US2142912A - Treatment of cellulose derivative materials - Google Patents

Description

Jan. 3, 1939.

R. W. MONCRIEFF ET AL TREATIIJENT OF CELLULOSE DERIVATIVE MATERIALS Filed Dec. 2'7. 193'? Patented Jan. 3, 1939 TREATMENT OF OELLULOS E DERIVATIVE Bobert'Wighton Moncrlei! and Frank Brentnall Hill, Spondon, near Derb England, assignors to Celanese corporation oi. America, a corporation Delaware Application Mma. :1, 1937, Serial No. 181,78

In Great Britain January is, 11m

scum.

This invention relates to improvements in the treatment of cellulose derivative materials, and particularly to improvements in processes wherein cellulose derivative filaments, yarn and similar materials are stretched.

In U. 8. application 8. No. 69,282, filed March 17, 1936, apparatus for stretching artificial filaments and similar materials in the presence of steam is described, which comprises a steam stretching chamber and an end pressure chamber for inert fluid connected therewith. -The specification also'describes a process of stretching using this apparatus in which the end pressure chamber contains compressed air or other inert gas.

It has now been discovered that the use of water in the end chamber improves the voluminosity oi the product, especially if the water is employed at a pressure slightly greater than W that of the steam.

According to the present invention therefore artificial filaments, yarns and similar materials made of cellulose acetate or other organic derivative of cellulose are passed through an end 5 pressure chamber containing water in substan:-

tially non-slipping contact with a positively driven reed device contained in the chamber and then through saturated or wet steam at a temperature above 100 C. in a steam chamber,

stretching being effected during the passage of the materials through the steam chamber.

The water is preferably circulated continuously through the end pressure chamber in order that it may be maintained at a constant temperature. The invention is particularly COR-r cerned with the use of water at approximately room temperature, e. g., -30 C., and while it may be employed at higher temperatures its temperature should not be so high as to bring the materials into a condition such that stretching takes place prior to their entering the steam stretching chamber.

The pressure of the water in the end chamber may be the same as that of the steam in the stretching chamber or below or above this Dressure. Any difierence between the pressures in the two chambers is, however, preferably small in any case, for example of the order or 1 or 2 up to 5 or 6 pounds per square inch.

The feed device contained in the end chamber may be a positively driven roller in combina-- tion with two guide bars or two or more positively driven rollers .not in contact with; each other, the combination of roller and guide bars or of rollers being so arranged that the angle oi.

lap of the materials on the roller or rollers is such that there is substantially no slip. Alternatively,;twoor more driven rollers which are in contact'with each other-may be employed, the yarn passing through the nip or nips oi the rollers.

Saturated or wet steam may be employed in the steam stretching chamber at a temperature of, for example, or C. or more, and the pressure oi the water in the end chamber may, torexamplabe 15, 25 or 35 pounds per square inch or more. In order to increase the wetnessoi the steam water may be sprayed into the steam chamber through one or more sprays positioned therein, e. g., near the yarn inlet. On the other hand, good results may be obtained without the use of the spray. I

The materials may be sprayed with cold water immediately on issuing from the steam stretching chamber in order that the action of the steam may be sharply confined to the materials during their passage through the stretching chamber. a

The position oi the end-box and stretching chamber maybe such that the materials pass through the apparatus substantially in a horizontal plane, or it may be such that they follow a path which. is inclined. to the horizontal, e. g., at 45 (2., or which is vertical.

The accompanying drawing illustrates diagrammatically anapparatus which may be employed in carrying out the process of the present invention, 7 i

Figure 1 being a longitudinal cross-section of the apparatus, and

Figure 2 a cross-section on the line 22 of Fis- 1.

In carrying out the process of the present invention using the apparatus illustrated in the accompanying drawing, a number of threads-I from a creel of bobbins 2 pass over a guide and through orifices 3 into an end chamber 4. In the end chamber they pass in contact with a .feed device 5, and then through orifices 6 into a steam chamber 1 from which they emerge through orifices I and pass in contact with a stretching device 0 and over a guide to a creel Y or bobbins Ill.

The end chamber 4 which is provided with a pressure gauge I2 is filled with water under pressure through the inlet II, the rate of flow oi the water being regulated by means of the valve on the outlet pipe 14. Steam is introduced into the steam chamber 1 through the steam inlets II, and this chamber ,is provided with a pres-- it in any way.

Example 1 Dry spun cellulose acetate yarn is passed in contact with a feed device contained in an end chamber through which water is passed under pressure, and then from the end chamber into and through a steam chamber in which it is stretched by means of a positively driven stretching device positioned outside the steam chamber. The water passed through the end chamber is at approximately atmospheric temperature and under a pressure of about 36 pounds per square inch, while the steam, which is wet, is under a pressure of about 38 pounds per square inch gauge. The length of the steam chamber is about 9 inches,- and the yarn is stretched to about 10 times its original length.

Example 2 'exception that the water pressure is about pounds per square inch below that of the steam.

Example 3 Dry spun cellulose acetate yarn is stretched as described in Example 1, with the exception that the water pressure is about /2 pound per square inch above that of the steam.

In each case a product having a considerably increased tenacity is obtained.

The properties of the materials, and particularly their tenacity and extensibility, may be varied considerably by variation of the stretching conditions, for example the temperature of the steam employed, the relation between the pressure of the steam in the steam chamber and the water in the end chamber, the degree 01' stretch, the size and number of the steam inlets and the length of the steam chamber. For example, by suitable variation of the conditions cellulose acetate yarns having a tenacity of 2, 4 or 5 grams per denier or even more may be obtained.

While the present invention is of particular importance in the treatment of materials made of cellulose acetate, it may alsobe employed in the treatment of materials made of other organic derivative of cellulose, for example cellulose propionate, butyrate and nitro-acetate, and methyl, ethyl and butyl celluloses.

Having described our invention, what we desire to secure by Letters Patent is: '51. Process for the treatment of artificial materials, which comprises passing artificial filaments, yarns and similar materials made of organic derivatives of cellulose through a body of water under superatmospheric pressure in an end pressure chamber and in substantially non-slipping contact with a positively driven feed device contained in the chamber and then through saturated or wet steam at a temperature above 100 C. in a steam chamber, and stretching the materials during their passage through the steam chamber.

2. Process for the treatment of artificial materiais, which comprises passing artificial filaments, yarns and similar materials made of cellulose acetate through, a body of water under superatmospheric pressure in an end pressure chamber and in substantially non-slipping contact with a positively driven feed device contained in the chamber and then through wet steam at a temperature above 100 C. in a steam chamber, and stretching the materials during their passage through the steam chamber.

3. Process for the treatment of artificial materials, which comprises passing artificial filaments, yarns and similar materials made of organic derivatives of cellulose through a body of water under superatmospherio pressure in an end pressure chamber and. in substantially non-slipping contact witlr a positively driven feed device contained in the chamber and then through saturated or wet steam at a temperature above 100 C. in a steam chamber, and stretching the materials during their passage through the steam chamber, the difference in pressure between the water and steam being 5 lbs. per square inch or less.

4. Process for the treatment of artificial materials, which comprises passing artificial filaments, yarns and similar materials made of cellulose acetate through a body of water under superatmospheric pressure in an end pressure chamber and in substantially non-slipping contact with av positively driven feed device contained in the chamber and then through wet steam at a temperature above 100 C. in a steam chamber, and stretching the materials during their passage through the steam chamber, the difference in pressure between the water and steam being 5 lbs. per square inch or less.

5. Process for the treatment of artificial mas terials, which comprises passing artificial filaments, yarns and similar materials made of organic derivatives of cellulose through a body of water under superatmospheric pressure in an end pressure chamber.and in substantially nonslipping' contact wtih a positively driven feed device contained in the chamber and then through saturated or wet steam at a temperature above 130 C. in a steam chamber, and stretching the materials during their passage through the steam chamber, the difference in pressure between the water and steam being 5 lbs. per square inch or less.

6. Process for the treatment of artificial materials, which comprises passing artificial filaments, yarns and similar materials made of cellulose acetate through a body of water under superatmospheric pressure in an end pressure chamber and in substantially non-slipping contact with a positively driven feed device contained in the chamber and then through wet steam at a temperature above 130 C. in a steam chamber, and stretching the materials during their passage through the steam chamber, the difference in pressure between the water and steam being 5 lbs. per square inch or less.

7. Process for the treatment of artificial materials, which comprises passing artificial. filaments, yarns and similar materials made of organic derivatives of cellulose through a body of water under superatmospheric pressure at a temperature of 30 C. or less in an end pressure chamber and in substantially non-slipping contact with a positively driven feed device contained in the chamber and then through saturated or wet steam at a temperature above 100 C. in a steam chamber, and stretching the materials during their passage through the steam chamber.

8. Process for the treatment of artificial materials, which comprises passing artificial filaments, yarns and similar materials made of cel- 'lulose acetate through a body of water under superatmospherlc pressure at a temperature of 30 C. or less-in an end pressure chamber and in substantially non-slipping contact with a positively driven feed device contained in the chamber and then through wet steam at a temperature above 100 C; in a steam chamber, and stretching the materials during their passage through the steam chamber, the difference in pressure between the water and steam being 5 lbs. persquare inch or less.

9. Process for the treatment of artificial materials, which comprises passing artificial filaments, yarns and similar materials made of cel- CERTIFICATE OF CORREG I'I 0N Patent No. 2,1) 2, 912.

ROBERT WIGH'ION MONCRIEFF ET AL.

superatmospheric pressure at a temperature of 30 C. or less in an end pressure chamber and in substantially non-slipping contact with a positively driven feed device contained in the chamber and then through wet steam at a temperature above 130 C. in a steam chamber. and stretching the materials during their e through the steam chamber, the diflerence in pressure between the water and steam being-1o 5 lbs. per square inch or less.

ROBERT WIGH'ION MONCRIEFF. FRANK BRENTNALL HILL.

January 3, 1939.

' .It is hereby certified that error appears in theprinted specification of the above numbered patent requiring correctionas follows: Page 2, first column, line 17, after the word "inc h" insert gauge; and" second column, line 75, claim 8, for the syllable cel-" read cellulose acetate through a body of water under; and that the said Letters Patent shouldbe read with' this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 7th day of Harch, A. D. 1939.

(seal) Henry Van arsdale.

Acting Commissioner of Patents.

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