Classifications

• • D—TEXTILES; PAPER
  • D02—YARNS; MECHANICAL FINISHING OF YARNS OR ROPES; WARPING OR BEAMING
  • D02G—CRIMPING OR CURLING FIBRES, FILAMENTS, THREADS, OR YARNS; YARNS OR THREADS
  • D02G3/00—Yarns or threads, e.g. fancy yarns; Processes or apparatus for the production thereof, not otherwise provided for
  • D02G3/44—Yarns or threads characterised by the purpose for which they are designed
  • D02G3/48—Tyre cords
• • D—TEXTILES; PAPER
  • D02—YARNS; MECHANICAL FINISHING OF YARNS OR ROPES; WARPING OR BEAMING
  • D02G—CRIMPING OR CURLING FIBRES, FILAMENTS, THREADS, OR YARNS; YARNS OR THREADS
  • D02G3/00—Yarns or threads, e.g. fancy yarns; Processes or apparatus for the production thereof, not otherwise provided for
  • D02G3/02—Yarns or threads characterised by the material or by the materials from which they are made
  • D02G3/04—Blended or other yarns or threads containing components made from different materials
  • D02G3/045—Blended or other yarns or threads containing components made from different materials all components being made from artificial or synthetic material
• • D—TEXTILES; PAPER
  • D10—INDEXING SCHEME ASSOCIATED WITH SUBLASSES OF SECTION D, RELATING TO TEXTILES
  • D10B—INDEXING SCHEME ASSOCIATED WITH SUBLASSES OF SECTION D, RELATING TO TEXTILES
  • D10B2331/00—Fibres made from polymers obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds, e.g. polycondensation products
  • D10B2331/02—Fibres made from polymers obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds, e.g. polycondensation products polyamides
• • D—TEXTILES; PAPER
  • D10—INDEXING SCHEME ASSOCIATED WITH SUBLASSES OF SECTION D, RELATING TO TEXTILES
  • D10B—INDEXING SCHEME ASSOCIATED WITH SUBLASSES OF SECTION D, RELATING TO TEXTILES
  • D10B2331/00—Fibres made from polymers obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds, e.g. polycondensation products
  • D10B2331/02—Fibres made from polymers obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds, e.g. polycondensation products polyamides
  • D10B2331/021—Fibres made from polymers obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds, e.g. polycondensation products polyamides aromatic polyamides, e.g. aramides
• • D—TEXTILES; PAPER
  • D10—INDEXING SCHEME ASSOCIATED WITH SUBLASSES OF SECTION D, RELATING TO TEXTILES
  • D10B—INDEXING SCHEME ASSOCIATED WITH SUBLASSES OF SECTION D, RELATING TO TEXTILES
  • D10B2331/00—Fibres made from polymers obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds, e.g. polycondensation products
  • D10B2331/04—Fibres made from polymers obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds, e.g. polycondensation products polyesters, e.g. polyethylene terephthalate [PET]
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T442/00—Fabric [woven, knitted, or nonwoven textile or cloth, etc.]
  • Y10T442/20—Coated or impregnated woven, knit, or nonwoven fabric which is not [a] associated with another preformed layer or fiber layer or, [b] with respect to woven and knit, characterized, respectively, by a particular or differential weave or knit, wherein the coating or impregnation is neither a foamed material nor a free metal or alloy layer
  • Y10T442/2008—Fabric composed of a fiber or strand which is of specific structural definition

Definitions

• the present invention concerns a composite layer suitable as a reinforcement means against heat and fatigue for use in products such as tires or belts
• the carcass reinforcement is usually based on polymeric multi-filament yarns with good
• Polyester can only be used for lower performance tires because of insufficient strength retention following high temperature exposure. However polyester yarns do provide components having high retained strength after fatigue.
• Para-aramid is strong and thermally very stable permitting a single ply construction.
• compression fatigue and riding comfort are sometimes considered insufficient.
• hybrid cords for reinforcing tires comprising steel strands wound with p-aramid strands, both with a steel core and a p-aramid core.
• US patent 4,176,705 describes wire reinforcement cords for tires.
• the cords consist of a p-aramid core, and steel strands comprised of steel filaments twisted together are disposed about the core.
• US patent application publication 201 1/0086224 describes a sheet and method of making a sheet for support structures and tires.
• US patent application publication 2005/0017399 discloses a multifilament aramid yarn with high fatigue resistance.
• This invention pertains to a fibrous cord comprising a blend of yarns twisted together wherein the cord
• (ii) comprises a blend of polyester yarns with either aromatic polyamide or aromatic copolyamide yarns, and,
• the invention further pertains to a composite layer comprising an elastomer and a fabric wherein the fabric
• (i) comprises from about 25 to 60 weight percent of the weight, equivalent to 5 to 40 volume percent, of elastomer plus fabric, and
• (ii) comprises a plurality of cords wherein a cord has a twist multiplier of from 5.0 to 12.0, and comprises a blend of aromatic polyamide or aromatic copolyamide yarns and polyester yarns.
• Figure 1 shows a cross section of a test sample.
• Figure 2 depicts the force-elongation relationship for the Examples 4-6 and G-
• String as used herein means a continuous band of material which band of material may comprise either a single filament or multiple filaments twisted together to form a yarn.
• Fiber as used herein means a relatively flexible, macroscopically homogeneous body having a high ratio of length to width across its cross-sectional area perpendicular to its length.
• the filament cross section can be any shape, but is typically circular.
• fiber with respect to aramid, is used
• filament means a strand comprising multiple filaments twisted together.
• Tex the weight in grams of one kilometer of filament, strand, yarn or cable.
• Decitex is one tenth of a Tex, abbreviated as dTex.
• Core as used herein means a product formed by twisting together two or more plied yarns.
• Hybrid cord as used herein means a cord comprising at least two yarns of different composition or, if of the same composition, having different physical properties. This is sometimes also known as a merge cord.
• twist multiplier or TM as used herein is defined as the product of twist level (in turns per meter, according to ASTM D1423) and the square root of the linear density (in dtex), divided by 3000.
• “Retained strength” is the strength measured after a particular event such as conditioning at a temperature of 1 10°C or after a specified number of fatigue cycles. It is frequently reported as a percentage which compares the after event result with the before event result.
• Ends Per Inch is a measure of cord end-count over the fabric width or length.
• the present invention aims at replacing a 2-layer carcass construction by a single layer design, hence saving rubber in the carcass layer leading to weight reduction while also achieving good fatigue performance and good strength retention after high temperature exposure.
• a fibrous hybrid cord of this invention comprises a blend of yarns twisted together wherein the cord
• (ii) comprises a blend of polyester yarns with either aromatic polyamide or aromatic copolyamide yarns.
• the cord has a twist multiplier of from 7.0 to 10 or from 7.5 to 10 or even from 8.0 to 10.0 or even from 9.0 to 10.0. If the twist multiplier is greater than 12.0, the cord will not provide adequate strength retention after high temperature exposure although fatigue strength is acceptable. If the twist multiplier is less than 5.0, the cord will not provide adequate fatigue strength although strength retention after high temperature exposure is acceptable.
• hybrid cords have compression fatigue values and thermal strength retention values that reflect the synergy from the combination of the component yarns. That is to say, the hybrid cord balances the best properties of the component yarns and does not exhibit the poorer performance characteristics. These cords are particularly useful for high performance tires and run-flat tire designs with a single carcass ply.
• the cord may be stretch broken or texturized.
• Component Yarns
• the aromatic polyamide or aromatic copolyamide yarns have a linear density of at least 400 dtex (360 denier) and are pre-twisted individually to a twist multiplier of at least 3.5. In some other embodiments, the linear density is at least 444 dtex (400 denier).
• composition is para-aramid or copolymers of p-phenylene diamine.
• this can be the products available under the tradenames Kevlar®, Twaron®,
• the aromatic polyamide or aromatic copolyamide yarn may be partially or totally replaced by a stretch-broken aromatic polyamide yarn.
• Exemplary constructions and properties of such stretch- broken yarns are (1 ) Nm 50/4/2 of dtex 81 1x2 with a yarn twist multiplier of 5, a yarn tenacity of 125 cN/tex and a yarn elongation at break of 3% or (2) Nm 50/3/2 of dtex 613x2 with a yarn twist multiplier of 5.4, a yarn tenacity of 132 cN/tex and a yarn elongation at break of 3%.
• the polyester yarns have a linear density of at least 444 dtex and are pre-twisted individually to a twist multiplier of at least 1 .1 .
• the twist mutiplier is at least 3.5.
• the polyester used in the composition is polyethyleneterephthalate, polybuthyleneterephtalate (PBT), polyethylenenaphtalene (PEN) or poly(trimethylene terephthalate) based on fermentation derived from 1 ,3-propanediol (bio-PDO) which is available as Sorona® from E.I. DuPont de Nemours and Company, Wilmington, DE (DuPont).
• the polyester yarn may be partially or totally replaced by a yarn comprising aromatic polyamide fiber and aliphatic polyamide fiber wherein the aromatic polyamide is itself a mixture of meta-aramid fiber such as Nomex® and para-aramid fiber such as Kevlar®, both available from DuPont.
• An example of such a composition is one comprising about 85 weight percent of Nomex®, about 10 weight percent of Kevlar® and about 5 weight percent of aliphatic polyamide such as nylon.
• An exemplary construction and properties of such a component yarn is Nm 55/2/2 of dtex 728 with a yarn twist multiplier of 5.4, a yarn tenacity of 40 cN/tex and a yarn elongation at break of 10%.
• the present invention includes a method of assembling a carcass structure comprising the highly twisted aram id/polyester hybrid cords into carcass plies.
• the hybrid cords may be assembled in a single step, combining the individual multifilament twisting and the cord assembling twisting steps
• the composite layer comprises an elastomer and a fabric wherein the fabric comprises
• cords comprising a blend of yarns twisted together wherein the cord has a twist multiplier of from 5.0 to 12.0, and comprises a blend of aromatic polyamide or aromatic copolyamide yarns and polyester yarns.
• the fabric may be a woven fabric or unidirectional fabric.
• a unidirectional fabric is a fabric in which all of the yarns are oriented in the same direction.
• a woven fabric is any fabric that can be made by weaving; that is, by interlacing or
• the woven fabric can have essentially any weave, such as, plain weave, crowfoot weave, basket weave, satin weave, twill weave, unbalanced weaves, and the like. Plain weave is the most common and is preferred.
• the fabric has a basis weight of from 64 to 740 g/m 2 . In some preferred embodiments the basis weight of the fabric is from 70 to 620 g/m 2 . In some most preferred embodiments the basis weight of a fabric is from 140 to 330 g/m 2 .
• the fabric yarn count is 20 to 50 ends per inch (80 to
• the elastomer used in the present composition may be a variety of rubber materials including nitrile butadiene rubber (hydrogenated and
• NBR nonhydrogenated
• EPDM ethylene-propylene-diene monomer rubber
• dienes as 5-ethylidene-2-norbornene (5-ethylidenebicyclo[2.2.1 ]hept- 2-ene), dicyclopentadiene(bicyclo[2.2.1]he pta-2,5-diene), and 1 ,4-hexadiene;
• ethylene propylene diamine monomer chlorosulfonyl-polyethylene (CSM); ethylene oxide and chloromethyl oxirane (ECO); hexafluoropropylene vinylidene fluoride (FPM); natural rubber (NR); styrene-butadiene rubber (SBR); and the like and mixtures thereof.
• CSM chlorosulfonyl-polyethylene
• ECO ethylene oxide and chloromethyl oxirane
• FPM hexafluoropropylene vinylidene fluoride
• NR natural rubber
• SBR styrene-butadiene rubber
• the composite layer has a compression fatigue value or a thermal strength retention value greater than the corresponding values of a similarly constructed composite layer comprising elastomer and either a fabric solely of aromatic polyamide or aromatic copolyamide yarns or a fabric solely of polyester yarns.
• Hybrid cords as described above and a composite layer comprising the cords can be utilized in mechanical rubber goods applications such as tires, belts and hoses.
• a method for producing a composite layer comprises at least the steps of preparing a fabric with a plurality of cords having a twist multiplier of from 5.0 to 12, wherein the cords are formed by blending aromatic polyamide or aromatic
• copolyamide yarns and polyester yarns wherein the polyamide or copolyamide yarns are pre-twisted to a twist multiplier of at least 3.5 TM before cord assembly and have a linear density of at least 444 dtex, and the polyester yarns have a twist multiplier of at least 1 .1 and a liner density of at least 444 dtex.
• Examples of possible carcass fabrics made solely of p-aramid cords are also presented. Tires built with rayon or polyester fabrics will require a double-carcass ply construction. All carcass constructions are chosen such that the overall tire carcass strengths are comparable and in the typical range of 7.3 to 8.3 kN/in. TEST METHODS
• Fatigue data was measured using a typical Scott-flex equipment as defined in ASTM D430-06.
• the pulley size of the Scott-flex machine was 19 mm in diameter.
• the force applied on the samples during the test was 30 kg for the rayon samples and 60 kg for the aramid and aramid/polyester hybrid samples except for
• Samples were prepared by embedding the two layers of reinforcement fabric into natural rubber after adhesion treatment of the fabric in a two-step RFL
• the rubber composite samples were belt shaped so that a full cycle travel of
• the hybrid cord comprising Kevlar® and polyester yarns had a retained compressive strength after fatigue cycling comparable to that of a cord comprising only polyester yarns and better than a cord comprising only Kevlar® yarns.
• the hybrid cord also demonstrated a 1 10°C thermal strength retention similar to a cord comprising only Kevlar® yarns and better than that of a cord comprising only polyester yarns.
• the hybrid cord was better in all respects when compared to a cord comprising only rayon yarns.
• a hybrid cord was made with a p-aramid staple spun yarn
• Example 5 (BS-612-127)
• a hybrid cord was made with a stretch broken p-aramid yarn component Nm 75/3/3 of dtex 133x3x3 with a yarn twist 400Z/400S/530Z and a polyester (PET) component dtex 1440x1 yarn with a twist multiplier of 9.0 in the Z direction.
• the hybrid cord was twisted in the S direction and had a cord tenacity of 67.3 cN/tex and an elongation at break of 1 1 .9%.
• a hybrid cord was made with a texturized p-aramid yarn component of dtex 1200/1 with a yarn twist multiplier of 9.0 in the Z direction and with a polyester (PET) yarn component dtex 1440x1 with a yarn twist multiplier of 9.0 in the Z direction.
• the hybrid cord was twisted in the S direction with a cord twist multipler of 9.0.
• the hybrid cord had a cord tenacity of 64.3 cN/tex and an elongation at break of 1 1 %.
• the final cord was made with p-aramid staple spun yarn component Nm 28/2 of dtex 365x2 with a yarn twist 600Z/300S.
• the cord had a yarn tenacity of 73.8 cN/tex and an elongation at break of 3.8%.
• the final cord was made with p-aramid stretch-broken yarn
• the cord had a tenacity of 126.3 cN/tex and an elongation at break of 3.2%.
• the final cord was made with p-aramid texturized yarn component dtex 1200/1 with a yarn twist multiplier of 0.
• the cord had a tenacity of 62.2cN/tex and an elongation at break of 5.7%.
• the final cord was made with polyester (PET) yarn component dtex 1440/1 with a yarn twist multiplier of 1 .1 .
• the cord had a tenacity of 71 .3cN/tex and an elongation at break of 10.3%.
• Fig. 2 depicts the force- elongation relationship for the examples 4-6 and G-J and clearly shows the benefits of a hybrid cord construction when compared to cords comprising only one type of component yarn.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Textile Engineering (AREA)
• Yarns And Mechanical Finishing Of Yarns Or Ropes (AREA)
• Treatments For Attaching Organic Compounds To Fibrous Goods (AREA)

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• 2013
  • 2013-10-25 JP JP2015539835A patent/JP6338291B2/ja not_active Ceased
  • 2013-10-25 EP EP13786848.5A patent/EP2912218A2/de not_active Withdrawn
  • 2013-10-25 US US14/063,225 patent/US20140120791A1/en not_active Abandoned
  • 2013-10-25 WO PCT/US2013/066804 patent/WO2014066754A2/en active Application Filing
  • 2013-10-25 CN CN201380055732.4A patent/CN104755663B/zh not_active Expired - Fee Related

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