US1945449A - Method of making resilient cellulosic textile fibers - Google Patents

Description

Patented Jan. 30, 1934 PATENT OFFICE METHOD OF MAKING aEslEIENT CELLULOSIC TEXTILE FIBERS Frank R. Redman, Upper Darby, Pa.,' assignor to Resilient Rayons, Inc., Philadelphia, Pa., a corporation of Delaware No Drawing. Application May 2, 1933 Serial No. 669,083

' 6 Claims.

My invention relates to the method of preparing improved cellulosic textile fibers in staple or yarn form, and more particularly it relates to the method of producing cellulosic textile fibers characterized by resiliency and other improved properties while at the same time possessing the properties of the fibers which make them applicable for the various textile fields. This application is filed as a continuation-in-part of my co-pending 10 application Serial No. 643,523, filed November 19,

One object of my invention is to provide cellulosic textile fibers in staple or yarn form which have a resiliency comparable to that which exists in certain animal fibers such as natural silk, high grade wool, and mohair,-and at the same time possess the soft texture characteristic of cellulosic fibers.

Another object of my invention is to provide an economical process of treating cellulosic textile fibers which, while increasing many desirable properties and imparting resiliency thereto, will in no way detract from those qualities such as appearance or ability to dye which are characteristic of the fibers.

I Other objects will be apparent from a consideration of the specification and claims.

The present invention relates to the treatment of cellulosic textile fibers either in staple or yarn form within which phrase is included cotton and those materials designated as rayon, artificial silk, wood silk, and synthetic fibers made from wood pulp, cotton linters, or the like, by any of the processes including the viscose, cupra-ammonia,

nitrocellulose and cellulose acetate processes. The invention contemplates the subjection of the cellulosic textile fibers in staple or yarn form to a chemical treatment which deposits on the surface of the individual fibers a transparent insoluble film. The film'results from the treatment of the fibers with an albuminous or gelatinous substance such as albumen, gelatine, or glue thereafter rendered insoluble by an agent capable of reacting therewith and imparting said property thereto. The cellulosic fibers are treated with the chemicals and are thereafter dried and treated mechanically to provide a discontinuous film of the insoluble material on each of the fibers. The discontinuous film ofinsoluble material contains a multitude of minute uneven cracks or breaks which allow solutions such as dye baths to seep through and penetrate the fibers evenly and completely so that no difliculty whatever is encountered in the subsequent processing 65 of the fibers.

Heretofore, in the manufacture of certain fabrics particularly rugs, carpets, plushes, tapestries, upholsteries and velvets, attempts have been made to produce a satisfactory product from cotton or rayon fibers. Since these fibers, however, are not esilient, fabrics made therefrom do not show any life when manufactured .uch as they would possess if manufactured from natural silk or animal fiber. Difliculty has been encountered particularly in the manufacture of pile fabrics from hese fibers due to the lack of resiliency thereof. This is manifested in a number of ways, for instance, pressure applied causes the fibers to mat with the consequent marking of the fabrics. Ordinary cellulosic textile fibers cannot be used successfully in the manufacture of pile fabrics for any appreciable length of pile since the fibers will not stand erect and pressure once applied to them will cause them to flatten so that the uniform appearance of the fabric is destroyed. This difficulty is increased as the length of the pile is increased since the longer the pile the more it will mat under pressure.

The product of ,the present invention has none of the .above cited disadvantages and, therefore, so may be used in the manufacture of all types of knitted and woven fabrics, and is particularly applicable for use in the production of pile fabrics. The treated cellulosic textile fibers of the present invention are resilient due to the transparent discontinuous film of insoluble material surrounding each fiber. The film is comparable to the center bone of animal fibers such as is found in hair, wool, and mohair which imparts resiliency to them. The process of the present invention furnishes to the fibers a strengthening transparent film which not only imparts resiliency thereto corresponding to the resiliency in animal fibers, but also presents a silky feel and appearance with the result that the fibers and fabrics made therefrom have a soft hand and a lustrous glossy appearance.

The film is insoluble in water and in the washing, bleaching, cleaning, dyeing and printing steps to which the material may be subjected during processing and, therefore, the fibers after treatment by the present invention may be processed in the same manner as untreated fibers without detracting from the resiliency imparted to them in accordanace with the present invention. For example, the treated fibers will dye perfectly and evenly and may be dyed either in staple or skein form or may be dyed or printed after being woven or knitted into fabrics. The transparent. discontinuous film of insoluble material with its multitude of minute cracks and breaks permits the penetration of dye into the fibers. This discontinuous film is a permanent part of the fiber and remains so after treatment and during use due to the tenacity to which it adheres thereto; thus resiliency is obtained by the fibers throughout their life.

The resiliency of the fibers of the present invention opens many new fields for their use. Dress goods, for example, made from the treated fibers will be rendered more wrinkle-proof than has been previously the case. The treated fibers having the same resiliency as natural silk or wool can be used in any length pile, even as long a pile as five-eighths of an inch, for example. The fibers will stand erect and will not mat under ordinary pressure any more than the-average wool or worsted yarn. If the pile lays over after being under pressure for an extended time, it can easily be brought back to'its original condition merely by brushing the fabric inthe presence of moisture. The treated fibers also stand apart which results in a greater coverage than has heretofore been possible. By virtue of the fibers being coated as herein described. increased resistance to abrasion is afforded. The fibers of the present invention have an increased elongation when wet. For example, in the case of resilient rayon of the present invention, the elongation when wet is increased to an extent of approximately 16%.

The cellulosic textile fibers either in staple or yarn form are subjected to the chemical treatment by immersing the fibers in two chemical baths, the first of which contains an albuminous substance while thesecond contains a material capable of rendering the albuminous substance insoluble. After the fibers have been thus treated they are dried, provision being made during the drying to bring about the cracking or breaking of the insoluble film so that the finished individual fibers are coated with a discontinuous film of the insoluble material.

The first chemical bath contains an albuminous substance, capable of being rendered insoluble by subsequent treatment, such as albumen, glue, or gelatine, preferably, however, the last named is employed due to its vavailability and freedom from contamination. Hereinafter the process will be described in which gelatine is employed specifically, but it is to be understood that the description given applies equally well to the use of other albuminous substances. In making up the bath, the gelatine is dissolved in water in a mediumly concentrated form, using, for example, about one pound of gelatine to ten pounds of water. After the gelatine is thoroughly dissolved, the proper amount of water is added to bring the final solution to a concentration in which there are about five ounces of gelatine to each gallon of water. This concentration is not critical and may be varied to obtain a thinner or thicker solution. For example, a solution may be employed varying from one ounce to twenty ounces of gelatine per gallon of water. the gelatine solution as well as its temperature and the time of immersion of the fibers in the bath may be varied as desired and these three factors determine the thickness of the resultant film. In general, the bath is heated to a temperature varying from 80 F. to a temperature below the boiling point of the solution. Usually the temperature employed will be between 80 F. and 160 F. and in most instances it has been found that 120 F. gives excellent results in an economical manner. The cellulosic textile fibers The concentration of tain from 50% to 200% of water by weight.

either in staple or yarn form, either in natural or dyed state, are brought into contact with the solution and are immersed therein for a relatively short period, in most cases one or two minutes immersion being sufficient to wet the fibers thoroughly. Longer periods of time may be employed if desired since the immersion does not deleteriously affect the fibers. 1

After the treatment of the fibers in the first chemical bath, a portion of the solution adhering thereto is removed by passing the fibers through squeeze rollsor by placing them in a hydroextractor. Although the moisture content of the fibers is not particularly critical, preferably sufiicient moisture is removed so that the moisture content of the fibers is from 50% to 200%.

The second chemical bath to which the fibers are subjected contains a setting agent which renders the gelatine adhering to the fibers insoluble. Any chemical rendering the gelatine insoluble may be used. Forexample, formaldehyde, tannic acid, a soluble chromium salt such as chrome alum or chromium chloride or sulphate, or a chromate or dichromate such as ammonium, potassium, or sodium chromate or dichromate are typical of this class of compounds. The amount of setting agent is suificient to combine with the gelatine which is on the fibers to render it insoluble, and the concentration of the second bath may vary widely, for example, from one and one-half ounces of setting agent per gallon of water to ten ounces per gallon of water. In the case a soluble chromium salt or chromate or dichromate is used, for example chrome alum, the best results are obtained by using eight ounces of chrome alum dissolved in seven gallons of water. In those cases where formaldehyde is employed, pound of 40% formaldehyde solution up to four pounds of said solution for each gallon of water may be used, a satisfactory percentage being two pounds of formaldehyde solution in a gallon of water. If tannic acid is employed as a setting agent, one pound to three pounds of tannic acid per gallon of water may be employed. The temperature of the second chemical bath may be the same as that of the first bath or it may be maintained at a different temperature, a temperature between F. to 100 F. being particularly applicable. In the second bath, the period of immersion may be varied depending upon the temperature and concentration of the bath, and in general one-half minute to thirty minutes are usually sufiicient. In any event, the fibers are allowed to remain in the second solution for a sufiicient length of time to bring the gelatine adhering to the fibers into intimate contact with the setting agent andto allow the formation of the insoluble compound. No deleterious effects are obtained if the fibers are allowed to stay in the bath for a considerable period of time.

After the material has been subjected to the second chemical bath, a portion of the solution is again removed therefrom, for example, by passing the fibers through a set of squeeze rolls or by subjecting them to the action of a hydroextractor. The moisture content of the fibers are reduced in this manner to a point where the fibers con- The moisture content, however, is not critical although it is desirable to leave sufiicient water associated with the fibers to insure an even drying effect. The fibers are then dried in suitable drying machinery at any desired temperature, generally varying between F. and 120 F. al-

though a higher temperature up to 160" F., for example, may be employed. During the drying operation, the fibers are subjected to mechanical motion, that is, to a gentle beating for the purpose of permitting the fibers to become separated one from the other and particularly for the purpose of causing the film of insoluble material to crack and break and thereby become discontinuous. If desired, the fibers may be dyed before the final drying step by immersing the fibers in the dye bath after treatment in the second bath and after the reaction forming the insoluble material has taken place.

In the case the cellulosic textile fibers are to be treated in the form of staple, they, either dry or associated with moisture, are processed as above described in baths I and II, and when a portion of the water has been removed from the fibers in this form after the treatment in the second bath, they may be dried in any typical standard stock drier provided with a mechanical device adapted to beat the staple slightly, for example, a continuous process drier provided with a beater box. The treated fibers may be blown through the chamber and beater box, and as they proceed through the apparatus they are subjected to mechanical beating which not only separates the fibers but destroys the continuous nature of the insoluble film and furnishes to the individual fibers a discontinuous coating of insoluble material containing a multitude of minute cracks or breaks. After the staple has been thus dried, it may be processed according to the usual practices employed in the textile industry; for example, it may be carded and spun either alone or mixed with other textile fibers, for example, wool or natural silk or untreated rayonor cotton. Obviously, also the treated staple of the present invention may be employed with other cellulosic textile fibers also treated as herein described, for example, the resilient rayon of the present invention may be spun with the resilient cotton of the present invention.

Referring to the treatment of rayon yarn, the process of the present invention is employed with the product either after it is completed and ready for shipment at the rayon plant or after it has been subjected to the final washing step and prior to the final drying step. If the wet rayon is employed, it is usually subjected to the first chemical bath after the removal of the yarn from the hydroextractor, at which time it may contain to of water, although larger amounts of water may accompany the yarn without interfering with the process. The yarn may be subjected to treatment in the chemical baths in skein form, in which case it may be suspended on racks which are immersed in the two solutions, or the skeins may be joined together in chain form and passed continuously through the first bath, through the squeeze rolls or hydroextractor, and through the second bath. In other instances, it will be desirable to process the yarn in beam form, in which case the unprocessed skeins are placed on spools which are then re-wound on a beam. The beam is then placed at the head of a slashing machine and the yarn is passed through the first bath, then through the squeeze rolls, followed by immersion in the second bath. Thereafter it is passed through squeeze rolls and thence to the drier or drying cylinder.

After the removal of a portion of the water subsequent to the treatment in the second chemidividual fibers making up the yarn separate one from the other so that they will not adhere together and at the same time to cause the formation of the discontinuous film. The drying and formation of the discontinuous film may be accomplished in a drying chamber by turning the skeins, which are supported on poles, for predetermined distances, for example, quarter turns. During the turning, the skein is spreadv outwardly a sufficient distance to prevent the fibers from sticking one to the other and during the turning the skein is lightly struck in order to separate the fibers and cause the formation of the multitude of minute cracks or breaks, thus making the discontinuous film desired. This action may also be accomplished mechanically by an arm which automatically turns the skeins and at the same time spreads the skeins outwardly, thereby separating individual fibers. The slight beating action of the fibers described may also be accomplished mechanically by providing a suitably adjustedmechanical arm. Other means of causing the formation of the cracks or breaks in the insoluble film may be employed. The drying may also be brought about by passing the yarn over a drying cylinder preferably artificially heated. This is particularly applicable when the yarn is processed in beam form and the dried yarn may be wound on a weaving beam after passing over the drying cylinder and-is then ready for use. In the use of the drying cylinder, the yarn as it is being passed over the cylinder is lightly beaten or struck to cause the formation of the discontinuous film of insoluble material.

When it is desired to decrease the stiffness of the treated fibers to render them more suitable for manipulation in the manufacture of specific fabrics and at the same time without destroying the coating which has been applied by the process, the treated fibers after removal from the second bath either before or after drying may be subjected to a softening agent, for example, sulpho-- nated castor oil and the like. This agent may be applied in any suitable manner, for example, by

spraying or by immersion or other mechanical means as are practiced. It may be applied in the dye bath if desired. If the fibers are treated while still moist from the solutionof the second bath, they are dried as hereinbefore described to form the transparent discontinuous film of insoluble material. The softening is only a temporary expedient and is subsequently removed.

The yarn of the present invention may be manufactured into fabrics of any type composed solely of the resilient fibers of the present invention, or it may be manufactured in conjunction with other textile fibers such as wool, natural silk or untreated cotton or rayon.

Considerable modification is possible in the choice of the chemical and in the concentration and temperature of the two chemical baths as well as in the drying and other steps without departing from the essential features of the present invention so long as the factors employed result in the transparent discontinuous film of insoluble material coating the individual cellulosic textile fibers and rendering said fibers resilient.

I claim:

1. The process of treating cellulosic textile fibers in staple or yarn form to render them resilient, which comprises immersing said fibers in a bath containing an albuminous substance in solution, immersing said moist treated fibers in a solution containing-an agent capable of reacting with said albuminous substance to form an insolution containing an agent capable of reacting with said gelatinous substance to form an insoluble material, and thereafter drying the fibers and during said drying treating said fibers mechanically to separate the fibers one from the other and to form a discontinuous insoluble film on the individual fibers.

3. The process of treating rayon in staple or yarn form to render it resilient, which comprises immersing said fibers in a bath containing an albuminous substance in solution, immersing said moist treated fibers in a solution containing an agent capable of reacting with said albuminous substance to form an insoluble material, and. thereafter drying the fibers and during said drying treating said fibers mechanically to separate the fibers one from the other and to form a discontinuous insoluble film on the individual fibers. 4. The process of treating cotton in staple or yarn form to render it resilient, which comprises immersing said fibers in a bath containing an albuminous substance in solution, immersing said moist treated fibers in a solution containing an agent capable of reacting with said albuminous substance to form an insoluble material, and thereafter drying the fibers and during said drying treating said fibers mechanically to separate the fibers one from the other and to form a discontinuous insoluble film on the individual fibers. 5. The process of treating rayon in staple or yarn form to render it resilient which comprises immersing said fibers in a bath containing gelatine in solution, immersing said moist treated fibers in a solution of formaldehyde, and thereafter drying the fibers and during said drying treating saidfibers mechanically to separate the fibers one from the other and to form a discontinuous insoluble film on the individual fibers.

6. The process of treating cotton in staple or yarn form to render it resilient which comprises immersing said fibers in a bath containing gelatine in solution, immersing said moist treated fibers in a solution of formaldehyde, and thereafter drying the fibers and during said drying 3 treating said fibers mechanically to separate the fibers one from the other and to form a discontinuous insoluble film on the individual fibers. FRANK R. REDMAN.