US3083435A

US3083435A - Method and apparatus for compressively pre-shrinking tubular knitted fabric

Info

Publication number: US3083435A
Application number: US707814A
Authority: US
Inventors: Cohn Eugene; Catallo Frank; Cohn Joseph
Original assignee: Compax Corp
Current assignee: Compax Corp
Priority date: 1958-01-08
Filing date: 1958-01-08
Publication date: 1963-04-02
Anticipated expiration: 1980-04-02

Description

Apr1l2, 1963 E. COHN ETAL METHOD AND APPARATUS FOR COMPRESSIVELY PRE-SHRI TUBULAR KNITTED FABRIC Filed Jan. 8, 1958 FIG. I

Eugene Co Fro/2A (a fa //0 BY Jhseph o/1h NKING INVENTO RS ATTORNEYS United States Patent C) METHGD AND APPARATU FUR CGMERE- SIVELY PRJSHRENKENG TUEULAP; KNITTED FABP-ilfi Eugene Sohn, Great Neck, Frank Cataiio, irnont, and Eoseph (John, New York, Nit! assignors to Qompax Corp, Woodside, N.Y., a corporation of New York Filed Jan 8, 1953, Ser. No. 707,8l i 5 Claims. {C 26-185) The present invention relates to a method and apparatus for preshrinking textile fabric, and more particularly to improved and efficient arrangements for treating tubular knitted fabric to provide a stabilized preshrunk fabric of improved quality and appearance.

Preshrinking of fabric may now be successfully carried out by means of mechanical compacting methods and apparatus, such as described and claimed in the copending application of Eugene Cuba at al., Serial No. 638,154, filed February 4, 1957 for Method and Apparatus for Treating Web Materials, Such as Fabrics. Mechanical compacting, in accordance with the Cohn et al. application involves, in general, feeding the fabric at a predetermined speed between a set of compacting rolls, one of which is traveling at the feeding speed and the other of which is moving at a lower speed. The fabric entering the compactin rolls is confined longitudinally up to a point immediately in front of the nip of the compacting rolls, and the action of the compactor is such that the fabric leaves the confined area at the feeding speed and passes through the roll nip at a lower speed. Deceleration of the fabric takes place in a compacting zone immediately preceding the roll nip, and the fabric in this zone is compressed longitudinally and thereby mechanically preshrunk.

The above described arrangements for mechanically preshrinking fabric are entirely effective for their intended purpose. However, mechanical compacting alone is not a complete solution to the problem of delivering finished preshrunk cloth to the cutting tables of clothing manufacturers, etc. Thus, the finished cloth must not only be shortened and stabilized longitudinally, but it must also be set to a desirable uniform width and must be uniform in appearance. Accordingly, the present invention provides improved methods and apparatus for handling tubular knitted which are capable of delivering the fabric in the desired finished form.

In accordance with one aspect of the invention the fabric, prior to compacting, is spread transversely, in fiattened form, and steamed. This sets the fabric to predetermined Width. In the treating of certain fabrics, a rather severe compacting may be required, and if this is done entirely at the compacting station the fabric may take on a different appearance on its opposite sides, which is to be avoided, if possible. In this respect, preshrinkiug of the material at the compacting station is accomplished by causing the compacting rolls to rotate at different speeds, and when the speed differential is excessive, in order to obtain a large amount of compacting, one side of the fabric (i.e. the side in contact with the feed roll) may become glazed or scuffed. The new method provides way to minimize or eliminate any differential in the appearance of the opposite sides of the fabric.

In its broadest aspects, the present invention provides a novel and improved method and apparatus for compressively treating tubular knitted fabric, to provide finished, pre-shrunk material suitable for manufacture into garments, the procedure of the invention comprising receiving the fabric in substantially dry state, setting the fabric to predetermined Width, steaming the spread fabric, immediately thereafter and in direct sequence compressively shrinking the fabric lengthwise by feeding the fabric across its width at a first speed, decelerating the fabric across its width in a predetermined compressing zone and subjecting the compressed fabric to localized pressure in the presence of heat at the end of the zone. The procedure and apparatus of the invention enables remarkable pie-shrinkage results to be achieved by enabling the fabric to be treated in substantially dry form, such that fabric emerging from the treatment can be taken directly to the cutting tables and does not require subsequent drying and finishing operations.

In accordance with another aspect of the invention, the material is spread and steamed at a point preceding the compacting station. if severe compacting is required, steam may be applied to one surface only of the fabric. Thus, it has been found that the application of steam to the fabric prior to compacting, while desirable from the standpoint of relieving some of the stresses in the material and setting it to width, tends to increase the coeflicient of friction of the material with certain parts of the compacting apparatus. In accordance with one aspect of the present invention, if severe compacting is required, steam is not applied to that surface of the fabric which is passed in contact with a fixed shoe in the compacting apparatus. This avoids excessive friction between the fabric and the shoe while at the same time providing a substantial amount of stress relief.

After compacting (and subsequent steaming, if desired), the preshrunk material may be, in accordance with the present invention, passed between calender rolls, which have the combined function of further stabilizing the compacted fabric and of calendering the surfaces of the material to give the material a finished appearance and to further equalize the appearance of the opposite sides of the fabric.

For a better understanding of the invention, reference should be made to the following specification and accompanying drawing, in which:

PK}. 1 is a side elevation of an apparatus made in accordance with the invention and adapted for use in carrying out the method of the invention, and

FIG. 2 is a fragmentary plan View of a modified form of the apparatus of FIG. 1.

Referring now to the drawing, the apparatus of the invention comprises several fabric treating stations, includa spreading station it steamim station 11, compacting station 12, steaming station 13, calendering station 14 and conveying and folding station 15. The spreading station comp-rises means to receive tubular knitted fabric 16 from a suitabl supply thereof, and means to spread and flatten the fabric. For this purpose, a propeller apparatus of the type shown in United States Patent 2,228,901 to S. Cohn et al., may advantageously be employed, it being understood, of course, that other propelling devices having similar operating characteristics may also be utilized.

As shown in FIG. 1, the spreadin means extends to a point designated by the numeral 13, which isadvantageously beyond the steaming station 11 in the direction of travel of the material. Accordingly, the material pass-,-

ing through the steaming station is in a transversely stressed condition. in accordance with one aspect of the invention, steam is applied to the material by a steamer 19 of a conventional type. in the illustrated form of the invention, the bottom surface of the fabric is subjected to steaming, if a substantial degree of compacting is required. The proper surface to be steamed is dependent upon the orientation of the subsequent processing apparatus, as will be explained.

After passing through the steaming station 11 the material enters the compacting station 12 which is advantageously an apparatus of the type described and claimed in the aforementioned pending application of Eugene Cohn et al. A compacting apparatus of this type comprises a fabric feeding roll 2% driven at a predetermined speed, a retarding roll21 driven at a lower speed, and a fabric confining shoe 22 positioned adjacent the feeding roll 25 and adapted to confine the fabric closely against the surface of the feeding roll, up to a point a short distance above the nip of the feeding and retarding rolls 26*, 21. The feeding roll 2% is driven at a speed corresponding to the reduced speed of the material through the last portion of the spreading station, so that the material is not subjected to tension after steaming. 'l' .e material, traveling at the speed of the feeding roll 20, is brought into contact with the retarding'roll 21, and thereupon caused to assume the slower speed of the retarding roll. As set forth ingreater detail in the application of Eugene Cohn et al., the arrangement of the rolls 2t 21, and confining shoe 22 is such that a compacting zone is defined between the lower end of the shoe and the nip of rolls 2? 21. Deceleration of the material from the speed of the roll 29 to the speed of the roll 21 takes place in this compacting zone, causing the material therein to be compressed longitudinally and thereby mechanically preshrunk.

As will be understood, the material passing over the feeding roll 29 and in contact with the shoe 22 is in constant motion relative to the shoe. Accordingly, it is desirable to maintain friction between the shoe and the material at'a minimum, and, for thisreason, the present invention contemplates that, if severe compacting is required, no steam'will be applied to the surface of the material contactingthe shoe.

As a general rule, the rolls 2t), 21 of the compacting apparatus have specially prepared surfaces adapted to grip the material in a desired manner, certain assemblies thereof being described in detail in the Eugene Cohn et a1. application. In the illustrated apparatus, it is contemplated that the surface of the feed roll 29 will be provided with diamond knurls approximately .068. of an inch deep, while the'ret'arding roll will be similarly knurled to a depth of approximately .O30'ofan inch, the foregoing being merely by way of example. The arrangement is such that the retarding roll 21 has a greater frictional grip upon the-fabric than the feeding roll 26 whereby the fabric is caused to assume the peripheral speed of the retar-ding roll 21 at the roll nip.

The material leaving the compacting station 12 is 1ongitudinally compressed, as explained in the Eugene Cohn et al. application. However, the material at this stage may not be in the desired finished form, since the opposite surfaces of the material may have different appearances, due to the speed differential between the feeding and retarding rolls 20, 21, particularly if a substantial degree of compacting has been effected. Moreover, the material may not be sufficiently stabilized in its preshrunk condition to withstand necessary further processing operations without some stretch. Accordingly, in the new method, the material leaving the compacting station 12 is passed through a steaming station 13-, comprising steamers 23, 24, wherein a certain amount of moisture is imparted to the fibers of the material. In this respect, at least one of the rolls of the compacting apparatus is heated, as a general rule, so that considerable moisture is driven off the fabric during the compacting operation. Restoring moisture to the fabric following the compacting operation tends to enlarge or puff up the fibers, so that both sides of the material assume the same appearance, and also seems to stabilize the fabric'in its compacted state so that such further processing operations as are required may be carried out without material loss of shrinkage.

As shown in FIG. 1, the material passing through the steaming station 13 is supported at one point by the rolls 20, 21 of the compacting apparatus and at another point by rolls 25, 26, of a calendering apparatus, to be described. It is desirable that the -material be subjected to a minimum of tension throughout the unsupported distance between rolls 2% 21 and rolls 2'5, 26 and, accordingly, the steamers 23, 24 are offset below the straight line path between the sets of rolls, so that the material is permitted to sag in the unsupported area. In addition, the how of steam upwardly from the bottom steamer 24 tends to support the material to a certain extent, so that the tensions thereon are maintained at a practical minimum. 7

Since the appearance of the finished cloth is an important consideration in the overall processing operation, the material leaving the dual steaming station 13 is advantageously passed through a oalendering station 14 comprising the calendering rolls 25, 26. The construction of the calendering station may be substantially the same as that shown in United States Patent 2,589,344 to S. Cohn et al. In general, this apparatus comprises a lower calendering roll 26 driven at an adjustable but normally fixed speed with respect to the compacting apparatus and the material propelling apparatus, and an upper calendering roll 25 which is adjustably supported with respect to the lower calendering :roll and is adapted to be brought to bear thereon under accurately adjustable pressures. Thus, the upper roll 25 will be supported on a bracket 27 pivoted at one end 28 to the frame of the apparatus and adjustably supported at its other end by springs 29, 30. The springs 29, 30 may be adjusted by means of a nut 31 in such a manner that the'roll -25is held resiliently in a precise relationship to the roll 26. Thus, the material passing between the calendering rolls may be subjected to a precise calendering pressure which may be very light, if desired. Advantageously, although not necessarily, the calendering rolls 25, 26, may be heated, as by a suitable steam supply, not shown.

The operation of calendering the material in the manner described, following compacting and dual steaming, is advantageous in that it tends to further equalize the appearance of the opposite sides of the fabric and also imparts to the fabric a smooth, calendered appearance which is desirable in the finished product.

After passing through the calendering station, the material moves to the conveying and folding station 15, comprising a conveyor 32 and a folding mechanism 33. The particular construction of theconveying and folding station does not form any part of the present invention. However, apparatus such as shown in the aforementioned Patent 2,589,334 to S. Cohn et a1. may be advantageously employed for this purpose.

Various alternatives for the specific apparatus illustratedin FIG. 1 may be utilized in carrying out the invention. Thus, by Way of example only, a wicket spreader of the type shown in FIG. 2 may be utilized in place of the propeller apparatus shown in FIG. 1. A spreader of this type includesa frame 34 adapted to be received internally of 'a'length of tubular fabric 16. One end of the frame 34 is positioned adjacent the nip of a pair of rolls 36, '37, the rollnip beingof smaller dimension than the frame 34, so that the frame cannot pass therethrough. The material 16 is fed over the frame in a direction from right to left, as shown in FIG. 2, so that the material is spread transversely and then carried through the nip of rolls '36, 37. The material leaving the roll nip passes directly to the compacting appanat-us, substantially as indicated in FIG. 1. Suitable steaming means, not shown, are placed adjacent the frame 34 so that the fabric is steamed while the fabric is in atransversely stretched condition and before the fabric passes to the compacting station.

Other alternative spreading and propelling arrangements for tubular material are exemplified by the apparatus of Patent 2,391,547, to S. Cohn et al.

As an alternative to the specific compacting apparatus illustrated in FIG. 1, it is contemplated that other mechani'cal'compacting apparatus may be utilized in the overall process. By way of example only, it may be advantageous, in connection with certain fabrics, to utilize the compacting apparatus and/or method described in United States Patents 2,765,513 and 2,765,514 to Richard R. Walton.

The method and apparatus of the invention are advantageous in that materials processed thereby have desirable improved characteristics, particularly in respect of its stabilized condition, uniform width and uniform finished appearance. The stabilized condition and uniform appearance of the material resulting from the new treatment is advantageous in that the treatment may be used as a finishing process. For example, the material may be steamed and set to predetermined width, and then corm pacted to a relatively small degree. Where the compacting apparatus is of the type described and claimed in the before-mentioned co-pending application of Eugene Cohn et al., Serial Number 638,154, the material issuing from the compacting rollers is substantially in a calendered condition and in a substantially finished form suitable for delivery to the cutting tables. Where a larger degree of compacting is effected it is usually desirable and advantageous to steam and calender the material after compacting. Any tendency for the material to assume a two-sided appearance as a result of severe compacting treatment may be offset substantially by steaming the material on one side only, prior to compacting, and steaming both sides of the material and calendering it following the compacting.

It should be understood that the specific apparatus herein shown and described is intended to be representative only, as many changes may be made therein without departing from the clear teachings of the invention. Likewise, the various steps of the new method may be combined in various ways differing somewhat from the exact method described. Accordingly, reference should be made to the following appended claims in determining the full scope of the invention.

The present application discloses in part subject matter previously disclosed in our prior application Ser. No. 638,154, filed February 4, 1957 (now U.S. Patent No. 3,015,145), and the benefit of the filing date of said previous application Ser. No. 638,154 is claimed with respect to the subject matter hereof which is disclosed in said prior application.

We claim:

1. The method of treating substantially dry tubular knitted fabric to provide finished, pre-shrunk material suitable for manufacture into garments which comprises, receiving the fabric in a substantially dry state, setting the fabric to predetermined width by spreading the fabric to substantially flattened form, steaming the spread fabric, discontinuing the spreading step and bringing the spread and steamed material into edge to edge contact with a surface moving at a predetermined first speed while maintaining substantial control over the dimensions of the fabric, and forcibly compressively shrinking the spread and steamed fabric lengthwise by feeding the fabric across its width on said surface and at said predetermined first speed into a predetermined compressing zone, decelerating the fabric across its width in said zone, and subjecting the compressed fabric to localized pressure in the presence of heat at the terminal end of said zone.

2. The method of claim 1, in which said fabric is subjected to the action of external heat substantially simultaneously with the application to said fabric of said localized pressure.

3. The method of claim 1, in which the fabric is conveyed, in the absence of any substantial tension, following the application of said localized pressure, and the conveyed fabric is controllably gathered in a series of adjacent layers in the absence of any substantial tension.

4. Apparatus for finishing substantially dry tnavelling tubular knitted fabric comprising means for flattening and spreading the fabric and setting it to predetermined width, means for steaming the fabric during its passage along said flattening and spreading means, and fabric treating means positioned to receive fabric substantially directly from the flattening and spreading means and while maintaining substantial control over the dimensions of the fabric, said treating means being adapted to forcibly compressively shrink said fabric lengthwise and comprising a pair of nip rollers forming a portion of a compression zone, one of said nip rollers being positioned to receive fabric substantially directly from said flattening and spreading means and being driven to propel said fabric across its width at a predetermined speed, the other of said nip rollers being positioned directly adjacent the first, to form a nip, and being driven to decelerate the fabric across its width to a predetermined decelerated speed.

5. Apparatus according to claim 4, which includes means for controllably gathering the material delivered from said zone, said gathering means being driven at a predetermined speed in relation to said nip rollers Whereby to controllably gather said fabric in the absence of any substantial tension.

References Cited in the file of this patent UNITED STATES PATENTS 2,228,001 Cohn et a1 J an. 7, 1941 2,263,712 Wrigley et al Nov. 25, 1941 2,391,547 Cohn et al Dec. 25, 1945 2,522,663 Chatfield Sept. 19, 1950 2,589,344 Cohn et al Mar. 18, 1952 2,590,938 Cohn et 'al Apr. 1, 1952 2,765,513 Walton Oct. 9, 1956 2,765,514 Walton Oct. 9, 1956

Claims

4. APPARATUS FOR FINISHING SUBSTANTIALLY DRY TRAVELLING TUBULAR KNITTED FABRIC COMPRISING MEANS FOR FLATTENING AND SPREADING THE FABRIC AND SETTING IT TO PREDETERMINED WIDTH, MEANS FOR STEAMING THE FABRIC DURING ITS PASSAGE ALONG SAID FLATTENING AND SPREADING MEANS, AND FABRIC TREATING MEANS POSITIONED TO RECEIVE FABRIC SUBSTANTIALLY DIRECTLY FROM THE FLATTENING AND SPREADING MEANS AND WHILE MAINTAINING SUBSTANTIAL CONTROL OVER THE DIMENSIONS OF THE FABRIC, SAID TREATING MEANS BEING ADAPTED TO FORCIBLY COMPRESSIVELY SHRINK SAID FABRIC LENGTHWISE AND COMPRISING A PAIR OF NIP ROLLERS FORMING A PORTION OF A COMPRESSION ZONE, ONE OF SAID NIP ROLLERS BEING POSITIONED TO RECEIVE FABRIC SUBSTANTIALLY DIRECTLY FROM SAID FLATTENING AND SPREADING MEANS AND BEING DRIVEN TO PROPEL SAID FABRIC ACROSS ITS WIDTH AT A PREDETERMINED SPEED, THE OTHER OF SAID NIP ROLLERS BEING POSITIONED DIRECTLY ADJACENT THE FIRST, TO FORM A NIP, AND BEING DRIVEN TO DECELERATE THE FABRIC ACROSS ITS WIDTH TO A PREDETERMINED DECELERATED SPEED.