US3181225A - Process of resin treating a cotton batting - Google Patents

Description

y 1965 N. B. KNOEPFLER ETAL 3,181,225

PROCESS OF RESIN TREATING A COTTON BATTING Filed April 8, 1963 2 Sheets-Sheet 1 INVENTORS NESTOR B. KNOEPF'LER HOMER K-GARDNER,JR. HENRY L.E.VIX

May 4, 1965 N. B. KNOEPFLER ETAL PROCESS OF RESIN TREATING A COTTON BATTING 2 Sheets-Sheet 2 Filed April 8, 1963 INVENTORS NESTOR B.KNOEPFLER HOMER K.GARDNER,JR. HENRY L.E. VIX BY /W ATTORNEYS United States Patent 3,181,225 PRGCESS 0F RESIN TREATING A COTTGN BATTING Nestor B. Knoepiler and Homer K. Gardner, Lira, New Orleans, and Henry L. E. Vix, Metairie, La., assignors to the United States of America as represented by the Secretary of Agriculture Filed Apr. 8, 1963, Ser. No. 271,525 9 Claims. (Cl. 28-45) (Granted under Title 35, US. Code (1952), see. 26d) A non-exclusive, irrevocable, royalty-free license in the invention herein described, throughout the world for all purposes of the United States Government, with the power to grant sublicenses for such purposes, is hereby granted to the Government of the United States of America.

This invention relates to a process for improving fibrous cotton batt as its dimensional stab'iilty, resilience, and compaction are improved. The process consists basically of the application of chemical substances to the opened and garnetted fibers of cotton, which can consist of a blend of various grades of cotton lint and linters to produce a superior batt with excellent variable properties.

This invention is a product of investigative eifort to combat the increasing competition to cotton material by the recent advances of the natural and synthetic foamed products, which are dimensionally stable, and which have significantly better coherence and resiliency than batting made from untreated cotton fibers or other such cellulosic materials.

The main object of this invention is to provide a process for the manufacture of fibrous batt with dimensional stability and improved resiliency under varying conditions of humidity and use. T he utility of the improved batting lies in the fact that the more economical material which the batting industry has been providing in the past can regain its markets lost to the synthetics and others by simple chemical processing of the low grade cotton materials. These have for years been employed in the furniture and automotive industries for such articles as mattresses, upholstering of many furniture pieces, automotive cushioning, etc.

Another object of this invention is to provide a process for making fibrous batt with improved resistance to compaction, and having better coherence than normal commercial batting.

A further object of this invention is to facilitate the production of an improved batt, which will retain its dimensions, and will resist compaction or settling in specific applications such as insulation.

The application of the chemical substances is done through a single or a plurality of nozzles, which wet the Web as it moves past the fine spray. The spray must be controlled as to avoid extremes in wetting the web. The application of a fine mist or a fog would dissipate the chemicals to the air or cause the chemicals to permeate through the fibrous structure without adhering to any surface, thereby wasting the chemicals, while a heavy spray would cause overwetting in that large droplets would lodge irregularly or nonuniformly throughout the structure of the web.

The economic feasibility or the products of our invention depend to a considerable extent upon the method of application of the chemicals. The chemicals employed here are formulations in which a crosslinking or reactive type resin can be used either alone or in combination with a film forming latex. Performance depends on the proper selection of resin and latex, and the uniform distribution of the resinous substances within the physical structure of the Web. The deposition of chemicals may occur on the surface, as a physical occlusion which bonds 3,lfil,ZZ5 Patented May 4, 1965 the fibers of the loose structure, or as a chemical reaction which might take place either on the surface or within the cellulosic molecular structure of the cotton fiber. A crosslinking reaction gives the cellulosic molecule a certain amount of rigidity, which in turn causes physical, as well as chemical, rigidity or resiliency-as desired-t0 the cotton batt.

The resins used in this process are selected for their inherent properties, which include the capability of reacting chemically with the cellulose of the cotton. These resins by virtue of the reaction with the cellulose molecules, by crosslinking or other phenomenon, enhance the resilience of the fibers, or improve their resistance to permanent deformation resulting from flexing or bending.

The function of the latex, which in eitect is a film forming resin, or coating, is to assure interfiber binding at points of contact between fibers. The latex then contributes to dimensional stability, coherence, and textile tensile and tear strength of the finished batt.

The application of a latex to the web yields a batt with improved tearing strength, dimensional stability, and resistance to compaction through physical shifting of fibers within the structure under varying conditions of humidity. The application or both crosslinking resin and latex to the web will yield a batt with these characteristics plus improved resiliency.

An important feature of this invention is the means employed for the application of the chemical substances to the webs, or layers of fibers, so that a great degree of uniformity of treatment can be obtained while the operation is of a continuous economic character.

The advantages and objectives are more apparent upon studying the accompanying figures. A better understanding of each step can be gained following the annexed schematic drawing of the flowsheet, FIGURES 1A and 1B, where the processing sequence for the production of batting, and one method of applying the appropriate resins and/ or latexes by spraying are shown, as well as the conventional method of crosslapping, and the reel type batt former.

FIGURE 2 shows a sectional view of a batt prepared by adherence to the process of this invention.

FIGURE 3 shows a cross section of a batt after spraying, and during drying, while said batt is restrained be tween frames spaced to regulate the density of the product.

Referring to FIGURES 1A and 1B, blended cotton fibers consisting of textile wastes and linters in various proportions are fed to the main cylinder 1 of the carding section of a conventional garnett, worked by worker rolls 2 stripped from the worker rolls and returned to the main cylinder by stripper rolls 3, removed from the main cylinder by conventional doifer roll 4, combed from the doiier roll by comb 5 which works against the doiter roll and baiiie 6, and transported in web form on travelling aprons 7 of FIGURE 1A, or alternatively, to reel 11 of FIGURE 18 for lap forming operations. The foregoing description relating to FIGURES 1A and 1B constitutes conventional commercial practice and as such is incidental to and forms no part of the instant invention.

Following removal of the web of carded cotton fibers from the main cylinder, the web is sprayed by means of spray device 8 and the sprayed web, now wetted with the severahcomponent reagent according to the instant invention, is lapped as shown in FIGURE 1A and collected on reel 11 as shown in FIGURE 1B.

The sprayed and layered webs are then condensed into batts through rolls or other suitable pressure means, not shown, to assure good contact between the successive layers 12 (FIG. 2) of webs.

In FIGURES 1A and 1B the feed material consists of a blend of 60% of first cut linters, and 40% of various grades of textile wastes. This mixture is an example, and in no way critical to the process. The blend is passed through suitable commercially available processing units to be formed into a web or layer of fibers, which are discharged unto a moving belt or conveyor. At this point the fibers are in an extremely open configuration, which makes possible the application of the resins and/ or resinous or other type latex by a spray system, using a single or a multiplicity of spray heads or nozzles in such a way as to achieve a uniform distribution of the chemicals on the web. The wet add-on of the solutions can be controlled to between 20 and 150% of the weight of the fiber feed by controlling the flow of solutions to the spray heads.

In specific examples of this invention the optimum wet add-on varied from 70 to 120%, depending on the properties desired in the finished products.

The concentration of the spray solution or suspension mixture can vary from 1 to 35% by weight total solids, depending on the resin to latex ratio, the nature of the reagents, and the properties desired in the finished product. After being sprayed, the web or layer of fibers is either crosslapped conventionally, and then condensed through suitable rolls or other means to assure good contact between successive layers or webs, or collected on a reel, where condensing is done on a layer for layer basis, as shown in FIGURE 1A. The formed batts are then constricted by frames 13 (FIGURE 3) in such a manner as to maintain a specific height during drying and curing; or dried and cured without restraint, depending on the desired physical properties, such as density. Since a structure consisting of cellulosic fibers which have been formed into batts tends to expand in volume when subjected to heat or hot air circulation, this invention takes advantage of this inherent characteristic in order to achieve a more open (less dense) finished product. The density of the product therefore can be varied by either varying the weight of the webs, the number of webs or layers of fibers used in the batt, or by varying the spacing between frames, as in FIGURE 3, or by adjusting the spacing between suitable open mesh dual belts for continuous drying.

Drying temperatures up to 325 F. can be used depending on whether drying will be carried out simultaneously with curing or as a separate unit operation to be followed by curing. In the latter instance drying temperatures up to 220 F. would be adequate for drying if followed by temperatures of up to 325 F. for curing. Suitable temperatures within this range can be selected depending upon the requirements of the chemicals employed. Evidence exists that the degree of expansion obtained in the finished product depends upon a relationship between the time of drying and the temperature employed. In general longer times at lower temperatures will result in a more expanded structure in the finished product.

Upon the completion of the drying and curing step or steps the product retains its preselected height, width, and length. Furthermore the product is one having improved resilience, a resistance to deformation from compressive loading much greater than untreated cotton batting, and demonstrates a cohesive structure and resistance to compaction in use. In addition the product made as a result of the practice of this invention has significantly greater tearing and tensile strength, up to twenty times as great as untreated cotton batting. The performance of the improved product can be demonstrated both at high and low relative humidities.

The spray from a single solution has been accomplished by investigative formulation, which included the search for compatible systems which can contain the resin, the latex, the catalyst, the thickening agent, the dyes, and the solvents, which go into the spray application in a single solution or suspension or both.

Pretreatments of the raw stock feed, such as mercerization, scouring, and wet processing with chemicals such as formaldehyde, significantly enhance the properties of the finished product.

The many facets of this process, and their proper application by adjusting to the most suitable variables make it evident that there are many advantages to be gained in the practice of this invention. The following specific examples refer to materials actually produced on an experimental basis, and are in no way to be construed as specific limits to the flexibility of the system.

The batts produced by the use of this invention are dimensionally stable and resilient, and demonstrate a marked ability to reproduce contours of the material used to restrain them during drying and curing.

Since the resins found to contribute the enhanced properties described herein for cotton fibers are known to chemically react with the cellulose of the cotton fibers such resins can be expected to react equally well with synthetic cellulosic fibers such as rayon. For this reason the process described herein for the manufacture of a fibrous cotton batt is equally applicable to the fibrous cellulosics or blends of these materials with cotton.

Such resins as the urea formaldehydes, tris(1-aziridinyl)phosphene oxide, melamines, triazines and others will react equally well with wool as with cotton. For this reason the process described herein for the manufacture of a fibrous cotton batt is equally applicable to wool or blends of wool and cotton.

Because textile wastes normally used in the production of cotton batting are derived from diverse sources, on occasion these wastes may contain varying nominal amounts of synthetic fibers such as polyesters or acrylics, polyethers or others either by chance or design. The presence of these synthetic fibers would not preclude the use of the waste in the practice of this invention.

In general, according to the invention, the method for producing a fibrous cotton batt with improved stability, coherence, and resilience, comprises the following operations carried out in sequence:

(a) forming webs of opened textile fibers of the group consisting of cotton fibers and chemically modified cotton fibers,

(b) treating the webs with a resin forming composition at least one component of which is a cellulose reactive, crosslinking reagent to a resin add-on of about from 3.76% to 24.2%, by weight of the cellulose reactive component based on the weight of the cotton,

(0) collecting and condensing the treated webs to form a batt of layered, treated webs, and

(d) curing the batt of layered treated webs under compression less than the ultimate use compression of the finished batt.

The above general procedure, wherein the webs are formed from mechanically opened cotton fibers and the resin forming composition comprises about 1 to 4 parts by weight of methylated methylol melamine and 1 part by Weight of vinyl acrylic polymer, illustrates one embodiment of the invention.

The above general procedure, wherein the webs are formed from opened cotton fibers and the resin forming composition comprises approximately equal parts by weight of a urea-formaldehyde resin and vinyl acetate copolymer, illustrates a second embodiment.

The said general procedure, wherein the webs are formed from opened cotton fibers and the resin forming composition comprises about 1 part, by weight, of a ureaformaldehyde resin and about 1 part, by weight, of a copolymer mixture of vinyl acrylic copolymer and styrenebutadiene copolymer, the two copolymers being in the approximate ratio of 3 parts, by weight, of vinyl acrylic copolymer to 1 part, by weight, of styrene-butadiene copolymer, represents a third embodiment of the invention.

The said general procedure, wherein the webs are formed from opened cotton fibers that have been chemically modified by the form W formaldehyde treatment and the resin forming component comprises about 7 parts, by

weight, of dimethylol ethyl carbamate and about 3 parts, by weight, of vinyl acetate copolymer, is an illustration of a fourth embodiment.

The said general procedure, wherein the webs are formed from opened cotton fibers that have been chemically modified by the form W formaldehyde treatment and the resin forming composition comprises approximately equal parts, by weight, of a urea-formaldehyde and vinyl acetate copolymer, represents a fifth embodiment.

The said general procedure, wherein the webs are formed from opened cotton fibers that have been mercerized and the resin forming composition comprises approximately equal parts, by Weight, of a urea-formaldehyde and vinyl acetate copolymer, represents a sixth embodiment.

The said general procedure, wherein the webs are formed from opened cotton fibers that have been mercerized and the resin forming composition comprises approximately 7 parts, by weight, of dimethylol ethyl carbamate and about 3 parts, by weight, of vinyl acetate, represents a seventh embodiment.

The said general procedure, wherein the webs are formed from mechanically opened cotton fibers and the resin forming composition comprises methylated methylol melamine, represents an eighth embodiment.

These various embodiments are set forth in greater detail in the following examples:

Example 1 Using a rawstock feed consisting of 60% first cut linters and 40% textile waste made up of willowed picker, 10% willowed sweeps, and willowed fiy a Web was made using a sample card. The web was sprayed while on the apron of the card with a treating media consisting of 22.8% solids. The solids consisted of 76%, by weight, of methylated methylol melamine and 24% vinyl acrylic copolymer. The wet add-on was approximately 100% by weight of the feed. The resulting product had therefore approximately 12% resin content (not including the latex), and a density of 2.86 pounds per cubic foot, which was equivalent in weight to a commercial cotton batting of 5.54 ounces per square foot. When this product was subjected to a cyclic compressive loading test to determine the percent set, taken after loadings at 1 pound per square inch it had an immediate set of 11%, under conditions of relative humidity, and an immediate set of 19%, under conditions of 100% relative humidity. One hour later this sample had a set of 8% or less, under both 60 and 100% humidity conditions. In contrast an untreated cotton batting of comparable weight subjected to the same test had an immediate set of 41.8% under the conditions of 60% RH. (relative humidity) and 45.5% under 100% RH. After one hour the untreated cotton had a set of 31% under the 60% RH. conditions and 42% under the 100% RH. Similar disparity in behavior was shown in energy absorption and stability to 15,000 cycles of loading.

Example 2 Using the same type feed as above and forming a web in a similar manner spraying was then carried out using a spray media containing 17.7% solids. The solids consisted of 58% urea-forrnaldehyde and 42% vinyl acetate by weight. The resulting sprayed webs were then collected on a reel with condensing being carried out on a web for web basis until 30 webs had been collected. The partially formed batts were removed from the reel by slitting, and then placed in frames spaced 4 in., 1 in., 1%. in., and 1% in. apart for drying and curing. The resulting products had densities of 3.22, 2.96, 2.91, and 2.58 pounds per cubic foot, respectively, and thicknesses of 1.14 in., 1.30 in., 1.38 in., and 1.45 in., respectively. After 50 cycles of compressional loading and unloading to 1 pound per square inch these products had immediate sets of 17.3, 13.2, 17.1, and 18.9% when the test was run at 6 60% R.H., and after one hour of recovery had sets of 8.7, 4.6, 5.7, and 12.2%. When this test was run at 100% RH. the samples had immediate sets of 20.0, 30.4, 28.5, and 32.5%, and after one hour recovery they had sets of 12.6, 22.7, 20.0, and 21.6% respectively.

Example 3 Three companion batts were made from a comparable feed to that described in Example 1, using a spray medium containing 10% solids, which was made up of methylated methylol melamine and 20% vinyl acrylic copolymer. The batts contained 20, 30, and 40 webs. The still spray damp webs were condensed by compression rolling to a thickness of about of an inch. They were then placed in frames spaced 1% in. apart, and dried and cured. The finished batts had densities of 1.48, 1.71, and 1.93 pounds per cubic foot, respectively. When tested by the cyclic loading and unloading compression test they had immediate set values of 29.0, 26.3, and 26.3% under conditions of 60% r.h., and 30 minutes later the respective values were 22.9, 18.8, and 21.5%. The values at RH. were 37.9, 4.10, and 37.2%, and these set values 30 minutes later were respectively 27.4, 34.7, and 33.7%. These values were significantly better than those achieved by comparable untreated cotton batts.

Example 4 Using a comparable feed to that described for Example 1, and spraying the web from the card with a media con taining 18.7% solids, which consisted of 53% urea-formaldehyde, 36% vinyl acrylic copolymer, and 11% styrenebutadiene copolymer batts consisting of 30 webs were built up on the reel device and condensed on a web for Web basis. The partially formed batts were placed in frames spaced in. and 1 in. apart. Following the drying and curing these batts had densities of 3.46 and 2.94 pounds per cubic foot, respectively. When subjected to the cyclic compressional loading and unloading compression test at 60% RH. these samples had set values of 9.4, and 12.9% immediately upon completion of the test, and 10 minutes later they had set values of 2.7, and 8.1%, respectively. Under conditions of 100% RH. the same samples showed sets of 15.2 and 21.0%, and after 30 minutes recovery these values changed to 8.3 and 16.2%, respectively. (Note: This is a significant improvement in performance at high relative humidity.) These samples were compressed to /2 their original height, and subjected to a temperature of 158 F. for 22 hours, and the set taken measured after /2 hour of recovery at ambient laboratory conditions of 60% RH. and 70-73 F. temperature. The set in this case was 18.9%, and 21.0%, which changed to 8.1 and 9.8%, respectively, after 5% hours.

Example 5 The feed for this experiment consisted of 42% textile Waste of various grades including picker, sweeps, and fly, and 58% first cut linters all of which had been scoured and mercerized. A portion of this material was formed into a web, and sprayed with a suspension of 15% solids, which consisted of 50% urea-formaldehyde and 50% vinyl acetate copolymer, and another portion sprayed with a combination solution suspension consisting of 20% solids made up of 70% dimethylol ethyl carbamate and 30% vinyl acetate copolymer. The product batts were obtained by lapping the web back and forth in a semi conventional manner by hand until 30 Webs had been built up in each case. The partially formed batts were condensed by rolling to a thickness of about 1 inch, and then placed in frames spaced 1% in. for drying and cur ing. When tested by the cyclic loading and unloading compression test these samples showed sets of 30.3% and 16.7% immediately upon completion of the test at 60% RH, and 30 minutes later had set values of 10.5 and 8.3%, respectively. When the same test was carried out at 100% R11". the samples had values of 32.4 and 23.0% immediately, and 28.8 and 19.2% respective values one half hour later.

Example 6 Scoured but not mercerized raw stock similar to that described for Example was treated with formaldehyde by the Wet treatment known as form W formaldehyde process. In this case a chemical reaction takes place. The formaldehyde reacts with the cellulose molecule. After washing and drying this material it was formed into a web, and a portion of the web was sprayed with a suspension containing solids, 50% of which was ureaformaldehyde, and the other 50% vinyl acetate copolymer. Another portion of the web was sprayed with a solution suspension consisting of 70% dimethylol ethyl carbamate and 30% vinyl acetate copolymer. Batts of 30 webs were made and condensed to about 1 inch, then dried and cured in frames 1 /2 inches apart. The products had densities of 1.69 and 1.81 pounds per cubic foot, respectively. The results of the cyclic compression loading test showed that these samples had set values of 19.4 and 21.6%, respectively, immediately after the completion of the test, and values of set of 9.7% and 14.9% one half hour later, under conditions of 60% RH. The set values at 100% RH. were at 29.0 and 21.6% immediately, and 17.7 and 14.9% one half hour later.

Example 7 The feed material for this example consisted of 60% first cut linters and 40% textile wastes of various grades similar to those in Example 1. One batt was made by spraying the web with a suspension of a vinyl acrylic copolymer at a solids content, and one batt was made by spraying the web with a solution containing methylated methylol melamine at 20% solids content. After spraying, forming, and condensing the batts were placed in frames Space 1 /2 in. In the case of the vinyl acrylate copolymer drying only suiiiced to set the resin because it is of the thermoplastic type. In the case of the methylated methylol melamine curing following drying is required, because it is of the thermosetting type. A comparison of these batts on an equal number of webs basis demonstrates the different characteristics conferred by the two types of resins. At 20 webs the sample sprayed with the vinyl acrylic copolymer hereinafter called sample (a) had a density of 1.63 pounds per cubic foot, while the sample sprayed with the methylated methylol melamine hereinafter called sample (b) had a density of 1.02 pounds per cubic foot. When these samples were evaluated by the cyclic compression loading and unloading test at 60% RH. sample (a) had a set of 33.4% immediately upon completion of the test, and 24.3% one hour later, while sample (b) had an immediate set value of 27.1%, and one hour later a set of 22.5%. Under conditions of 100% RH. the cyclic compression loading test gave an immediate set value in sample (a) of 45.5%, and one hour later 36.4%, while sample (b) had a set value of 38.7% imme- Example 8 Using a feed material similar to Example 1, and spraying the webs with a solution suspension containing 22.8% solids made up of 76% methylated methylol melamine and 24% vinyl acrylic copolymer by weight, hand forming batts, and condensing to 1 inch, followed by drying and curing in frames spaced 1 inch during drying and 1%. inches during curing a batt was produced which had a density of 1.71 pounds per cubic foot. This batt was subjected to 15,000 cycles of loading and unloading at the rate of 132 cycles per minute, and approximately 1 pound per square inch. The immediate set for this sample was 11.2%, and after recovering for 24- hours at 60% RH.

o and 70 F. the sample had a set value of 3.3%. An untreated control cotton batting of comparable weight showed an immediate set of 40.6%, and after 24 hours the set was 29.7%. The experimental sample showed no tendency to compact under these conditions while compaction was evident in the untreated cotton batting.

Example 9 Using a feed material similar to Example 1, and spraying the web as discharged from the card to a wet pickup of 130%, with a solution containing 10% solids, which was made up of 40% methylated methylol melamine and 60% vinyl arcylic copolymer by weight, a hand forming operation was performed to yield a 20 web batt. This batt was condensed to 1 inch, followed by drying and caning in frames spaced 1 /2 inches. The product had a resin add-on of 4.55%, and had a density of 1.42 pounds per cubic foot, which was equivalent to a commercial batting standard of 2.09 ounces per square foot. This product showed a compression set of 35.7% after cyclic loadings at a load of 1 pound per square inch at R.H., and 46.4% at 100% RP. After 30 minutes of recovery the sample had a set value of 19.6% at 60% RH, and 39.3% at 100% RH. The product required a load of 5.38 pounds for a foot 50 square inches on a 100 square inch sample to reduce its thickness 25%. When held compressed to /2 its normal thickness at a temperature of 158 F. for 22 hours and then allowed to freely recover for 30 minutes at ambient room conditions the batt showed a set of 21.4%. This performance is better than that of untreated cotton batting as can be seen by referring to the data given in Example 1.

Example 10 Using a feed material of the same make up as shown for Example 1 the web Was sprayed to a wet pickup of about with a media containing 20% solids made up of methylated methylol melamine and 20% vinyl acrylic copolymer a batt containing 40 web was formed. This batt was condensed to a thickness of about 1 inch, and then placed in frames spaced 1% inches, and dried and cured. The resulting product had a resin add-on of 9.8%, and a density of 1.89 pounds per cubic foot, and was equivalent in weight to a standard untreated cotton batting of 3.97 ounces per square foot. This product required a load of 6.93 pounds load for a 50 square inch foot on a 100 square inch sample to compress it 25% of its original height. When tested for compression set at 60% and 100% relative humidity after 50 cyclic loadings at 1 pound per square inch it had initial set values of 12.5% and 31.6%, respectively. Thirty minutes later these values were 10% and 25%, respectively. When held compressed to /2 its normal thickness at 158 F. for 22 hours, and then allowed to recover for 30 minutes at ambient room conditions this sample had a set of 21.2%. By referring to Example 1 it can be seen that these samples performed better than untreated cotton batting.

Example 11 Using a feed material similar to Example 1 and spraying the Web as it is discharged from the garnett with a solution containing 10% solids of which 40% was methylated methylol melamine and 60% vinyl acrylic copolymer, followed by hand layup, a batt consisting of 30 webs was produced. This batt was placed in frames spaced 1 /2 inches apart and dried at 200 F. for minutes and then cured at 300 F. for 30 minutes. The resulting cured batt had a resin add-on (excluding latex) of 3.76%, a density of 1.98 pounds per cubic foot and was equivalent in weight to a commercial untreated batt of 3.63 ounces per square foot. This product when tested by the cyclic compression method had a set of 22.8% immediately upon completion of the test at 60% relative humidity, and a set of 46.2% under conditions of relative humidity. Ten minutes later the values were 15.8% and 37.2%

9 respectively. When subjected to a compression to /2 its original thickness at a temperature of 158 F. for 22 hours and allowed to recover for 30 minutes at ambient room temperature this material had a set of 24.3%.

Example 12 Using a feed material similar to that used for Example 1 and spraying the web as it is discharged from the garnett with a solution containing 20% solids all of which was in the form of methylated methylol melamine a product was produced which had a resin add-on of 24.2%. The product required a load of 5.72 pounds on a compression foot of 50 square inches to reduce the thickness of a 100 square inch sample to 75% of its original thickness. This product had a textile breaking strength of 24.5 lbs. in the direction of the fiber lay compared with a textile breaking strength of 5.20 pounds for untreated cotton batting sample of comparable weight. Similar differences were shown when the treated sample was tested for breaking strength in the direction transverse to the fiber lay and compared with the breaking strength of comparable weight untreated batting.

Example 13 Using a feed material similar to that shown for Example 1 and spraying the web as it is discharged from the garnett with a solution containing 15% solids of which 60% was methylated methylol melamine and 40% was vinyl acrylic copolymer followed by hand layup, a batt was produced having 40 Webs. This product had a resin add-on of 10.2% (excluding latex) after drying and curing in frames spaced 1% inches apart. The density was 1.80 pounds per cubic foot, and on a Weight basis was equivalent to untreated batting of 3.68 ounces per square foot. When tested for compression set under conditions of 60 and 100% relative humidity this sample had set values of 24.4 and 41% immediately, and values of 20.5% and 37.2% after 4 minutes. This product required a load of 7.48 pounds on a 50 square inch foot to reduce the thickness of the sample by 25%. When compressed to A2 its original thickness and held at 158 F. for 22 hours this sample demonstrated a set due to heat under load of 25.5% permitted to recover for /2 hour under room conditions without load. This sample showed a textile breaking strength in the direction of fiber lay of 44 pounds compared with 5.2 pounds for untreated cotton batting.

We claim:

1. The method for producing a fibrous cotton batt with improved stability, coherence, and resilience, which method comprises these several operations carried out in sequence:

(a) forming webs of opened textile fibers of the group consisting of cotton fibers and chemically modified cotton fibers,

(b) treating the webs with a resin forming composi tion at least one component of which is a cellulose reactive, crosslinking reagent to a resin add-on of about from 3.76% to 24.2%, by weight of the cellulosic reactive component based on the weight of the cotton,

() collecting and condensing the treated webs to form a batt of layered, treated webs, and

10 (d) curing the batt of layered treated webs under compression less than the ultimate use compression of the finished batt.

2. The method of claim 1, wherein the webs are formed from mechanically opened cotton fibers and the resin forming composition comprises about 1 to 4 parts by weight of methylated methylol melamine and 1 part by weight of vinyl acrylic copolymer.

3. The method of claim 1, wherein the Webs are formed from opened cotton fibers, and the resin forming composition comprises approximately equal parts by weight of a urea-formaldehyde resin and vinyl acetate copolymer.

4. The method of claim 1, wherein the webs are formed from opened cotton fibers, and the resin forming composition comprises about 1 part, by weight, of a ureaformaldehyde resin and about 1 part, by Weight, of a copolymer mixture of vinyl acrylic copolymer and styrenebutadiene copolymer, the two copolymers in the approximate ratio of 3 parts, by weight, of vinyl acrylic copolymer to 1 part, by weight, of styrene-butadiene copolymer.

5. The method of claim 1, wherein the webs are formed from opened cotton fibers that have been chemically modified by formaldehyde in a form W formaldehyde treatment and the resin forming component comprises about 7 parts, by Weight, of dimethylol ethyl carbamate and about 3 parts, by weight, of vinyl acetate copolymer.

6. The method of claim 1, wherein the webs are formed from opened cotton fibers that have been chemically modified by formaldehyde in a form W formaldehyde treatment and the resin forming composition comprises approximately equal parts, by weight, of a urea-formaldehyde and vinyl acetate copolymer.

7. The process of claim 1, wherein the webs are formed from opened cotton fibers that have been mercerized, and the resin forming composition comprises approximately equal parts, by weight, of a urea-formaldehyde and vinyl acetate copolymer.

8. The process of claim 1, wherein the webs are formed from opened cotton fibers that have been mercerized, and the resin forming composition comprises approximately 7 parts, by weight, of dimethylol ethyl carbamate and about 3 parts, by weight, of vinyl acetate.

9. The method of claim 1, wherein the webs are formed from mechanically opened cotton fibers and the resin forming composition comprises methylated methylol melamine.

References Cited by the Examiner UNITED STATES PATENTS 2,336,797 12/43 Maxwell 28-723 2,528,793 11/50 Secrist 28-723 2,774,126 12/ 56 Secrist 28--72.3 2,774,128 12/56 Secrist 28-7 3 2,795,823 6/57 Wade 1966 2,900,291 8/59 OConnell 28-75 X 3,085,911 4/63 Leupold et al ll7145 X 3,122,447 2/ 64 Sexsmith 117145 X 3,148,164 9/64 Enders et al 117--145 X DONALD W. PARKER, Primary Examiner. MERVIN STEIN, Examiner,

Claims (1)

1. THE METHOD FOR PRODUCING A FIBROUS COTTON BATT WITH IMPROVED STABILITY, COHERENCE, AND RESILIENCE, WHICH METHOD COMPRISES THESE SEVERAL OPERATIONS CARRIED OUT IN SEQUENCE: (A) FORMING WEBS OF OPENED TEXTILE FIBERS OF THE GROUP CONSISTING OF COTTON FIBERS AND CHEMICALLY MODIFIED COTTON FIBERS, (B) TREATING THE WEBS WITH A RESIN FORMING COMPOSITION AT LEAST ONE COMPONENT OF WHICH IS A CELLULOSE REACTIVE, CROSSLINKING REAGENT TO A RESIN ADD-ON OF ABOUT FROM 3.76% TO 24.2%, BY WEIGHT OF THE CELLULOSIC REACTIVE COMPONENT BASED ON THE WEIGHT OF THE COTTON, (C) COLLECTING AND CONDENSING THE TREATED WEBS TO FORM A BATT OF LAYERED, TREATED WEBS, AND (D) CURING THE BATT OF LAYERED TREATED WEBS UNDER COMPRESSION LESS THAN THE ULTIMATE USE COMPRESSION OF THE FINISHED BATT.

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