US2144354A - Textile material and its preparation - Google Patents

Description

Patented Jan. 17, I939 TEXTILE MATEB AND HTS PREPA'EHGN- William tehead, berland, Mai, assignor to Celanese Corporation of erica, a corporation of Delaware No Drawing.

Application September 26, 1936,

.r I Seriai No. 102,812

This invention relates to the treatment or preparation of staple fibres which are more suitable for spinning or other textile operations than those heretofore produced.

An object of the invention is the preparation of staple fibres by coating the same in a manner and with a particular coating compound to produce staple fibres which may be easily carded, drawn, combed, etc. to produce a uniform and homogeneous web, sliver, or yarn of fibres without piling or otherwise tangling and loading on the card-clothing, or forming slubs and pills in the resulting yarn. Other objects of the invention will appear from the following detailed description.

The formation of spun yarn from comparatively "short lengths or staples of filaments or threads composed of organic derivatives of cellulose present serious dimculty. This is due in part to the fact that such organic derivatives of cellulose have a very high dielectric constant and are very poor conductors of electricity, and when the filaments are rubbed together or against machine parts during the various operations involved in mixing, carding, drafting, combing, spinning and like operations a heavy charge of static electricity is produced. Because of the static electrical charge, the staple fibres containing organic derivatives of cellulose do not adhere to each other readily, tend to adhere to machine parts and otherwise cause great difiiculty in textile operations.

In the past when attempting to produce yarns from staple fibres containing organic derivatives of cellulose it has been customary to apply thereto a coating composition to reduce the static electrical charge by making the fibres conductors of the electricity. Some of these coating compositions used prior to this invention, although making the fibres conductors of electricity, gave to them a property which caused them to load in between the wires of the card clothing, necessitating frequent stopping to strip the card, also in poor uniformity of sliver obtained from the card, thereby influencing the strength of yarns subsequently. obtained. Some other of these finishesnated fatty alcohol in water, that the fibres are made conductors of electricity, are given the proper co-efilcient of friction such that they slip over each other and may be drafted to fine yarns,

are given a slight crinkle or curl which causes.

them to form slivers, webs and the like without matting into the carding cloth, combs,-etc. and

the distortion or crinkle also assists in holdin together the web orsliver and are non-corrosive to the metal parts of the machine with which they contact. The finish furnishes a lubricant for the fibres to slip over one another in drafting operations, permitting the formation of yarns of 30's count or finer according to the cotton system of number yarn. If fibres are too scroopy they drag on each other and do not draft, while if they are too slippery the fibres slip apart too readily making a weak web or sliver. The finish, in accordance with this invention, gives the proper balance between scroop and lubrication to fibres which hold to each other smoothly and uniformly. Furthermore, staple fibres maybe run on cotton card machines for weeks without requiring a cleaning of the carding cloth on same.

Heretofore when carding of acetate staple according to the cotton system with what is known in the trade as a rotary fiat card, the tendency for the fibres to lie between the wires and load on the card clothing generally, including the flats, the cylinder, and the dofier, has been very marked and it has been usually necessary, in order to obtain continuous running, to employ some continuous stripping device, such as a fancy! roll. Such devices are not employed in the normal trade where it is possible to avoid their use as they introduce a complication in respect to their infiuence on the condition of the wires of the card clothing and the life of such and further are apt to throw small tufts of filaments forward which carry forward on the web and into the sliver coming off the card and are apt to produce an unevenness and slubbiness of yarn in spite of drawing and doubling in the processes which follow. Ac-

,cording to the process of my invention, the staple fibres so produced may be carded 'without any need for such stripping mechanisms.

Several finishes applied heretofore, because of the lack of lubricative quality and the scroopiness, in order that they may be carded on any of the carding systems, for example, cotton, wool or worsted, it has been necessary to reduce the speed of the cards in order to avoid tearing and breaking down of stock. Staples produced according to the process of my invention, however, may be processed at least as fast as has been customary in the carding of natural fibres and in fact have been processed at speeds resulting in yields 20% greater per unit time than has heretofore been customary.

A further advantage of my invention is that the mixture or emulsion of sulphonated fatty alcohol may be applied to fibres consisting of a mixture of woolen or animal fibres and staple length fibres of organic derivatives of cellulose. The emulsion prepared in accordance with my invention has no deleterious efiect upon wool, cotton or silk and does not interfere with textile operations to which these materials may be subjected. It may, therefore, be applied to mixtures of organic derivatives of cellulose. wool and/or cotton, or it may be applied to staple fibres of organic derivatives of cellulose which are to be mixed with wool and/or cotton. The sulphonated fatty alcohol left on the yarn by treatment in accordance with this invention have a high softening power and they lend to the finish the advantage of scouring in hard water, which advantage is of particular significance when the organic derivatives of cellulose are to be blended with wool'and subjected to contact with lime soaps.

In accordance with my invention, I treat or prepare staple fibres with a mixture or an emul sion of a sulphonated fatty alcohol in an aque ous medium at elevated temperatures. This emulsion, when applied to the staple fibres at elevated temperatures, acts as a finish for the fibres, a softener for the artificial fibres and imparts to the artificial fibres a slight curling or a crlnkling of the fibres sufficient to greatly enhance their drafting. The term sulphonated fatty alcohol, as employed in the specification and in the appended claims, is to be construed as including within its scope fatty alcohols having one or more HSO3 or S04 groups linked through the oxygen or a carbon of the alcohol, and the alkali salts of these compounds. sulphonated fatty alcohols, therefore, include the sulphonic acid derivatives and sulphate derivatives of the fatty alcohol.

The sulphonated fatty alcohol may contain from a. trace to as high as 5 to 10% or more, based on the weight of the sulphonated fatty alcohol, of the free or unsulphonated alcohol. All or a part of the sulphonated fatty alcohol may be used in the form of its sodium, potassium or amine salts. The sulphonated fatty alcohol may be the sulphonated product (which includes either or both the sulphonic derivatives and sulphate) of any suitable fatty alcohol, for instance lauryl, oleyl, stearyl, palmityl, etc.

The sulphonated compound may be rather viscous at room temperature in which case it may be thinned with a suitable sulphonated vegetable oil, such as sulphonated olive oil and/or with a. sulphonated fatty acid. Also volatile solvent thinners may be employed such as gasoline, benzene, kerosene, etc. The mixture or emulsion of sulphonated fatty alcohol in an aqueous medium may be incorporated in the relatively continuous lengths of artificial filaments in any suitable manner and the continuous lengths may then be cut into staple fibres or, more preferably, the staple fibres may be treated with the mixture or emulsion of the sulphonated fatty alcohol in an aqueous medium. This preferred method of treating the staple fibres should be carried out by submerging the staple fibres in a heated aqueous bath containing dispersed or emulsified there in sulphonated fatty alcohol with or without a sulphonated oil thinner.

While this invention is of general application and is applicable. to the treatment of natural fibres, such as cotton or wool, or staples cut from natural silk or filaments made of reconstituted cellulose (such as may be made by the viscose,

cuprammonium or nitrate method), it is of particular importance in connection with staple fibres made of organic derivatives of cellulose, such as organic esters of cellulose and cellulose ethers, upon which it has a penetrating or selfdistributing property as well as the lubricative and anti-static property. Examples of organic derivatives of cellulose are the cellulose esters and ethers. Examples of the cellulose esters are cellulose acetate, cellulose formate, cellulose propionate and cellulose butyrate, while examples of the cellulose ethers are methyl cellulose, ethyl cellulose and benzyl cellulose. However, this invention will be described more particularly in connection with the preparation or treatment of staple fibres made of cellulose acetate or other organic derivatives of cellulose.

The artificial filaments of organic derivatives of cellulose may be formed from solutions of the same in suitable solvents by extruding said solution through orifices into a dry or evaporative atmosphere as in dry spinning or by extruding through orifices into a bath containing a precipitating liquid as in wet spinning. Such filaments may be treated at this point by my process. While in the untwisted state two or more filaments may be associated together by twisting to form yarns or threads, which yarns or threads may be treated by my process. Although the filaments or yarns made from same may be treated in accordance with my process prior to being cut into staple length, I prefer to first cut the filaments into staple lengths and then submerge the staples in the heated treating bath. This may be accomplished by placing the cut staple in boxes. wire mesh containers or other containers which permit the fibres to contact readily with a treating bath and submerging them in this condition in a heated treating bath.

The treating bath comprises a sulphonated fatty alcohol emulsified in water. I may employ an emulsion containing from 2 to 15%, on the weight of the water, of sulphonated fatty alcohol. As stated above, the sulphonated fatty alcohol employed, if it is one which is pasty or solid at room temperature, may be mixed with a thinner such as sulphonated vegetable oils prior to forming the emulsion. The amount of treating bath employed compared with the weight of the staple fibre is preferably such that there is placed upon the fibre from .75 to .85%, on the weight of the fibre, although larger amounts may be employed, of sulphonated fatty alcohol. The treatment of the staple fibre in the emulsion containing sulphonated fatty alcohol is preferably carried out at elevated temperatures, for instance from 50 C. to 85 C., with best results on cellulose acetate accomplished at around 60 C. If desired the staple fibre may be treated at the boil giving a coated staple that is delustered and dull.

If the staple fibres have been lubricated with mineral oils, vegetable oils and like lubricating agents in processes prior to the treatment in accordance with this invention, it is preferable to scour the same in a soap solution to remove said finishes prior to the treatment with the emulsion of sulphonated fatty alcohol. For instance, stock which contains a mineral oil finish may be washed for from 3 to 10 minutes at about 60 C. in 1 to 10 grams per litre of soap or other scouring agent or solution such that there remains on the fibre less than .2% of the mineral oil prior to treatment in the emulsion of sulphonated fatty alcohol. The oils may also be extracted with benzene or other extractant to reduce the oil content of the fibres to a substantially low figure such as 0.2% or less.

As to the length of staple fibres, lengths ranging from inch or more than 10 inches are suitable. The artificial filaments may be of any suitable weight per unit length, say from 1 to 30 amass-1 or more denier, examples of which are 1.9, 2.5, 3 or 5 denier or more.

After treatment in accordance with this invention, the short lengths of filaments or fibres are then subjected to suitable spinning operations, such as those operations used for the spinning of the short lengths of natural silk, cotton or wool fibres to form threads. Any of the well known systems may be employed to form the yarns or threads, such as the cotton system, the woolen system, the Bradford worsted system, the French system, the spun silk dressing system, the spun silk carding system, etc. These spinning operations also include the preliminary treatments necessary to pressing filaments or fibres in the form required for the actual operationof twisting them into yarn. This may include picking, forming of laps, mixing with other fibres of a different nature, carding, drawing, gilling. slubbing, spinning, etc.

In order to further illustrate my invention but without being limited thereby, the following examples are given:

- Example I Staple fibre containing 2% on the weight of the fibre of a lubricant coating of mineral oil is washed about five to fifteen minutes at 60 C. in 1 gram per litre of soap solution, run out and centrifuged dry to the touch, then immersed in a 5% emulsion of the sodium salt of sulphonated lauryl alcohol maintained at 60 C. and worked for five minutes, run out and centrifuged down to 50% moisture on the original weight of the fibre, then spread out on a floor or rack and allowed to air dry. The amount of emulsion employed is such that from .75 to .85% sulphonated alcohol remains on the fibres. If desired, the air drying operation may be carried out at elevated temperatures, say 48 hours at 40 C. or 72 hours at C. After drying the staple is put through an opener and spun by the cotton method of spinning yarns. The staple fibre is found not to load on the card clothing, is sub- I stantially free from fiy and is capable of being drafted to a yarn of count by the cotton method of measuring yarn even though the fibre is 3 to 3.5 in denier.

Example II Cellulose acetate staple fibre substantially free of finish (i. e. containing less than .2% finish) is submerged in a 5% emulsion of the sodium salt of sulphonated lauryl alcohol at 60 C. and worked for 5 minutes, run out and centrifuged down to 50% moisture, then spread out on a fioor or rack and allowed to air dry. The amount of emulsion employed is such that from .75 to .85% sulphonated alcohol remains on the fibres. After drying to a moisture regain of about 7%,

the staple is put through an opener and passed.

to a cotton card where it is formed into yarns of 30 count by the cotton method of measuring yarn. 'I'he staple fibre is found not to mat on the card clothing and has the proper co-efflcient of friction that it drafts to the fine yarn without diificulty.

It is to be understood that the foregoing detailed description is given merely by way of illustration and that many variations may be made thereinwithout departing from the spirit of my invention.

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

1. In a method of forming spun yarns containing comparatively short lengths of artificial fibres,

the step of subjecting the short lengths of fibres to a heated bath containing a sulphonated fatty alcohol, the temperature of the bath being between-50 and 85 C., and then subjecting the fibres to carding, drawing and spinning operations. m

2. In a method of forming spun yarns containing short lengths of fibres of organic derivatives of cellulose, the step of subjecting the short lengths of fibres to a heated bath containing a sulphonated fatty alcohol, the temperature of the bath being between 50 and 85 C., and then subjecting the fibres to carding, drawing and spinning operations.

3. In a method of forming spun yarns containing short lengths of fibres of cellulose acetate,

the step of subjecting the short lengths of fibres to a heated bath containing a sulphonated fatty alcohol, the temperature of the bath being between 50 and 85 C., and then subjecting the fibres to carding, drawing and spinning operations.

4. In a method of forming spun yarns containing short lengths of fibres of cellulose acetate.

the step of subjecting the short lengths of fibres to a heated emulsion of sulphonated fatty alcohol in water, the temperature of the emulsion being between 50 and 85 0., and then subjecting the fibres to carding, drawing and spinning operations.

5. In a method of forming spun yarns containing short lengths of fibres of cellulose acetate, the step of subjecting the short lengths of fibres to an aqueous emulsion of sulphonated fatty alcohol at about 60 C., and then subjecting the fibres to carding, drawing and spinning operations.

6. In a method of forming spun yarns containing short lengths of fibres of cellulose acetate, the step of subjecting short lengths of fibres to an aqueous emulsion of sulphonated lauryl alcohol, the temperature of the emulsion being between 50 and 85 0., and then subjecting the fibres to carding, drawing and spinning operations.

-7. In a method of forming spun yarns containing short lengths of fibres of cellulose acetate, the step of subjecting short lengths of fibers to an aqueous emulsion of sulphonated oleyl alcohol, the temperature of the emulsion being between 50 and 85 C., and then subjecting the fibres to carding, drawing and spinning operations.

8. In a method of forming spun yarns containing short lengths of fibres of cellulose acetate. the step of subjecting the short lengths of fibres to a 2 to 10% emulsion of sulphonated fatty alcohol in water, the temperature of the emulsion being between 50 and 85 0., and then subjecting the fibres to carding, drawing and spinning operations.

9. In a method of forming spun yarns containing short lengths of fibres of cellulose acetate, the step of subjecting the short lengths of fibres to a 2 to 10% emulsion of sulphonated fatty alcohol in water at from 50 to 70 0., and then subjecting the fibres to carding, drawing and spinning operations.

10. In a methol of forming spun yarns containing short lengths of fibres of cellulose acetate, the step of subjecting the short lengths of fibres to a 2 to 10% emulsion of sulphonated fatty alcohol in water at 60 C., and then subjecting the fibres to carding, drawing and spinning operations.

WILLIAM WHITEHEAD.