US2290929A - Production of artificial filaments - Google Patents

Description

y 28, 1942. w. WHWE EAD 2,290,929

PRODUCTION OF ARTIFICI'Z L FILAMENTS Filed March 20 1940 INVENTOR ATORNEY5 Patented July 28, 1942' PRODUCTION OF ARTIFICIAL FILAMENTS William Whitehead, Rye, N. Y., assignor to Celanese Corporation of America, a corporation of Delaware Application March 20, 1940, Serial N0. 324,965

4 Claims.

This invention relates to the manufacture of artificial or synethetic filaments, and relates more particularly to a novel method of an apparatus for the manufacture of artificial or syntlietic filaments of improved textile character- 18 s.

In the manufacture of artificial or synthetic filaments from solutions of cellulose derivatives in volatile solvents by methods in which the solutions are extruded into a setting medium, the extruded filaments, either singly or associated together agflthreads, are led, with or without twisting, to bobbins or other winding supports or devices, located outside of the spinning cabinet on which they are wound. Heretofore the thread of associated filaments was led through aguide positioned substantially at the opening leading from the spinning cabinet, passed through said opening, wound about a feed or godet roller and finally wound on to a bobbin or like support, the feed or godet roller operating at such a speed that the filaments were drawn down or extended mor or less to produce filaments of increased strength and of the denier desired.

I have now found that cellulose derivative filaments of highly desirable characteristics may be obtained by extruding the cellulosev derivative spinning solution into the form of filaments and then collecting them without drawing them down. In accordance with my process, the extruded filaments are permitted to fall of their own weight whereby they are allowed to contract in length. The denier of the filaments formed by my novel process will vary with the length of the cabinet or the length of the fall of the filaments. Thus, where the formed filaments fall through a greater distance the filaments have a greater unsupported length and the weight thereof tends to stretch the same. Accordingly, filaments of the finer denier result.

' Furthermore, the denier of th filaments formed may be varied by varying the size of the orifices in the spinnin nozzle.

Filaments produced in accordance with my invention have been found to have increased strength and an elongation from '40 to 50% greater than filaments produced by prior methods, greater resiliency and greater thermal insulating properties. Moreover, the filaments produced according to my novel process have a rougher surface longitudinally thereof than filaments made by prior processes, i. e. they have a plurality of continuous or irregular relatively deep indentations or canals extending along the length thereof. Such rough surface filaments are particularly suitable for the production of staple fiber since they have natural, inherent good spinning qualities and substantially permanent binding power, thereby obviating the necessity of putting a crimp in the same. Blankets, suitings and like fabrics made from such staple fibers are substantially free from shedding and have higher thermal insulating qualities presumably on account of the air spaces'between the deep striations in the filaments.

It is an important object of this invention to provide a process for the economic and expeditious manufacture of artificially produced filaments having increased strength and elongation, greater resiliency and greater thermal properties than artificial filaments heretofore made.

Another object of this invention is the production of staple fibers of improved textile characteristics.

A further object of this invention is the provision of a simple, efiicient and inexpensive apparatus for producing the improved filaments.

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

In the accompanying drawing, wherein one embodiment of my invention is shown,

Fig. 1 is a diagrammatic representation of a portion of a metier with means for withdrawing the filaments therefrom, and

Fig. 2 is a detailed view showing the filaments being led to a device for converting the same into staple fiber.

Like reference numerals indicate like parts in both views of the drawing.

Referring now to the drawing, the metier, which is generally indicated by reference numeral 3, may contain any desired number of spinning nozzles l arranged in the upper part of the metier, each being formed with a number of spinning orifices to form a corresponding number of filaments. While Fig.1 shows a metier having five compartments or cells 5 separated from each other by vertical partitions 6 and each containing one spinning nozzle, it is to be understood partments or cells may be arranged in a row and that each of said compartments or cells have more than one spinning nozzle. The spinning nozzles are, of course, supplied with the spinning solution from any convenient supply header, not

shown, and the metier is insulated in any suitable manner as is well known in the art.

The filaments I as they are formed are permitted to fall of their own weight upon an endless conveyor belt 8, carried by pulleys 9 and II that any suitable number of such comdriven in any suitable manner, which conveyor belt removes the filaments from the metier. Since no tension is applied to. the filaments they contract in length before meeting the conveyor belt 8. Preferably, the conveyor belt is arranged to travel at a linear speed equal to or less than the rate of speed at which the filaments fall. The lower edges of the walls-of casing 3 should be as close as possible to the conveyor belt 8 or otherwise so arranged as to admit little external air.

A roller l2, which may be an idler and of any suitable size, is positioned above the pulley H and with the conveyorbelt 8 acts as a nip roller ar- 01 celllulose such as, for example, acetates of cellulose hydroxy ethyl-ethers may be employed.

-It is to be understood that the foregoing detafled description is merely given by way of illustration and that many variations may be made therein without departing from the spirit of my invention.

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

rangement through which the collected filaments pass and are fed forward. Suitably spaced from the pulley, II and the roller l2 are nip rollers l 3 and H which preferably rotate at a. peripheral speed greater than that of the roller I2 and the conveyor belt 8, whereby the filaments in the /sliver l5 are caused to straighten out.

The nip rollers l3 and I4 feed the sliver into a coiling can It. Or the sliver may be wound upon a support by any suitable winding device. However, as shown in Fig. 2, a sliver I 5 may be passed. from the conveyor belt 8 towards a cutting device, generally indicated by reference II, by the agency of an ejector device generally indicated by reference numeral I 8,the sliver passing through the cone I! of the ejector device and a blast of compressed air or other fluid admitted from the conduit to annular space 2|, which blast of compressed air draws or sucks the filaments of the sliver through the apex of the cone carrying'the sliver to the cutting devices.

The cutting device comprises a, rota ing member 22 mounted on a rotating shaft 23 and has any suitable number of plates or knives 24. These blades or knives cooperate with a stationary blade 25 mounted on a block 28 which may be adjustable with respect to the rotating blades or knives 24 by means of a screwbolt-fl. The

' cut staple made up is blown into a chute 28 and collected in a suitable receptacle not shown. If it is desired to app y a finish to the filaments, it is preferable to apply the same while the filaments are still on the conveyor belt.

My invention is particularly applicable to the production of artificial filaments or staple fibers having a basis of cellulose acetate or other cellulose derivative produced by the dry or evaporative method of spinning. Examples of other cel-- lulose derivatives which may form the basis of the filaments or staple fibers are cellulose propionate, cellulose butyrate, cellulose aceto-propionate, cellulose aceto-butyrate, thiocarbamic and alkoxy alkacyl esters of cellulose, cellulose condensation products of cellulose with glycols or other polyhydric alcohols. Similarly ester-ethers 1. Process for the production of artificial filaments or threads, which comprises extruding in a downward direction a spinning solution into a setting medium, permitting the formed filaments to fall of their own weight, without the application thereto of extraneous tension, on to a conveying surface moving at substantially the same rate of speed as the speed at which the formed filaments fall on to said surface and transportethers such as ethyl and benzyl cellulose, and theing the filaments on said surface from beneath the point at which they are extruded.

2. Process for the production of artificial filaments or threads, which comprises extruding in a downward direction a spinning solution containing cellulose acetate and a volatile solvent therefor into an evaporative atmosphere, persetting medium and permitting the formed filaments to fall of their own weight, without the application thereto of extraneous tension, on to a conveying surface moving at substantially the same rate of speed as the speed at which the formed filaments fall on to said surface, collecting the filaments from said surface in the form of a sliver and applying'a tension on said sliver to straighten the filaments thereof.

4. Process for the' production of artificial filaments or threads, which comprises extruding in a downward direction a spinning solution containing cellulose acetate. and a volatile solvent therefor into an evaporative atmosphere and permitting the formed filaments to fall of their own weight, without the application thereto of extraneous tension, on to a conveying surface moving at substantially the same rate of speed as the speed at which the formed filaments fall on to said surface, collecting the filaments from said surface-in the form of a sliver and applying a tension on said sliver to straighten the filaments thereof. 7

Images