Classifications

• • D—TEXTILES; PAPER
  • D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
  • D06M—TREATMENT, NOT PROVIDED FOR ELSEWHERE IN CLASS D06, OF FIBRES, THREADS, YARNS, FABRICS, FEATHERS OR FIBROUS GOODS MADE FROM SUCH MATERIALS
  • D06M11/00—Treating fibres, threads, yarns, fabrics or fibrous goods made from such materials, with inorganic substances or complexes thereof; Such treatment combined with mechanical treatment, e.g. mercerising
  • D06M11/07—Treating fibres, threads, yarns, fabrics or fibrous goods made from such materials, with inorganic substances or complexes thereof; Such treatment combined with mechanical treatment, e.g. mercerising with halogens; with halogen acids or salts thereof; with oxides or oxyacids of halogens or salts thereof
  • D06M11/11—Treating fibres, threads, yarns, fabrics or fibrous goods made from such materials, with inorganic substances or complexes thereof; Such treatment combined with mechanical treatment, e.g. mercerising with halogens; with halogen acids or salts thereof; with oxides or oxyacids of halogens or salts thereof with halogen acids or salts thereof
  • D06M11/155—Halides of elements of Groups 2 or 12 of the Periodic Table
• • 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
• • D—TEXTILES; PAPER
  • D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
  • D06M—TREATMENT, NOT PROVIDED FOR ELSEWHERE IN CLASS D06, OF FIBRES, THREADS, YARNS, FABRICS, FEATHERS OR FIBROUS GOODS MADE FROM SUCH MATERIALS
  • D06M11/00—Treating fibres, threads, yarns, fabrics or fibrous goods made from such materials, with inorganic substances or complexes thereof; Such treatment combined with mechanical treatment, e.g. mercerising
  • D06M11/07—Treating fibres, threads, yarns, fabrics or fibrous goods made from such materials, with inorganic substances or complexes thereof; Such treatment combined with mechanical treatment, e.g. mercerising with halogens; with halogen acids or salts thereof; with oxides or oxyacids of halogens or salts thereof
  • D06M11/11—Treating fibres, threads, yarns, fabrics or fibrous goods made from such materials, with inorganic substances or complexes thereof; Such treatment combined with mechanical treatment, e.g. mercerising with halogens; with halogen acids or salts thereof; with oxides or oxyacids of halogens or salts thereof with halogen acids or salts thereof
• • D—TEXTILES; PAPER
  • D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
  • D06M—TREATMENT, NOT PROVIDED FOR ELSEWHERE IN CLASS D06, OF FIBRES, THREADS, YARNS, FABRICS, FEATHERS OR FIBROUS GOODS MADE FROM SUCH MATERIALS
  • D06M11/00—Treating fibres, threads, yarns, fabrics or fibrous goods made from such materials, with inorganic substances or complexes thereof; Such treatment combined with mechanical treatment, e.g. mercerising
  • D06M11/07—Treating fibres, threads, yarns, fabrics or fibrous goods made from such materials, with inorganic substances or complexes thereof; Such treatment combined with mechanical treatment, e.g. mercerising with halogens; with halogen acids or salts thereof; with oxides or oxyacids of halogens or salts thereof
  • D06M11/11—Treating fibres, threads, yarns, fabrics or fibrous goods made from such materials, with inorganic substances or complexes thereof; Such treatment combined with mechanical treatment, e.g. mercerising with halogens; with halogen acids or salts thereof; with oxides or oxyacids of halogens or salts thereof with halogen acids or salts thereof
  • D06M11/13—Ammonium halides or halides of elements of Groups 1 or 11 of the Periodic Table
• • D—TEXTILES; PAPER
  • D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
  • D06M—TREATMENT, NOT PROVIDED FOR ELSEWHERE IN CLASS D06, OF FIBRES, THREADS, YARNS, FABRICS, FEATHERS OR FIBROUS GOODS MADE FROM SUCH MATERIALS
  • D06M11/00—Treating fibres, threads, yarns, fabrics or fibrous goods made from such materials, with inorganic substances or complexes thereof; Such treatment combined with mechanical treatment, e.g. mercerising
  • D06M11/32—Treating fibres, threads, yarns, fabrics or fibrous goods made from such materials, with inorganic substances or complexes thereof; Such treatment combined with mechanical treatment, e.g. mercerising with oxygen, ozone, ozonides, oxides, hydroxides or percompounds; Salts derived from anions with an amphoteric element-oxygen bond
  • D06M11/36—Treating fibres, threads, yarns, fabrics or fibrous goods made from such materials, with inorganic substances or complexes thereof; Such treatment combined with mechanical treatment, e.g. mercerising with oxygen, ozone, ozonides, oxides, hydroxides or percompounds; Salts derived from anions with an amphoteric element-oxygen bond with oxides, hydroxides or mixed oxides; with salts derived from anions with an amphoteric element-oxygen bond
  • D06M11/38—Oxides or hydroxides of elements of Groups 1 or 11 of the Periodic Table
• • D—TEXTILES; PAPER
  • D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
  • D06M—TREATMENT, NOT PROVIDED FOR ELSEWHERE IN CLASS D06, OF FIBRES, THREADS, YARNS, FABRICS, FEATHERS OR FIBROUS GOODS MADE FROM SUCH MATERIALS
  • D06M11/00—Treating fibres, threads, yarns, fabrics or fibrous goods made from such materials, with inorganic substances or complexes thereof; Such treatment combined with mechanical treatment, e.g. mercerising
  • D06M11/32—Treating fibres, threads, yarns, fabrics or fibrous goods made from such materials, with inorganic substances or complexes thereof; Such treatment combined with mechanical treatment, e.g. mercerising with oxygen, ozone, ozonides, oxides, hydroxides or percompounds; Salts derived from anions with an amphoteric element-oxygen bond
  • D06M11/36—Treating fibres, threads, yarns, fabrics or fibrous goods made from such materials, with inorganic substances or complexes thereof; Such treatment combined with mechanical treatment, e.g. mercerising with oxygen, ozone, ozonides, oxides, hydroxides or percompounds; Salts derived from anions with an amphoteric element-oxygen bond with oxides, hydroxides or mixed oxides; with salts derived from anions with an amphoteric element-oxygen bond
  • D06M11/44—Oxides or hydroxides of elements of Groups 2 or 12 of the Periodic Table; Zincates; Cadmates
• • D—TEXTILES; PAPER
  • D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
  • D06M—TREATMENT, NOT PROVIDED FOR ELSEWHERE IN CLASS D06, OF FIBRES, THREADS, YARNS, FABRICS, FEATHERS OR FIBROUS GOODS MADE FROM SUCH MATERIALS
  • D06M13/00—Treating fibres, threads, yarns, fabrics or fibrous goods made from such materials, with non-macromolecular organic compounds; Such treatment combined with mechanical treatment
  • D06M13/10—Treating fibres, threads, yarns, fabrics or fibrous goods made from such materials, with non-macromolecular organic compounds; Such treatment combined with mechanical treatment with compounds containing oxygen
  • D06M13/152—Treating fibres, threads, yarns, fabrics or fibrous goods made from such materials, with non-macromolecular organic compounds; Such treatment combined with mechanical treatment with compounds containing oxygen having a hydroxy group bound to a carbon atom of a six-membered aromatic ring
• • D—TEXTILES; PAPER
  • D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
  • D06M—TREATMENT, NOT PROVIDED FOR ELSEWHERE IN CLASS D06, OF FIBRES, THREADS, YARNS, FABRICS, FEATHERS OR FIBROUS GOODS MADE FROM SUCH MATERIALS
  • D06M13/00—Treating fibres, threads, yarns, fabrics or fibrous goods made from such materials, with non-macromolecular organic compounds; Such treatment combined with mechanical treatment
  • D06M13/10—Treating fibres, threads, yarns, fabrics or fibrous goods made from such materials, with non-macromolecular organic compounds; Such treatment combined with mechanical treatment with compounds containing oxygen
  • D06M13/224—Esters of carboxylic acids; Esters of carbonic acid
  • D06M13/228—Cyclic esters, e.g. lactones
• • D—TEXTILES; PAPER
  • D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
  • D06M—TREATMENT, NOT PROVIDED FOR ELSEWHERE IN CLASS D06, OF FIBRES, THREADS, YARNS, FABRICS, FEATHERS OR FIBROUS GOODS MADE FROM SUCH MATERIALS
  • D06M13/00—Treating fibres, threads, yarns, fabrics or fibrous goods made from such materials, with non-macromolecular organic compounds; Such treatment combined with mechanical treatment
  • D06M13/322—Treating fibres, threads, yarns, fabrics or fibrous goods made from such materials, with non-macromolecular organic compounds; Such treatment combined with mechanical treatment with compounds containing nitrogen
  • D06M13/402—Amides imides, sulfamic acids
• • D—TEXTILES; PAPER
  • D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
  • D06M—TREATMENT, NOT PROVIDED FOR ELSEWHERE IN CLASS D06, OF FIBRES, THREADS, YARNS, FABRICS, FEATHERS OR FIBROUS GOODS MADE FROM SUCH MATERIALS
  • D06M15/00—Treating fibres, threads, yarns, fabrics, or fibrous goods made from such materials, with macromolecular compounds; Such treatment combined with mechanical treatment
  • D06M15/19—Treating fibres, threads, yarns, fabrics, or fibrous goods made from such materials, with macromolecular compounds; Such treatment combined with mechanical treatment with synthetic macromolecular compounds
  • D06M15/21—Macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds
  • D06M15/244—Macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds of halogenated hydrocarbons
• • D—TEXTILES; PAPER
  • D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
  • D06M—TREATMENT, NOT PROVIDED FOR ELSEWHERE IN CLASS D06, OF FIBRES, THREADS, YARNS, FABRICS, FEATHERS OR FIBROUS GOODS MADE FROM SUCH MATERIALS
  • D06M15/00—Treating fibres, threads, yarns, fabrics, or fibrous goods made from such materials, with macromolecular compounds; Such treatment combined with mechanical treatment
  • D06M15/19—Treating fibres, threads, yarns, fabrics, or fibrous goods made from such materials, with macromolecular compounds; Such treatment combined with mechanical treatment with synthetic macromolecular compounds
  • D06M15/21—Macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds
  • D06M15/327—Macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds of unsaturated alcohols or esters thereof
  • D06M15/333—Macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds of unsaturated alcohols or esters thereof of vinyl acetate; Polyvinylalcohol

Definitions

• ABSTRACT A method of treating fibrous materials to render them more amenable to subsequent textile and papermaking processes employing aqueous media which comprises: treating fibrous materials with a softening and swelling agent whereby the individual fibers become soft, limp and swollen; exposing said fibrous materials to textile or papermaking processes employing aqueous media wherein the individual fibers show less tendency toward undesirable fiber agglomeration, exhibit greater tendency toward fiber individualization, and demonstrate enhanced response and receptivity to fiber processing or manipulation because of their soft, limp and swollen nature; and forming a nonwoven fabric of the individual fibers. Also included are methods combining (1) the treating of the fibrous materials with the softening and swelling agent and (2) the textile processes into a single operation.
• Such nonwoven fabrics have usually been manufactured by laying down one or more fibrous layers or webs of textile length fibers by textile carding techniques which generally align the majority of the fiber segments lengthwise of the fibrous web being laid down.
• one of the key steps in the operation is the treatment of the fibrous web with resin binders, usually in the form of aqueous emulsions or dispersions, to bond the individual fibers into a stronger and more coherent nonwoven fabric.
• the carded fibrous webs be given a pretreatment under the influence of aqueous media prior to the bonding process whereby the individual fibers of the fibrous webs are rearranged, reorganized, or otherwise manipulated to form fibrous webs of improved properties and characteristics.
• aqueous media pretreatments are noted. in the following issued patents: U.S. Pat. Nos. 2,862,251 (note FIGS. 7 and 23), 3,025,585 (note FIG. 1), 3,033,721 (note FIG. ll), 3,485,706 (note FIG. 2), and British Pat. No. 1,088,376 (note FIG. 2).
• U.S. Pat. Nos. 2,862,251 note FIGS. 7 and 23
• 3,025,585 note FIG. 1
• 3,033,721 note FIG. ll
• 3,485,706 note FIG. 2
• British Pat. No. 1,088,376 note FIG. 2
• the fibrous layer is usually treated with a resin binder, again usually in the form of an aqueous system, to bond the individual fibers into a stronger and more durable fabric.
• paper formation aids or dispersing agents be added to the aqueous slurry of fibers at an early stage or at an intermediate stage, such as the furnish in the stuff box, or perhaps at the fan pump of head box, immediately prior to delivery of the aqueous fiber slurry to the papermaking machine proper, whether it be a Fourdrinier of a cylinder machine.
• textile length fibers have been mildly successful and, as a result, textile length fibers of from about 1% to about 3 denier having a length of about one-fourth inch and even ranging up to about threeeighths inch have been used and moderately well- .formed fibrous webs have been obtained.
• textile length fibers is intended to include fibers having an average length of at least about one quarter inch and preferably greater, say, on the order of at least about one-half inch or three-fourths inch and up to about 2 inches or more.
• Such fibers, and especially those longer than one-half inch, are often referred to in the textile industry as cardable" fibers, indicating that they have sufficient length as to be used in carding processes on conventional textile carding machines.
• Such textile length fibers are to be distinguished from papermaking fibers which are extremely short and are usually in the range of from about one-twentieth inch or less up to about one-sixth inch.
• Wood pulp fibers are, of course, the best known example of papermaking fibers.
• Such shorter fibers are not of textile length, are not cardable, but are still applicable to some of the narrower aspects of the present invention.
• the natural fibers such as the cellulosic fibers including cotton, flax, jute, ramie, etc., and other natural fibers such as wool, silk, etc.
• the textile length synthetic organic polymeric fibers may be selected from a large group of commercially known synthetic fibers such as the cellulosics (regenerated cellulose rayon, cellulose acetate, cellulose triacetate, etc.); polyamides (nylon 6/6, nylon 6, nylon 610, nylon 10, nylon 11, etc.); polyethylene terephthalate polyesters (Dacron, Kodel, etc.); acrylics (Acrilan, Orlon, etc.); modacrylics (Dynel, Verel, etc.); polyolefins (polyethylene, polypropylene, etc.); and other synthetic fibers.
• cellulosics regenerated cellulose rayon, cellulose acetate, cellulose triacetate, etc.
• polyamides nylon 6/6, nylon 6, nylon 610, nylon 10, nylon 11, etc.
• polyethylene terephthalate polyesters Dacron, Kodel, etc.
• acrylics Acrilan, Orlon, etc.
• modacrylics Densel, Verel
• any one of those fibers may be the only type of fiber present in the fibrous layer or web, or such fibers may be used in blends in any and all proportions.
• the denier of these synthetic fibers is dependent upon the demands and requirements of the desired fibrous webs. As such, deniers in the range of from as low as about three-fourths or 1 denier up to as large as about l deniers or more are of value depending upon the needs of the particular circumstances. Within the more commercial aspects of the present invention, a denier range of from about 1 /2 to about 3 is preferred.
• the lengths of these synthetic fibers are as low as about one-fourth inch and as long as about 2 inches, or longer, if desired or required. Such lengths are normally obtained by cutting or staplizing synthetic continuous filament tow to the desired lengths.
• the swelling agents which are used to render the fibers soft, limp and swollen may be selected from a wide variety of swelling agents known in industry which are capable of use in such concentrations and in such a way that they swell the fibers but do not dissolve, degrade, discolor, or decompose them.
• swelling agents for rayon include a large number of water soluble chemical compounds: alkali metal hydroxides, such as sodium hydroxide, potassium hydroxide, lithium hydroxide, etc.; cuprammonium hydroxide; liquid ammonia; quaternary ammonium compounds such as tetramethyl ammonium chloride; tetra methyl benzyl ammonium chloride, etc.; strong acids such as phosphoric acid, sulfuric acid, nitric acid, etc.; strongly acidic salts such as zinc chloride; relatively neutral salts such as lithium chloride; etc.
• alkali metal hydroxides such as sodium hydroxide, potassium hydroxide, lithium hydroxide, etc.
• cuprammonium hydroxide liquid ammonia
• quaternary ammonium compounds such as tetramethyl ammonium chloride; tetra methyl benzyl ammonium chloride, etc.
• strong acids such as phosphoric acid, sulfuric acid, nitric acid, etc.
• strongly acidic salts
• Swelling agents for polyamides include solutions of phenol, diethyl formamide, dimethyl formamide, concentrated formic acid, xylenol, trifiuoroethanol, zinc chloride, chloral hydrate, 'y-butyrolactone, etc.
• Swelling agents for polyolefins include petroleum ether solutions of tetrahydronaphthalene (tetralin), decahydronaphthalene (decalin), carbon tetrachloride, toluene, xylene, etc.
• Swelling agents for polyesters include hot phenolic compounds, chloral hydrate, n-methyl pyrrolidone, etc.
• Swelling agents for acrylics include aqueous solutions of dimethyl formamide, diethyl formamide, dimethyl sulfoxide, etc.
• Swelling agents for modacrylics include aqueous solutions of dimethyl formamide, diethyl formamide, dimethyl sulfoxide, etc.
• the concentration of the swelling agent, the duration of time and the temperature of the pretreatment may be varied relatively widely but it is essential that the conditions be sufficient to induce a soft, limp and swollen state in the fibers. Once such a soft, limp and swollen state is reached, additional pretreatment does not add materially to the efficacy of the subsequent fiber dispersion and web formation steps or other aqueous media processing and, in fact, may be undesirable inasmuch as the possibility of fiber discoloration, dissolution, degradation, or decomposition may arise. Also, it is possible that the swelling action could be too drastic in which case the fibers could become so swollen as to result in gelation at their surfaces whereby they could adhere to each other.
• concentration of the swelling agent and the other factors of the pretreatment must be such that merely a softening and swelling of the synthetic fibers is obtained and that no material solubilization, degradation, discoloration, or decomposition of the synthetic fibers take place.
• concentrations of aqueous sodium hydroxide of from about 0.5 percent to about 8 percent are satisfactory, with a preferable range of from about 2.5 percent to about 7 percent.
• phenol is the preferred swelling agent and concentrations of phenol in water in the range of from about 1 percent to about 5 percent are utilizable, with preferred ranges extending from about 2 percent to about 5 percent.
• the temperatures of the swelling pretreatments are preferably room temperature for most synthetic fibers but may range in special cases up to elevated temperatures of C. or more, where such temperatures may be desired or required.
• the duration of the time of the swelling pretreatment may be varied from as short a period as a few seconds for some synthetic fibers up to about 3 or 5 minutes for other fibers. Continued pretreatment for longer periods, for example, up to about 100 or more minutes does not produce materially improved results. As a matter of fact, such extended periods may be undesirable inasmuch as the possibility of fiber dissolution, discoloration, degradation, or decomposition may arise.
• the fibrous materials have been treated with the swelling agent and the individual fibers have become soft, limp and swollen, they retain such properties as long as they remain wet or damp. While they are in such a state, they respond quite readily and are very receptive to processing in aqueous media.
• Such a soft, limp and swollen physical condition naturally leads to a low fiber modulus and may also have a profound effect on the interaction between fiber surface and aqueous environment, which is not the case for fibers which have not been pretreated by the method of our invention.
• the soft, limp and swollen nature of the fibers also permits a closer, more intimate and more frequent contacting relationship between the individual fibers of a web inasmuch as the fibers are not as resilient and springy and do not have as great a tendency to spring apart into less dense fibrous configuration in which the individual fibers have less intimate and fewer contacting relationships with each other.
• the existence of a greater number of contacts between the individual fibers is, of course, conducive to better bonding and adhering by aqueous resin binder dispersions.
• the swelling agent physically be removed from the fibrous materials or be inactivated in all cases prior to the subsequent processing in aqueous media. If such processing takes place in a large excess of an aqueous medium, whereby the concentration of the swelling agent is diluted and falls off to extremely low or negligible values, then the swelling agent is permitted to remain in the fibrous materials in such diluted form. However, if the subsequent processing takes place in relatively small amounts of water, so that the concentration of the swelling agent would remain at a relatively high or objectionable value, then it must be removed by either a dilution or washing technique, or neutralized, or rendered inactive or inoperative as a swelling agent prior to the subsequent processing operation.
• the effect of the swelling agent is not reversed by dilution, washing, neutralization, or the like, and the soft, limp and swollen nature of the fibrous materials remains substantially greater than fibers which have only been immersed in water, so long as the pretreated fibrous materials are not dried, but remain wet or damp.
• the fibrous materials remain amenable to and responsive or receptive to the subsequent aqueous media processing after the swelling agent has been removed.
• the fibers may not be allowed to dry or else they will lose their soft, limp and swollen nature and will return to their original physical characteristics and thus will no longer be responsive or receptive to the subsequent processing in aqueous media.
• rayon fibers which have been treated with caustic may be neutralized and introduced into a paper sheet mold on the acid side, that is, a pH of less than 7 and the desirable properties and characteristics of the soft, limp and swollen fibers still remain.
• the principles of the present inventive concept are applicable to a very wide range of processing in aqueous media.
• some fibrous webs containing certain synthetic organic polymeric filaments or fibers are very difficult to bond particularly by aqueous emulsions, dispersions or latexes or resin binders.
• synthetic fibers are given a pretreatment with a swelling agent and become soft, limp and swollen, they respond very readily and can be bonded with aqueous binder resins to yield bonded nonwoven fabrics having significantly improved properties and characteristics, particularly tensile strengths, over the properties and characteristics of nonwoven fabrics not given such a swelling pretreatment.
• a pretreatment with a swelling agent whereby the textile length fibers are rendered soft, limp and swollen produces improved responsiveness and receptivity to papermaking techniques.
• the use of the swelling pretreatments of our invention permits the use of appreciably longer fine denier textile fibers in the denier range of from about 1% to about 3 and having lengths of about one-half inch or even five-eighths inch, without using any paper formation aids or dispersing agents in the aqueous media.
• the use of the swelling pretreatments of the present invention provides for the dispersion of fine denier textile length rayon fibers of about three-fourths inch or more in aqueous media by the addition of much lower amounts of such paper formation aids or dispersing agents.
• the amounts of paper formation aids or dispersing agents required for the papermaking techniques can be reduced to as little as only one-twentieth of the previous requirements.
• the amount of beating and working of the textile length fibers required to insure a uniform dispersion can be drastically reduced.
• the number of strokes required to insure a uniform dispersion of fibers in a sheet mold can be reduced from 50 strokes to as few as 5 strokes.
• the individual soft, limp and swollen fibers show a greater tendency toward fiber individualization and a lesser tendency toward agglomeration and clumping into tangles and bundles of matted fibers in the papermaking process.
• bundles were originally present, such as following a cutting or staplizing operation, there is an increased tendency for such bundles to break up into individual fibers during the papermaking process in aqueous media whereby a more uniform fibrous web is obtained.
• This easier breakdown of the bundles into individual fibers is particularly noted in the case of rayon, nylon, polyester, acrylic and polyolefin fibers.
• Still another field wherein vastly improved response and receptiveness to aqueous media processing is noted in the rearranging, reorganizing or manipulating of individual fibers subsequent to their original formation as a fibrous web.
• the soft, limp and swollen fibers are to any chemical change.
• the soft, limp and swollen fibers have a low modulus and yield more readily to applied forces and also appear to possess some form of surface lubricity or slipperiness whereby they do not cling or stick to each other.
• Water pressures up to about 1,000 pounds per square inch gauge or even 5,000 pounds per square inch gauge are, of course, of use in the present invention but such is undesirable, particularly for practical and economical operating reasons. Within the more practical commercial aspects of the present invention, a range of from about 50 pounds per square inch gauge to about 190 pounds per square inch gauge is preferable.
• Greater pressures are, of course, of use for specific needs and requirements. For example, greater pressures are of value when very high production line speeds are desired or necessary and the fibrous materials are being fed through the treating apparatus at very high rates of speed. Processing with low pressuresoccasionally yields unsatisfactory results when production line speeds are too great.
• Jets or streams of water having a substantially columnar shape are preferred in some of the applications of the principles of the present inventive concept inasmuch as they are easier to control, prevent undesirable overlapping of fluid rearranging effect, and minimize fluid and air disturbance and turbulence in the fibrous materials being reorganized and rearranged.
• Jets, sprays, or streams having a conical or fan-shape are of use, particularly where some degree of overlapping and fluid or air disturbance and turbulence can be tolerated or possibly desired under the circumstances and where the desired design or pattern in the rearranged fabric permits such use.
• the jets be substantially parallel or that they be directed at right angles to the plane of the fibrous materials being rearranged.
• the jets may be at various angles to each other instead of being parallel and they may be at angles, such as 30 or 45 to the plane of the fibrous web.
• One particular configuration comprises a row of nozzles facing forwardly at an angle of 45 to the direction of travel of the fibrous materials with the succeeding adjacent row facing rearwardly at an angle of 135 to the direction of travel of the fibrous materials.
• Such an arrangement provides for an increase in the amount of turbulence and swirling of the rearranging fluid which is highly desirable in some applications of the present invention.
• One desirable result of the permissible use of lesser water pressures by the present inventive concept is the corresponding lowering of the total energy or momentum required in achieving the same desired results which can be obtained by other techniques only through the expenditure of far greater energy or momentum.
• orifices are usually circular and possess sizes of from about 0.002 inch to about 0.060 inch which are of use, with a preferred commercial range of from about 0.003 inch to about 0.020 inch.
• Such supporting members are of the type of stainless steel, plastic, or similar screen-like member illustrated in FIG. 5 of U. S. Pat. No. 3,025,585, having a mesh size per inch ranging from 3 X 3 to as high as X 80, and commercially preferably from about 10 X 10 to about 30 X 30.
• Unequal sizes having different numbers of warp wires and filling wires are, of course, possible to create different designs and patterns.
• the openings, orifices, apertures, or the like may be uniformly arranged as is normally present in a woven wire screen, or they may be arranged in a square, staggered or clustered arrangement, as desired or required.
• the openings, orifices, apertures, or the like may be formed in plate members and may merely comprise holes drilled to the desired size, or they may be tapped openings into which are fitted devices capable of forming jets and other columnar streams of fluid.
• the fibrous materials being arranged pass under the rearranging jets of water merely once, whereby greater productivity and higher through-put is achieved, several passes under the jets is, of course, utilized where such is desired or required for special or additional rearranging effects.
• Another variation is the passage of the fibrous materials under the water jets a second or additional times in reverse fashion or with the axis of long direction of the fibrous materials at various directions to the direction of movement during the preceding rearranging process.
• the physical properties of the resulting fabrics are also remarkably improved over the physical properties obtained by techniques not utilizing the advantages of the present invention.
• tensile strengths and normalized tenacities in the long and cross direction are increased up to 38 times the long and cross tenacities of untreated control samples.
• the modulus in pounds per inch in the long and cross directions is increased up to 31 times the modulus in the long and cross directions of. untreated control samples.
• the toughness in pounds per inch in the long and cross directions is increased up to 112 times the toughness in the long and cross direction of untreated control samples.
• the physical properties of the resulting fabrics are particularly improved in those cases where fibers are used which possess low wet modulus.
• Such fibers possess very limp properties and characteristics in water and are very responsive to the application of the principles of the present invention.
• Viscose rayon fibers are an outstanding example of such fibers and it is to be noted that the wet modulus of such viscose fibers is extremely low and that they are considered to be one of the limpest forms of fibers in water.
• Such a combined operation may be obtained by using a softening and swelling agent as the fluid which issues in the form of jets, streams, or sprays during the textile process, whereby the need for the prior pretreatment with a softening or swelling agent is obviated. Care must be exercised in such a process that the apparatus does not comprise aluminum, brass, or other materials which are apt to be affected chemically by the-softening and swelling agent and that resistant metals and materials such as selected plastics and stainless steel be used.
• EXAMPLE 1 Bright, no finish, 1.5 denier rayon filaments are cut to a length of one-half inch. These fibers are cut in the wet state and are used in a damp state. Their moisture content is 38 percent, based on the total weight of the fibers and water. There are a considerable number of fiber clumps and bundles in the cut rayon fibrous materials. A 25.6 gm. sample of these fibers is added to milliliters of 5 percent (by weight) sodium hydroxide solution. The fibers are allowed to stand in contact with the caustic solution for 5 minutes at room temperature. At the end of this time, the fibers are softer, limper and are swollen, and show a strong tendency toward separation of bundles of fibers into individual fibers.
• the fiber-caustic solution is then dumped into a 23 X 23 inch sheet mold filled to a height of 16 /2 inches with water (0.008 percent consistency).
• the sheet molds contents are subjected to a standard number of 50 up and down strokes with a paddle consisting of a flat plate attached at right angles to a metal rod. Such stirring is more than ample.
• a valve at the bottom of the sheet mold is then opened, draining away the water and leaving the rayon fibers in a flat mat on the sheet mold collecting screen.
• the fibrous web is removed from the screen, sprayed with a 2 percent polyvinyl alcohol solution, and dried on a hot plate.
• the resulting web having a weight of about 400 grains per square yard, is very uniform in appearance with virtually no evidence of tangling and clumping of fibers. It is essentially free of bundles of fibers, since virtually all of the bundles are broken down into individual fibers. It possesses excellent isotropicity and has equal properties and characteristics in all directions. Fibrous webs made by these techniques are commercially acceptable and are well suited for further processing into nonwoven fabrics.
• Example ll The aqueous media papermaking procedures of Example I are followed substantially as set forth therein with the exception that the concentration of the swelling agent is lowered from 5 to 3 percent (by weight) sodium hydroxide solution. The results are generally comparable. The individual rayon fibers become softer, limper and are swollen. Fibrous webs made by these techniques are commercially acceptable and are suitable for further processing into nonwoven fabrics.
• EXAMPLE IV The aqueous media papermaking procedures of Example I are followed substantially as set forth therein with the exception that the swelling agent is 4 percent (by weight) potassium hydroxide. The results are generally comparable. The individual rayon fibers become softer, limper and are swollen. Fibrous webs made by these techniques are commercially acceptable and are suitable for processing into nonwoven fabrics.
• Example V The aqueous media papermaking procedures of Example I are repeated except that the .rayon fibers are soaked for 5 minutes in plain water instead of5 percent sodium hydroxide solution. The individual fibers do not become as soft, limp or swollen as in Example I. The resulting web has poor uniformity, and tangling and clumping of fibers is very evident. In addition, many rayon fiber bundles are still intact. Fibrous webs made by these techniques are not commercially acceptable and are not suitable for further processing.
• Example VI The aqueous media papermaking procedures of Example I are repeated except that the rayon fibers are treated for 5 minutes with 5 milliliters of 52 percent solution of zinc chloride in water. The individual fibers become softer, limper and are swollen. The resulting web is uniform in appearance with little or no tangling and clumping in evidence. The results are comparable to those obtained in Example I with respect to both uniformity and lack of fiber bundles. Fibrous webs made by these techniques are commercially acceptable and are suitable for further processing into nonwoven fabllCS.
• Example VII The aqueous media papermaking procedures of Example I are repeated except that the rayon fibers are treated for minutes with 100 milliliters of 43.6 percent lithium chloride solution in water. The individual fibers become softer, limper and are swollen. The resulting web is substantially more uniform and untangled than the web of Example V which is merely pretreated with plain water. The degree of bundle breakup is not quite as good as that of Example I and VI,
• Fibrous webs made by these techniques are commercially acceptable and are suitable for further processing into nonwoven fabrics.
• a neutralization step is used first wherein a sufficient amount of acetic acid is added to the sheet mold which will neutralize the sodium hydroxide. This is done before the fibers are dumped into the sheet mold. Care is taken, however, that the fibers are not permitted to dry out at any time before they are dumped into the sheet mold. This change creates no adverse effects and the results are comparable to those obtained in Example I.
• Example IX The aqueous media papermaking procedures of Example I are followed substantially as set forth therein with the exception that the consistency in the sheet mold is reduced from 0.008 to 0.004 percent by merely using a 12.8 gram sample of cut rayon fibers in the sodium hydroxide swelling treatment and by keeping the water content in the sheet mold the same.
• the resulting web has a grain weight of only about 200 grains per square yard and is also essentially free of bundles of fibers. It possesses excellent isotropicity and has equal properties and characteristics in all directions.
• Example I The procedures of Example I are followed substantially as set forth therein with the exception that threefourths inch long, 1.5 denier, bright, no finish rayon fibers are used, and in addition to a swelling pretreatment with sodium hydroxide, a 10 ppm Polyox Coagulant Polyethylene oxide solution is used in the sheet mold. Instead of using the standard 50 up and down stroke stirring, only 5 up and down strokes are required. Furthermore, essentially equally good results are obtained when the concentration of Polyox is reduced as low as 0.6 ppm.
• EXAMPLE XI Semi-dull, 3-denier polyamide nylon 66 tow is cut to a staple length of 1.2 inches. There are a considerable number of fiber clumps and bundles, resulting from the tow cutting process. To 9.7 grams of these fibers is added 100 ml. of 4 percent aqueous phenol solution. After a treatment of 5 minutes, during which time the fibers become soft, limp and swollen, the fibers and phenol solution are dumped into the sheet mold described in Example I. The sheet mold is filled to a height of 16 /2 inches with a ppm solution of Polyox Coagulant polyethylene oxide.
• the purpose of the Polyox Coagulant is to act as a dispersant and to reduce the tendency of the fibers to tangle with one another. After 200 vigorous strokes with the paddle described in Example I, the water is drained off leaving a web which, after drying, is reasonably uniform in appearance and contains few, if any, of the original bundles resulting from the tow cutting process. Fibrous webs made by these techniques are commercially satisfactory and are well suited for further processing into nonwoven fabrics.
• Example XII The aqueous media papermaking procedures of Example XI are followed substantially as set forth therein with the exception that the concentration of the swelling agent is lowered from 4 to 2 /2 percent phenol solution. The results are generally comparable. The individual nylon fibers become soft, limp and swollen. Fibrous webs made by these techniques are commercially acceptable and are suitable for further processing into nonwoven fabrics.
• Example XIII The aqueous media papermaking procedures of Example XI are followed substantially as set forth therein with the exception that the concentration of the swelling agent is lowered from 4 to 1% percent phenol solution. The results are generally comparable. The individual nylon fibers become soft, limp and swollen and have less fiber-to-fiber surface friction. Fibrous webs made by these techniques are commercially acceptable and are suitable for processing into nonwoven fabrics.
• Example XIV The aqueous media papermaking procedures of Example Xl are repeated except that the nylon fibers are soaked for 5 minutes in plain water instead of in 4 percent phenol solution. The individual fibers do not become as soft, limp and swollen. The resulting nylon web gives the appearance of being a very lightweight sheet owing to the fact that many of the fibers are still bound up in the original bundles which resulted from two cutting. Literally hundreds of these bundles are easily identifiable. Fibrous webs made by these techniques are commercially unacceptable and are unsuitable for further processing.
• Example XV The aqueous media papermaking procedures of Example XI are repeated except that the nylon fibers are treated for 5 minutes with 50 gm. of 40 percent aqueous zinc chloride solution. The individual nylon fibers become soft, limp and swollen. As in Example XI, the resulting web contains very few bundles of the type which are formed during tow cutting. Fibrous webs made by these techniques are commercially acceptable and are well suited for further processing into nonwoven fabrics.
• Example XVI The aqueous media papermaking procedures of Example XI are followed substantially as set forth therein and the nylon fibrous web made in accordance with such aqueous papermaking procedures is impregnation-bonded with an aqueous dispersion of polyvinyl acetate 15 percent resin binder solids). The impregnation takes place on the wet or damp fibrous nylon web while the individual fibers are still soft, limp and swollen. The resulting bonded fibrous web is improved in wet and dry tensile strengths, both in the long and cross directions, as compared to similarly bonded fibrous webs which are not given a pretreatment with 4 percent phenol swelling agent.
• the tensile strength of the bonded nylon fibrous web is improved in both the long and in the cross direction in the dry state as well as in the wet state. In some tests, the improvement ranges as high as 50 percent or more.
• Example XVII Aqueous media papermaking procedures as described in Example XI are followed substantially as set forth therein except that the 9.7 grams of nylon fibers is replaced by 4.85 grams of 1.5 denier, 1% inch rayon fibers and 4.85 grams of 1.5 denier, l inch polyamide nylon 66 fibers.
• the rayon fibers are pretreated with 5 percent by weight sodium hydroxide for 3 minutes and the polyamide nylon 66 fibers are separately treated with 4 percent phenol solution for 3 minutes.
• the two batches of fibers are then dumped, while still wet and while they are still soft, limp and swollen, into the large excess of water in the sheet mold.
• the fiber dispersion is stirred and the water is drained to produce a 50-50 rayonnylon fibrous web.
• the properties and characteristics of such blended fibrous web are excellent and the web is well suited for further processing.
• One advantage of this blending purpose is the neutralization of the sodium hydroxide and the phenol in the sheet mold aqueous media, whereby the necessity for subsequent processing is reduced.
• Example XVIII The aqueous media papermaking procedures of Example XVII are followed substantially as set forth therein except that the rayon and nylon fibers are treated together in 5 percent sodium hydroxide as the swelling agent.
• the rayon fibers become softer, limper and are swollen.
• the nylon fibers are relatively unaffected by the sodium hydroxide and do not become soft, limp and swollen;
• the batch of mixed fibers is dumped into a sheet mold and a fibrous sheet made in the usual way.
• the sheet is marginally satisfactory and is not as well formed or as uniform as the sheet made in accordance with Example XVII wherein both types of fibers are pretreated and are soft, limp and swollen.
• Example XIX The aqueous media papermaking procedures of Example XVIII are followed substantially as set forth therein except that the rayon and nylon fibers are treated together in 4 percent phenol as the swelling agent. The nylon fibers become soft, limp and swollen, whereas the rayon fibers are not as affected. Sheets made of such a mixture of fibers in a sheet mold are satisfactory but are not as well formed or as uniform as the sheets made in accordance with Example XVII wherein both types of fibers are pretreated and are soft, limp and swollen.
• EXAMPLE XX A carded fibrous web having a weight of about 300 grains per square yard and comprising 100 percent semi-dull polyamide nylon 66 fibers having a denier of 3 and a staple length of 1% inches is treated with a 4 percent phenol solution until the fibers become soft, limp and swollen. The carded fibrous web is then washed in water to remove the phenol and is forwarded for the subsequent textile treatment while still in the wet or damp state. The fibrous web is then bonded with an aqueous dispersion of polyvinyl chloride (15 percent resin binder solids) by impregnation bonding techniques.
• polyvinyl chloride 15 percent resin binder solids
• the tensile strength of such nylon fibrous web in both the long direction and the cross direction is improved over the tensile strength of nylon fibrous webs not given a pretreatment with a swelling agent.
• the improvement in wet and dry tensile strength, both in the long and in the cross direction ranges up to 50 percent.
• Example XXI The procedures of Example XX are followed substantially as set forth therein with the exception that the resin binder which is used to bond the carded nylon fibrous web is a polyvinyl acetate aqueous dispersion rather than a polyvinyl chloride dispersion.
• the wet and dry tensile strengths, both in the long and cross directions, are again increased in some cases up to about 50 percent.
• EXAMPLE XXII A carded fibrous web having a weight of 300 grains per square yard and comprising 75 percent (by weight) viscose rayon fibers having a denier of 1 /2 and a length of2 inches and 25 percent (by weight) bleached cotton fibers averaging about one-half to three-fourths of an inch is passed through a tank of swelling agent wherein it is treated with a 5 percent (by weight) sodium hydroxide solution for 20 seconds at room temperature.
• the treated carded fibrous web containing soft, limp and swollen fibers is then passed through fiber rearranging apparatus disclosed in FIGS. 7-10 of U. S. Pat.
• the carded fibrous web is placed on a rotatable supporting drum having apertures therein and is covered by a continuous movable screen belt having openings therein which are smaller than the apertures in the rotatable drum.
• the pressurized jets or streams of water are directed from inside the drum and pass through the larger apertures in the drum, then through the fibrous web, rearranging the individual fibers therein, and ultimately pass through the smaller openings in the screen belt.
• the rearrangement of the individual fibers is facilitated to a great extent by the soft, limp and swollen nature of the fibers which more readily respond to and are more amenable to the rearranging techniques.
• the multiplicity of yarnlike fiber groups which are interconnected at junctures are more clearly defined whereby the holes which are formed are cleaner and possess fewer stray fibers therein.
• the predetermined pattern is very distinct which is brought about by the fact that the individual fibers were more responsive and more amenable to the rearranging techniques.
• Example XXIII The procedures of Example XXII are followed substantially as set forth therein with the exception that the caustic pretreating step and the rearranging step are combined into a single operation. This is accomplished by omitting the caustic pretreatment step and by using 5 percent sodium hydroxide solution as the rearranging fluid.
• Example XXII The results are generally comparable to the results obtained in Example XXII. It is to be appreciated that the improved results are due, in part, to the fact that the viscose rayon fibers have an extremely low wet modulus and the bleached cotton fibers have a low wet modulus whereby they are very limp in water and thus are exceptionally adaptable for use within the principles of the present invention.
• EXAMPLE XXIV A mixture containing 25 percent (by weight) of papermaking fibers, 2 to 3 millimeters in average length, and percent (by weight) of inch, 1% denier viscose rayon fibers is treated with 5 percent (by weight) sodium hydroxide solution for 4 minutes at room temperature. This fibrous mixture containing soft, limp and swollen fibers is then water-laid to provide a web having a grain weight of 250 grains per square yard. It is treated as in Example XXII and the improved results are comparable. The resulting rearranged fibrous web is compared to the fibrous web resulting from the process described in Example II of U. S. Pat. No. 2,862,251 which does not involve a swelling pretreatment, and is deemed to be superior thereto.
• EXAMPLE XXV A carded fibrous web weighing about 300 grains per square yard and containing 75 percent (by weight) viscose rayon fibers having a denier of 1% and approximately 2 inches long and 25 percent (by weight) of bleached cotton fibers averaging about one-half inch to about three-fourths inch in length is passed through a treating trough containing 5 percent (by weight) sodium hydroxide for 10 seconds at room temperature.
• the treated carded fibrous web containing soft, limp and swollen fibers is then passed through the double screen belt fiber rearranging apparatus disclosed in FIG. 23 of U. S. Pat. No. 2,862,251.
• the carded fibrous web is placed on an endless supporting flexible belt screen having openings therein and is covered by another endless flexible belt screen having openings therein which are larger than the openings in the supporting belt screen.
• the pressurized jets or streams of water are directed from within the covering flexible belt and pass through the larger openings therein, then through the fibrous web to rearrange the individual fibers therein, and ultimately to pass through the smaller openings in the supporting flexible belt screen.
• the multiplicity of yarn-like fiber groups are interconnected at junctures and are very clearly defined.
• the openings in the rearranged fibrous web are clean and are distinct.
• the fibrous web is compared to the fibrous web resulting from the techniques of Example Ill in U. S. Pat. No. 2,862,251 which does not include a swelling pretreatment and is deemed to be superior thereto. Increased production rates are also obtained where the fibers are given a swelling pretreatment.
• Example XXV-A The procedures of Example XXV are followed substantially as set forth therein with the exception that the caustic pretreatment step and the rearranging step are combined into a single operation. This is accomplished by omitting the caustic pretreatment step and by using percent sodium hydroxide solution as therearranging fluid.
• Example XXVI The procedures of Example XXII are followed substantially as set forth therein with the exception that the treated carded fibrous web containing soft, limp and swollen fibers is passed through apparatus disclosed in FIG. 11 of U. S. Pat. No. 3,033,721 wherein the jets or streams of water pass through the small apertures of the screen first, then through the fibrous web, and finally through the larger apertures of the rotating drum.
• the rearrangement of the individual fibers is facilitated by their soft, limp and swollen nature and the predetermined pattern of protuberant pivotal packings of fibers protruding out of the plane of the flatwise bundles is clearly and distinctly defined in sharp outline.
• the resulting fibrous web is compared to the fibrous web pre pared in accordance with the procedures of the example in U. S. Pat. No. 3,033,721 which does not include a swelling pretreatment and is deemed to be superior thereto. Increased production rates are also made possible, as well as the use of lower effective water pressures for the jets or streams of water.
• Example XXVII The procedures of Example XXVI are followed substantially as set forth therein with the exception that the caustic pretreatment step and the rearranging step are combined into a single operation. This is accomplished by omitting the caustic pretreatment step and by using 5 percent sodium hydroxide solution as the rearranging fluid.
• EXAMPLE XXVIII A fibrous web comprising irregularly-arranged fibers and having a weight of 300 grains per square yard and comprising 75 percent (by weight) viscose rayon fibers having a denier of 1V2 and a length of 2 inches and 25 percent (by weight) of bleached cotton fibers averaging about one-half to three-fourths inch is passed through a tank of 5 percent (by weight) of sodium hydroxide solution for 15 seconds at room temperature.
• the treated fibrous web containing soft, limp and swollen fibers is then passed through fiber rearranging apparatus described in U. S. Pat. No. 3,025,585 (FIG. 1).
• the web is placed on a supporting carrying screen having tapered projections and the individual fibers are rearranged to define a predetermined pattern of holes or openings around the tapered projections.
• the fiber rearrangement is made much easier by the swelling pretreatment and increased production speeds are made available.
• EXAMPLE XXIX Rayon fibers having a denier of 1.5 denier per filament and a staple length of one-half inch are treated with a 5 percent sodium hydroxide solution for 4 to 5 seconds. Without removing the sodium hydroxide, these fibers are then quickly dumped into a large excess of water contained in a 23 inch by 23 inch sheet mold at room temperature and formed into a sheet.
• the break-up of bundles into individual rayon fibers is excellent and rapid and the fiber dispersing characteristics in the aqueous medium is excellent, thus showing that the swelling action of the sodium hydroxide is very rapid.
• Example XXX The procedures of Example XXVIII are followed substantially as set forth therein with the exception that the caustic pretreating step and the rearranging step are combined into a single operation. Specifically, the fibrous web of irregularly arranged viscose rayon fibers and bleached cotton fibers, instead of being pretreated with the 5 percent sodium hydroxide solution and then subsequently rearranged in the fiber rearranged apparatus described in U. S. Pat. No. 3,025,585 (FIG. 1), are rearranged in such apparatus by substituting 5 percent sodium hydroxide solution for water as the rearranging fluid.
• EXAMPLE xxx Twelve fibrous card webs are prepared, each having a weight of 350 grains per square yard and comprising viscose rayon fibers having a denier of l k and a length of 2 inches. Six of these webs are pretreated by being passed through water at room temperature and six webs are pretreated by being passed through 5 percent sodium hydroxide solution at room temperature. All 12 webs then are rearranged under the conditions set forth in the following table.
• the fiber rearranging apparatus is illustrated in FIGS. 1 and 4 in U. S. Pat. No. 3,025,585, with the variation that the upper spray diffusing belt is omitted as proposed therein.
• the permeable, endless, lower supporting belt is the high knee type of forming wire screen fabric illustrated in H6. 5 of the patent and has a 14 X 14 mesh. Needle jets of water are used to provide the tangling and rearranging effect.
• the tenacities which show the normalized tensile strengths are markedly increased by the pretreatment with the sodium hydroxide solution, both in the long and cross direction, as well as in the wet and dry condition.
• the modulus values which show the resistance to tension and thus denote the tensile firmness or apparent bonding of the fabric are dramatically improved.
• the toughness values which show the area under the stress-strain curve and describe the total force required to break the fabric are also improved many fold.
• viscose rayon fibers are one of the limpest of all fibers in water, possessing an extremely low wet modulus, whereby they are exceptionally adaptable for use within the principles of the present invention.
• Example XXXll The procedures of Example XXXl are followed substantially as set forth therein with the exception that the weights of the fibrous card webs which are used are increased to 600 grains per square yard. Processing conditions are otherwise kept identical to that set forth in Example XXXI.
• Example XXXI obtained in Example XXXI but it is noted that the l3 X 13 high knee wire and the patterning belts are more effective at developing web strengths than the 22 X 22 screen belt.
• Example XXXIV The procedures of Example XXXI are followed substantially as set forth therein with the exception that (1 air-formed isotropic fibrous webs made on a Curlator web former and (2) wet-formed isotropic fibrous made by modified papermaking processes described in US. Pat. application Ser. No. 810,573 (and particularly Example I therein) are used as the starting materials.
• Example XXX The results are generally superior to the results obtained in Example XXX], from which it would appear that the present inventive concept is more applicable to and more effective with isotropic fibrous webs rather than carded fibrous webs.
• viscose rayon fibers are one of the limpest of all fibers in water, possessing an extremely low wet modulus, whereby they are exceptionally adaptable for use within the principles of the present invention.
• Example XXXV The procedures of Example XXXlV are followed substantially as set forth therein with the exception that the caustic pretreating step and the rearranging step are combined into a single operation. This is accomplished by omitting the pretreatment with 5 percent sodium hydroxide solution and replacing the water in the rearranging apparatus by 5 percent sodium hydroxide solution.
• Example XXXlV The results are generally comparable to the results obtained in Example XXXlV. Again, it is to be appreciated that the improved results are due, in part, to the fact that the regenerated cellulose viscose fibers are perhaps the limpest fibers in water and thus are exceptionally responsive to the application of the principles of the present invention.
• Example XXXI The procedures of Example XXXI are followed sub- These results also indicate that the increased strength stantially as set forth therein with the exception that the is not brought about by autogenic bonding of the indicaustic pretreating step and the rearranging step are vidual fibers. This is shown in samples 3 and 4 wherein combined into a single operation. Specifically, six of the residual caustic left in the web in sample 3 does not the samples (samples 7-12), instead of being precause autogenic bonding during drying.
• the slightly treated with 5 percent sodium hydroxide solution and 10 l was strength of sample 4 may be due to the additional then subsequently rearranged by means of needle jets handling and processing involved in the neutralization of water, are rearranged by means of needle jets sup- 0f the caustic with acetic acid, followed by a dewaterli d ith 5 ent odi m h d id i i ing by a wringer, rinsing with water, and a second de-
• the results are generally comparable to those ()bwatering by a wringer, after the fiber rearrangement tained in Example XXX]. and prior to drying.
• Example XXXVIl the starting fibrous materials substantially as Set forth th r in as r gards Samples are fibrous webs comprising viscose rayon fibers, three- With the exception that the pretreatment of the fourths inch in length and 1.5 denier per filament.
• pretreating solution is 5 percent sodium erties set forth in the following table are determined on hydroxide, the standard pressure of the water jets is dry samples. 100 pounds per square inch gauge, the production line TABLE 7 WW Tenacity (1bs./in./100 gr. wt.) Modulus (lbs/in.) Toughness (lbs/in.)
• Prc-swelling Rayon Webs With 5% NaOH Solution Tenacity lhs./in./l Modulus Toughness gr. wt. lbs/in. lbs./in.
• Example XLI The procedures of Example XL are followed substantially as set forth therein with the exception that the caustic pretreatment is omitted and the openings on the orifice plates emit jets of 5 percent sodium hydroxide solution for rearranging purposes.
• EXAMPLE XL The following experiments are carried out on fibrous webs made in a papermaking sheet mold.
• the fibrous webs consist of randomly distributed V2 inch length, 1.5 denier per filament, precision-cut, bright, no-finish, vis cose rayon tow.
• the fibers Prior to the formation in the sheet mold, the fibers are pretreated with 5 percent caustic soda solution to facilitate and expedite breakup of the fiber tow bundles and to improve the uniformity and strength of the resulting fibrous web.
• a concentration of parts per million of Polyox polyethylene oxide coagulant having a molecular weight in excess of 5 million is used in the sheet mold to promote wcb formation.
• Acetic acid is subsequently added to the sheet mold water to ncutralize the caustic treated fibers.
• the wet laid webs are removed from the sheet mold and are air-dried .on screens and yield essentially unbonded samples which are suitable for subsequent rearranging processing.
• a grain weight of 400 grains per square yard (dry basis) is used in all experiments.
• the following rearranging conditions are used: the apparatus used in that described and illustrated in U. S. Pat. No. 3,485,706 (FIG. 2); the water jet pressure is 125 lbs. per square inch gauge; the orifice size is 0.015 inch straight cylindrical holes; the orifice spacing is one 6 inch row of orifices, with the orifices spaced 16 to the inch; the orifice to fibrous web distance is 1 inches; and the supporting pattern belt is a 23 X 23 mesh woven high knee polypropylene screen.
• Samples of the fibrous web derived from the papermaking process in the sheet mold are cut to a size of 5% X 5% inches and are placed on the supporting pattern screen and are pretreated by being dipped either in water or in 5 percent caustic soda solution depending upon whether or not a blank control pretreatment or a caustic pretreatment is desired.
• the samplesand the supporting screen are then removed beneath the manifold of the orifices.
• a vacuum of 5 inches of mercury is used beneath the supporting pattern screen.
• the rate of speed of movement between the orifice manifold and the samples on the supporting screen is approximately 5 yards per minute.
• samples on the screen are then rotated and a second pass is made with respect to the water jets in which the samples receive a second rearranging treatment.
• Two passes at 90 to one another are designated as one rearranging treatment. This procedure is then repeated, if necessary, to obtain the desired number of treatments.
• Samples are then dried and pressed on a photographic print drier at a temperature of about 250 F. The strengths or tenacities of the samples in the dry machine direction are then determined.
• the pretreatment with caustic soda solution greatly accelerates and increases the benefits and advantages of the rearranging process.
• One rearranging treatment of a caustic pretreated web yields strength of tenacity values which are almost as high as the strength or tenacity values which are obtained only by three rearranging treatments of an untreated web.
• Example XLll the results are generally comparable to those obtained in Example XLll except that in a few cases the strengths or tenacities in the long or machine direction are lower for the combined operation.
• Example XLlV The procedures of Example XLll are carried out substantially as set forth therein with the exception that the fibrous web is placed between two patterning screens and rearranged while so positioned. The sandwich of two patterning screens and the interleaved fibrous web is then turned over and subjected to a second rearranging process. The strengths or tenacities in the machine direction are then determined for those samples which are treated with water and with 5 percent caustic soda solution as the rearranging fluid. It is noted that improved strengths or tenacities are obtained when the 5 percent caustic soda solution is used. It is also observed that the sandwich technique reduces the effectiveness of the rearranging process and this is believed to be due to the attenuation of the jet energy by the top screen.
• Example XLll EXAMPLE xLv EXAM PLE XLVl
• the procedures of Example XLll are carried out substantially as set forth therein with the exception that the fibrous materials are rearranged on a plate having staggered rows of 0.067 inch diameter circular holes on 0.1 l 1 inch centers. The staggered eenter-to-eenter distance between adjacent rows is 0.093 inch.
• This particular plate yields a rearranged fabric which more closely resembles the type of fabric which is obtained by the techniques described and illustrated in U. S. Pat. No. 3,033,72l.
• This patent may be described as possessing compact masses of entangled fibers which are intercom nected by ordered fiber groups. It is noted that this particular form of patterning plate develops strengths and tenacities in rearranged fabrics faster than the high knee wire patterning screen used in Example XLIl.
• EXAMPLE XLVIII Kodel" polyethylene terephthalate polyester continuous filament tow 1 /2 denier per filament) is cut on a guillotine-type tow cutter to a staple length of onehalf inch.
• the resulting fibers are found to be in clumps and are not loose or individualized.
• the clumps of fibers are particularly held together at their ends, due most likely to the mechanical pressure crushing of the thermoplastic polyester fibers during the cutting prouniform fiber slurries of individualized fibers which are easily made into excellent, uniform fiber sheets in a conventional sheet mold.
• a method of treating fibrous materials to render them more amenable to subsequent hydraulic nonwoven textile manufacturing processes employing aqueous media which comprises: treating fibrous materials with an effective amount of a swelling agent whereby the individual fibers become soft, limp and swollen but do not discolor, dissolve, degrade, or decompose and do not gel at their surfaces to adhere to each other; rendering said swelling agent inactive and inoperative as a swelling agent and incapable of further swelling said fibrous materials but keeping said fibrous materials wet: exposing said fibrous materials and the soft, limp and swollen fibers therein to hydraulic nonwoven textile manufacturing processes employing fluid rearranging forces in aqueous media wherein the individual fibers show less tendency toward undesirable fiber agglomeration, greater tendency toward fiber individualization, and enhanced response to fiber processing and manipulation by said fluid rearranging forces because of their soft, limp and swollen nature; and forming a nonwoven fabric of the individual fibers.
• fibrous materials comprise regenerated cellulose viscose rayon fibers and the swelling agent is sodium hydroxide.
• fibrous materials comprise regenerated cellulose viscose rayon fibers and the swelling agent is zinc chloride.
• fibrous materials comprise regenerated cellulose viscose rayon fibers and the swelling agent is lithium chloride.
• fibrous materials comprise polyamide nylon fibers and the swelling agent is phenol.
• a method of treating fibrous materials to render them more amenable to subsequent hydraulic nonwoven textile manufacturing processes employing aqueous media which comprises: treating fibrous materials with an effective amount of a swelling agent whereby the individual fibers become soft, limp and swollen but do not discolor, dissolve, degrade, or decompose and do not gel at their surfaces to adhere to each other; rendering said swelling agent inactive and inoperative and incapable of further swelling said fibrous materials by diluting the concentration of said swelling agent by introducing said soft, limp and swollen fibers into a large excess of aqueous media wherein the individual fibers show less tendency toward undesirable fiber agglomeration and are readily capable of individual independent relative movement in response to applied fluid rearranging forces in said aqueous media because of their soft, limp and swollen nature and form a uniform dispersion having excellent fiber individualization; applying fluid rearranging forces to said fibers in said aqueous media; and forming a nonwoven fabric of the individual fibers.
• fibrous materials comprise regenerated cellulose viscose rayon fibers.
• a method of treating fibrous materials to render them more amenable to subsequent hydraulic nonwoven textile manufacturing processes employing aqueous media which comprises: treating fibrous materials with an effective amount of a swelling agent whereby the individual fibers become soft, limp and swollen but do not discolor, dissolve, degrade, or decompose and do not gel at their surfaces to adhere to each other; rendering said swelling agent inactive and inoperative as a swelling agent and incapable of further swelling said fibrous materials but keeping said fibrous materials wet; supporting said fibrous materials and the soft, limp and swollen fibers therein on a member having apertures therein; exposing said fibrous materials and the soft, limp and swollen fibers therein to fluid rearranging forces in the form of streams of aqueous media wherein the individual fibers have an enhanced response to fiber manipulation because of their soft, limp and swollen nature; and forming a nonwoven fabric of the individual fibers containing discrete areas of fiber entanglement interconnected by fibrous elements.
• the fibers are cellulosic fibers and the softening and swelling agent is sodium hydroxide.
• a method of treating fibrous materials to render them more amenable to subsequent hydraulic nonwoven textile manufacturing processes employing aqueous media which comprises: treating fibrous materials with an effective amount of a swelling agent whereby the individual fibers become soft, limp and swollen but do not discolor, dissolve, degrade or decompose and do not gel at their surfaces to adhere to each other; rendering said swelling agent inactive and inoperative as a swelling agent and incapable of further swelling said fibrous materials but keeping said fibrous materials wet; supporting said fibrous materials and the soft, limp and swollen fibers therein on a member having apertures therein; covering said fibrous materials with a member having apertures therein which are smaller than the apertures in said supporting member; exposing said fibrous materials and the soft, limp and swollen fibers therein to fluid rearranging forces in the form of streams of aqueous media wherein the individual fibers have an enhanced response to fiber manipulation by said fluid rearranging forces because of their soft, limp and swollen nature, said streams passing in turn through said supporting member
• the fibers are cellulosic fibers and the softening and swelling agent is sodium hydroxide.
• a method of treating fibrous materials to render them more amenable to subsequent hydraulic nonwoven textile manufacturing processes employing aqueous media which comprises: treating fibrous materials with an effective amount of a swelling agent whereby the individual fibers become soft, limp and swollen but do not discolor, dissolve, degrade, or decompose and do not gel at their surfaces to adhere to each other; rendering said swelling agent inactive and inoperative as a swelling agent and incapable of further swelling said fibrous materials but keeping said fibrous materials wet; supporting said fibrous materials and the soft, limp and swollen fibers therein on a member having apertures therein; covering said fibrous materials with a member having apertures therein which are smaller than the apertures in said supporting member; exposing said fibrous materials and the soft, limp and swollen fibers therein to fluid rearranging forces in the form of streams of aqueous media wherein the individual fibers have an enhanced response to fiber manipulation by said fluid rearranging forces because of their soft, limp and swollen nature, said streams passing in turn through said covering

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Citations (8)

• 1971
  • 1971-01-05 US US00104148A patent/US3736097A/en not_active Expired - Lifetime
  • 1971-12-23 DE DE2164385A patent/DE2164385A1/de active Pending
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