US1941666A - Machine for preparing or spinning yarns or threads - Google Patents

Description

Jan. 2, 1934. 1 w. A. D1cK|E ETAL 1,941,666

MACHINE FOR PREPARING OR SPINNING'YARNS OR THREADS Filed Nov. 12, 1930 WILLIAM A. DK/KIE FRANK c. HALEW Patented Jan. 2, 1934 MACHINE FQR PREPARHNG 0R SPINNING YARNS OR THREADS vWilliam Alexander Dickie and Frank lorbyn Hale, Spondon, near Derby, England, assignors to Celanese Corporation oil America, a corporation of Delaware Application November R73, 1936, Serial No.

495,165, and in Great Britain January 3,

2 @laims. ((311. 19-45%) This invention relates to machines for preparing or spinning textile yarns and threads made of or containing artificial filaments, and in particular to the production of spun. yarns or threads, 1. e. yarns or threads made of or containing artificial staple fibres.

in the production of spun yarns or threads from staple lengths of artificial filaments, particularly when the filaments consist of a material which is practically nun-hygroscopic such as cellulose acetate or other cellulose derivative, difiiculty arises in various stages of the spinning process, due to the fact that the filamentous material becomes charged with electricity engendered by friction arising either from the spinping operation itself or by the'sliding oi the material over parts of the spinning apparatus. While the staple lengths are only loosely associated together, i. e. before they have reached a point where twist has been imparted, the result of the electrification is that continuity of the spinning operation is interfered with, the mass of staple fibres, whether as a web, sliver or roving, being attracted towards or adhering to the-- tallic parts of the apparatus lying close to or in thepath'of the mass. Since the mass has not sufiicient strength to overcome this tendency to attraction or adhesion, it frequently becomes torn or broken, with the result that continuous spinning becomes impossible.

' In the operation of carding, for example, the staple lengths are removed from the doffing roller as a wide flimsy web by a dofling knife or comb. The web, which is drawn from the deffing knife by calender rolls, passes close to the dofier knife shaft and, the fibres of the web having become fairly highly electrified during the carding operation, they are attracted to the doifer knife shaft against the pull of the calender rolls, so that rupture of the web ensues.

This difiiculty is of major importance, since breakage of the web renders impossible the collection of the fibres in the form of a sliver, as is required for the subsequent operation of spinnmg. It has been been discovered that the sliver can be successfully formed from the web by applying a neutralizing charge to the doiier knife shaft so as to prevent the attraction and break-v age of the web, or, alternatively or in addition, in the case of cellulose ester materials, by slightly saponifying the filamentous mass before the carding operation.

Further dimculties are experienced, however, when the material carries an electric charge wards such parts is prevented.

after leaving the calender rolls as a sliver, the sliver adhering to these rolls and to the calender rolls and other parts of the coiler top through which it has to pass to the sliver can, as well. as to machine parts with which it contacts on its no way to the coiler top. I

A further example of similar trouble occurs in the operation of drawing or slubbing, when several slivers are passed through a series of pairs of drawing-rollers, each pair moving faster than the last, so that the combined slivers are drawn out and fined down, and the staple fibres are brought into parallel relationship with each other in readiness for being twisted into a thread. On passing the last pair of drawing rolls the filaments which are still only loosely associated together, are apt to adhere to the lower roller, which is of steel, the sag of the material as it leaves the roller assisting the efiiect of the electric charge in causing the attraction to the roller. As in the case of carding previously mentioned, breakage again frequently occurs.

The principal object of the present invention is to avoid the above-mentioned difficulties aris- '80 1 ing from electrification of the material being spun.

According to the invention a machine for use in the preparation of spun yarns or threads from artificial materials has those parts over or near which the material passes while still in a substantially untwisted state made of or covered, with a non-conducting material, whereby the attraction of the electrically charged material to- In this manner the attraction and adherence of the filaments to parts of the spinning apparatus are overcome to such an extent that continuity of spinning is made possible, the weal: web or sliver even when charged with electricity to a high degree being no longer attracted to such parts as are treated according to the invention.

Thus in a carding engine, wherein the web of material is removed from the cylinder by means of a dofier knife, the shaft carrying such knife, which generally has a tendency to attract the web, may be covered with a non-conducting material. Also, in a carding engine or in a gill box, the calender rolls from which the web collected as a sliver is forwarded to a coiler can, may be made of or covered with non-conducting material, and in a draw-frame, the last lower draw roll may be similarly constructed. These and further instances of the application of the invention are described in detail hereafter. 1

Any suitable non-conducting material may be used for the purpose of the invention, and the parts of the machine concerned may be made wholly of such material, or covered or surfaced with such material. Wood, paper and cardboard, and cellulose acetate or other derivatives of cellulose are examples of materials which may be used for the purpose of this invention.

The invention will now be described in greater detail with reference to the accompanying drawing, but it is to be understood that this description is given by way of example only, and is in no respect limitative.

Fig. 1 shows a carding engine constructed according to the invention;

Fig. 2 shows a draw-frame or slubbing frame constructed according to the invention.

Referring to Fig. l, a carding engine constructed according to the invention comprises the usual carding cylinder 5 which carries on the points with which it is clothed fibres of the material under preparation. The fibres are removed from the carding cylinder 5 by means of a doffer cylinder 7 from which they are removed in the form of a web 6 by means of a doifer knife 8. The web 6 passes to a pair of calender rolls 9 by which it is fed forward in the form of a sliver 10. The doffer knife 8 is carried by a shaft 11 running across the machine, which shaft may if desired be covered with non-conducting material so that the broad web 6 is not attracted thereby. Alternatively the doffer knife shaft 11 may be subjected to the application of a neutralizing charge adapted to make equal the electrical potential between such shaft 11 and the web 6. The latter course, however, is not conveniently applicable to other and more remote parts of the machine by which the light, weak web 6 is apt to be attracted. It is therefore preferred to provide a shield 12 of non-conducting material, e. g. of cellulose acetate below the web on its passage from the dofier knife 8 to the calender rolls 9, to prevent it from being attracted by metallic parts beneath. The calender rolls 9 are made of or covered with celluloseacetate or other nonconducting material. After leaving the calender atinas rolls the sliver may pass up an inclined guide 14 leading towards the coiler can 15. If such a guide be provided it also will be covered with nonconducting material. Similarly the funnel 16. leading the sliver 10 into the top of the coiler can 15 and the calender rolls 17, which draw the sliver through such funnel 16, will be rendered harmless in the same manner. a

Fig. 2 shows a. draw-frame or slubbing frame, in which several slivers 20 are passed through a set of feeding rollers 21, over a guide 22 and a guide plate 23, and so through a series of pairs of drawing rollers 24, of which each pair rotates faster than the preceding pair, so that the composite sliver 25 is drawn out and the staple fibres brought into parallel relationship prior to being twisted into a thread. On passing the last pair of drawing rollers, the filaments are apt to adhere to the lower roller 26, which is generally of steel, the sag of the material augmenting and encouraging such an effect. According to the invention therefore, the lower roller of the last pair of drawing rollers is made of or covered with non-conducting material. Conveniently, the roller is made solidly of nonconducting material. The sliver then passes to a coiler can 15 through a funnel-16 and calender rolls 1'7 all of similar construction to those described with reference to Fig. 1.

What we claim and desire to secure by Letters Patent is:--

1. A carding engine for use in the preparation of spun yarns from artificial fibres, said carding engine comprising a vibrating dofi'er knife to remove the material from the carding cylinder,

and a shaft carrying said knife, said shaft having a surface of cellulose acetate.

2. Apparatus for use in the preparation of spun yarns from artificial fibres, comprising a guide member and.a pair of calendar rolls for leading the material being spun while it is substantially in an untwisted state into a coiler can, said guide member and calender rolls having surfaces of cellulose acetate.

WILLIAM ALEXANDER DICKIE. FRANK CORBYN HALE.

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