au point de fusion de l'élastomère de copolyétherester
de coeur.
11. Le matériau de support de tapisserie de l'une quelconque des revendications 1
à 10 dans lequel le rapport d'orientation du produit est d'au moins 3,0×.
12. Le matériau de support de tapisserie de l'une quelconque des revendications 1
à 11 dans lequel la valeur de facteur K de fluage statique sous charge morte est de
moins de 3000 pour cent de variation de fléchissement-grammes/mètre carré et le facteur
K de fluage dynamique est de moins de 2500 pour cent de variation de fléchissement-grammes/mètre
carré.
13. Le matériau de support de tapisserie de l'une quelconque des revendications 1
à 12 dans lequel le fluage statique sous charge morte est de moins de 20,0 pour cent
de variation de fléchissement et le fluage dynamique est de moins de 22,0 pour cent
de variation de fléchissement.
14. Le matériau de support de tapisserie de la revendication 11 dans lequel le fluage
statique sous charge morte est de moins de 14,0 pour cent de variation de fléchissement
et le fluage dynamique est de moins de 8,0 pour cent de variation de fléchissement.
15. Le matériau de support de tapisserie de l'une quelconque des revendications 1
à 14 dans lequel l'élastomère thermoplastique présente une résistance mécanique M20 de 34 à 310 MPa.
16. Le matériau de support de tapisserie selon la revendication 15 dans lequel l'élastomère
thermoplastique présente une résistance mécanique M20 de 103 à 172 MPa.
17. Le matériau de support de tapisserie de l'une quelconque des revendications 1
à 16 dans lequel l'élastomère thermoplastique est choisi dans le groupe formé par
les copolyétheresters, les polyuréthanes et les polyesteramides.
18. Le matériau de support de tapisserie de l'une quelconque des revendications 1
à 17 dans lequel les fils d'élastomère sont espacés en sorte que le nombre de duites
par mètre soit de 16/(a) à 160/(a), (a) étant l'aire de section droite de fil en mm2.
19. Le matériau de support de tapisserie de l'une quelconque des revendications 1
à 18 dans lequel:
(a) l'élastomère est un copolyétherester ayant une résistance mécanique M20 de 103 à 172 MPa,
(b) le fil d'élastomère est un monofilament du type gaine/coeur dans lequel la gaine
contient au moins 25 pour cent en poids de motifs ester à chaîne courte, le coeur
contient au moins 50 pour cent en poids de motifs ester à chaîne courte et l'élastomère
de gaine présente un point de fusion inférieur d'au moins 20°C au point de fusion
de l'élastomère de coeur, et
(c) les fils d'élastomère sont solidarisés aux points où ils se croisent par fusion
partielle de l'élastomère de gaine.
20. Un fond de siège réalisé à partir du matériau de support de tapisserie selon l'une
quelconque des revendications 1 à 19.
21. Un dossier de siège réalisé à partir du matériau de support de tapisserie selon
l'une quelconque des revendications 1 à 19.
22. Un système de support de couchage réalisé à partir du matériau de support de tapisserie
selon l'une quelconque des revendications 1 à 19.