US2403515A - Sizing material - Google Patents

Description

comma UR PLASTIC l 9 9 Patented July 9, 1946 QUCH bli SIZING MATERIAL Allen R. Fuller, Decatur, Ill., assignor to A. E.

Staley Manufacturing 00., Decatur, 111., a corporation of Delaware No Drawing. Application May 31, 1943, Serial No. 489,191

6 Claims. 1

The present invention relates to sizing materials for textiles. More particularly, it pertains to a sizing material for textiles, such as, for example, rayon or the like, the chief sizing agent of which consists solely of xylan.

Continuou filament rayon yarn consists of a number of individual continuous filaments held together by a slight twist. During the weaving operation the warp yarn is exposed to abrasion and tension. The abrasion is caused by the constant lowering and raising of the individual warp ends during weaving and also the passage of the yarn through the drop wires, heddle eyes and reed of the loom. The tension is necessary to keep the warp ends in proper alignment. These abrasion and tension characteristics will cause the warp yarns to fray and break unless protected. It is desirable, therefore, that the warp yarn be coated with a film-forming substance to protect it. This process is called slashing or warp sizing and the machine used in the proces is known as a slasher. The use of starch for sizing has become conventional and undoubtedly has proven, thus far, to be the most suitable for this purpose generally. However, rayon, particularly cellulose acetate rayon yarn, does not take up enough starch to be well sized. In addition, starch is not easily removed from woven rayon cloth. It has been, therefore, usually necessary to remove the starch size by passing the yarn through a weak solution of an amylolytic enzyme. Therefore, the cloth is permitted to stand for several hours to allow the enzyme to solubilize the starch. It is then passed through water to remove the soluble starch. Rayon fabrics are usually weak when wet, especially the regenerated cellulose type, such as viscose, and the less handling the fabric receives in the wet stage the better it is for the material.

A particular object of the present invention is the provision of a size material which will overcome the foregoing difiiculties and disadvantages and which consists essentially of xylan as the sole sizing agent.

Specific objects of the invention are the provision of a starch-free sizing paste which readily can be removed from the cloth after weaving by passing the same through water and subsequent drying without the use of an enzyme; which, in addition to forming a protective coating, should have sufficient resilience so that the yarn may be bent without breaking or kinking; which will lend sufficient toughness to a yarn so coated to withstand the abrasive action of weaving; and,

in which a yarn so coated, if it does break, will not fray but rather break off cleanly.

Other objects of the invention will in part be obvious and will in part appear hereinafter.

The invention accordingly comprises the several steps and the relation of one or more of such steps with respect to each of the others, and the product possessing the features, properties, essential characteristics and relation of constituents, which are exemplified in the following detailed disclosure, and the scope of the applica- I tion of which will be indicated in the claims.

My invention is based on the discovery that films made from xylan proved to be quite resistant to abrasion and the further fact that such material is easily dispersible in water. xylan in concentrated aqueous form is obtained. for example, by the alkaline extraction of corn hulls, or other pentosan containing material, which is then filtered and the filtrate concentrated. In dry form, it is obtained b acidifying such a concentrate, followed by alcohol precipitation. This substance, as far as I am aware, has never been used for sizing textiles and particularly for warp sizing rayon yarns of the viscose and acetate type. I have also found that xylan is easily applied to yarn by passage through a water dispersion preferably containing, in addition to the xylan, a softening agent and a penetrant or wetting agent which readily thereafter can be passed through squeeze rolls and dried either in a heated chamber or on heated rolls.

Such a size can be prepared, for example, by gradually adding dry xylan to water, at room temperature, contained in a steam jacketed kettle provided with an agitator. Agitation should be constant until the xylan is well suspended. Sulphonated castor oil, or any other suitable softener or plasticizing agent, may be used, and also a suitable penetrant or wetting out agent, such as a Tergitol penetrant (Carbide and Chemicals Corporation). The Tergitol penetrants are the sodium salts of the sulfuric acid esters of secondary higher aliphatic alcohols. Their general structural formula is where R1 and R2 are alkyl groups. The temperature of the mixture may be maintained at any suitable degree until the size is ready for use and can be transferred to the size box of a slasher. The sulfonated castor oil is added merely to soften while the penetrating agent assists in llUU wetting the yarn so that the xylan will flow around the fibers.

Example 1 168 parts of dry xylan was added gradually to 1000 parts of water at room temperature and agitated until a mixture free from lumps was Obtained. 3 parts of 75 percent sulfonated castor oil and .6 part Tergitol penetrant .08 were then added. The temperature was then raised slowly to 185 F. with constant agitation.

The above composition was applied to 75 denier 52 filament bright acetate rayon and 150 denier 40 filament dull acetate rayon, by passing the yarn through the paste at 185 F., then passed between soft rubber rolls under pressure to remove the excess size and then drying.

Examination of the sized yarn showed that it had the necessary strength, resistance to abrasion and flexibility to make a weavable warp. When the yarn was broken by tension a clean break was obtained without excess fuzziness. The size was easily removed from the yarn by passage through water at 180 F., removal of excess water by means ofrubber squeeze rolls and then drying.

Example 2 96 parts dry xylan was added gradually to 1000 parts of water at room temperature and agitated until a mixture free from lumps was obtained. 3 parts '75 per cent sulfonated castor oil and .6 part Tergitol penetrant .08 were then added. The temperature was raised slowly to 145 F. with constant agitation.

The above composition was applied to 150 denier, 40 filament bright viscose rayon, by passing the yarn through the paste at 145 F., then between soft rubber rolls under pressure to remove the excess size and drying.

Examination of the sized yarn showed that it had the necessary strength, resistance to abrasion, and flexibility to make a weavable warp. When the yarn was broken by tension a clean break was obtained without excess fuzziness. The size was easily removed from the yarn by passage through water at 145 F., removal of excess water by passage through squeeze rolls and then drying.

It will thus be seen that the objects hereinbefore set forth may readily and efliciently be attained by the use of xylan as the sole sizing agent without reliance on any other materials, other than the optional plasticizing and wetting agents, and since certain changes in carrying out the above improvements and certain modifications in the product which embodies the invention may be made without departing from its scope, it is intended that all matter contained in the above description shall be interpreted as illustrative and not in a limiting sense.

It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described, and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween.

Particularly, it is to be understood that in said claims, ingredients or compounds recited in the singular are intended to include compatible mixtures of such ingredients wherever the sense permits.

Having described my invention, what I claim as new and desire to secure by Letters Patent, is:

1. In the process of weaving rayon or the like, the improvement which comprises coating such material, preliminary to weaving it, with a starchfree sizing paste, the chief sizing ingredient of which is xylan.

2. In the art of weaving textile materials, the improvement which comprises coating said textile materials with xylan, as the sole sizing agent, to prepare them for weaving.

3. A starch-free sizing composition 01 matter containing xylan as its sole sizing ingredient together with sulfonated castor oil as a plasticizer and a penetrating agent which is a sodium salt of a sulfuric acid ester of secondary higher aliphatic alcohol.

4. In the process of weaving rayon or the like, the improvement which comprises coating a warp of such material, preliminary to weaving it, with a starch-free sizing paste composition containing xylan as its sole sizing ingredient together with sulfonated castor oil as a plasticizer and a wetting agent consisting of a sodium salt of a sulfuric acid ester of secondary higher aliphatic alcohol.

5. In the process of preparing rayon yarn or the like for weaving, which comprises coating the warp yarn with an aqueous dispersion of a major proportion of film-forming substances and a minor proportion of substances that serve as wetting agents for the yarn and as plasticizers for the film that is subsequently formed on the yarn by drying the coating, whereby the warp yarn is protected against abrasion during the weavin operation, the improvement which consists of coating the warp yarn with such aqueous dispersion wherein the sole film-forming substance is xylan.

6. A composition of matter adapted to the warp sizing of rayon yarn and the like comprising an aqueous-dispersion of a major proportion of a film-forming substance and a minor proportion of substances that serve as wetting agents for the yarn and as plasticizers for the film that is subsequently formed on the yarn by drying the coating, wherein xylan is the sole film-forming substance present.

ALLEN R. FULLER.