US2098633A - Apparatus for the production of artificial thread - Google Patents

Description

Nov. 9, 1937. 'o. s. PETRESCU APPARATUS FOR THE PRODUCTION OF ARTIFICIAL THREAD Filed Sept. 26, 1934 2 Sheets-Sheet l R. E mu MM C R N6 0 wm6fi d A P 1W/ 5 d .v 0. G1 Y I B "I" NOV. 9, 1937. s, scu 2,098,633

APPARATUS FOR THE PRODUCTION OF ARTIFICIAL THREAD Filed Sept. 26, 19:4 2 Sheets-Sheet 2 FIG. 4-.

FIG. 5.

INVENTOR. Ovid 5. .Petmsvu BY I C; ATToRiEY. I

Patent ed Nov. 9, 1937 UNITED STATES PATENT OFFICE,

APPARATUSARFOR THE PRODUCTION TIFIOIAL- THREAD Ovid S. Petrescu, Nashville, Tenn., assignor, by mesne assignments, to E. I. du Pont de Nemours & Company, Wilmington, Del., a corporation of Delaware Application September as, 1934, Serial No. 745,575

1 Claim.

high speed operation, and in which the artificial thread is more completely protected against damage from treating liquids.

In the manufacture of artificial thread from viscose, centrifugal buckets may be used for a great many purposes. The thread may first be spun into a centrifugal bucket to produce what is commonly known in the art as a bucket cake. The bucket cake may be treated in a centrifugal bucket with various treating solutions, in which case, the treating solutions, such as washing liquids, bleaching liquids or desulfurizing liquids are passed through the cake by centrifugal force. It may further be desired to remove as much liquid as possible from the cakes which have been treated with the treating solutions, and this is commonly done by submitting the cakes to wring- 25 ing or whizzing at high speeds in centrifugal buckets. In all of these operations, it is of primary importance to remove liquid adhering to the thread or cake and passing it from the bucket. The constant tendency of the artificial thread manufacturing industry is to increase the speed of centrifugal buckets to gain increased efllciency of production. The speed at which buckets may be rotated is at. present materially limited because of the bucket construction which 35 is necessary to obtain the desired drainingof the liquids therefrom without undue corrosion of the bucket and damaging of the yarn-by contamination with products of corrosion.

To properly drain the liquids from the bucket,

40 it was found necessary to perforate the walls of the same so that the said liquids may be forced therefrom. To prevent contamination of the yarn, the buckets must be made of a material which is inert to the various treating solutions.

45 =Since none but very-expensive, and consequently uneconomical, commerciallyavailable metals are entirely inert to the treating solutions commonly used, the art has almost uniformly adopted resinous condensation products, such as, for example,

50 a phenol formaldehyde condensation product, for

the construction of buckets or bucket liners.

Various attempts have been made to improve the construction of centrifugal buckets so as to be able to'increase the speed with which the buckets are rotated. These improvements include the moulding of buckets from plastic material in which is embedded fabric, metallic bands, wire or similar reinforcing materials. Buckets have also been made of aluminum, aluminum alloy or other metals, andother improvements have been made in which metal wire, bands, or a' sheet covers the outer periphery of the moulded bucket. In all of these prior art improvements, the buckets were provided with perforations through the walls thereof, and due to the high corrosive action of treatment liquors, they were soon rendered worthless and the products of corrosion often produced irreparable damage to the thread.

It has furthermore been suggested that buckets be made of metal such as aluminum with a liner of suitably inert material such as a resinous condensation product and in which drainage perforations are provided only through the said liner, the liquids being passed laterally through the liner and outwardly through a suitable bore or groove between the liner and the outer shell.

Although the latter improvement has permitted a material increase in the bucket strength with a consequent increase in bucket speed, there are some disadvantageous features in this-construction in that it does not sufficiently prevent deleterious corrosion of the outer metallic she'll 'and that it does not entirely eliminate contacting of the yarn with products of corrosion.

It is therefore an object of this invention to provide a new and improved centrifugal bucket of artificial thread in which neither the liner nor the outer shell has perforations therein.

A still further object of this invention is the production of a centrifugal bucket liner which is efficient, of low cost production and easy tofabrlcate.

Other objects of the invention will appear herelnafter.

The objects of the invention are accomplished in general by constructing a bucket with a strong shell, preferably of metal, anda liner of corrosion-resisting material, said liner being pro- -vlded with axial grooves on the inner surface thereof, and constructed in such a manner as to of the bucket, without passing through either the liner or the shell.

The details of the invention and the advantages thereof will become more clearly apparent by reference to the following description taken in connection with the accompanying illustrations in which:

Fig. 1 is a vertical sectional view of a wringing bucket shell and liner constructed in accordance with this invention.

Fig. 2 is a top plan view of the wringing bucket shown in Fig. 1.

Fig. 3 is a vertical sectional view of a washing bucket and liner therefor, constructed in accordance with this invention.

Fig. 4 is a top plan view of the liquid treatment bucket shown in Fig. 3.

Fig. 5 is a vertical sectional view of a liner for a spinning bucket constructed in accordance with this invention. i

Fig. 6 is a fragmentary view oi. a washing bucket liner showing a modified form of groove.

Referring more in detail to the drawings, reference character I I designates a wringing bucket shell which is preferably composed of a corrosion resistant material having a high tensile strength such as,- for example, forged aluminum, Monel metal, or stainless steel. The shell I I is provided with an externally projecting flange i3 through which it may be fastened to the flange of 'a drive shaft (not shown) by means of screws or bolts. The shell is also provided with an internally projecting member l8 opposite the flange I3. The flange l3 and member l8 are provided with a common bore I! for reception of the drive shaft by means of which the bucket is to be rotated. Due to the provision of this internally projecting member l8, the flange l3 may be positioned closely adjacent the bottom of the bucket, thus adding materially to the strength of the bucket and eliminating any undesirable wabbling thereof. This is particularly important in the construction of wringing buckets in view of their high rotational speed, as a result of which severe, unbalancing forces are set up. A bucket liner Hi is iltted snugly into the internal surface of the shell II. This liner is preferably composed of a material substantially chemically inert to the liquid content of the bucket cake, such as hard rubber, or a resinous condensation product. The liner I4 is imperforate and substantially covers all portions of the shell H which might otherwise be contacted by the bucket cake.

Inasmuch as bucket cakes, which are to be subjected to a wringing operation, are somewhat uneven and contain a certain amount of slack. the wringing bucket liner I4 is constructed with a plurality of somewhat flattened internal portions i! which are adapted to take up such slack and unevenness of the cake. Due to the highv speeds at which wringing buckets. are rotated, the flattened portions l1 eliminate injury to the thread by preventing rotation of the bucket relative to the bucket cake. The internal surface of the bucket is provided with a plurality of comparatively narrow, axially'extending grooves I! for removai of theliquid forced from the bucket cake. The width of these grooves is of the order of a! to M; of an inch, and in the wringing bucket illustrated by Figs. 1 and 2 they are preferably about A, of an inch inwidth. The depth of the grooves may vary between and Y; of an inch and is preferably about 1 of an inch. The upper portion of the liner I4 is constructed with an internally bevelled edge I6 so that the bucket cake may be easily inserted into the bucket with 'which y it has a comparatively snug fit.

The bucket illustrated in Figs. 3 and 4 is particularly adapted for the liquid treatment of bucket cakes, such as, washing, desulfuring,

bleaching, etc. Since these operations are usually carried out at considerably lower speeds than the above described wringing operation, and inasmuch as a great volume of treating liquid is.

ordinarily forced through the bucket cakes in the liquid treatment thereof, the flattened por- -tions, the internally bevelled edge and the interuid to approximately the same extent as the other portions thereof. The liner 24 is provided on its internal surface with axially extending grooves similar to the grooves in the wringing bucket. These grooves may vary considerably in width, but are preferably kept at approximately the same width as those of the wringing bucket to prevent damaging the bucket cake thread. Since these grooves must be made rather narrow to prevent damaging the thread, but must necessarily conduct a large volume of liquid from the bucket, they may be constructed in the manner shown by Fig. 6, in which 24 designates a section of the liner. The liner is provided with enlarged grooves 28 which communicate with the internal surface through the comparatively narrow slots 25, thus allowing the removal of a large volume of liquid without the use of large gaps between adjacent portions of the bucket. Alternatively.

the grooves in the washing bucket may be made of greater depth to take care of the large volume of liquid.

Fig. 5 shows a liner for a spinning bucket. This liner is preferably made with an outside section 3| of a resinous condensation product, such as product, reinforced with a fabric, and an inside section 33 of a smooth surfaced resinous condensation product. I The inner surface of the spinning bucketliner is provided with axially extending grooves 34 similar to the grooves of the wringing and washing buckets. The grooves 34 are preferably made considerably narrower than the grooves l5 and 25 to prevent deformation of the freshly formed and somewhat plastic er when it is forced against the side walls of t e spinning bucket. The number of grooves can also be materially reduced inasmuch as the volume of coagulating fluid adhering to the thread and which is to be removed from the bucket is comparatively small. The depth of the grooves 34 is preferably about of an inch through the greatest part of their length; but adjacent the top of the bucket upon which a cover (not shown) is usually positioned, the slots are shown by numeral 35 as being upwardly inclined and of considerably greater depth so as to permit the fluid to pass around the cover and to remove, more efllciently, the liquid therefrom. Obviously, this liner can a phenol-fornialdhyde condnsation be made of a single piece instead of the two-piece construction shown.

In the various modiflcations'illustrated, the

liquid is drained from the cake by centrifugal grooves. The liquid travels upwardly in the K grooves in a substantially vertical direction to be thrown from the bucket adjacent the upper edge thereof.

The liquid, as passed from the bucket, cannot contact the metallic outer shell and again flow back into contact with the yarn of the cake.

Such liquids as remain in the bucket to recontact the yarn will notv have had any contact with the metallic portions of thecbucipet. thus eliminating the damaging of thread by contact with products of corrosion. I

A further advantage, derived from the use of the imperforate shell and liner, is that buckets of greatly increased strength can be manufactured, and with very little danger that the buckets will deteriorat from corrosive action of treating liquids accumulating between the shell and liner. Consequently, considerably greater rotational speeds can be safely employed than were possible heretofore. Furthermore, the cost of the buckets can be very materially reduced in view of the simple design.

Since it is obvious that various changes and modifications may be made in the above description and accompanying illustrations, without departing from the nature and spirit thereof, it is to be understood that the invention is not to be limited thereto except as set forth in the appended claim.

I claim:

In a centrifugal bucket for the production and treatment of a bucket cake, an imperiorate side wall, the thread-contacting surface of which is composed oi a substance which is substantially inert to liquids used in the production and treatment of said artificial thread, aplurality of axially extending grooves in the said side wall surface thereof, and narrow slits connecting the said grooves with the thread-contacting surface of said side wall;

DVD 8. PE'IRESGU.

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