US2555561A

US2555561A - Chemically treated laundry bag

Info

Publication number: US2555561A
Application number: US673626A
Authority: US
Inventors: Whitehead William
Original assignee: Celanese Corp
Current assignee: Celanese Corp
Priority date: 1946-05-31
Filing date: 1946-05-31
Publication date: 1951-06-05
Anticipated expiration: 1968-06-05

Description

FABRIC OF H IGH-TENACITY I W. WHITEHEAD CHEMICALLY TREATED LAUNDRY BAG Flled May 31, 1946 June 5, 1951 Patented June 5, 1951 CHEMICALLY TREATED LAUNDRY BAG William Whitehead,.Forest Hills, N. Y., assignor to Celanese Corporation of America, a corporation of Delaware Application May 31, 1946, Serial N0. 673,626

2 Claims.

This invention relates to a process for the treatment of textile materials and relates more particularly to the treatment of fabric materials Woven, knitted, netted or knotted of continuous filament, high-tenacity regenerated cellulose yarns, whereby the resistance of said fabric materials to laundering is substantially improved.

In the commercial laundering of garments and other fabric materials, strong chemical washing agents are employed to produce the desired cleansing effect. White fabrics are usually subjected to the most harsh conditions since the attainment of a bright color in the laundered material usually entails the use of bleaching agents in addition to the customary soaps, chemical softeners and the like which are employed. The net eifect of these various compounds on cellulosic materials, for example, is to produce a rapid tendering, degradation or weakening of the cellulosic fibers. This undesirable weakening effect is also observed in the case of fabrics woven of high-tenacity regenerated cellulose yarns formed by stretching and then saponifying yarns and filaments having a basis of cellulose acetate or other organic acid ester of cellulose. Various attempts have been made to increase the resistance of said high-tenacity regenerated cellulose fabric materials to the harmful eifects of the chemical agents which are employed in washing operations but the results obtained have not been entirely satisfactory.

It is, therefore, an important object of this invention to provide improved regenerated cellulose fabrics which are highly resistant to the tendering and degrading effect of laundering operations.

Another object of this invention is to provide a novel process for the treatment of fabrics woven of high-tenacity regenerated cellulose yarns and. filaments, formed by stretching and then saponifying yarns and filaments having a basis of cellulose acetate or other organic acid ester of cellulose, whereby the strength and service life of said fabric materials is substantially increased.

Other objects of this invention will appear from the following detailed description.

In the accompanying drawing, the figure represents a type of laundry bag made in accordance with my invention.

I have now found that the strength and re sistance to laundering agents of fabrics Woven, knitted, netted or knotted of continuous, hightenacity regenerated cellulose filaments formed by stretching and then saponifying filaments having a basis of cellulose acetate or other organic acid ester of cellulose may be substantially improved by subjecting said fabrics to treatment with an aqueous solution of an alkali metal hydroxide before said fabric materials are subjected to laundering operations. In accordance with my novel process, I immerse said fabrics in an aqueous solution containing from 4 to 12% by weight of sodium hydroxide, or other alkali metal hydroxide such as potassium hydroxide, at a temperature of 15 to 25 C. for 2 to 60 minutes and the fabrics so-treated are then rinsed, scoured and dried. The fabrics obtained by my process exhibit a very marked improvement not only in strength but also in their resistance to the degrading effects of the chemical agents employed in the laundering operations so that said improved fabrics are capable of under going a substantially increased number of laundering cycles without excessive tendering, degradation or rupture than fabrics heretofore employed. Optimum results are achieved employing an 8% by Weight aqueous solution of sodium hydroxide for the treating bath and maintaining the fabrics in said solution for about 20 minutes with said sodium hydroxide solution at a temperature of about 20 C.

While I preferably treat said high-tenacity regenerated cellulose materials after they have been woven, knitted, netted or knotted into the form of fabrics, it will be understood, of course, that the high-tenacity regenerated cellulose materials may be subjected to said alkaline treatment in the form of hanks of yarn, and the like, and the treated yarns then woven, knitted,

' netted or knotted into the desired fabric.

The high-tenacity regenerated cellulose yarns from which said fabrics are formed by Weaving, knitting, netting or knotting operations are obtained by stretching and then saponifying yarns having a basis of cellulose acetate or other organic acid ester of cellulose. The yarns are stretched during a suitable stage in their manufacture, and the yarns may be increased in length, as a result of the stretching operation, to the extent of 200, 300, 500, or even 1000 or 2000% of their original length. The yarns acquire a relatively high tenacity on being stretched, the tenacity being retained and in many instances enhanced by the saponification which effects a regeneration of the cellulose. The resulting regenerated cellulose yarns are of great strength.

The saponification of the stretched yarns, as such or in a fabric form, may be effected by means of any suitable basic agents. The saponifying agent may be inorganic in nature such as, for example, sodium hydroxide, potassium hy- For example, when aqueous solutions of sodium hydroxide are employed as the. saponifying, agent,

the sodium hydroxide may be presentin a concentration of from 0.1 to. 5% by weight and saponification may be effected in from I to 60 minutes with the solution at a temperature of from 30 to 90 C. When employing aqueous solutions of sodium hydroxide as the saponifying medium, it is preferable to include a salt such as sodium sulfate or sodium acetate in said solution- To efiect the desired saponification, the stretched yarns are led directly into the saponitying bath, therpath through thesaponifyingba'th being sufficiently extended and the speed at which the yarns; pass through the bath being such that. theyarns, under the conditions of both temperature and concentration employed; are completely saponified before leaving the bath. Speeds of to l00'meters per minute are satisfactory.

The process of my invention is particularly valuable for the treatment of those open-mesh fabric bags woven of high-tenacity regenerated cellulose yarns which are employed in commercial laundering operations. During commercial laundering operations, the various types of garments to be laundered are sorted out and each groupof garments obtained is then placed in. a loosely woven mesh bag which is closed and then entered into the laundry wheel in which the washing operation takes place. The mesh structure of the bag allows free circulation of the washing solution and rinse water but retains the various garments therein so that they may be easily separated: from the many other garments or bundles of garments which are usually washed at the same time. While ordinary untreated open-mesh fabric bags woven of high-- tenacity regenerated cellulose yarns lose a sum-- cient proportion of their strength to render them unusable after only a relatively few laundry cycles, the open-mesh high-tenacity regenerated cellulose materials treated in accordance with my novel process retain their strength and are entirely satisfactory after a considerably greater number of cycles.

In order further to illustrate the novel process of, my invention, but without being limited thereto, the following example is given:

Example inch Z-twist plied together with the insertion of 11 turns per inch S-twist, the final yarn containing 2880 filaments. The regenerated cellulose yarns employed are prepared by stretching a suitable cellulose acetate yarn nine times its original length, saponifying said yarn and then twisting and doubling. The mesh laundry bag obtained is then immersed in an. 8% by weight aqueous solution of sodium hydroxide at 20 C. for 20 minutes, after which the laundry bag is rinsed, scoured and dried. When loaded with clothesand. employed in the usual laundry cycle, the laundry bag so formed satisfactorily withstands a total of 150 laundry cycles or more. Laundry bags: which have not been subjected to said alkaline treatment prior to being employed in the usual laundry cycle fail after undergoing the action of about'50 laundry cycles. Ordinary cotton laundry bags, of similar weight and construction for example, fail after only 30 cycles.

It is to be understood that the foregoing detailed description. is given merely byway ofillustration and: that many variations may be madethere-in; without departing from the spirit of my invention.

Having described my invention, what I desire to secure by Letters Patent is:

1. As a. new article of manufacture, a fabric laundry bag having a basis of. high-tenacity regenerated cellulose yarns tormedby stretching and then saponifying yarns having a basis of treated with an aqueous solution of. sodium hydroxide.

WILLIAM WHITEHEAD.

REFERENCES CITED.

The following references are of record in the.

file of this patent:

UNITED STATES PATENTS I Date.

Number Name 2,020,303. Dreyfus, Mar. 12, 1935- 2,053,767 Dreyfus Sept. 8, 1936 2,132,734. Hartet al Oct.11, 1938 2,173,241 Young Sept. 19, 1939- 2,243,877 Mann .June 3., 1941. 2,252,554. Carothers Aug. 12, 19.41 2,289,085 Arnhem July 7, 1942 2,337,398- Marsh et al Dec. 21, 19.43v 2,343,039 Smith Feb. 29, 1944. 2,352,707 Goldthwait July 4, 1944 2,416,747 I Geimer Mar. 4, 19.417 2,467,792 Wenzel et a1 Apr- 19, 1949 2,504,124 Hicls Apr..18f, 1950 2,511,664- Liss June 13, 1950.

FOREIGN PATENTS Number Country Date 501,768 Great Britain Mar. 6, 1939 560,378 Great Britain Apr". 3, 1944

Claims

1. AS A NEW ARTICLE OF MANUFACTURE, A FABRIC LAUNDRY BAG HAVING A BASIS OF HIGH-TENACITY REGENERATED CELLULOSE YARNS FORMED BY STRETCHING AND THEN SAPONIFYING YARNS HAVING A BASIS OF AN ORGANIC ACID ESTER OF CELLULOSE, WHICH LAUNDRY BAG HAS BEEN TREATED WITH AN AQUEOUS SOLUTION OF AN ALKALI METAL HYDROXIDE.