US2142721A

US2142721A - Manufacture of artificial yarns or other materials

Info

Publication number: US2142721A
Application number: US121150A
Authority: US
Inventors: Dreyfus Henry; Finlayson Donald
Original assignee: Celanese Corp
Current assignee: Celanese Corp
Priority date: 1935-02-01
Filing date: 1937-01-18
Publication date: 1939-01-03
Anticipated expiration: 1956-01-03
Also published as: US2142716A

Description

Jan. 3, 1939. DREYFUS r AL 2,142,721

MANUFACTURE OF ARTIFICIAL YARNS OR OTHER MATERIALS Original Filed Feb. 1, 1935 Patented Jan. 3, 1939 UNI-TED STATES PATENT OFFICE MANUFACTURE OF ARTIFICIAL YARNS OR OTHER MATERIALS Henry Dreyfus, London, and Donald Finlayson, Spondon, near Derby, England, assignors to Celanese Corporation 01 America, a corporation oi Delaware Original application February 1, 1935, Serial No. 4,511. Divided and this application January 18, 1937, Serial No. 121,150. In Great Britain February 2, 1934 10 Claims. (Cl. 8-132) lose ester or ether and having improved properties, particularly improved tensile strength,

The application is a-divisional application of our application S. No. 4,511 filed February 1, 1935.

The production of materials of the above character, and particularly filaments and similar textile materials, having an increased tensile strength is of considerable importance from the commercial point of view. The processes which have been hitherto proposed with this object have involved subjecting the threads or other materials to a stretching'operation, and in order to obtain substantial increases in tensile strength it has been considered necessary to subject the materials to the action of liquids which are solvents or swelling agents for the materials, for example dioxane, acetone, acetic acid, and'diacetone alcohol, all applied for example in aqueous solution. It has also been suggested to use such liquids in the vapour state.

. square inch above atmospheric pressure. The

best conditions for treatment are dependent upon the degree of stretch required and the rate of stretching and upon a number of factors to be referred to hereinafter. For relatively low degrees of stretch the pressure may be only slightly above atmospheric pressure, for example only a few pounds above atmospheric pressure. I

By the new process degrees of stretch of 200% or more may be obtained, particularly when the water is employed at a temperature above 125 0., for example stretches of many hundreds per cent.

By employing appropriate temperatures for giving high degrees of stretch, filaments and threads of very fine denier and similarly thin foils, films and the like may be obtained.

Textile materials to be treated in accordance with the invention may be threads or other materials composed of continuous filaments, or may be spun yams made of short or more or less long lengths of filament, and'may be obtained by-cutting up or by any other suitable process, ior example the process of U. S. Patent No. 2,077,078. The materials may initially have any desired lustre from a high lustreto medium lustre or approximately the lustre of natural silk or even a dull lustre or no lustre at all. Thus, the materials may have a low lustre due to the presence therein of titanium dioxide or other pigments. Preferably the materials on entering the hot Water are substantially free from volatile solvents.

The operation maybe carried out on the materials in any suitable form; for example threads may be stretched in hank form, for instance between rollers positioned in a vessel containing the hot water. Preferably, however, stretching of the materials is effected during the course of their travel from one point to another. The .treatment may be applied to a single thread, e. g. during winding from a cake or cheese orbobbin on to a bobbin, or it may be applied to a .number of threads simultaneously. Thus, artificial threads may be stretched while running from one creel of bobbins to another creel. When simultaneously stretching a number of threads, it is advantageous to arrange the threads in parallel alignment in the form of a sheet or, if desired, in the form of two parallel sheets.

The stretching operation may be carried out so that the desired degree of stretch is obtained ina single stage of stretching or, if desired, intermediate rollers or other stretching devices may be provided so as to carry out the stretch in more than one stage.

Apparatus enabling the stretching to be car ried out is described in our co-pending application No. 47,798 filed November 1, 1935. Broadly the apparatus comprises a substantially closed chamber for the hot water provided with heating 7 means for water in the chamber and with one or moreinlet and outlet orifices for the materials, associated with means for stretching the materials while in the chamber. may be provided with a source of supply of water under pressure and means for removing the water continuously. The water chamber may further be provided with a pressure-relief valve, a water drain-ofl and a pressure gauge. The water chamber is constructed to resist the required pressure and the inlet and outlet orifices for the materials are sufliciently small to enable the pressure to be maintained.

The accompanying drawing illustrates diagram-- matically a suitable apparatus for carrying out the stretching with hot water under pressure.

Figure 1 shows a longitudinal view of the ap- The chamber paratus, largely in section, while Figure 2 shows a horizontal cross-section of the hot water chamber.

The threads I from a creel oi bobbins 2 are carried through nip rollers 3 into the hot water chamber 4, are drawn therethrough by nip rollers 5 and taken up on a creel of bobbins 6. To the hot water chamber 4 are secured closure plates 1 and 8 suitably perforated for the passage of the threads as illustrated in Figure 2. Water enters the chamber 4 by a pipe 9 from a suitable reservoir (not shown) maintained under pressure, for example by means of compressed air, and leaves the chamber by a pipe Ill. The chamber 4 is further provided with a pressure gauge H and with a steam heating coil H for maintaining the desired temperature. catch trays, illustrated diagrammatically at l3 and I4, provided with drains, serve to catch the water exuded through the orifices in the closure plates 1 and 8. A drain I5 is provided for draining the hot water chamber 4, for example for threading up the apparatus.

The length of thread subjected to the action of the hot water may be quite short and good stretching may be obtained with a length of less than one foot. However, it is preferable to extend the length of the hot water chamber to some feet, for example 3-6 feet or more, the precise length depending upon the temperature and the amount and rate of stretching.

For any particular degree of stretch and rate of stretching, a range of temperatures is available. The best temperature at which to work '5 depends upon a number of factors, including the twist on the initial thread which for quick stretching should be as small as possible, the

nature of the cellulose derivative under treat- -ment, materials made of high viscosity cellulose derivatives requiring in general rather higher temperatures than materials made of low viscosity cellulose derivatives. Furthermore, the size of the inlet and outlet orifices may have an influence upon the optimum temperature for any particular degree and rate of stretching. As previously indicated, the inlet and outlet orifices are sufllciently small to enable the pressure to be maintained. Their size may be varied with the denier of the threads undergoing stretching. In general, the temperature is preferably adjusted to enable as low a stretching tension as possible to be used.

The stretched materials may be subjected to any desired after-treatment processes. Thus, the filaments, threads and other materials may be treated with shrinking agents to improve their extensibility. Suitable processes for this 'purpose are described in U. S. Patent No. 2,058,422. In particular reference is made to the latent solvents referred to in that specification, for example a mixture of methylene chloride and benzene.

Again, stretched cellulose ester materials may be subjected to processes of saponification. The saponification may be such as to lead to a relatively small loss in weight, for example suflicient to give the materials an aflinity for cotton dyestufls, or may be complete or substantially complete, i. e. so as toeliminate all or substantially all of the ester content. The saponification may be effected under such conditions of tension that shrinkage takes place during or immediately after the saponification, this being advantageous from the point of view of the extensibility of the products.

Suitable Such further {treatments may be carried out as operations separate from the stretching or may be carried out continuously with stretching. Thus, for example, the invention includes a continuous operation which involves first stretching and then shrinking, for example a stretching to several hundreds per cent. of the original length of the material followed by a shrinking by [-12% of the length of the stretched material; a continuous operation involving stretching followed by saponification; and a continuous operation involving stretching, finally saponification.

'While the invention has been described above more particularly with reference to cellulose acetate, it may also be applied to materials containing other cellulose esters or ethers, for example cellulose formate, cellulose. propionate, cellulose butyrate, methyl, ethyl, or benzyl cellulose, or mixtures of esters and/or ethers or of mixed esters, ethers, or ether-esters. Furthermore, ribbons, foils, films, sheets and the like may be stretched by the processes described, and in the case of foils, films and the like the stretching may be either longitudinal and/or lateral or a lateral tension may be applied sufficient to prevent lateral shrinkage during the application of rials have an improved tenacity, which comprises stretching the materials to a degree greater than the dry extensibility thereof in hot water under pressure at a temperature between and C. during their travel from one point to another.

3. Process for improving the strength of filaments, threads and similar textile materials and of foils, films and the like made of cellulose acetate, which comprises stretching the materials to a degree greater than the dry extensibility thereof in hot water under pressure at a temperature between 100 C, and 110 C. during their travel from one point to another.

4. Process for improving the strength of filaments, threads and similar textile materials and of foils, films and the like made of an organic substitution derivative of cellulose, which comprises stretching the materials to a degree greater than the dry extensibility thereof in hotv water under pressure at a temperature of 110 to C. during their travel from one point to another.

5. Process for improving the strength of filaments, threads and similar textile materials and of foils, films and the like made of cellulose acetate, which comprises stretching the materials to a degree greater than the dry extensibility thereof in hot water under pressure at a temperature of, 110 to 125 C. during their travel from one point to another.

6. Process for improving the strength of filaments, threads and similar textile materials and of foils, films and the like made of an organic substitution derivative of cellulose, which comprises stretching the materials in hot water under pressure at a temperature above 125 C.

shrinking, and

7. Process for improving the strength of filaments, threads and similar textile materials and of foils, films and the like made of cellulose acetate, which comprises stretching the materials to a degree greater than the dry extensibility thereof in hot water under pressure at a temperature above 125 C. during their travel from one point to another.

8. Process for improving the strength of filaments, threads and similar textile materials made of cellulose acetate, which comprises stretching the materials to at least 200% of their original length during the course of their travel through hot water under pressure at a temperature of 15 '110 to 125 C. v,

9. Process for improving the strength of filaments, threads and similar textile materials made of cellulose acetate, which comprises stretching the materials to at least 200% of their original length during the course of their travel through hot water under pressure at a temperature above 125 C.

10. Process for improving the strength of fila merits, threads and similar textile materials made of an organic substitution derivative of cellulose, which comprises stretching the materials to at least 200% of their original length during the course of their travel'through hot water'under pressure at a temperature above 125 C.

HENRY DREYFUS. DONALD F'INLAYSON.