IL26415A - Coating materials for glass fibers - Google Patents

Description

COATING MKSRIALS FOR GLASS FIBERS OW S-CORNING PIBERGLAS CORPORATION The present invention relates to coating materials for protecting glass fibers from thei forming operation through their weaving operation? and to the glass fibers coated therewith.

Fibers for textiles are made by simultaneously attenuating several hundred small streams of molten glass to produce monofilaments each having a diameter of less than 0.0005 inch, These monofilament© are coated at forming with a protective coating material usually comprising a binder and lubricant by pulling the fbers over a pad saturated with the coating material. The monofilaments are thereafter brought together into a strand by being pulled through a gathering head and the strand is wound upon a revolving spool or drum which pulls the monofilaments through the above mentioned apparatus. Although glass has a tensile strength of over 400#000 pounds per square inch, prior art strands have never been this strong because of breakage of the monofilaments during forming. Glass is easily broken when scratched and the monofilaments are extremely sensitive to abrasion because of their large surface to volume ratio. Abrasion of the monofilaments may occur either when they are drawn over stationary guide surfaces or when they are rubbed together. Since the glass fibers are subjected to numerous bending operations during their fabrication* and since glass breaks easily when its surface is scratched any abrasion of the monofilaments may result in fracture of these monofilaments, and the ends adjacent the fracture project outwardly of the strand to produce what is known as fuzz.

Strands of glass fibers produced as above described are subjected to numerous types of twisting, bending, and textile product. The conditions which are experienced in this multiplicity of rubbing and bending operations are so varied that it is difficult, if not impossible, to produce a single coating lubricant which will completely protect the fibers against breakage during twisting and weaving. She forming coatings must be applied to the filaments from a solution in order that they will completely coat the filaments, fhis solution is preferably an aqueous solution in order to obviate explosion and other hazards. Some forming coatings protect the fibers adequately before the water has been removed from the coating, but do poorly in the later stages of the fabricating process where the coating has been dried substantially completely. ihe forming packages which are produced as above described are usually allowed to remain under ambient conditions for a sufficient length of time for approximately half of the water to migrate to the surface of the package, so that the remaining water is only approximately 6 of the total weight of the package. As the water is moving to the surface of the package some types of coating materials migrate therewith, to produce a phenomenon known as "migration" wherein the fiber at the outer portion of the package has a higher solids content than does the fiber at the center of the package. A good forming coating must not "migrate" excessively.

After the moisture in the forming package has been reduced to approximately 6$, the glass fibers are unwound under ambient conditions and twisted onto a new package. This is called the "twisting" operation. Filaments that are broken during unwinding of the forming package will usually be stripped from the strand into what is known as a "ringer", which then than 1# water when passing from the forming package through the twisting operation onto the twist package lose moisture to the surrounding air. The fibers on the twist package contain no more than approximately 1«6 water. If more than approximately of water remains, shrinkage of the tube onto which it is wound may result, and this shrinkage changes the lay of the fibers to bind the colls together and cause breakage of the strands upon removal from the twist package. Excess moisture in the twisted strands will also cause fuzzing in subsequent operations. If the integrity of the film former is not adequate, the film former will powder during the twisting operation.

The twisted strand from twist packages constitutes the basic material from which glass textiles are made* A plurality of the twisted strands may be brought together to produce a yarn. A plurality of yarns may be simultaneously wrapped upon a cylinder at spaced apart locations to produce a beam, and the beams may thereafter be removed to a loom for use as the warp in a weaving operation. Yarn for the fill will be wrapped into small packages called quills and these will be fed through automatic machinery to the shuttle which glides back and forth across the loom. It will be apparent that in all of these operations, the strands will be pulled over stationary guide surfaces at which time they will be flexed back and forth, and that later while being woven, they will be bent in one direction and then another until the weave is set. A coating lubricant which is too brittle may crack when dry to expose the fibers either to each other or to the guide surfaces, following which breakage is sure to occur. If the coefficient of friction of the coating material is too high with respect to the guide surfaces, the coating will be pulled from the fibers.

- - If the coating is unduly rough , it will be caught by the guide surfaces and pulled from the fibers. In addition, the coating materials must not rub off of the fibers onto the guide surfaces to gum up the textile fabricating machinery, nor must the coatings be too powdery* The production of glass fibers into fabrics is a major industry and a great amount of research has been done with coating lubricants for glass fibers in an effort to develop a material which would be good in all of the operations involved from forming through weaving. All types of known lubricants have been tried in various combinations. Patent 2,272,588 discloses' the coating of glass fibers at forming with a molten wax material which solidifies on the fibers immediately upon being cooled. Patent 2,323,684 discloses the application of wax to glass fibers either in a molten condition or as an aqueous emulsion. Patent 2,723,215 teaches glass fibers coated with mineral wax, an organo-silane compound and polyethylene. All of the prior are coating materials for glass fibers which have included wax, including the materials of the above enumerated patents, are deficient in that the coating smears off of the fibers onto the guide surfaces, particularly during the later stages of fabrication to both gum up the machinery and expose the fibers to abrasion and thereby produce too high a fuzz level in the finished product.

An object of the invention is the provision of a new and improved coating material for glass fibers which will more adequately protect the fibers during the later orming operations following twisting than have prior art materials.

Another object of the invention is the creation of a ew and improved coating material of the above described type - - A still further object of the invention is the provision of a new and improved ooating material of the above described type which retains a desired amount of water in the forming package, and which loses a desired amount of this water while the glass fibers are being trans erred from the forming package to the twist package. further objects and advantages of the invention will become apparent to those skilled in the art to which it rela es from the following description of several preferred embodiments described herein and which are intended to illustrate the principles of the invention.

It has been discovered that a coating material comprising wax particles below a predetermined size and spaced apart by a film forming material can when applied to glass fibers produce a lower fuzz level as well as lower tensions (50$ less) in the later stages of manufacture of glass textiles than have prior materials. In addition the tensions are more uniform - varying between 5 to 6 grams compared with a range of 40 grams in prior art materials that do not contain the small wax particles. In addition fabrics woven from the materials of the present invention have a lower broken filament level and an absence of powder on the looms. It has further been found that such a distribution of wax particles and film former can be laid down from an aqueous solution in which the wax particles are molten and are held spaced apart by a stabilizer which may be a surface active agent having a proper hydrophilic-lipophilic balance hereafter called HLBj or a polysaccharide having lipophilic side chains. The surfactant in order to be effective must have a portion of the molecule soluble in the wax particles» and another portion which - - from the surface of the wax particles keep the wax particles from agglomeratin , during the time that the particles are molten and are present in an aqueous solution. Likewise the lipophilic side chains of the polysaccharide are drawn to the wax particles when in a mobile condition and the polysaccharide forms a protective film around the wax particles.

Where a surface active agent is used, a proper amount of film former dispersed throughout the aqueous solution, causes a physical arrangement of wax and film former in which the film former is held in position around each particle of wax. The film former may be of any suitable type for the application involved, such as starch, polyvinylalcohol, gelatin, alginate, resin, etc. It appears that the hydrophilic portion of a surfactant having a proper HLB helps to hold hydrolyzed ilm forming molecules in position around the molten wax particles to produce a unique physical arrangement when the material is dried in situ on glass fibers. In this respect a cationic lubricant helps to stabilize the emulsion and also helps form the film since the cationic lubricant has a portion which is attracted to the surface of the glass. It appears that the cationic lubricant causes the wax partieles to be deposited adjacent the surface of the glass with more of the film former over the top of the wax particles, so that less smearing of the wax takes place when the coated fibers are pulled over stationary surfaces such as "guide eyes* etc. By having the film former coat the wax particles, the film former will be between guide surfaces and the wax to prevent adherence of the wax to the guide surfaces, while still allowing the wax to contribute its shear properties to the coating.

Broadly, the coatings of the invention are dispersions Wax particles (emulsion size) 10-80$ Stabilizer and film former 20-90 Cationic lubricant 0-30$ with the stabilizer being more than approximately 1$ of the wax. In an aqueous vehicle the above solids will usually comprise from approximately 2$ to approximately 8$ by weight for ease of application to the fibers, but may be applied in a much higher solids ratio as a gel. The above is illustrated by the following example.

Example 1 A preferred composition comprises the following: Ingredients Hydroxy ethylated potato starch 2.97$ Acetylated com starch produced by the acetylation process of Patent 2,461,139 0.99 Cationic lubricant (reaction product of tetraethylene pentamine and stearic acid in a molar ratio of 1 to 1.8 0,18 Paraffin wax (126°F melting point) 1.70$ Polyoxethylene sorbitan monostearate (HLB equal to 15.9) 0.13$ Sorbitan monostearate (HLB equal to 5.9) 0.12$ Polyvinylalcohol 0.10$ Organo-tin bacterial inhibitor 10 ppm The material is prepared by adding a total of 3*96 parts comprising both starches and 0.10 part of polyvinylalcohol to sixty parts of cold water in a mix tank. The mixture is continually stirred and heated to a temperature of 200°F, and is held at that temperature for thirty minutes. Thereafter twenty parts of cold water are added, and the temperature is reduced to 155°p. i a separate vessel, 1.7 parts of wax is heated to 150 ° mixed therewith. Three parts of water at a temperature of between 150 to 170°F is slowly mixed with the molten wax and surfactant until the emulsion inverts and thins out. Thereafter another approximately six parts of water at 150 to 170°F is added. The emulsion is then homogenized in a jet homogenizer at 2,000 pounds per square inch pressure, and is added to the main body of materials previously described. The organo-tin material mixed with a quarter part of warm water is added to the mixture, and additional water is added to adjust to the desired solids. The material is maintained at a temperature between 130 and 140°F and is applied to glass fibers at forming using a conventional applicator pad over which the monofilaments are drawn.

Strands coated as above described, and having a coating solids of approximately 1.2 of the total weight of the strands has a migration index of 1,29, a fuzz index of 1,26, has twist breaks, a quilling tension of 26 and 34 grams with no quilling fuzz or powder, has 4.6 broken filaments in the quilling operation, a beaming tension of 16 to 28 grams without deposit on the creel.

By way of contrast the previously used production material that did not contain wax but used a starch of 5¾¾ amylose content with some of the starch material being in a partially cooked condition, gave a coating of 1.50 by weight of the coated strand. This material had: a migration index of 1.37, a twist fuzz index of 1.35 with 8# twist breaks, a quilling tension of 48 to 70 grams, very light quill fuzz with light powder observed in quilling, and five broken filaments during quilling. This same material gave a beaming tension of 40 to 60 grams with very light fuzz, and moderate to heavy powder Although, the starches used in the preferred example above were selected because of their substantially complete bum-off during coronizing, the synergistic effect which is achieved by combination with the wax, can be had with any type of starch or suitable film former. As previously stated, the cationic lubricant appears to coact with the wax to give a preferred physical arrangement on the glass fibers. The cationic holds the wax adjacent the surface of the glass, so that the starch more fully surrounds and covers the small particles of wax. Any type of cationic lubricant can be used, as for example, any of those mentioned in the patent literature. The particular molar ratio of 1.8 parts of the stearic acid to one part of the tetraethylene pentamine gives particularly good results and is a preferred material.

The two emulsifiers used above in approximately equal proportions gives an HLB of approximately 10 which is found to be the preferred HLB for a paraffin wax. Other types of waxes can be used, as for example, bees wax, canauba wax, cerese wax, mineral waxes, Japan wax, vegetable waxes, microcrystalllne wax, or the like, and mixtures thereof. The optimium HLB may vary slightly with the individual wax used but will fall generally between 8 and 16. The waxes used should preferably be of a low melting nature, so that the waxes can be applied in the molten condition without the temperature of the aqueous emulsion being excessive. Preferably the wax should have a melting point below 160°]?, usually below 140°F and most preferably below approximately 130°P.

The polyvinyl alcohol is an additional film former which helps to give a smooth uniform body to the water surrounding necessary, but others which can be used, are gelatin, animal ¾1 β, water soluble acetates, hydroxyethyl cellulose, etc* and are helpful in improving the efficiency in the twisting operation. Polyvinyl alcohol is a preferred material, however, because it burns off completely during coronization after the fibers have been woven.

Starch is a preferred film former for glass fibers because of its properties when dry. Generally speaking, the aqueous emulsified wax and film former coating materials should comprise from approximately 1$ to approximately 7$ by weight of solids, with the film former comprising from approximately 15 to approximately &5 by weight of the solids. The wax should comprise from approximately 10$ to approximately 80$ by weight of solids* The surfactant should comprise more than approximately 0*01 part per part of wax, usually between 0.1 to 0.2, and preferably have an HLB between approximately 3 and Ϊ6. The cationic lubricant is not necessary and may vary from 0 to approximately 0.80 part per part of wax and is preferably between 0.010 and 0.50 part per part of wax. A second film former is not necessary, and is effective between 0 and 0*25 part per part of film former to vary its properties.

It is not necessary that a single surfactant be used to give the proper HLB. Any two surfactants having knows HLB's can be combined using the proper proportions, and if the HLB is not known for a particular surfactant, it can be calculated by one of the two following formulasί HLB=20 (1-S) HLB=E†P I 5 wherein: S is the ester saponification number} A is the acid per cent ethoxy content; and P is the weight per cent of the polyol content. For a more complete explanation of HLB and its use in surfactant chemistry, reference can be had to the article of W. 0. Griffin, entitled: "Calculation of HLB iionio ic Surfactant", found in the December, 1954 issue of the Journal of the Society of Cosmetic Chemistry.

As previously indicated, the coating composition is kept at a temperature above the melting point of the wax before application to the fibers, so that the particles of the wax will remain in a stable small condition. The coating composition is cooled down after application to the fibers, during which time it achieves the proper distribution on the fibers, and during which time no appreciable agglomeration takes place* The particle size of the wax on the fiber therefore, would be substantially the same as that produced in the emulsion. Max emulsions will generally have a particle size of between 0.1 micron and 10 micron, and in the preferred homogenized condition will have a particle size of between 3 and 5 micron. Because the synergistic effect of wax dispersions in protective coatings for fibers, and in particular glass fibers, is a physical one, the synergistic effeet will be noted at very low concentrations.

Example 2 A protective coating material for use on glass fibers at forming and having a low concentration of wax, comprises the following? Per cent Ingredients by weight Hydroxy ethylated potato starch 2,437 Acetylated com starch produced by the acetylation process of Patent 2,461,159 0,809 Polyvinyl aooohol 0.082 Hydrogenated coconut oil 1.042 Emulsifier (Pol oxethylene sorbitan monooleate) 0.104 Emulsifier (Polyoxyethylene sorbitan monostearate) 0.002 Emulsifier (Sorbitan monostearate) 0.020 Cationic lubricant of Example 1 0.147 Paraffin wax (126°P melting point) 0,348 Balance Water This material may be prepared using the same procedure as given in Example 1, and provides an improvement over prior art starch protective coatings which do not contain these wax emulsions. Yarns coated with the material of Example 2 have lower, and more uniform tensions than do the similar materials which do not include the wax emulsion. This material, however, does not have the low level of tensions and uniformity that is provided by the preferred materials of the Example 1, The upper limit of the amount of wax emulsion which can be used is depended only upon the ability of the surfactant and the film former to prevent agglomeration, both when in the aqueous emulsion form, and when it is subjected to shear and turbulence during application to the fibers. The following is an example of a high concentration of wax which is stabilized in the aqueous emulsion form by the surfactant, and which can be applied to the fibers without difficulty.

Example 5 Ingredients Per cent by weight Hydroxy ethylated starch 0.75 Hydroxy ethyl cellulose 0.2 Paraffin wax (126°F melting point) 2.5 Polyoxethylene sorbitan monostearate 0.22 Sorbitanmonostearate 0.20 Cationic lubricant of Example 1 0.147 Nonylphenoxypoly (Ethylene oxy) ethanol 0.046 This material is prepared in the same manner as that of Example 1, and when so prepared, provides a protective coating for use in the forming of glass fibers, to produce coated fibers having low and uniform tensions. There is, however, a tendency for some wax build-up on guide surfaces.

The purpose of the surfactant, and the manner in which it operates, have already been explained. The surfactant must have an oleophilic portion for attachment to the wax, and a hydrophilic portion which will hold water, and hydrolyzed or water dispersed film formers, around the outside of the wax particles, to keep the particles from agglomerating in the aqueous emulsion form. In addition, the surfactant separates the particles of wax to cause the wax to be laid down on the fibers as separate and distinct particles separated by the film former. The surfactant should be nonionic, and the following is an example of a stable, protected coating material formed using a nonionic surfactant having a low HLB ratio.

Example 4 Ingredients Per cent by weight Partially cooked high am lose corn starch 2.437 Acetylated com starch of Example 1 0.809 Hydroxy ethyl cellulose 0.300 Cationic lubricant of Example 1 0.147 Paraffin wax (126°P melting point) 0.500 Ethoxylated castor oil (HLB 3.6) 1.200 This material produces a generally stable emulsion adequate for protective coatings on fibers, but generally necessitates a higher percentage of the surfactant in order that there is sufficient retentive power for the water soluble film formers around the outside of the wax particles.

Polysaccharide with Iilnophillc Side Chain A preferred stabilizing material is a polysaccharide with a lipophilic side chain which causes the polysaccharide containing the side chains to be drawn to the wax particles when in a mobile condition. Thereafter the side chains adhere to the wax particles while the polysaccharide portion of the molecule surrounds and protects the particle of wax. The coating materials may also include a water soluble film former which is a lubricant when dry and which also positions itself between the coated wax particles.- The film former in the dry condition of the coatings, prevents the wax particles from smearing together and thereby coating or plugging up stationary guide surfaces, etc. in the textile machinery. The wax particles, however, are more mobile than the film former and therefore help to decrease friction when they are engaged by stationary surfaces, or when the fibers are coiled into ena ement with, e h other The wax - - The materials of the present invention before being applied to the fibers are usually aqueous dispersions of wax particles which are in either a solid or liquid form, and which are stabilized by polysaccharides containing the lipophilic side chains♦ When mixed with water, the film former may be either in solution between the wax particles, or dispersed as solids in the water between the wax particles? so that when the material is applied to the glass fibers, the polysaccharide coated wax particles are separated by the film former and this physical arrangement is thereafter dried in situ. The coating materials will preferably also include a cationic lubricant which by nature has a lipophilic portion and a. cationic portion. The lipophilic portion also adheres to the wax particles and may help to stabilize the wax dispersion while the cationic portion of the molecule projects away from the wax particles and is attracted to the surface of the glass. Coating materials of the present invention which include the cationic lubricant are the preferred materials, because the cooperation of the cationic lubricant and wax particles causes the wax particle to be laid down more closely to the surface of the glass with the bulk of the film former being positioned between and on top of the wax particles. This arrangement aids in preventing the wax particles from smearing together when the coated strands are drawn over stationary guide surfaces. This arrangement also helps in texturizing fibers because it causes the film former to break between the saccharide coated wax particles to leave the wax in position as discrete particles on the individual strands.

The polysaccharides containing lipophilic side chains and which are used as a stabilizer for the wax emulsion also help to provide a preferred "lay down" of the material on the fibers, because the long chain polysaccharide molecules will generally bridge two or more wax particles to space and hold the wax particles apart, fhe polysaccharide stabilizer is compatible with the film former which is then distributed in and among the stabilizer strings to provide a better physical wax-stabilizer-film former arrangement than has been produced in any coating material heretofore.

Any long chain polysaccharide can be used as the stabilizer material so long as it contains the lipophilic side chains, $he lipophilic side chains are preferable organo groups of from 2-10 carbon atoms. These lipophilic side chains may include one or more hydrop ilic groups such as hydroxyl, ether, or carboxyl groups but must not be so numerous as to do away with the lipophilic nature of the side chain.

Where the lipophilic side chains are propylene radicals, they may include one hydroxyl group; where the lipophilic side chains contain six carbon atoms, they may include two OH groups? and where they contain ten carbon atoms, they may contain three hydroxyl groups. In each instance the preferred material will not have the OH group located at the end of the side chain. It will be seen that an OH group at the end of the lipophilic side chain necessitates the adherence to the wax at the middle of the side chain, whereas a hydrocarbon end to the side chain allows a better and preferred attachment to the wax. he length of the lipophilic side chains should be kept below ten carbon atoms in order that the polysaccharide will be more closely held to the surface of the wax, the side chains are preferably no longer than about six carbon atoms and most The polysaccharides which can he used as a stabilizer will include the starch fractions, amylose and amylopectin, the polyuronides such as the pectins, the arabans, galactans, pentosans, plant gums, polysaccharides containing nitrogen and sulphur, chi in, heparan, xylans, and the alginates. Bach of these materials can be at least part of the film former and when they contain the lipophilic side chains above described, are also compatible with wax so that they produce the unique physical arrangement of the coating compositions of the present invention.

The film formers will include the above polysaccharides, with or without the lipophilic side chains, as well as whole starch, gelatin and polyvinyl alcohol* In a preferred embodiment the forming size composition comprises the combination of starch and a suspension of minute particles of solid wax as shown by the following example: Example ¾ ¥ax suspension (40 solids) 6.1$ by weight Hydroxyethylated amylose starch 1,0 by weight Water remainder In the above formulation, the wax suspension comprised particles of a paraffin wax having a melting point of 125°F. , and an average diameter of 1 micron and in the preparation of such suspensions, stabilizers or protective colloids are preferably employed.

In preparing the forming size composition 40 parts by weight of the paraffin wax were melted at 160°F« , and added with mixing to 60 parts by weight of water maintained at - - alginate having a molecular weight of approximately 3»000 which acts as a stabilizer for the suspension. The resulting system was then homogenized until the average wax particle size was 1 micron. The system was then permitted to cool to room temperature and below the solidification point of the wax. A stable, readily dilutable suspension resulted and was added with agitation to a cooked starch solution of 10 parts by weight of the starch in 100 parts by weight of water. he above composition was applied to glass fibers at forming which maintained at temperatures both above and below the melting point of the wax. Consequently, the wax was applied as a suspension of both solid and liquid particles. Application of the size composition was achieved by means of the belt or apron applicator of U.S. 2*873»718 and the composition was applied to fibers traveling at a rate of 12,000 feet per minute. The stabilizer comprises propylene glycol esters of alginic acid derived from several species of brown seaweed. This cream-colored fibrous powder is approximately 80 mesh, is readily soluble in water to form a solution having a pH of about * Example 6 The method of Example 5 was repeated with the addition of 0,5 by weight of gelatin to the forming size compositions.

Example 7 Example 5 was repeated with the addition of 1$> by weight of a cationic lubricant comprising an imidazoline modified polyester. This lubricant is the reaction product of diethylene glycol, malelc acid, diethylene triamine and stearic acid as disclosed by U.S. 3,097,963. This reaction product of an unsaturated polyester and the fatty acid derivative of a diamine or imidazoline, is a cationic lubricant with an affinity for the glass surface.

Example 8 Example 5 was repeated without the homogenlzation of the wax suspension. As a consequence, the average diameter of the wax particles present in the forming size composition was 40 microns* Bxaarole 9 A forming size composition was formulated from the following ingredients: Wax emulsion (40# solids) 6.0 Propylene glycol alginate 0.1$ Cora starch 1*5$ Water Remainder The above wax emulsion comprised a melted scale wax having a melting point of 123°F. , and was a true emulsion in that the wax was dispersed in an aqueous phase while in a molten form, and was constantly maintained above the melting point of the wax including at the time of application of the composition to the glass fibers at forming, fhe starch was cooked at a temperature of 212° . Although in this example the application was made at a temperature higher than the melting temperature of the wax, this is not necessary nor necessarily preferred. The treating compositions are applied generally at a temperature "between 80-100°F.

Example 10 An improved forming size comprises the following ingredients in weight per cent: Wax emulsion (20$ solids) 6.1 Stabilizer 0,03 Imidazoline modified polyester (cationic lubricant) 0,50 Starch 1»05 Gelatin 0.62 While this example uses a paraffin wax melting between 120° to 125°i1., other waxes having higher melting points can be used. The wax emulsion preferably includes propylene glycol alginates, i.e., propylene glycol esters of alginic acids which serve as a stabilizer. The mix solids are 3.5$ and the pE about 4.6.

The small amount of gelatin acts as a film former to provide improved yarn integrity and its presence in the treatment improves twist operating efficiencies. A preservative suoh as tertiary butyl tin oxide or phenyl mercuric acetate salt may be added to preserve the starch and gelatin before and after application to the fibers. fhe cationic lubricant added to the Example 10 composition was Increased without changing the other ingredients or their proportions. When 0.75 per cent was added, improved yarn integrity was achieved and fuzziness was reduced. The percentage of cationic lubricant was increased to 1#05# with good results.

Preferred compositions for application to texturlzable strands comprise the following, by weight: Wax emulsion 0.5~5 Stabilizer 0.1-1 Cationic lubricant 0.5-3 Starch 0.5-5 Gelatin or polyvinyl alcohol 0-1 Remainder water Various cooked starches have been used* Bon-modified potato starch, cationic com starch, ethylated corn starch, modified potato starch and non-modified corn starch can be used. The cationic lubricant can also be octadecyl amine aeetate or a quaternary ammonium product.

The preferred compositions are prepared by mixing the starch and water in a main tank with good agitation to prevent lumping. The mixture is heated while agitation is continued and then cooled by addition of water. The cationic lubricant is mixed with hot water in a separate container and then added to the starch with mild agitation. The gelatin is added to warm water and, after it is dissolved, added to the main mix, with gentle, agitation. Propylene glycol alginate is added to water in a separate tank with rapid agitation to prevent lumping. The stabilizer and water are heated to form a solution. The wax is heated in a separate container and then added slowly to the - 25 - stabilizer and water with rapid agitation. The wax emulsion is homogenized and then added to the main mix along with water. The solids content is then adjusted. The pH is adjusted by addition of acetic acid or ammonia to about 4,6.

Of primary significance, fibrous glass yams coated with the inventive compositions are possessed of vastly superior processing characteristics. Very little migration of the coating materials occur in the forming package, so that the yarns texturize uniformly. In the first instance, broken filaments and fly are practically non-existent in the processing of the inventive products. Yarn integrity is excellent. Still further, fabrics woven from the inventive yarns are free from the previously mentioned streak or color banding problem thus demonstrating the ready removability of the coating compositions. The yarns heat clean better, In addition, it is possible to use as little as one tenth of the quantity of coating composition required in the case of conventional coatings with attendant savings, and still derive superior properties. Furthermore, the inventive yarns have yielded pronounced superiority in texturizing processes in which the yarns are bulked by means of a fluid yet to yield an aesthetic or novelty effect in the finished fabric. Conventionally coated fibrous glass yams have consistently yielded problems in such processing in failing to be uniformly bulked or texturized probably as the result of excessive and non-uniform quantities of the coating material and the stiff inter-filament bonding effect of coating compositions such as starch. Finally, apparatus used in the processing of the inventive products are markedly free from flaked off coating composition and ibrous fly with consequent reductions in down time and maintenance. The treating compositions of this invention are relatively non-migrating as compared to other commercial size compositions.

In regard to the previously discussed reduction of the requisite quantity of coating material and the necessity for a dry film former in the coating composition, experimentation has graphically demonstrated these aspects. In one series of trials identical fibrous glass yarns were sized at forming with 0.2, 0.4» 0.6 and 1.5% by weight of the composition of Example 6 and with 0.75, 1.1, 1·7 and 2.2 and 3. % ¾ weight of a starch forming size composition presently applied to the preponderance of fibrous glass yarns employed by weavers.

In all instances, the yarns sized with the varying quantities of the inventive composition were greatly superior to all of the yarns sized with the conventional compositions in every respect. First, all of the inventive yarns were substantially devoid of fuzz or projecting filament ends after twisting and quilling. In contrast, the yarns sized with the conventional compositions were characterized by appreciable fuzz in each instance and the yarns having a coating of 0.75 and 1.1% were so fuzzy as to be rejeoted as inoperable in a weaving process as the result of the inadequate protection of the filaments by the reduced quantities of the coating composition despite the fact that between three to five times as much coating was employed as in the case of the satisfactory inventive yarn bearing 0.2% by weight of coating

Claims (1)

1. CLAIMS A protective coating material for application to glass fibers and consisting essentially of the following percentages by from approximately to approximately of wax from approximately 20 to approximately of a film former such as a a polysaccharide having side chains of from 2 to 10 carbon gelatin or and a stabilizer the such as a surface active agent having an HLB between 8 and or a polysaccharide having lipophilic side chains of from 2 to 10 carbon with the stabilizer being more than approximately of the and from 0 to of a said wax being dispersed throughout the stabilizer and film former as particles no larger than approximately 10 micron in An aqueous coating material of Claim 1 wherein said solids comprise between approximately and approximately by weight of the material and the balance being essentially The coating material of Claim 1 including from approximately to approximately of a ca The coating material of Claim 1 wherein said wax is a paraffin ax having a melting point above approximately An aqueous protective coating material of Claim 1 comprising the following percentages by weights from mately to approximately of from approximately approximately of from approximately to approximately of cationic from approximately 26 Glass fibers having a coating thereon consisting essentially of the following percentages by from approximately to approximately of wax from to of a film former such as a polysaccharide having a lipophilic side chain of from 2 to 10 carbon gelatin or polyvinlalcohol and a stabilizer for the wax such as a surface active agent having an between 8 and 16 or a polysaccharide having a lipophilic side chain of from 2 to 10 carbon said wax being dispersed throughout the coating as particles no larger than approximately 10 microns in The coated glass fibers of Claim 6 including up to by weight of a ca The coated glass fibers of Claim 7 wherein the wax is a wax having a melting point above Glass fibers having a coating thereon consisting essentially of the following parts by from approximately part to approximately 5 part of wax particles no Ifirger than approximately 10 micron in from approximately part to approximately 1 part of a polysaccharide having lipophilic side chains of from two to ten from a proximately to approximately 3 parts of a catlonic lubrican from approximately to approximately 5 parts of a and up to approximately 1 part of an additional film fibers having a coating thereon consisting essentially of the following parts by Wax particles less than 10 parts micron in size Starch 1 part 27 The aqueous protective coating material of Claim 1 comprising the following percentages by of paraffin of of a cationio of a surface active material having an of and of polyvinyl the balance being essentially Glass fibers having a coating thereon consisting essentially of the from approximately to approximately by weight of a film from approximately to approximately by weight of and more than approximately part per part of wax of a said wax being dispersed throughout the coating as particles no larger than approximately 10 microns in The coated glass fibers of Claim 12 wherein the film former is The coated glass fibers of Claim 12 wherein the coating includes from approximately to approximately part per part of wax of a cationic The eoated glass fibers of Claim 13 wherein the wax is a paraffin wax having a melting point above approximately For the Applicants insufficientOCRQuality