US3670375A

US3670375A - Apparatus and method for tenter processing of open width fabric

Info

Publication number: US3670375A
Application number: US68646A
Authority: US
Inventors: Eugene Cohn; Andrew P Cecere; Robert Frezza
Original assignee: Samcoe Holding Corp
Current assignee: Samcoe Holding Corp
Priority date: 1970-09-01
Filing date: 1970-09-01
Publication date: 1972-06-20
Anticipated expiration: 1989-06-20

Abstract

The invention is directed to a fabric tenter apparatus and related method, intended especially for the processing of geometrically distortable fabrics in flat, open width form. The apparatus includes opposing sets of tenter chains for engaging the fabric margins, and the chains are divergently related at the entry end section and arranged in parallel relation along a processing section located downstream of the entry end. Means are provided for overfeeding of the fabric edge margins onto the tenter chains at the entry end. Additionally, as a unique feature of the combination, controllably driven web-supporting elements (e.g., tapes) are provided to support the center portions of the fabric web. These web-supporting elements engage the web commencing at a point upstream of the entry end section and extending well downstream therefrom, usually well into the processing section of the tenter. The supporting elements are driven at a controlled ''''overfeeding'''' or an ''''underfeeding'''' rate, so that the center portions of the fabric continue to be advanced at the controlled rate even after the fabric has been engaged by the slower moving tenter chains. The apparatus and the related process provide for an advantageous degree of control over the geometry of the cross lines of the fabric.

Description

United States Patent Cohn et al.'

[ 1 June 20, 1972 [72] Inventors: Eugene Cohn, Great Neck; Andrew P. Cecere, Valley Stream; Robert Frezza, Carle Place, all of NY. [73] Assignee: Samcoe Holding Corporation, Woodside, NY.

22 Filed: Sept. 1, 1970 21 Appl. No.: 68,646

Related US. Application Data [62] Division of Ser. No. 698,899, Jan. 18, 1968, Pat. No.

[52] U.S.'Cl. ..26/57 A, 26/513, 26/52, 26/57 E 51 Int. Cl. ..D06c3/02 [58] Field ofSearch ..26/52, 57A, 57 R,57E,51.3, 26/5l.4

[56] References Cited I UNITED STATES PATENTS 3,150,432 9/1964 McCreary ..26/57 E 2,450,022 9/1948 Schreiner... .26/52 X 2,591,861 4/1952 Pannaci.. ..26/52 2,618,012 11/1952 Milne. 26/57 R UX 3,031,732 5/1962 Carlisle... ..26/57 R 3,235,931 2/1966 Bruckner ..26/52X FOREIGN PATENTS OR APPLICATIONS 90,046 l/l897 Germany ..26/57R 521,464 5/1940 Great Britain ..26/57R Primary Examiner-Robert R. Mackey Attorney-Mandeville and Schweitzer [57] ABSTRACT The invention is directed to a fabric tenter apparatus and related method, intended especially for the processing of geometrically distortable fabrics in flat, open width form. The apparatus includes opposing sets of tenter chains for engaging the fabric margins, and the chains are divergently related at the entry end section and arranged in parallel relation along a processing section located downstream of the entry end. Means are provided for overfeeding of the fabric edge margins onto the tenter chains at the entry end. Additionally, as a unique feature of the combination, controllably driven websupporting elements (e.g., tapes) are provided to support the center portions of the fabric web. These web-supporting elements engage the web commencing at a point upstream of the entry'end section and extending well downstream therefrom, usually well into the processing section of the tenter. The supporting elements are driven at a controlled overfeeding or an underfeeding rate, so that the center portions of the fabric continue to be advanced at the controlled rate even after the fabric has been engaged by the slower moving tenter chains. The apparatus and the related process provide for an advantageous degree of control over the geometry of the cross lines of the fabric.

6 Claims, 4 Drawing Figures 1W2 l l I fill: 1] l u lllw' ulu...

SHEET 2 0F 3 APPARATUS AND METHOD FOR TENTER PROCESSING OF OPEN WIDTH FABRIC RELATED APPLICATIONS The present application is a division of our copending application Ser. No. 698,899, filed Jan. 18, 1968, now US. Pat. No. 3,551,970 grantedJan. 5, 1971.

BACKGROUND AND PRIOR ART In the commercial manufacture and processing of knitted fabrics, large quantities of such fabrics are manufactured on circular knitting machines, which initially construct the fabric in tubular form. To a large extent, such circular or tubular knitted fabrics have been handled substantially throughout the entire processing sequence in tubular form, and a variety of processing and handling equipment is available, which accommodates the knitted fabric in its tubular form. To an increas ing extent, however, newer types and styles of tubular knitted fabrics, and more demanding end use specifications for such fabrics, are compelling the fabric processor to process knitted fabric in open width form, even though the fabric may have been initially constructed in tubular form. For example, many modern fabrics, when passed through a processing nip or otherwise subjected to pressure while in tubular form, will form an edge crease, particularly when the fabric is in a" wet condition. With some fabrics, this creasing is an irreversible process in that the crease mark cannot subsequently be completely removed. Accordingly, it is becoming desirable to an increasing extent to process many knitted fabrics by first slitting and opening the fabric, before it is subjected to any processing steps involving the application of pressure. Thereafter, the fabric is handled and processed in flat, open width form, so that there is no occasion for edge creases to be imparted to the fabric.

In the processing of woven goods, which typically are initially constructed in flat form, it has long been the practice to handle and process such fabrics in open width form. This being the case, there are certain similarities between the open width processing of knitted fabrics and woven fabrics. However, by reason of the unique construction of the knitted fabric by interlocking loops, rather than by interwoven warp yarns extending lengthwise and woof yarns extending widthwise, the knitted fabric has an inherent interdependence of length and width dimensions and an inherent geometric instability. These characteristics of the knitted fabric differ not only in degree but also in kind from the characteristics of woven fabric, such that the equipment and technology long available to the woven goods industry is not easily translatable to the knit goods processing industry, accounting for the fact that open width processing of knitted fabric now is practiced only in limited volume relative to the processing of fabric in tubular form.

The present invention concerns itself generally with the processing, as by drying, heat setting, or curing of an open width knitted fabric, and is directed more specifically to the handling of the fabric immediately prior to and/or in conjunction with such processing.

SUMMARY OF THE INVENTION In accordance with the present invention, a novel and improved processing tenter apparatus and method are provided, which enable highly distortable open width knitted fabrics to be conveyed and tenter-processed with a high degree of control over the geometry of the fabric, particularly with regard to the straightness of the cross lines. A typical processing tenter includes a pair of tenter elements, usually chains, arranged to engage the edge extremity of the fabric and convey it forward. At the entry end of the apparatus, the tenter elements are divergently related, so that the fabric, after its initial engagement, is laterally distended to a desired width. Immediately downstream of the entry end section, the tenter elements typically are arranged in parallel relation, so that the fabric continues to advance in a downstream direction without further change in width. During this subsequent processing stage, the fabric may be treated, as by being steamed, if it is dry fabric being dn'ed, if it is wet fabric, etc.

Because a knitted fabric has a substantial interdependency of its length and width dimensions, lateral distention of the fabric in the entry end stage of the tenter will effect a reduction in the length of the fabric. Also, certain of the subsequent processing operations (e.g., drying) may involve a lengthwise shrinkage of the fabric. As a result, the fabric edges are desirably (and conventionally) overfed onto the tenter elements at the entry end. That is, the fabric is conveyed onto the tenter chains at a higher rate of speed than the tenter chains themselves are conveying the fabric in a downstream direction. Even though the fabric is thus overfed onto the tenter chains, undesirable degrees of fabric distortion still may be experienced as a result of the lengthwise shortening of the fabric resulting from lateral distention and/or processing.

In accordance with one aspect of the invention, cross line distortion in a laterally distended fabric web may be significantly reduced by conveying the center sections of the fabric at the overfeeding rate of speed, not only up to the point of transfer of the fabric onto the tenter elements, but for a substantial distance downstream of that point. Thus, after the fabric edge margins are engaged by the tenter chains and are being advanced thereby at a desired speed, the center sections of the fabric are still advanced at a higher rate of speed for a substantial distance, advantageously well into the processing stage of the tenter. This arrangement provides a significant and advantageous degree of control over cross line geometry. In accordance with another aspect of the invention, an even further degree of cross line control may be effected by providing for variable speed control of the tape-like elements supporting the central areas of the web, enabling controlled variation of that speed from the basic speed of the tenter chains. The center portions of the fabric thus may be conveyed at a lower rate of speed than the tenter chains, if desired, in order to correct a forward bow condition in the cross line of the fabric.

For a better understanding of the above and other advantageous features of the invention, reference should be made to the following detailed descriptions and to the accompanying drawings.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a simplified top plan view of a complete processing system, including the improved tenter means of the invention, for the handling and processing of knitted or other fabric web in open width form.

FIG. 2 is a simplified elevational view of the system of FIG. 1.

FIG. 3 is an enlarged fragmentary plan view showing the novel and improved tenter frame apparatus of the invention, as utilized in the system of FIG. 1.

FIG. 4 is an enlarged fragmentary cross-sectional view taken generally along line 4-4 of FIG. 3.

Referring now to the drawings, and initially to FIGS. 1 and 2 thereof, there is illustrated a processing line incorporating to advantage the tenter means of the invention. At the upstream end of the processing line there is shown a supply container 20 holding a supply of, in the illustrated instance, tubular knitted fabric 21, typically in a wet condition. The fabric 21, in rope form, is drawn out of the supply container, over a roller 22, beingde-twisted as necessary by an attendant operator. The fabric 21 then advances into the input of a slitting and opening stage generally designated by the numeral 23.

Most advantageously, the slitting and opening stage 23 is constructed in accordance with the teachings of the Sidney L. Carter et al., US. Pat. No. 3,289,510, to which reference should be made for further details. In addition, the slitting and opening stage may incorporate improvements described and claimed in the Eugene Cohn et al., United States application Ser. No. 629,326, now US. Pat. No. 3,551,969, granted Jan. 5, 1971.

In general, the slitting and opening stage includes a slitting knife 24, which cuts the advancing tube of knitted fabric, and incorporates 'a pair of divergently

related tenter chains

25, 26, which engage the newly formed edges of the fabric immediately adjacent the slitting knife. The arrangement is such that the edges of the slit fabric are simultaneously advanced and separated, until the fabric is converted from a slit, but otherwise tubular form, to a fiat, open width form, substantially as indicated at 27 in FIG. 1.

At the discharge end of the slitting and opening stage 23, the now open-width fabric 27 proceeds on to a padding stage, generally designated by the numeral 31, where it is subjected to liquid processing.

Fabric discharged from the padding stage 31 advances to a tenter stage, generally designated by the numeral 38 and constituting the subject matter of the present invention. In this stage, the fabric edges are applied over the pins of spaced tenter chains and conveyed in an advantageous manner for further processing. As will be described in more detail, the tenter pinning stage 38 may include fabric edge-seeking controls for manipulating the input ends of the tenter chains inward and outward, as required, in order that the tenter pins engage the fabric edges along a desired margin. The edgeseeking portions of the tenter chains are manipulated independently of the basic width adjustment of the chains, such that the pinned fabric ultimately is conveyed through the remainder of the process at a uniform, preadjusted width.

At the tentering stage, the fabric is desirably applied to the tenter pins in such a way as to provide a predetermined amount of overfeed of the fabric in a length direction, to accommodate a reasonable amount of lengthwise shrinkage of the fabric during the subsequent heat processing stage and also to accommodate shortening of the fabric which accompanies its widthwise distention. Significant features of the invention, to be described, are directed to the more effective controlling of the fabric in conjunction with the overfeeding thereof onto the tenter pins.

In the system of FIGS. 1 and 2, the open width fabric, now pinned on the tenter chains, is conveyed into a heat processing stage 34 described more fully in the parent application Ser. No. 698,899.

After leaving the processing stage 34, the fabric is conveyed to a suitable gathering stage, generally designated by the numeral 42, which typically may be a horizontal plane folder, or may be a wind-up apparatus, as will be understood.

Referring now to FIGS. 3 and 4, the fabric 27, received from the padding stage 31, is directed through reverse bends about a pair of speed-controlled overfeed rollers 157, which are driven at a predetermined (higher) speed relationship to the tenter chains to provide for a desired degree of overfeeding of the fabric onto the tenter pins. Desirably, the overfeed rollers 157 are separated, so as not to nip the fabric, but are provided with suitable friction surfacing which, by reason of the considerable area of contact with the fabric, afiords an adequate grip for controlling the fabric speed in an effective manner.

Fabric discharged from the upper overfeed roller 157 passes between pairs of

air jet uncurlers

158, 159 carried by edge seeking tenter input sections generally designated by the

numerals

160, 161, which are connected to and form the entry ends of a pair of tenter

chain guide channels

150, 151. The edge uncurlers 158, 159 are arranged to direct jets of air outwardly across the top and bottom surfaces of the fabric, to at least momentarily flatten the edge margins of the fabric. In this respect, it will be understood that many slit and opened tubular knitted fabrics, for example, have a pronounced tendency to curl at the edges, particularly when subjected to any lengthwise tension during processing, and it is often necessary to de-curl the fabric at one or more stages for effective handling.

While the fabric edges are held flat by the uncurling

jets

158, 159, the fabric passes between an edge sensing control 162, typically consisting of means such as a light source 163 and a pair of

photoelectric cells

164, 165. The sensing controls are provided at both sides of the equipment, of course, to detect the opposite edges of the fabric. The arrangement of the control is such that, if neither of the photoelectric cells is covered by the fabric edge, the edge-following section of the tenter chain will automatically adjust in an inward direction, until it finds the fabric edge. The adjustment will terminate when the inside cell 165 is covered by the fabric edge, while the outside cell remains uncovered. If the fabric edge wanders in an outward direction, to cover both of the photo cells, an outward adjustment of the tenter section will automatically follow, until the outer photoelectric cell 164 is again uncovered.

Still referring to FIGS. 3 and 4, the uncurled fabric edge, properly tracked by the sensing control 162, passes directly between a trimming roll 166, driven by a motor 170, and a pinch roller 167 cooperating therewith, whereby the fabric edge is positively advanced at a predetermined, controlled speed, somewhat greater than that of the tenter chains, designated by the reference numeral 105. The fabric edges are then advanced between driven brush wheels 168 and cooperating, opposed plates 169. The brush wheels are disposed directly above the tenter chains and have their bristles projecting slightly below the upper extremities of tenter pins 108 carried by the chains. The brush wheels 168 are driven at such a speed that their bristle extremities are traveling at a higher rate of speed than the tenter chains 105, enabling the fabric to be impaled upon the tips of the tenter pins 108 in a uniformly and controllably overfed condition.

The lightly pinned fabric then advances to a second, nondriven brush wheel 171, the bristles 172 of which project substantially to the base ends of the tenter pins 108. The arrangement is such that, as the fabric passes under the brush wheel 171, it is pressed downward to a fully pinned condition. The idling speed of the brush wheel 171 is, of course, such that its bristles 172 are substantially synchronous with the tenter chains 105.

Advantageously, the overfeed rollers 157 are speed controlled relative to the speed of the tenter chains, by means of a so-called tach-follower control (not shown). The tach-follower control, which is available from commercial sources and by itself forms no part of this invention, drives the overfeed rollers 157 at a preset but adjustable percentage of the tenter chain speed. Typically, this is set to provide a predetermined percentage (e.g., 20-30 percent for some knitted fabrics) overfeed of the fabric to the tenter input. The overfeed trimming rolls 166 and brush wheels 168 at each side are in turn controlled by separately adjustable tach-follower controls related to the speed of the overfeed rolls 157. This enables a degree of separate overfeed control of the opposite fabric edges, for final cross-line straightening as the fabric is applied to the tenter pins.

As illustrated in FIG. 3, the entry end of the tenter apparatus includes tenter chain

guide channel sections

150, 151, which are adjusted at their upstream extremities to engage the fabric 27 at its incoming width. Typically, this is at least slightly narrower than the desired width, and in many cases the incoming width will be substantially narrower than the finished width. Thus, the entry end tenter chain guides are arranged to be disposed in divergent relation.

The divergently directed tenter chains 105, in the entry end section, convey the fabric edges outwardly, while advancing it in a downstream direction, until the fabric is flattened and/or distended to the desired width. At that stage the tenter chains are engaged by the

guide channels

150, 151 which are disposed in parallel relation, and the fabric is thereafter conveyed with its edges parallel. For purposes of this description, the portion of the tenter apparatus commencing with, or just prior to the parallel guiding of the tenter chains by the

channels

150, 151 will be referred to as the processing section, because it is contemplated that, during the further conveyance of the fabric, it will be subjected to processing action, such as by steaming, drying, etc. In the system specifically illustrated herein, the fabric is conveyed, by an extended processing tenter section, through a'rotary drying stage 34, where the fabric is subjected to drying and/or curing, as described more fully in the before-mentioned application Ser. No. 698,899.

In accordance with one of the important aspects of the invention, means are provided for supporting and controlling the advancement of portions of the fabric web 27 spanning the area between the respective tenter chains, and in particular the center regions of the web. Of particular importance, the center portions of the web are caused to be driven at a speed controllably related to that of the tenter chains 105 commencing at a point somewhat in advance of the engagement of the fabric by the tenter chains and extending at a substantial distance in a downstream direction from that point, typically well into the processing section of the tenter. Typically, the center portions are driven at a higher speed than the tenter chains, but a slower speed may be desired for certain conditrons.

In the specific form of apparatus illustrated herein, sets of web-supporting tapes 198, 198a are provided for this purpose. One or more of the tapes 198 (depending on overall web width) are trained about the upper speed control roller 157 and about an idling roller 199 joumaled directly underneath the upper reaches of the tenter chains, in the entry end section. As will be seen in FIG. 3, the tapes 198 first engage fabric web slightly in advance ofthe trimming rolls 166, and they extend downstream somewhat beyond the brush wheels 168,

171 which serve to engage the fabric margins with the tenter pins 108. The supporting tapes 198 are frictionally driven by the upper speed control roller 157, and therefore are operated at the overfeeding speed at which the fabric is delivered to the entry end of the tenter apparatus. At the downstream end, the tapes 198 frictionally engage the idling roller 199 and cause that roller to be driven at a corresponding speed.

The web-supporting tapes 198a of the second set are trained about idling

rollers

199, 199a, and extend in a downstream direction somewhat beyond the commencement of the processing section of the tenter. The tapes 198a have driving engagement with the idler roll 199, which is in turn driven by the tapes 198. Accordingly the downstream tapes 198a are also driven at the overfeeding speed. The tapes 198a are disposed directly underneath the upper reaches of the tenter chains, so that the fabric web, allowing for a slight amount of normal sag in the center areas, is supported and drivingly engaged by the belts 198a, as well as by the belts 198.

As will be understood, the edge portions of the fabric are advanced at the overfeeding rate only up to the point at which the edges are engaged by the pins 108 of the tenter chains. Thereafter, the edge margins are advanced at the somewhat slower rate of advancement of the tenter chains themselves. The center portions of the fabric, however, continue to be advanced by the tapes I98, 198a, at the overfeeding" rate to a point downstream of the point at which the fabric edges are engaged by the tenter chains. Since these portions of the fabric tend to be driven at the overfeeding rate, the center portions of the fabric will tend to be advanced relative to the edges during at least the initial portions of the tentering operation, providing a desired and advantageous control over the geometry of the cross lines, which otherwise would tend to become distorted in a rearward or upstream direction.

In the illustrated apparatus, the supporting tapes 198, 198a are driven by the overfeed control rollers 157, which may be variably adjusted relative to the speed of the tenter chains to accommodate various processing conditions. In addition, however, the invention further contemplates that the supporting tapes I98, 198a may be driven and controlled independently of the rollers 157, enabling the tapes to be operated either above or below the basic speed of the tenter chains rate.

In a typical processing of a tubular knitted cotton fabric, for example, with the system of the invention, the tubular knitted fabric, typically in a non-uniformly wet form in its as-received condition from a previous wet processing operation, is drawn out of the supply container 20 and converted, in the slitting and opening stage 23, to a flat, open width form. The open the fabric may be impregnated with a processing solution, such as a wash and wear" type resin. If no processing solution is used, the fabric still may be run through the padding stage and made uniformly wet.

The uniformly wetted fabric from the padding stage is advanced to the entry end of the tenter, where the edges are uncurled, if necessary, and engaged by the tenter mechanism. The fabric edges are then advanced, usually, divergently, so that the fabric is laterally distended somewhat. Thereafter, the fabric is conveyed by the tenter chains at a predetermined, uniform width. During the initial portion of the tenter stage, prior to the entry of the fabric into the processor housing, the fabric is supported at several places between its edges by the supporting tapes 198, 198a. Where the fabric is in a wet condi-' tion, the tapes 198, 198a prevent excessive sagging of the center areas of the web from the weight of the contained liquid. More importantly, however, and as one of the significant features of the invention, the supporting tapes 198, 198a are operated at a (e.g., greater than that of the tenter chains and extend well downstream of the entry end extremities of the tenter apparatus. The supporting tapes thus cause the center portions of the fabric web to be advanced at a somewhat greater rate of speed than the speed of the tenter chains, causing a desired forward displacement of the fabric center relative to its edges. This efiectively counteracts distortion otherwise induced in the fabric as a function of its lateral distention by the tenter and as a function of its geometrical changes e.g., shrinkage) during subsequent processing on the tenter.

In the illustrated arrangement, the supporting elements 198, 198a are driven directly by the overfeeding system of the tenter apparatus, at the overfeeding speed. It will be appreciated, however, that where a greater degree of control flexibility is desired, the operation of the supporting elements may be subject to separate speed control from either the overfeeding system or the tenter chains.

A particularly important feature of the invention which appears to have broad applicability to the-tenter handling of knitted fabrics, and perhaps also certain other types of fabrics, particularly those which are relatively unstable geometrically, is the provision of one or more narrow supporting tapes between the tenter chains. The supporting tapes extend parallel to the tenter axis, and typically are disposed substantially in the plane defined by the spaced tenter chains. These supporting tapes are arranged to be driven at a speed which differs from and is greater than the speed of the tenter chains themselves. This provides for an advantageous measure of cross line straightness control, which is particularly effective where a variable speed relationship is provided for between the supporting tapes and the tenter chains. Particularly where cross line control is important, as in the handling and processing of knitted and other distortable fabrics, it is significant that the arrangement of the supporting tapes be such as to support principally the central areas of the fabric, so that speed differentials between the supporting tapes and the tenter chains will have the effect of adjusting the center region of the fabric relative to its edges.

The invention may be particularly advantageous for use in processing of piece dyed fabrics, because of its superior control over cross line straightness. In piece dyed fabric, cross line distortion is not as readily apparent, and the distortion may ultimately show up as a fabric shrinkage non-uniformity. However, by continuing to convey the center portions of the fabric at the overfeeding speed for a sufficient distance after overfeeding and pinning of the edges, the normal distortions of the fabric are compensated for and substantially reduced or eliminated. The resulting fabric can have a substantially uniformly relaxed condition over its full width.

It should be understood, of course, that the specific form of the invention herein illustrated and described is intended to be representative only, as certain changes may be made therein without departing from the clear teachings of the disclosure. Accordingly, reference should be made to the following claims in detennining the full scope of the invention.

We claim:

1. In a fabric tenter apparatus intended especially for processing geometrically distortable fabrics, and having a fabric distending station with a set of opposed tenter elements at each side of said station and divergently related to effect widthwise distention of a fabric web; and a processing station on which said opposed tenter elements are arranged in generally parallel relation; the combination which comprises a. a plurality of longitudinally disposed movable web supporting elements disposed between said opposed tenter elements and engageable with the web being carried by said tenter elements across the transverse extent thereof;

b. said web supporting elements being arranged to simultaneously controllably advance a fabric web toward said tenter elements and to support said web throughout and terminating at the end of said distending station;

c. means for driving said tenter elements at a predetermined speed;

d. infeeding means for controllably advancing said fabric web toward and into operative association with the tenter elements of the entry end section of said distending station;

e. control means for operating said infeeding means at a speed of advance in excess of the speed of advance of said tenter elements, whereby said fabric web is delivered in controllably overfed engagement with the tenter elements; and

f. means for driving said web-supporting elements at the overfeeding speed of said infeeding means, whereby the geometric stability of the fabric is maintained throughout the distending station. The apparatus of claim 1, further characterized by a. said web-supporting elements extending from a point upstream of said distending station to the terminating point downstream thereof.

3. The apparatus of claim 1, further characterized by a. the tenter elements of said distending station and said processing station at each side, constituting a continuous endless tenter element extending over both stations.

4. The apparatus of claim 1, wherein the infeeding means comprises by a. a fabric feeding roll, and

b. said web-supporting elements comprising tape-like bands trained about and driven by said feeding roll.

5. A method of tenter-processing a geometrically distortable fabric, which comprises a. advancing the fabric in flat, open width form and at a first predetermined rate of advancement,

b. engaging the fabric by its edge extremities and advancing said fabric by such edges at a second and slower rate of advancement and in a divergent manner to efiect lateral distention of the fabric,

c. continuing to advance the edges of the distended fabric substantially at said second rate of advancement and in a substantially parallel disposition, and

d. engaging, supporting and advancing a plurality of intermediate portions of the fabric web between margins of the fabric engaged and being advanced throughout the divergent advance and terminating at the end of the divergent advance thereof,

e. said intermediate portions being advanced at the first predetermined rate of advancement whereby the geometric stability of the fabric is maintained throughout the area of divergent advance.

The method of claim 5, further characterized by a. the intermediate portions of the fabric being thus engaged, supported and advanced from a point upstream of the point of commencement of divergent advancement of fabric edge margins to the terminating point downstream thereof.

Claims

1. In a fabric tenter apparatus intended especially for processing geometrically distortable fabrics, and having a fabric distending station with a set of opposed tenter elements at each side of said station and divergently Related to effect widthwise distention of a fabric web; and a processing station on which said opposed tenter elements are arranged in generally parallel relation; the combination which comprises a. a plurality of longitudinally disposed movable web supporting elements disposed between said opposed tenter elements and engageable with the web being carried by said tenter elements across the transverse extent thereof; b. said web supporting elements being arranged to simultaneously controllably advance a fabric web toward said tenter elements and to support said web throughout and terminating at the end of said distending station; c. means for driving said tenter elements at a predetermined speed; d. infeeding means for controllably advancing said fabric web toward and into operative association with the tenter elements of the entry end section of said distending station; e. control means for operating said infeeding means at a speed of advance in excess of the speed of advance of said tenter elements, whereby said fabric web is delivered in controllably overfed engagement with the tenter elements; and f. means for driving said web-supporting elements at the overfeeding speed of said infeeding means, whereby the geometric stability of the fabric is maintained throughout the distending station.

2. The apparatus of claim 1, further characterized by a. said web-supporting elements extending from a point upstream of said distending station to the terminating point downstream thereof.

4. The apparatus of claim 1, wherein the infeeding means comprises by a. a fabric feeding roll, and b. said web-supporting elements comprising tape-like bands trained about and driven by said feeding roll.

5. A method of tenter-processing a geometrically distortable fabric, which comprises a. advancing the fabric in flat, open width form and at a first predetermined rate of advancement, b. engaging the fabric by its edge extremities and advancing said fabric by such edges at a second and slower rate of advancement and in a divergent manner to effect lateral distention of the fabric, c. continuing to advance the edges of the distended fabric substantially at said second rate of advancement and in a substantially parallel disposition, and d. engaging, supporting and advancing a plurality of intermediate portions of the fabric web between margins of the fabric engaged and being advanced throughout the divergent advance and terminating at the end of the divergent advance thereof, e. said intermediate portions being advanced at the first predetermined rate of advancement whereby the geometric stability of the fabric is maintained throughout the area of divergent advance.

6. The method of claim 5, further characterized by a. the intermediate portions of the fabric being thus engaged, supported and advanced from a point upstream of the point of commencement of divergent advancement of fabric edge margins to the terminating point downstream thereof.