US 2442880 A
Description (OCR text may contain errors)
June 8, 1948.
A. SCHWARTZ 2,442,880
TEXTILE PRODUCT Filed April 4, 1944 J INVENTOR.
AARON SCHWARTZ BY x ATTORNEYS.
Patented June 3, i948 raxma rnonuo'r Aaron Schwartz, New York, N. Y., assignor to Celanese Corporation of America, a corporation of Delaware Application April 4, 1944, Serial No. 529,455
6 Claims. (31. 19-455) This invention relates to the treatment of artificial staple fibers and relates more particularly to the formation from artificial filamentary textile materials of staple length, of webs and rovings suitable for. spinning into yarns, by methods involving the application of electrostatic charges to the artificial staple fibers.
An obi ect of this invention is to provide a novel process for the production of webs of artificial staple fibers suitable for the formation of rovings to be spun into yarns on the woolen or worsted or cotton system.
Another object of this invention is the formation of webs of artificial staple fibers wherein the fibers are obtained in oriented relationship without conventional combing, carding or like processing of the textile fibers.
Yet another object of this invention is the provision of novel apparatus for the formation of webs of staple fibers by means involving the application of electrostatic charges to the staple fibers.
Other objects of this invention will appear from the following detailed description and the accompanying drawing.
In the drawing,
Fig. l is a perspective view of one form of apparatus for the production of webs of artificial staple fibers, employing electrostatic charges to effect an orientation and parallelization of staple fibers, and i Fig. 2 is a perspective view of another embodiment of my invention whereby webs of staple artiflcial fibers may be produced by the application of electrostatic charges.
Like numerals indicate like parts throughout both views of the drawing.
In forming yarns from staple textile fibers in accordance with the usual operations, the fibers are first subjected to a combing or carding operation to form a web in which the fibers are oriented and placed in substantially parallel relationship. The web of parallelized fibers, thus formed, is gathered to form a roving or tow and the latter is then subjected to a series of drafting operations whereby it is converted into a yarn. During drafting, the fibers are gradually drawn out and the relatively thick roving is progressively reduced in diameter to yield a mass of fibers of greater length but of decreased bulk. The drafting operations are continued until the roving is reduced to the desired denier and the only step remaining in forming a yarn which will be suitable for weaving into fabric is to insert a twist in the fibers. Combing and carding operations remove some shorter lengths of fibers in the process of parallelizing and orienting the fibers. The shorter lengths are usually waste. Furthermore, the combing and carding also tends to reduce the length of fibers which is quite disadvantageous since generally the longer the staple fiber length the more desirable are the yarns and fabrics produced therefrom.
I have now discovered that staple fibers having a basis of cellulose acetate or other or anic derivative of cellulose, or other textile fibers possessing dielectric properties, may be oriented and parallelized and associated in web form by employing electrostatic charges. Combing. carding and like textile operations may in this way be eliminated. With this method the shortening of the staple fibers effected during combing and carding operations is eliminated and the percentage of waste staple fibers is substantially reduced.
Referring now to the drawing, and more particularly to Fig. 1, cellulose acetate staple fibers, generally indicated by reference numeral 3, are charged into a hopper I, formed of a suitable conducting or non-conducting material, positioned adjacent to a continuous belt 5 driven, in the direction shown, by means of geared or toothed rotating rollers 6 and i. with a shaft 8 rotating in bearings 9 while roller 1 is mounted on a shaft l0 rotating in bearings I I Power for rotating rollers 6 and l is supplied through a drive chain i2 which meshes with a sprocket i3 keyed to shaft 3 and moves in the direction shown. Shaft 8 also carries a sprocket M keyed thereto which by means of a chain l5 meshing with a sprocket i6 keyed to shaft i0, causes roller i to rotate. Belt 5 is formed of a material highly conductive to electricity, such as copper, silver or other suitable metal. Belt 5 may be woven or formed in any other manner so as to be extremely flexible and capable of being bent through sharp angles without permanent deformation. Eelt 5 passes over rollers ii and I8 which are of relatively small diameter wherebv belt 5 forms a sharp angle as it passes around said rollers. Roller il is set on a shaft i9 rotating in journals 2i while roller iii is provided with a shaft 2! rotating in journals 22. The belt 5 and the entire driving mechanism are suitably insulated from the ground by means of an insulating plate 23 on which the entire device is mounted. At a point where belt 5 passes over roller i8 and out of contact with said belt is a terminal 26 of an electrostatic generator (not shown) which terminal is suitably charged with Roller ii is provided a positive or a negative charge. Terminal 24 is formed in a series of points 25. When terminal 24 is placed in close proximity to belt 5, said charged terminal induces a bound electrostatic charge on belt of opposite sign to that of the charge on the terminal. In accordance with the well-known behavior of electrostatic charges, this charge is concentrated at the point of greatest curvature where belt 5 passes over roller l8. The presence of this induced electrostatic charge of opposite sign to that of the charge on terminal 24 induces a second charge at'the opposite end 01' belt 5. This second charge is concentrated at the point where belt 5 passes over roller ll. This second induced electrostatic charge is of the same sign as that on points 25 of terminal 24. When the staple fibers 3 are allowed to fall freely to the base of hopper 4, the electrostatic charge on belt 5 attracts the fibers to the moving belt with the result that the fibers leave the hopper 4 and assume an oriented, and substantially vertical position on the belt. The horizontal motion of belt 5 carries the oriented fibers along until they are brought under a pair of endless driven belts 25 and 21. The latter are driven through a sprocket 28 keyed to shaft Ill which drives a chain 29 passing around a sprocket 30 mounted on drive shaft 3|. Shaft 3| carries a gear 32 which meshes with a gear 33 keyed to a shaft 34. Shafts 3| and 34 carry rollers 35 and 36, respectively and the rotation of said rollers causes belts 26 and 21 to move. Belts 26 and 21 are held taut by rollers 31 and 38. The mountings for all of said rollers 35, 36, 31 and 38 are not shown for the sake of clarity. Belts 25 and 21 rotate in close proximity to each other to effect a nipping action which nips the oriented fibers and causes them to be carried upward between said belts. The fibers retain their oriented position and are discharged in the form of a web 39 at the discharge end of said belts. The web may be gathered to form a roving which may be spun into a yarn in the manner heretofore described.
In the modification of my invention shown in Fig. 2 of the drawing, cellulose acetate staple fiber 3 is charged into a hopper 4 and allowed to discharge continuously on to an endless belt 40 formed of a suitable non-conducting material such as cotton. Belt 40 is driven as by roller 4| and 42. Spaced above belt 40 and substantially co-extensive therewith is a second belt 43 of like material and driven as by rollers 44 and 45. Suitable roller driving means (not shown) are provided. The shafts 46 and 41 on which rollers 4| and 44 are mounted are journaled in posts 48 while shafts 49 and 50 of rollers 42 and 45 are journaled in posts 5|. The arrangement of the belts is such that the space therebetween gradually diminishes in the direction of movement and at the discharge end of the belts they are substantially in contact. Inside each of the moving belts are terminals 52 and terminals 53, each of which are connected to a suitable electrostatic generator (not shown). Terminals 52 are positively charged and terminals 53 are negatively charged. As the moving cellulose acetate staple fibers are carried along by belt 40 they come under the influence of the electrostatic charges on the terminals 52 and 53. The action of the charges on said terminals induces positive and negative charges on the individual fibers 3 and causes the latter to become oriented to assume a parallel vertical position in the manner shown. Belts 40 and 43 gradually grip the parallelized fibers as they are carried along and, due to the gradually diminishing space between said belts, the fibers are flattened and then finally drawn out of the influence of the induced electrostatic field. The fibers are discharged on a moving belt 54 in the form of a web 55 which may be gathered to form a roving and the latter may then be spun into a yarn.
It is to be understood that the foregoing detailed description is given merely by way of illustration and that many variations may be made therein without departing Irorn the spirit of my invention.
Having described myinvention, what I desire to secure by Letters Patent is:
1. Process for the production of a web of oriented, parallelized artificial staple fibers, which comprises subjecting loose artificial staple fibers to the action of an electrostatic field so as to cause said fibers to become oriented and parallelized in a vertical plane, pressing said fibers between moving, relatively smooth surfaces to fiatten the same, and continuously removing said fibers from said electrostatic field in the form of a. fiat web of oriented, parallelized fibers.
2. Process for the production of a.web of oriented, parallelized artificial staple fibers having a basis of an organic derivative of cellulose, which comprises subjecting loose artificial staple fibers to the action of an electrostatic field so as to cause said fibers to become oriented and parallelized in a vertical plane, pressing said fibers between moving, relatively smooth surfaces to flatten the same, and continuously removing said fibers from said electrostatic field in the form of a fiat web oforiented, parallelized fibers.
3. Process for the production of a web of oriented, parallelized artificial staple fibers having a basis of cellulose acetate, which comprises subjecting loose artificial staple fibers to the action of an electrostatic .field so as to cause said fibers to become oriented and parallelized in a vertical plane, pressing said fibers between moving, relatively smooth surfaces to fiatten the same, and continuously removing said fibers from said electrostatic field in the form of a flat web of oriented, parallelized fibers.
4. Apparatus for the production of oriented. parallelized artificial staple fibers in web form, comprising a source of staple fiber supply, means including a flexible, endless driven belt for receiving said fibers, means for inducing an electrostatic field so as to cause said fibers to become oriented and parallelized on said belt, means including at least one moving surface for pressing said fibers to flatten the same and to remove said oriented, parallelized fibers from said belt in web form.
5. Apparatus for the production of oriented, parallelized artificial staple fibers in web form, comprising a flexible endless driven belt of an electrically conductive material, guide means for said belt adapted to cause said belt to be bent through a plurality of relatively sharply curved sections, means adjacent to one of said sharply curved sectiins adapted to induce a bound electrostatic charge and a free electrostatic charge on said belt, said charges being concentrated at different sharply curved portions, and a source of staple fiber supply adjacent to the sharply curved section carrying the free electrostatic charge, whereby said fibers are attracted to said moving belt and oriented and parallelized and means for removing said oriented and parallelized fibers from the belt in web form.
6. Apparatus for the production of oriented, parallelized artificial staple fibers in web form, comprising a pair of spaced, driven endless belts in superimposed position, said belts being substantially coextensive with each other and the space therebetween gradually diminishing in the direction of movement, a source of staple fiber supply at one end of said belts adapted to feed staple fiber between said belts, and means adapted to induce electrostatic charges on the fibers carried between said belts over a part of the path traversed by said belts, whereby said fibers are oriented and parallelized, and then discharged from between said belts in the form of a web of oriented, parallelized fibers after being withdrawn from. the field by the gripping action of the moving belts.
narnnanons orrm) 7 The following references are of record in the file of this patent:
UNITED STATES PATENTS Number Crompton Feb. 11, 1941