Classifications

• • D—TEXTILES; PAPER
  • D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
  • D04H—MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL; FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING ; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION
  • D04H3/00—Non-woven fabrics formed wholly or mainly of yarns or like filamentary material of substantial length
  • D04H3/08—Non-woven fabrics formed wholly or mainly of yarns or like filamentary material of substantial length characterised by the method of strengthening or consolidating
  • D04H3/16—Non-woven fabrics formed wholly or mainly of yarns or like filamentary material of substantial length characterised by the method of strengthening or consolidating with bonds between thermoplastic filaments produced in association with filament formation, e.g. immediately following extrusion
• • D—TEXTILES; PAPER
  • D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
  • D04H—MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL; FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING ; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION
  • D04H1/00—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres
  • D04H1/40—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties
  • D04H1/54—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties by welding together the fibres, e.g. by partially melting or dissolving
• • 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
  • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10S8/00—Bleaching and dyeing; fluid treatment and chemical modification of textiles and fibers
  • Y10S8/04—Polyester fibers
• • 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.]
  • Y10T442/60—Nonwoven fabric [i.e., nonwoven strand or fiber material]
  • Y10T442/696—Including strand or fiber material which is stated to have specific attributes [e.g., heat or fire resistance, chemical or solvent resistance, high absorption for aqueous compositions, water solubility, heat shrinkability, etc.]

Definitions

• Woven fabrics usually include knitted fabrics and may be defined as fabrics formed by the interlacing in a predetermined regular geometrical pattern of one or more long lengths of yarns or filaments.
• Non-woven fabrics are usually formed by a random or controlled deposition of filamentary strands to form a sheet or batt followed by binding these strands in some way to provide strength and dimensional stability.
• the advantage of low processing cost is one of the very desirable features of non-woven fabrics. All of the various processing steps which are required in the preparation of woven and knitted fabrics add considerably to the cost of the final product.
• the wool fibers must be formed into a yarn, the yarn must be twisted or plied, and the resulting final yarn product must then be woven into a fabric. It would be extremely desirable to provide a process which would involve simple well-known papermaking procedures but would produce a textile fabric having the properties of a woven fabric.
• Non-woven fabrics could find extended utility if ways could be found to alter their dimensions and thickness after formation in a controllable and permanent manner. Fabrics having such properties would permit the manufacture of apparel which could be shaped or molded to the body of the user. Moreover, if the thickness dimension of such fabrics could be increased without shrinkage of the lateral dimensions even greater versatility would be afforded the fabric. Furthermore, if fabrics of such a conformable and bulkable nature were available, they could be employed in many non-apparel uses such as upholstery, home furninshings, and even many industrial uses as fabric-covering materials for rigid three-dimen- Patented Jan. 7, lllfid "ice sional articles, where the conformability would avoid or at least reduce the need to fold, pleat, tuck and otherwise shape an essentially fiat material in conformity with a three-dimensional curved surface.
• Some fabrics can be made to retract under certain conditions. Woolen clothes, for example, are shaped into conformity with the human body with the use of steam irons, etc., but this shapeability is of very limited nature. Furthermore, the change in dimension is in one direction only; that is, the fabric can be shrunk but they cannot be caused to expand to any appreciable extent. Shrinkable synthetic fibers are also known, but up to now there has not been available any non-Woven synthetic fabric which was extensible, bu kable, and conformable.
• a further object is to provide a process for the production of non-woven bonded fabrics of synthetic fibers, which fabrics exhibit a combination of high tensile strength, conformance, bulk and high drape thereby affording aesthetic and physical properties comparable to those of woven or knitted textile fabrics of the same weight and fiber composition.
• the products of this invention are conformable, bulkable non-woven fabrics of synthetic fibers comprising at least 50% by Weight of synthetic organic spontaneously elongatable fibers, as defined in detail below, together with from 3% to 50% by weight of a synthetic organic polymer binder dispersed uniformly throughout the nonwoven web, said binder having a modulus between about 0.002 and about 25 grams per denier (g.p.d.).
• the nonwoven webs of this invention have the capacity upon heating to form a bonded non-woven fabric in which the fibers contain at least 30 crimps/ inch (c.p.i.) and in which the fibers are bonded at spaced points throughout the fabric such that the average total length of an individual fiber element between adjacent fiber bond points is at least 1.25 times the straight line distance between the same fiber bond points.
• the binder is present in an amount such that Percent biDLlGIXR ZMZ of binder l0 where the percent binder is based on the total weight of the fabric, including the binder.
• the modulus (Mi) of the binder is between about 0.002 and about 25 grams per denier.
• nonwoven fabrics of synthetic organic fibers are formed by preparing a suspension of synthetic organic spontaneously elongatable staple fibers and a synthetic organic binder in water, the suspension containing less than about 10% solids by weight.
• spontaneously elongate.- ble fibers fibers which are capable of elongating spontaneously at least 3% upon heating at a tempera- .ture 30 C. above the second order transition temperature of the fibers for five minutes.
• a waterleaf is prepared from the slunry and dried at a temperature below that at which the fibers elongate spontaneously and also below the fusing temperature of the binder. The water leaf is then heated at a temperature sufficient to fuse the binder and also to elongate the fibers at least 3%, based on their original length, while restraining the fabric from increasing more than 3% in linear growth in any surface direction.
• the individual filamentary components of preferred fabrics prepared by the process of this invention possess a high degree of lateral freedom and flexibility in three dimensions between intersection points and points of bonding, thereby providing these fabrics With a high degree of drape and softness, high tensile strength, low bulk and a soft handle in the same range as Woven fabrics.
• the fabrics are characterized by a fabric density of 0.28 to 0.6 g./cc., a drape stiffness of not over 1.0 inch, a ratio of tensile strength to drape stiffness of at least 12.0 lbs., and a sonic velocity-elongation differential of at least 1.3. They are, therefore, readily distinguished from papers on the one hand and conventional thick and bulky nonwoven felts on the other.
• the novel non-woven fabrics of this process of this invention are equivalent in handle, thickness drapability, strength and other aesthetic and physical properties to a wide spectrum of woven fabrics.
• Waterleaves are prepared according to the conventional papermaking technique from a loose slurry or suspension of fibers and binder, usually containing less than about 5% solids and preferably less than about 1% solids in water.
• liquids other than water may be used so long as they are inert to the solids, but economy and convenience favor water as the liquid phase.
• greater concentrations of solids may be employed, say up to or more, but the most useful sheets are obtained with 5% solids or less.
• Spontaneously elongatable fibers are disclosed in Belgian Patent 566,145, granted September 27, 1958.
• Synthetic organic fibers may be prepared capable of elongating spontaneously up to 30% or more under the above stated conditions.
• Patricularly suitable for preparing spontaneously elongatable fibers are polyesters, such as polyethylene terephthalate, polyhexahydro p xylylene terephthalate, and similar polymers of monomers prepared by reacting terephthalic acid with ethylene glycol or similar glycols.
• Polyamides are also useful for this purpose, particularly poly(p-xylylene azelaeamide).
• spontaneously elongatable fibers include those composed of polyurethanes, acrylonitrile polymer fi ers, and the like.
• Polyolefins such as polypropylene and other addition type polymers may also be used, but polyester fibers are the preferred spontaneously elongatable fibers used in this invention.
• spontaneously elongatable fiber and binder utilized in the process of this invention minor amounts of other fibrous materials may also be employed although it is preferred that these be kept at a minimum in order to achieve the most desirable properties in the products produced.
• ordinary staple fibers of synthetic organic polymers such as any of the polyamides, polyesters, polyurethanes, acrylic fibers, and polyolefins mentioned above, and additionally cellulosic fibers such as rayon, cellulose acetate, and the like, may be used in minor amounts, preferably less than about by weight based upon the dry weight of the web produced.
• certain natural fibers, such as goat hair can 'be used in amounts up to and preferably between 5% and 15 to give fabrics of high resiliency.
• non-fibrous materials may be added to an extent not greater than 10% by weight of the final dry web to obtain a wide variety of particular product advantages such as color, surface proper-ties, and the like.
• Binders used in the process of this invention are synthetic organic polymers having an initial tensile modulus of between about 0.002 and about 25 grams per denier.
• the binder is used in the form of a fibrid, which term designates a non-rigid, wholly synthetic polymeric particle capable of forming paper-like structures.
• a particle must possess an ability to form a waterleaf having a couched wet tenacity of at least about 0.002 gram per denier when a multitude of the said particles are deposited from a liquid suspension upon a screen, which waterleaf, when dried at a temperature below about 50 C., has a dry tenacity at least equal to its couched wet tenacity, and a capabilit when a multitude of the said particles are deposited concomitantly with staple fibers from a liquid suspension upon a screen, to bond a substantial weight of the said fibers by physical entwinement of the said particles with the said fibers to give a composite waterleaf with a wet tenacity of at least about 0.002 gram per denier.
• a capability to bond a substantial weight of (staple) fibers is meant that at least 50% by weight of staple based on total staple and fibrids can be bonded from a concomitantly deposited mixture of staple and fibrids.
• fibrid particles have a Canadian freeness number between and 790 and a high absorptive capacity for water, retaining at least 2.0 grams of water per gram of particle under a compression load of about 39 grams per square centimeter.
• Any normally solid wholly synthetic polymeric material may be employed in the production of fibrids. By normally solid is meant that the material is non-fluid under normal room conditions.
• the fibrid characteristics recited above are a result of the combination of the morphology and non-rigid properties of the particle.
• the morphology is such that the particle is non-granular and has at least one dimension of very minor magnitude relative to its largest dimension, tie, the fibrid particle is fiber-like or film-like.
• the individual fibrid particles are not identical in shape and may include both fiber-like and film-like structures.
• the nonrigid characteristic of the fibrid which renders it extremely supple in liquid suspension and which permits the physical entwinement described above, is presumably due to the presence of the minor dimension. Express ring this dimension in terms of denier, as determined in accordance with the fiber coarseness test described in Tappi 41, A7A, N0. 6 (June) 1958, fibrids have a denier no greater than about 15.
• Fibrid particles are usually frazzled, have a high specific surface area and, as indicated, a high absorptive capacity for water.
• Preferred fibrids are those the waterleaves of which when dried fora period of twelve hours at a temperature below the stick temperature of the polymer from which they are made (i.e., the minimum temperature at which a sample of the polymer leaves a wet molten trail as it is stroked with a moderate pressure across the smooth surface of a heated block) have a tenacity of at least about 0.005 gram per denier.
• Fibrid particles and their preparation are described in more detail in Belgian Patent 564,206. Fibrids can be prepared from a number of polymeric compositions, and a wide range of such fibrids can be used in the present invention, leading to a spectrum of fabrics as indicated above.
• the web products of this invention contain between about 50% and about 97% spontaneous.y elongata'olc fiber and bet-ween about 3% to about 50% binder based on dry weight of the web.
• Other fibers may be present to provide special effects such as extra strength, dyeability, etc., in amounts up to 40% but preferably less than by weight of the web.
• Elastomeric binders useful in this invention (which are characterized by an initial modulus (Mi) of between about 0.002 and about 0.9) should be used whenever a binder content greater than about by weight is desired and then preferably in the form of fibrids. Binders having an initial modulus greater than 0.9 should be used in quantities of less than about 25% based on the dry Web weight. Obviously, the procedure used for preparing these webs may employ comparable quantities of fibers and binder since there is usually no appreciable loss of solids during the process.
• a waterleaf is prepared containing between 50% and 75% spontaneously elongatab-le staple fibers having a length of between and inch and from 25% to 50% elasto-meric fibrids. In this embodiment, less than about 15% of ordinary hard fibers (non-elongatable) should be present.
• Representative el astome-ric binders are the various butadiene-styrene copolymers containing from to 70% combined butadiene, and also terpolymers of but-adiene, styrene, and acrylonitrile.
• el'astorneric binders include a mixture of 98% polyimethyl methacrylate plus 2% glycidyl methacrylate in the amount of 10 parts, and about 86 parts of an acrylate ester terpolymer; a mixture of 49 parts polyhexylmethacrylate, 49 parts polyethyl aorylate, and 2 parts polyacrylic acid prepared by solution polymerization, for example, in benzene using benzoyl peroxide as initiator; poly(ethylene/propylene) polymerized using 3% dicurnyl peroxide; a copolymer of an aliphatic ester of acrylic acid and up to 5% acrylic acid, such as, for example, a copolymer of 98% ethyl acrylate and 2% acrylic acid.
• Another useful eliastomeric binder is obtained by reacting poly(tetramethy1ene ether) glycol of approximately 1000 molecular Weight with tolylene 2,4-d iisocyanate to give a glycol-terminated macrointerrned-iate and this is treated to give an isocyanate-ended, low molecular weight polymer by combining the macrointerme-diate with methylene bis(4-pl1enylisocyanate). This low molecular weight polymer is then reacted further with hydrazine to give a high molecular weight elastomer polymer in accordance with the disclosure of French Patent 1,172,566.
• non-elastomeric binders useful in this invention are polyamides such as polyhexamethy-lene adipamide, polycaproamide, copolyrners of polyhexa-rnethylene adipamide and polycaproamide (preferably an 80/20 coplymer, respectively), poly(hexahydro-p-xylylene teradipamide and the like.
• Representative polyesters useful as binders include polyethylene terephthalate, polyethylone isophthalate, copolymers of polyethylene terephthalate and polyethylene isophthalate (prefenably an 80/20 copolymer, respectively), poly(hexahydro-p-xylylene terephthalate) etc.
• Particularly useful polyurethane binders are the polyurethanes formed by reacting piper-azine and ethylene bis-chloroformate, the urethanes of polyhexamethylene adip-amide and ethylene bis-chlorofornrate, etc.
• non-woven materials from wholly synthetic sheet forming particles is described in some detail in Belgian Patent 564,206.
• Webs containing spontaneously elongatable fibers in the form of continuous filaments can be pre pared by processes employing electrostatic phenomena to control the formation of the non-woven structure, as described in copending application S.N. 859,614, filed by Kinney on December 15, 1959 (RD658A), whereby the filaments, relaxed during or after web formation, are thereafter capable of spontaneous elongation upon heating.
• the waterleaf is dried at a temperature loW enough to avoid any fusing or melting of the binder or elongation of the fibers. Drying of the waterleaf at from C. to about C. is generally suitable for production of the novel webs of this invention. Drying in the range 100 C. to 120 C. is preferred.
• the Web After drying, the Web is then heated to elongate the fibers and fuse the binder to the fibers at their cross-over points While restraining the fabric from enlarging in surface area substantially. Sufiicient restraint should be applied to prevent more than 3 increase in linear growth of the fabric in any direction. This is preferably accomplished by pressing the dry web between two screens or similar foraminous members. During pressing, the fibers elongate and crimp in the thickness direction of the fabric, thereby giving additional bulk to the final product and providing a fabric-like hand both due to the bulk thus attained and due to the pattern thus embossed on the fabric by the screen or other foraminous member.
• Restraint may be applied by other means, however, such as pressing between two fiat or curved surfaces, whereby surface friction provides sufficient restraint.
• a curved surface and a screen may be employed, as well as other techniques known in the art of shaping, vacuum forming, etc.
• Elongation of the fibers in the web is usually achieved by heating the dry web at C. to 250 C. for a few minutes, usually less than 10 minutes. it is essential that some fusing (bonding of the fibers) of the binder occurs before all of the desired amount of elongation of the fibers is completed, and likewise it is essential that some elongation occurs before all of the desired amount of bonding is completed. Preferably, both elongation and bonding take place simultaneously, and this is easily achieved by choice of a suitable temperature dependent upon the compositions of binder and fibers. Usually, pressing the web at a temperature between 150 C. and 220 C. will suffice. Naturally, the precise degree of fusion and amount of elongation will depend upon the temperature and time of pressing and pressure used. Under extreme conditions of pressing when a fibrid binder is present, the fibrid particle identity is lost and the fibrids become fused completely into the non-woven structure.
• the embossing procedure offers a valua ble improvement in the woven-like characteristics which are desired.
• the self-elongatable fibers elongate and assume a third-dimensional configuration on the surface of the fabric, due to penetration of portions of the fibers into the interstices of the screen.
• Such configuration gives desirable bulk to the fabric.
• Similar response to other preferred embossing techniques is also possible, and such third-dimensional configurations make an important contribution to the suppleness and drapability of the products obtained thereby. In general, to obtain products of greatest interest, it is usually found that a moderate degree of pressing is most satisfactory.
• Drapability is measured by determining the length of fabric which is necessary to cause the fabric to bend from the horizontal plane when under no constraint to such an extent as to contact a declining angle of 4l.5 of slope from the point of departure of contact.
• a strip of fabric one inch wide is placed upon a block of wood or other horizontal surface. Abutting the horizontal surface of this material is a 41.5 inclined plane, which at its top adjoins the horizontal surface.
• the test specimen is placed with the narrow edge at the juncture of the horizontal and the inclined surfaces. It is then moved forward over the inclined surface until the free end touches the 41.5 slope of the testing block.
• the drape stiffness, designated C is measured in inches, being one-half of the free length of specimen extending beyond the horizontal sur- '5 face edge.
• An equivalent test, the cantilever test of ASTM Dl388-55T gives values in the range of 50 to 2,000 mg.-cm., in measuring the stiffness of fabrics.
• Bulk of a fabric is determined by cutting a square portion of the fabric of uniform thickness, measuring its dimensions, including its thickness, and then calculating its volume.
• the fabric sample is measured for thickness by means of a conventional fabric thickness caliper device such as an Ames gage (manufactured by B. C. Ames Company, Waltham, Mass). The fabric sample is then Weighed and the bulk expressed in terms of volume per unit weight.
• Tensile strength is determined on a one-inch strip of fabric in conventional manner employing an lnstron Tensile Tester.
• tensile streng'. is determined at room temperature under ambient conditions of 65% relative humidity.
• the ratio of tensile strength of a fabric to its drape-stiffness is useful for comparing the fabrics of this invention with conventional woven fabrics, felts, and papers.
• Sonic velocity-elongation clifierential is a measurement of the effect of fabric elongation (and tension) on the velocity of sound transmission in the plane of the fabric. Measurement of sound velocity in fabrics is well known (see article "by W. H. Charch, W. W. Mosery in 29 Textile Research Journal, page 525 (1959)) and involves wel established principles and techniques. The velocity of propagation of sound waves in a fabric is dependent on fabric tension and is indicative of certain fabric properties.
• Woven fabrics, and also the non-woven fabrics of this invention provide media through which sound travels at a velocity which is strongl dependent on the elongation (and the tension) in the fabric, indicating that both have very similar structural characteristics and properties despite their vastly different coarse structure (e.g., woven vs. non-woven).
• Sonic velocity in a fabric can be measured using a piezoelectric crystal signal source (or other source) to provide vibrations of the desired frequency. Frequencies in the range of 1,069 to 40,000 c.p.s. are conveniently employed.
• a search transducer a piezoelectric crystal is again suitable
• Pulse propagation timing or Wavelength measurement are suitably used to determine sonic velocity.
• the source and detector can both be placed in contact with a fabric sample which is placed in the jaws of an 'Instron Tensile Tester or other elongation device. The sonic velocity is then measured as a function of elongation. Table 1 summarizes the data obtained.
• the paper material while having a high critical sonic velocity value, shows no substantial change as it is tensioned.
• the woven fabric and the non-woven fabrics of the present invention show a sonic velocity value which increases by at least 36% when the fabric is elongated 6%.
• non-woven materials from wholly synthetic sheet forming particles is described in some detail in Belgian Patent 564,206. in that p tent it is shown that polymeric materials may be prepared in the form of particles which have the property of interentungling with one another and with staple fiber materials to form strong sheet materials.
• Sucl sheets are advantageously prepared by deposition of the fibrid particles from an aqueous slurry onto a screen in laboratory operations. Watcrleaves or hand sheets may be prepared on a small scale by pouring a suitable amount of the slurry onto a small rectangular screen and draining the water down through the screen.
• Such hand-sheet Watrleaves are suitable for the practice of the present invention in that they permit a simple, small-scale preparation of non-woven structures which can then be tested for physical properties, strength, and the like.
• papermaking mt chinery such as the Fourdrinier machine and other comarable pieces of apparatus, as well as carding machines, Rando-Webber machines, and other equivalent devices.
• both small-scale experimental units of nonwvoven fabrics can be prepared in accordance with the teachings of the
• the non-woven fabrics of the process of this invention are characterized by a high degree of drapability and flexibility, and a desirable level of loftiness, and handle. Because of these and other properties, they are well suited to end uses which have heretofore employed woven fabrics of varying weights and weaves. Among such uses may be listed apparel; draperies; upholstery materials; house hold furnishings, such as table cloths, napkins, and bed linens; shaped articles, such as gloves, head coverings, brassiere cups; fabric stitfeners, such as interliners, peplums, cuff and collar liners, and the like.
• the fabrics of the present invention are specifically well suited to work and service clothing, sports wear, outer Wear, bathing suits, shirts, and the like.
• Other fabric utilities include foundations for leather-like laminates, backings for vinyl-coated upholstery, and other fabrics, automobile and airplane headliners (in this use the embossable nature of the non-woven fabrics of this invention is particularly desirable) filter cloths and other industrial felts.
• These fabrics are also suitable with proper coatings or surface treatment for use as fuel pump diaphragms, hosing flexible couplings, and air bellows for use in instrumentation work and decorative covers for desk equipment, radios, ash trays, cigarette boxes, and the like.
• the products of the present invention be heat-treated to a degree sufficient to fuse at least a portion of the fibrid binders.
• non-fused products are also of interest and have found applications in a number of the utilities indicated above.
• the non-woven fabrics of the present invention are embossable and can be obtained with any of a Wide variety of surface patterns which may be impressed upon the fabric during the pressing or fusing process.
• Such embossed configurations not only supply decorative and attractive appearance, but can be used to control the physical properties of the fabric.
• an embossing pattern consisting of a number of parallel fine lines in one direction only produces a fabric which has a greater flexibility in one direction than in the other direction. Embossing with a crosshatched. type of pattern of fine lines increases the stiffness of the fabric in both directions.
• embossing techniques can be used to alter the handle and feel of the fabric and also to control the receptivity of the fabric to printing, dyeing, and other coloring post-treatments.
• the bulk of the non-woven fabric can be controlled to any desired degree, and compression can be introduced to lead to a more compact structure, if this is desired.
• Fabrics of the present invention can be buffed to expose surfaces which are densely populated with uniformly distributed fiber ends of equal length. Such buffed surfaces are very attractive and resemble to a surprising degree in hand suede leather and other similar products.
• the products obtained through the practice of the present invention have a number of advantages in comparison to previously known non-woven fabrics.
• the present materials show equal or higher strength, greater dimensional stability, and greater flexibility.
• the non-woven fabrics of the present invention have a much softer handle, greater strength and flexibility, and a better dyeability and printability.
• the fabrics of the present invention show an excellent degree of postformability, high elongation and liveliness, excellent washwear characteristics, outstanding tensile and stitch strength, and, as has already been indicated, a degree of drapability and controllable handle which has not hitherto been achieved in non-woven fabrics in the art.
• Particularly desirable fabrics of the present invention are those prepared from formulations comprising at least 25% of a fibrid binder prepared from an elastorneric polymer, together with at least 50% of a spontaneously elongatable fiber material having, under the conditions described for determination of spontaneous elongation, an elongation of at least 10%.
• drapable and flexible but somewhat more crisp and firm non-woven fabrics prepared from formulations comprising at least 75% of a spontaneously elongatable fiber having a minimum of 10% spontaneous elongation, together with a fibrid binder based upon a synthetic polyester polymer to the extent of at least 3 and not over by weight.
• any of the techniques which are known for the processing of conventional staple fibers in the preparation of non-woven fabrics can be used in the present invention.
• it is sometimes desirable to prepare a layered type of structure by depositing upon the surface of the fabrics of this invention small amounts of additional fibrid binder, say in the order of 0.10 oz./sq. yd., in order to provide a firmer and more completely bonded surface.
• Deposition of the binder is followed by fusion, and sheets prepared in this way show an improved resistance to surface wearing, marring, fuzzing, pilling, and the like.
• While several of the preferred embodiments of the present invention employ fairly short staple fibers, that is, A long or less, it is possible and at times desirable to use longer fibers, including staple fibers as long as three inches. Dispersion and deposition of such fibers into a sheet product are made easier by the use of foamdispersion processes or liquids of viscosity, rather than the water-dispersion processes described in connection with shorter fibers. Other web-forming processes may also be used. The use of longer fibers or continuous filaments increases the tensile strength and tear strength of the non-woven materials of this invention.
• EXAMPLE 1 Three parts self-elongatable polyethylene terephthalate staple fibers 0A" long, three denier per filament) prepared according to the process of Belgian Patent 566,145 and having a spontaneous elongation of 12%, are admixed by vibration stirring (using a Vibro Mixer) with 8000 parts of water. The fibers are pre-wetted with a small amount of a polyethylene oxide ether fatty alcohol as wetting agent.
• This synthetic elastomer is soluble in dimethylformamide.
• a solution is p epared containing 12% synthetic elastomer solids and 4% polyvinylchloride solids in dimethylformamide.
• Fibrids are then prepared according to Belgian Patent 564,206 by placing 400 ml. of glycerol together with 0.5 ml. of an organic surfactant in a one quart Waring Blendor and adding the polymer solution while running the Blendor at full speed. The glycerol precipitates the polymer from solution, and the Waring Blendor subjects the precipitating polymer to high shear to give elastomeric fibrids.
• the washed fibrids are stirred for a few seconds in water to break up agglomerates, and the fibrids thus obtained are then maintained in water suspension ready for use.
• This stock is poured into a head box of a sheet mold, and a waterleaf is deposited onto an 8" by 8 MiG-mesh screen.
• the screen with the deposited water-leaf is removed from the sheet mold and placed between absorbent cloths and rolled with a steel rolling pin to remove excess water.
• the sheet is then dried between 50 mesh screens at C. and 50 lbs/sq. in. pressure for 10 minutes.
• the screens give a pattern to the resulting non-woven fabric similar to a woven fabric.
• the fabric is tested and found to have a tongue tear strength of 1.31 lbs./oZ./yd. and a drape stiffness of 0.81 inch.
• EXAMPLE 2 A 46% solids dispersion of a polymeric acrylate ester elastorner containing 92% ethyl acrylate, 6% methyl 1 4 acrylate and 2% acrylic acir. fibrids as follows:
• diepoxide resin a monomeric bis-glycidyl ether of diphenylol propane having an epoxy equivalent of l752l0 (Epon 828, sold by Shell Chemical Corporation) and 5 parts of butylated melamine formaldehyde resin containing one part melamine to 45 parts formaldehyde (Uformite MM-46, sold by Rohm and Haas Company) and 5 parts of titanium dioxide pigment.
• diepoxide resin a monomeric bis-glycidyl ether of diphenylol propane having an epoxy equivalent of l752l0 (Epon 828, sold by Shell Chemical Corporation) and 5 parts of butylated melamine formaldehyde resin containing one part melamine to 45 parts formaldehyde (Uformite MM-46, sold by Rohm and Haas Company) and 5 parts of titanium dioxide pigment.
• the compounded mixture is converted to fibrids by adding the resin blend to a Waring Blendor containing a 5% solution of sodium sulfate in hot water (75 C.) with 0.01% of an organic quaternary ammonium salt as wetting agent.
• the Blender is operated to full speed during the addition.
• the resulting fibrids are used in the form of the slurry thus prepared.
• the staple fibers employed are similar to those of Example 1 with a spontaneous elongation of when immersed in boiling water for 5 minute
• a slurry of 3 parts of the above fibers with 2 parts of fibrids, in 10,000 parts of water, is prepared as in Example 3 and a we. erleaf is prepared in the manner of Example 3 also.
• the sheet is removed from the screen, placed between a cotton cloth sheet and a l2-mesh wire screen, and dried at 120 for 3 minutes.
• the dried sheet is then placed between 50-inesh screens and embossed and bonded by pressing at 205 C. for one minute at 200 p.s.i.
• the sheet is further cured by exposing to air at 165 C. for 5 minutes and then washed and tumble dried before testing.
• the fabric has a tensile strength of 5.9 lbs./in./oz./yd. a drape stiffness of 0.75 inch, and a wet tensile strength of 4.5 lbs./in./oz./yd.
• the fabric is found to have good strength retention when exposed to dry-cleaning solvents.
• the embossing treatment produces a fabric resembling Oxford cloth in appearance, with excellent whiteness, good retention of whiteness under laundering and pressing, medium porosity, and good handle.
• the sheet can be conformed, if desired, to a three-dimensional shape, of the flat sheet.
• Example 3 The compounded elastomeric mixture of Example 2 is used in this example without conversion into fibrids.
• the self-elongatable fibers are also the same.
• the fibers are formed into a web by slurrying in water using a conventional fiber wetting agent and forming a waterleaf.
• the Waterleaf is air-dried on the screen, since it cannot be handled unsupported.
• Example 2 The elastorneric mixture of Example 2, diluted with an equal volume of 5% aqueous sodium sulfate solution, is used as a dip-bath.
• the waterleaf on the screen is immersed in the dispersion and excess bath is removed by blotting.
• the impregnated Waterleaf is placed in an oven at 160 C. with air circulation for 3 minutes, and the resin is coagulated by the action of the salt and the heat.
• the waterleaf is removed and placed between SO-mesh screens and treated as in Example 5.
• the resulting sheet which has the appearance of Oxford cloth, is composed of 66% fibers and 40% resin binder by weight.
• This sheet while equivalent to the fibrid-bonded sheet in physical strength properties, is somewhat more porous and has a lower covering power.
• a solution of the compounded resin of Example 5 is prepared by adding acetone to make a 4.5% solids solution.
• the unbonded Waterleaf is immersed in this solution, the excess solution is drained off, and the impregnated waterleaf is placed in a pan of hot water (75 C.). This precipitates the resin and causes bonding.
• the sheet is dried on a sheet drier and is embossed and bonded and cured as in Example 2.
• the resulting sheet is equivalent to the fibrid-bonded structure in all physical properties.
• Example 2 A variety of synthetic elastomer resins are formed into fibrids by the procedure of Example 2.
• Table ll shows the results obtained by making non-woven fabrics employing 40% of these fibrids as binders, with 60% of the self-elongatable fibers of Example 1, using the procedure of Example 2.
• a suspension of fibers is prepared by combining 10,000 parts of water with 3 parts of A1" long, 3 denier per filament self-elongatable polyester fibers of Example 1 (but having a spontaneous elongation of 10%) thoroughly wetted with a 5% solution of polyethylene oxide ether fatty alcohol surface active agent (Alkanol l-IC). To this suspension of fibers is added a sufficient portion of a slurry of 45/55 butadiene/styrene elastomer fibrids to provide 2 parts of fibrids in suspension form.
• Alkanol l-IC polyethylene oxide ether fatty alcohol surface active agent
• fibrids are prepared by combining a 45/55 butadiene/ styrene polymer in the form of a 56% solids dispersion in water with compounding agents as follows: 5 parts of finely divided pigment grade rutile titanium dioxide; 5 parts of zinc oxide; and 2 parts of Antioxidant 425, an antioxidant sold by American Cyanamid. This is dispersed with 12 parts of water to give a 50% solids dispersion. This is added to parts of the butadienestyrene polymer in a 56% solids dispersion in water. From this compounded resin dispersion fibrids are prepared by shear precipitation and coagulation.
• the coagulating system consists of a solution of 400 parts of water containing 0.31 part of aluminum sulfate 0.31 part of sulfuric acid and a small amount of organic surfactant (Triton X-100) wetting agent.
• a Waring Blendor is set to operate at low speed, and to the slowly stirred system is added a fine even stream of the compounded polymer dispersion described above. Suflicient quantity of the dispersion is added to be equivalent in volume terms to 2 /2 of the coagulation solution. After all the dispersion has been added, the system is allowed to stir for an additional two minutes to allow the binder particles to coagulate thoroughly to avoid agglomeration.
• the polymer from this reaction is obtained in the form of a fibrid slurry suitable directly for use in the preparation of a waterleaf.
• This fiber-binder suspension is then poured into a headbox of a sheet mold, and a waterleaf is deposited onto an 8" x 8 IOU-mesh screen. Excess water is squeezed from the waterleaf by placing it while still on a IOU-mesh screen between absorbent cloths and rolling it with a steel rolling pin. The waterleaf is then removed from the screen and placed between SO-mesh screens, which in turn are placed between sheets of pulp board and dried in a press at C. and 95 lbs/sq. in. pressure for 10 minutes.
• the non- Woven sheet is obtained in the form of a fabric having a woven texture due to the imprint of the lOO-mesh screen and the SO-mesh screen which had been in contact with l3 it during pressing.
• the sheet is tested for physical properties and found to have a tensile strength of 3.12 lbs./ in./oz./sq. yd. and a tongue tear strength of 1.01 lbs./ oz./ sq yd.
• the drape stiffness in inches of the sheet 1% without printing, but dyed a red color with a dispersed dye.
• a third fabric, weight 4.5 ozs./sq. yd, is prepared as above, except that 50-mesh screens are used instead of is 0.796. It is observed that Washing this sheet in a syn- 60-n1esh.
• This fabric is embossed in the same manner as thetic detergent followed by drying at 80 C. increases before and then dyed with a tan dispersed dye. This its strength as follows: tensile strength of 5.27 lbs./in./ material is used to make a wind breaker jacket and a pair oz./sq. yd; tongue tear strength of 1.16 lbs. /oz./sq. yd. of trousers. A separate portion of the same material is The drape stiffness is decreased slightly to 0.722 inch. screen printed with five colors, red, green, turquoise, gray,
• a number of fabrics are prepared in accordance with f??? piecrued, fahdricgeigltn 5.3 0.22] the procedures of Example 5 in different fabric weights L Fm a 2 W1 e d for evaluation as apparel fabrics.
• the first of these is Oosmg' Thfi pumgd fabric is then cut mic 9 an p p with a Wiqht of 2 5 OZ q y and is of a embossed between 24-mesh screens mounted on stainless v c 0 I Weight and handle ihdicating suitability for a shirting plfltes priss 3213 fabric.
• a sheet 5 feet long and 28 inches wide of the i i- Tie ii- 52 deposited waterleaf from a Fourdrinier machine is placed gnd gilg iidzc gteg a .10 rustle s ig L ,1, etween 60-mesh screen sheets which are in turn mounted l n n n 1 on stainless steel plates and placed between the platens th In -f j n fi gr a g fii a of a press and held there for 5 minutes at 140 C. and l e 0i l WeIgMLSi -f, i 135 lbs./ sq. in. pressure.
• the pressed piece obtained in igig l gg sg gg 3323 z gif g ig g g: as a sewn, and in every Way are equivalent to satisfactory i with a Weight of 3 5 07 q y is P1180 5 Woven fabrics, even though as already indicated they conc a prepared.
• This fabric is of a weight suitable for use as tam no Wovbn maienal' dress goods.
• the fabric is embossed between EXAMPLES :2 60-: esh screens mounted on stainless steel plates.
• the white fabric, after pressing, is evaluated for sereen-pig- Table lll illustrates the advantages of the present inment printing.
• a pattern is applied with four diiferent vention and compares the fabrics produced with other colors: orange, yellow, black, and olive.
• the printed non-woven fabrics and also with conventional woven fabric is cured for 15 minutes at 350 F.
• the pattern is fabrics.
• a comparison of Examples 10 and 17 of Table sharp and the colors bright.
• Two dresses and two skirts III shows that, compared to the product of this invention, are prepared from the printed material, and in addition r self-elongation and development of crimp prior to web a skirt is prepared from a separate portion of the fabric 0 formation give a relatively inferior product.
• Fiber A % 5.13. Fiber A; 3.5 14.0 0. 40 5.5 0.75 26 Very similar to woven 40% Fib id B, fabric; good covering power. 60% 5.13. Fiber A; 40% 5. 7 17.0 0.53 6.2 0.97 38 Like woven fabric.
• Fibrid B 60% SE. Fiber C; 3.5 13.0 0.42 4.2 0.75 20 Do.
• Fiber A 40% Fibrid B. 8.13. Fiber A; 5% 3.5 19.0 0.28 3.4 0.07 12 Between woven fabrics Fibrid D. and felts. 14"," Non-woven resin bond- 60% SE. Fiber A; 40% 3. 6 14. 0 0.41 6.7 0.80 30 More porous than fibridd, Acrylate tcrpolymcr bomlcd fabric; good properties. 15 lo 60% 8.13. Fiber A; 40% 3. 6 14.0 0.41 5.7 0.80 26 Like woven fabric.
• acrylatc terpolymcr 16 Commercial wool felt... wool fibers 5.5 39.0 0.18 7.5 1.28 32 Typipal felt; bulky and 1 17 Non-woven fibrid bond- 60% modified Fiber A; 3.3 11.0 0.47 4.1 1.14 12 Papery; too stiff.
• a non-woven fabric is prepared from a formulation comprising self-elongatable fibers of the type described in Example 1, together with fibrids as described in Example 24 using the procedure of Example 5. Because a highly efficient bonding is realized in this sheet, a low proportion of binder gives very satisfactory results.
• a sheet is prepared from 92.5% of the spontaneously elongatable fibers and 7.5% of the copolyester fibrids. After formation of the waterleaf, the fabric is dried at 130 C. between screens under a pressure of 50 p.s.i. and then fused between the same screens at 190 C. and 10 p.s.i. pressure.
• the sheet so prepared has a weight of 3.1 ozs./yd. a thickness of about 18 mils, a tensile strength of about 8.0 lbs./in./oz./yd. and a firm but flexible handle, rendering it suitable for use as a suiting interliner.
• a polyarnide is prepared by melt polymerization from para-xylylene diamine and azelaie acid by conventional procedures. The polymer is then melt spun to give continuous polyamide filaments which are used to prepare spontaneously elongatable fibers. The spun filaments are drawn 3 at room temperature after being wetted with water and then relaxed in a 50 C. water bath to shrink them 45% of their drawn length.
• the filaments are then cut into A staple lengths and are found to have a spontaneous elongation of 7% when immersed in 100 C. water for 5 minutes.
• a non-woven fabric is prepared using 60% of these staple fibers lengths) and 40% of fibrids of Example 1 according to the procedure of Example 2.
• the sheet is dried on a screen in an oven at 120 C. giving a soft, drapable fabric with good handle.
• EXAMPLE 26 Sheets are prepared from poly(ethylene terephthalate) using the apparatus shown in FIGURE 5 of S.N. 859,614 of Kinney, filed December 15, 1959.
• filaments 1 spun from spinneret 2 pass in the manner shown over the bar guides 3, 4, and 5, thence to aspirating jet 6 supplied with air under pressure through inlet 7.
• Aspirating jet 6 embodies extended filament passageway extension 8 fiared outwardly (6) at the terminus 9.
• the charged filaments 10, which separate on exiting the extension of jet 6, are collected on receiver 11, an aluminum plate.
• the various components downstream from spinneret 2 are grounded through leads 12.
• the pertinent distances along the filament line are as follows:
• the filaments are quenched with air, applied 6 inches below the spinneret face.
• the guide bars 3, 4, and 5 are 1" X 1" with rounded edges and are composed of chromic oxi'e.
• Guide bar 4 i.e., the functional surface thereof, is offset from the filament line by 2 /2 inches.
• the entire jet assembly is fabricated from brass.
• poly(ethylene terephthalatc) 34 relative viscosit is spun through a 30-hole spinneret at a rat of 10 grams (total) polymer per minute. Each spinneret sole is 0.007 inch in diameter. The spinning temperature, measured at the spinneret, is 284 C. The following results are obtained:
• the filaments When each of the above runs is repeated excepting that the filaments are collected on a moving belt partially submerged (over the area on which the filaments are collected) in 75 C. water, the filaments again relax, leading to the development of crimp up to levels of 50 or more crimps per inch (based on in situ examination). The filaments also spontaneously extend upon subsequent treatment at elevated temperatures.
• the filaments also may be caused to relax by employing a heated gas in the aspirating jet.
• a heated gas in the aspirating jet.
• air at 90 p.s.i.g. and C. was employed, leading to results similar to those described in the foregoing.
• Continuous filament sheets of this type may be bonded with fibrids or with resin dispersion as shown in earlier examples.
• the sheets formed in all cases are equivalent to those obtained using self-elongat-able staple fibers and comparable bonding systems. Such sheet products are useful in all aspects of the present invention.
• non-woven fabrics can be prepared in accordance with the present invention.
• Such non-woven fabrics vary in fabric weight, fabric density, flexibility, strength, and handle. However, all 'of these materials have in common characteristics which suit them to meet the requirements and standards of woven fabrics, although they are, in fact, prepared without weaving operations.
• EXAMPLE 27 Poly (ethylene terephthalate) continuous filaments were spun from a 34 hole spinneret to give a non-woven web of polyester fibers.
• the web consisted of individually dis posed randomly oriented filaments deposited through an air-jet which forwarded the filaments from the spinneret over a chromic oxide charging bar which caused the generation of a static electrical charge in the individual fibers, in accordance with the teaching of the previous example.
• the web contained oo-spun binder filaments of a copolymer of poly(ethylene isophthalate) and poly (ethylene tetrephrthalate) (20/ 80 composition) making up 10% of the total Weight of the web.
• the homopolymer polyQethylene terephtha'late) was spun under conditions to give filaments with controlled orientation to give from 25% to 55% shrinkage on treatment with 75 C. water for 1 minute.
• the non-woven material was shrunk at controlled dimensions (on a tenter frame) to allow an area shrinkage of 50%, by treatment with 105 C. air with residence time of 1 minute.
• the filaments of the web were then found to be spontaneously elongatable, the average filament showing an elongation of 11% on treatment with boiling water for minutes.
• the resulting material was a soft, flexible non-woven fabric having a textile pattern imposed by the embossing function of the screens.
• the fabric bad a tensile strength of 7.0 lb./in./oz./yd. an elongation of 73%, a drape stiffness of 1.16 inches.
• a c omformable, bulkable, non-woven web comprising at least 50% by weight of synthetic organic spontaneously elongated fibers, said fibers being capable of elongating spontaneously at least 3% upon heating at a temperature 30 C. above its second order transition temperature for five minutes, the web containing from about 3% to 50% by weight of a synthetic, organic polymer binder dispersed uniformly throughout the web, said binder having an initial tensile modulus of between 0.002 and 25 grams per denier.
• spontaneously elongatable fibers are polyester fibers.
• polyester fibers are staple fibers.
• the binder consists of continuous filaments of a polyester having a melting temperature at least 20 C. below the melting temperature of said polyester fibers.
• the binder consists of fibrids of an elastomeric, synthetic polymer, which in fisher form has an initial tensile modulus of less than 0.9 g.p.d.
• the elastomeric polymer is a 'copolymer of an aliphatic ester of acrylic acid and up to 5% acrylic acid.
• the binder is composed of an elastomeric synthetic organic polymer having an initial tensile modulus of less than 0.9 g.p.d.
• polymer is a copolymer of an aliphatic ester of acrylic acid and up to 5% acrylic acid.
• composition of claim 1 wherein the spontaneously elongatable fibers are polyarnide fibers.
• polyamide consists essentially of a polymer of p-xylylene diamine and azelaic acid.

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  • NL NL264539D patent/NL264539A/xx unknown
• 1960
  • 1960-05-09 US US2747660 patent/US3117056A/en not_active Expired - Lifetime
• 1961
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