US3695064A

US3695064A - Imparting stretch characteristics to woven fabrics

Info

Publication number: US3695064A
Application number: US48673A
Authority: US
Inventors: Leslie A Runton
Original assignee: JP Stevens and Co Inc
Current assignee: JP Stevens and Co Inc
Priority date: 1964-08-03
Filing date: 1970-05-25
Publication date: 1972-10-03
Anticipated expiration: 1989-10-03
Also published as: US3528763A

Abstract

The present invention relates to an apparatus wherein a fabric is treated with a shrinking agent and then led through a series of zones under successively increasing warp tension to thereby produce stretch characteristics in the fill direction of the fabric.

Description

United States Patent 11:1 3,695,064 Runton 1 51 Oct. 3, 1972 IMPARTING STRETCH 2,955,345 10/1960 Howe ..28/7l.3 X CHARACTERISTICS TO WOVEN 2,179,505 11/1939 Huey ..8/125 FABRICS 3,032,856 5/1962 Fleissner ..28/71.3 X

[72] Inventor: keslie A. Runton, Middle Haddam, FOREIGN PATENTS OR APPUCATIQNS onn. 375,836 6/1962 Japan ..68l5 E [731 Stevens (30-1 Inc-1 New York 277,525 11/1964 Netherlands ..68/5 E [22] Filed; Ma 25, 1970 Primary Examiner-Robert R. Mackey 1 pp No: 48,673 Attorney-Thomas M. Hammond and J. Bradley Cohn Related us. Application Data 1571 ABSTRACT [62] Division f s No. 387,10], Aug 3, 1964, The present invention relates to an apparatus wherein Pat. No. 3,528,763. a fabric is treated with a shrinking agent and then led through a series of Zones under successively increasing 52 us. c1. ..68/5 E, 26/185, 68/43 Warp tension to thereby Produce Stremh charac- 511 1m. (:1. ..D06c 1/00, D06c 3/00 eristics in the fill directifin of the fabric- [58] Field of Search ..26/18.5; 8/125; 68/5 E, 43; 28/713, 76 E [56] References Cited 2 Claim, 4 Drawing figures UNITED STATES PATENTS 3,449,060 6/1969 Schenck ..8/125 PHENTEDM 3 1922 SHEEI 1 OF 2 8408 m 20 w 20M 8 68 03 wzo- Proxy wmaIh m ZON 2.05 Q30 wzON X00 JOGFZOU mvmon LESLIE A. RUNTON A TTORNEY [MPARTING STRETCH CHARACTERISTICS T WOVEN FABRICS The present application is a division of Application Ser. No. 387,10l, filed Aug. 3, 1964, and now U. S Pat. No. 3,528,763, granted Sept. 15, 1970.

This invention relates to textiles. More particularly, the invention relates to a process and apparatus for the production of stretchable woven fabrics having the ability to stretch and to recover substantially completely after repeated extension throughout the life of the fabrics.

Fabrics having substantially permanent stretch and recovery properties are known. Although these known fabrics have achieved wide commercial acceptance, it is desirable to provide fabrics of this type which have increased stretch while maintaining properties of recovery. Current processes and apparatus are suitable for the production of such fabrics having a stretch factor of just over 20 percent in a filling-wise direction as well as in a warp-wise direction. However, attempts to produce fabrics having much more than 20 percent filling-wise stretch by present methods and apparatus have generally not been successful or result in complete breakdown of the fabric by fiber and/or yarn breakage. On the other hand, the present process and apparatus provide woven fabrics having filling-wise stretch as high as 50 percent and more, as well as substantially complete recoverability from repeated extension throughout the life of the fabrics.

In accordance with the invention there is provided a process for producing woven fabric having stretch characteristics comprising disposing woven fabric having a tension applied to the warp yarns sufficient to straighten the yarns in a warp-wise direction in a treatment zone for a period of time and at a temperature sufficient to cause deformation of the filling yarns in the fabric, conducting the fabric from the first zone to one or more additional zones while increasing the warp tension on the fabric in an amount sufficient to take up any slack which has formed in the warp yarns due to elongation thereof, and maintaining the fabric in the additional zone or zones for a time and at a temperature sufficient to cause further shrinkage of the filling yarns and fonning fabric having stretch characteristics.

In the practice of the invention, the instant process can be carried out continuously, semicontinuously, or as a unitary process and the fabric treated in accordance therewith exhibits excellent properties of stretch in a filling-wise direction.

Fabric which can be treated in accordance with this invention varies widely with respect to the materials from which it is made. The fabric can be made from filamentary synthetic materials such as polyamides, polyesters, acrylics, polyolefins and other suitable synthetic filamentary materials. The fabric can also be made from natural fibers such as wool, cellulosics, such as cotton, or proteinaceous material such as silk and the like. If desirable, fabric processed in accordance with the invention can be made of a blend of natural and synthetic fibrous materials in either the filling and/or the warp yarns. On the other hand, the filling yarns or the warp yarns can be made entirely of one type of fiber. in those cases where fabric which contains a blend of natural and synthetic fibrous materials is processed in accordance with the invention, the blend of fibrous materials is one in which the individual fibrous materials in the blend generally attain stretch characteristics when treated under similar conditions.

For example, in order to get maximum benefit of the instant process, fabric containing a blend of polyamide 5 and wool in the filling yarns can have filling stretch properties imparted thereto by application of heat and moisture at a temperature of about l05C.

Regardless of the particular fibrous material in fabric processed according to the invention, the fabric is woven fabric with the weave being sufficiently open to provide space between neighboring yarns. Moreover, the yarns in the fabric can be in a twisted or untwisted state, depending at least in part on the particular material from which the fabric is made. As an example, where a single continuous filament yarn, such as a polyamide or polyester yarn or the like is being utilized, twist is not necessary. On the other hand, where the yarn is made up of a number of filaments or if it is a spun yarn, at least enough twist is needed to hold the yarn together and to eliminate felting and fiber migration. In this connection where spun yarns are utilized, twist should be normal to percent above normal. On the other hand where a number of continuous filaments are employed to make up a yarn, a producer's twist of approximately one-half turn to one turn is often sufficient to hold the filaments together.

As mentioned hereinabove the process includes disposing the fabric in a series of zones, at least two in number. However, the exact number of zones employed will depend upon the particular fabric being processed. For example, cotton fabric having desirable stretch characteristics s obtained by carrying out the process in an apparatus having four zones. On the other hand, a polyamide fabric having good stretch characteristics can be obtained by using only two zones. The exact number of treatment zones is dependent upon the ability of the fabric being treated to be further elongated in a warp-wise direction without breakage. As with the number of zones, the temperature in each zone varies in accordance with the fiber being processed.

In general, temperatures in a range of about room temperature, that is, about C to just less than that which will damage the fibrous material present in the fabric being processed are employed in carrying out the process in the various treatment zones. The temperature for a specific fabric being processed is readily determinable.

Deformation of the yarns in accordance with this invention is to be understood to mean both physical and chemical modification thereof, including crimping and the spatial relationship of the filling yarns with respect to each other and with respect to the warp yarns. The physical and chemical deformation is brought about not only by the application of warp tension to fabric being processed, but also by the temperature to which the fabric is subjected and by the optional use of a chemical agent having the ability to modify as, for example, by shrinking the yarns and fibers to which it has been applied. Moreover, each of these factors aid in setting the yarns in their deformed condition.

Any chemical reagent which is compatible with the fabric being processed and which has the ability to modify, as by shrinking or otherwise, and to set the yarns is suitable for use in the practice of this invention. An excellent reagent which can be utilized when wool fabric is being processed is monoethanolamine sulphite. Other known wool modifying agents are also suitable. An excellent reagent which can be utilized. in the processing of cotton fabric in accordance with the invention is sodium hydroxide. Numerous other reagents are available as will be apparent to those skilled in the art. It is to be noted, however, that the particular reagent being utilized should not have an effect on yarns present in the fabric other than those which are to be modified by the reagent. In this connection, hot water or steam or the application of dry heat itself are also excellent reagents for bringing about deformation and setting. Where a chemical modifying agent is used, it is normally employed in dilute aqueous solutions of about 50 parts water to 1 part chemical, about 2 percent solution.

As mentioned hereinabove, the number of zones through which a fabric is passed will vary depending upon the particular fabric being treated. Wool, for example, can have the desired stretch properties imparted thereto by first treating it with the shrinking agent and then passing it through three zones wherein the temperature is maintained at approximately 105 C in each zone, and wherein the warp tension of the fabric is increased by about three percent to four percent between the end of the first zone and the end of the second zone and further increased by a like amount between the second and third zones. On the other hand, excellent stretch properties are imparted to a cotton and Dacron blend fabric in a four zoneoperation wherein the fabric is first padded with sodium hydroxide solution and then conducted through the first zone under slight tension at a temperature of 20 C, then to second zone wherein the temperature remains at about 20 C and the tension is increased by about two percent to three percent, then to a third zone wherein the temperature is increased to about C and the tension is further increased by about an additional 2 to 3 percent, and finally to a fourth zone wherein the temperature is maintained at about I05 C and the tension is further increased by additional 2 to 3 percent. Nylon fabric, however, is susceptible to having stretch properties imparted thereto merely by subjecting it to a temperature of about l40 that is, somewhat below the heat setting point thereof, and subsequently subjecting the fabric to an increased tension of about 4 to 6 percent at substantially the same temperature in an additional zone. C,

Tension placed on a fabric being processed in accordance with this invention and which tension is increased as the fabric is led from one zone to another is dependent upon the time and speed with which the fabric is being led from one zone to another of the apparatus. In this case it is to be noted, as mentioned hereinbelow, that the tension is increased by means of a variable speed device, such as a motor or a positive infinitely variable transmission unit which operates rolls or other advancing means in each zone. In order to obtain increased tension, therefore, the variable speed device of the second zone will operate at a speed greater than the motor of the first zone, and the speed of the rolls in each successive zone is increased by an increase in the speed of the variable speed device operating in conjunction with the rolls of that zone. Generally, the surface speed of the rolls in each successive zone is increased by about 2 to 6 percent. For example, if a woolen fabric is being processed at the rate of 94 feet per minute through the first zone, the speed in the second zone is increased to about 97 feet per minute, and speed in a third or final zone is increased to about I00 feet per minute. Obviously the surface speed of the rolls in each zone which are advancing the fabric through the zones are, accordingly, increased by a factor of about 3 percent in the case illustrated. Since modification of fibers in a fabric takes place relatively instantaneously once the conditions of temperature and tension are attained in each zone, the time a fabric remains within a particular zone is not critical, so long as the total times in all of the zones when accumulated does not exceed a period which will damage the fabric. For wool, the time factor is about l min. 10 sec. The particular total time factor for a specific fabric being processed is readily determinable. Consequently, once the desired conditions of time, temperature, and tension are attained in a zone, the speed with which the fabric is passed from that zone to the next successive zone can be as great as is practical under normal operating conditions. In this case, as pointed out above the fabric can be processed as fast as feet per minute and higher, the upper limitation being dependent only upon the ability of the fabric and the machinery to withstand the higher speeds without damage thereto, once each successive zone has been brought to a temperature and the required tension is applied to a fabric being processed therethrough for a sufficient period of time.

After a fabric has been treated to impart the desired amount of stretch thereto, it is generally led into a drying and/or cooling zone. As a practical matter, although a treated fabric can be permitted to cool or dry in air, it is preferred that positive cooling and drying step be taken in order to complete the setting. Such measures can include optional washing in water or other reagent to remove any excess modifying reagent which may be retained thereon, or the fabric can be passed through an atmosphere of conditioned air in order to lower the temperature thereof. Drying can be carried out at temperatures in a range of I00C to C or less to as high as temperatures just below that which will damage the fabric. Regardless to what positive steps are taken, the fabric, during this cooling and/or drying treatment, is maintained in a substan tially completely relaxed condition in order to permit additional shrinkage and/or setting to take place.

In order to more properly understand the instant process and apparatus useful for carrying it out, reference is made to the attached drawings wherein:

FIG. I is a schematic view of the process as applied to a cotton and Dacron blend fabric;

FIG. 2 is a sectional elevation showing one form of apparatus for treating a fabric according to the inven tion;

FIG. 2A is a sectional elevation showing the part of the apparatus which is located after the treatment zones; and

FIG. 3 is a sectional elevation of a drying and/or cooling means suitable for treatment of a fabric which has been processed in the treatment zones.

Generally, apparatus suitable for carrying out the process comprises means, such as one or more enclosed treatment zones, means for applying tension to the fabric while it is advancing through successive treatment zones including means for progressively increasing the tension on the fabric, and means for regulating the temperature of the treatment zones. In addition, a preferred apparatus will include means for applying a modifying agent to a fabric which is subsequently passed through the treatment zones, and means for washing the fabric after treatment in the zones as well as means for collecting the fabric after it has been treated and washed. As an optional part of the apparatus a drying means can also be included in carrying out the practice of the invention. Normally the drying means as set forth more fully hereinbelow is located a after the washing means through which a fabric passes after it leaves thetreatment zones and before collection thereof on a roll or the like.

Referring more particularly to the drawings, in FIG. 1 the schematic view shows a first station wherein a chemical solution such as sodium hydroxide is applied to a cotton and Dacron fabric to be processed. From there, the fabric is conducted into the autoclave forming zone one wherein a tension is applied thereto in a warp-wise direction and the fabric is subjected under slight tensionto the action of the sodium hydroxide at a relatively low temperature, that is, about 20 C. From zone one, the fabric is then conducted to zone two where the tension is increased by about 2 to 3 percent and the temperature maintained at 20 C. Thereafter, the fabric is led into zone three wherein it is subjected to a further increase of about 2 to 3 percent in tension but at a temperature of 105 C. Finally, the fabric is conducted to the fourth treatment zone wherein the tension is further increased by a factor of about two to three percent and the temperature is maintained at about l05 C. The temperature is normally increased and decreased by the addition of hot water or steam and cold water. When steam is used, the apparatus is constructed so that the zones are sufficiently sealed from the atmosphere to allow enough pressure build-up therein to maintain steam in that state. After the fabric has been passed through the four treatment zones, it is then passed into a drying means where drying takes place while the fabric is maintained in a substantially completely relaxed condition. In actual operation, it is to be noted that before drying, a cotton fabric so treated is also passed through a washing step to remove excess sodium hydroxide therefrom.

With reference to FIGS. 2 and 2A of the drawings, there is shown an apparatus for carrying out the present invention by either a unitary, semicontinuous or continuous process. A strip of fabric 11 is fed from a supply roll by feed rolls 12 and into a J-box 13 where it forms a series of loose folds. It is withdrawn from the J box over a roll 14 and led to a means for applying a modifying agent thereto by introduction between guide rolls 15 and thence to a tank 16 which contains a solution of chemical reagent such as those mentioned hereinabove. The fabric strip 11 then passes in a succession of folds under a set of other rolls 17 and over a roll 18, the former being immersed in the reagent in tank 16. From the tank 16 the fabric 11 passes over a roll 19 into a tank 20 around a roll 21 which is submerged in the solution in the tank, thence over a roll 22 to the bite of a pair of squeeze rolls 23 and 24 which remove excess reagent therefrom. A drain returns solution from the tank 20 to the tank 16. The upper roll 23 of the squeeze rolls is loaded so as to leave a pickup of about 60 to 80 percent of the fabric weight in reagent 5 on the fabric. The lower roll 24 dips into the solution in tank 20. From the pair of squeeze rolls the fabric passes over a guide roll 25 under a control roll 26 or like means upon which tension is placed by weight 27 regulated through control box 28. Next the fabric is passed over a guide roll 29 and under a guide roll 30 into the first treatment zone 31 equipped with a vent 32 by way of vestibule 33 which is equipped with a seal 34 to permit entrance of the fabric into the treatment zone without affecting the operating conditions therein and also to minimize the escape of steam if it is to be utilized during the process. The control roll 26 or like means actuates control box 28 which is connnected to the drive of the squeeze rolls 23 and 24 insequence so that the fabric strip entering the treatment zone is maintained under a constant tension in the warp-wise direction.

In the treatment zone 31 of the fabric passes around a series of upper rolls 35 and a series of lower rolls 36 or like means in the form of a series of vertical loops. Steam, or cold or hot water is supplied to the zone 31 through supply pipes 37 and 38 equipped with a series of headers of other suitable means.

Treatment zone 31 is enclosed within walls of which end panel 39, top member 40, separating petition 41 and base number 42, are shown. Separating petition 41 forms a common wall with treatment zone 43 and the upper end of petition 41 is formed by panel 44 suspended from top member and equipped with a seal 45 so that as the fabric passes out of zone 31 to zone 43 the conditions within are not changed. Treatment zones 46 and 47, located downstream from zones 31 and 43 and which next receive the fabric, are enclosed by separating petitions 48, 49 and 50, and base members 51, 52 and 53, respectively. The top member 40 forms a common panel with these zones and with zone 31. Finally, end panel 54 and base member 55 form part of a tank 56 containing water functioning as a seal at the exit end of the treatment zones through which the fabric next passes. The tank is equipped with an exit vestibule S7 and an overflow pipe 58. Located in the tank are guide rolls 59, under which, and 60, over which, the exiting fabric passes to the vestibule 57.

Treatment zones 43, 46 and 47 are all equipped with upper and lower rolls 61, 62, 63, 64, 6S and 66, respectively, or like means, which correspond to

rolls

35 and 36 in zone 31. Zones 43, 46 and 47 also are equipped with supply pipes and headers 67, 68 and 69 below, and 67A, 68A and 69A above, connected to sources (not shown) to permit entrance of steam or the like into each zone. Moreover panels '70, 71 and 72 suspended from top member 40 and equipped with seals 73, 74 and 75 serve to isolate each zone from the preceding and subsequent areas and maintain conditions within each zone. Side panels (not shown) complete the enclosure of the treatment zones and vents (not shown) permit exit of steam or the like therefrom.

Located above top member 40 is a constant speed main driving motor 76 connected to one of upper rolls 35 through a belt drive 77 which passes outside member 40. Driving motor 76 is also connected through belt drive 78 to means such as variable speed device 79, located above member 40 and connected to one of the upper rolls 61. Variable speed device 79 is in turn connected to a like device 80 which is then connected to still another like unit 81 located above zones 46 and 47, respectively.

Devices

79, 80 and 81 are connected to the upper rolls 61, 62 and 63 by means of belt drives 82, 83 and 84.

As fabric leaves the exit vestibule 57, a guide roll 85 is provided under which the fabric passes and from which it is led over guide roll 86 and thence under a control roll 87 which has tension placed thereon by weight 88 regulated through control box 89 and on its way to the washing means next passes over guide roll 90 and between rolls 91 under a set of other rolls 92 and over a roll 93, the former being immersed in a washing tank 94. Passing from tank 94 the fabric is led over roll 95 and under roll 96, the latter being disposed in a second washing tank 97, over a roll 98 to the bite of a pair of squeeze rolls 99 and 100 which are adjusted to remove the water from the fabric and leave it in only a moistened condition. From the squeeze rolls the fabric is led to collecting means and passes over a guide roll 101 between a pair of rolls I02 and between a pair of reciprocating rolls 103 which reciprocate through a connection to eccentric 104 and is laid in folds below.

The fabric as it is laid in folds on pallet 106 is then transferred to a drying means such as slack loop dryer 107 as shown in FIG. 3. In those instances where the process is being carried out in a continuous or semicontinuous manner, the pallet I06 may be replaced by a J- box or other suitable arrangement (not shown) from which the fabric is withdrawn at a slower speed than the speed with which it is being introduced in the J-box or the like. This is done in order to maintain the fabric in an essentially tensionless state and in order to feed it in to the loop dryer in a substantially completely relaxed condition. The fabric is led over a roll 108 and between driven rolls 109 located within the walls of the slack dryer and over a plurality of spaced bars "0 which are continuously advanced by chain 11] so as to form a plurality of fabric loops 112 which hang from the bars 110 in tensionless state. Hot air, or if desirable, cold air is supplied to the slack dryer 107 through passages by way of the floor plate U3 which contains passages 114 to permit the hot or cold air to enter. Accordingly the dryer is maintained at a temperature suitable for removing the remaining liquid from the fabric being dried. in the dryer some additional modification of the fabric takes place although it remains in essentially a smooth condition. Generally a fabric being processed in a dryer can be subjected to a wide temperature range of l00 C or less to as much as 150 C until the moisture content of the fabric is substantially completely removed. The best temperature for drying a particular fabric is readily determinable. if desirable, the temperature may be measured by an infra-red sensing device and controlled by means used in ordinary dryers of this type. From the dryer, the fabric is delivered between rolls 115 and taken up on a roll ll6.

Fabrics treated in accordance with this invention readily lend themselves to a wide variety of uses. For example, since woolen fabrics when treated with the disclosed process possess excellent stretch characteristics, they are useful in the manufacture of garments such as men's and boy's suits, slacks, sport coats, ladies and childrens dress fabrics and sportswear, and the like. Such garments due to treatment in accordance with this invention generally conform to the body of the wearer with a snug fit and because of the stretch characteristics thereof readily expand and contract permitting the wearer to be comfortable while at the same time allowing for freedom of movement. In addition, because of the stretch characteristics of a garment manufactured from material treated in accordance with the invention, flexibility at the elbows and knees overcomes rapid deterioration to the shape of the garment and adds to the durability of the wearing qualities.

in addition to the garment field, fabrics treated in accordance with the invention, such as for example, nylon fabrics, make excellent furniture coverings and upholstery fabrics which readily conform to the shape of the article to which they are applied. Moreover, due to the excellent stretch properties of all fabrics processed in accordance herewith, stretch and recovery is substantially permanent and results in long fabric life. However, in the case of cotton fabrics recovery is improved by subsequent known processes which will give the cotton a permanent set. Such cotton fabrics are useful in the manufacture of outer garments and denims which are particularly useful in the field of sportswear.

The term stretch characterisitics" as employed throughout this specification and in the appended claims is to be understood to mean that a fabric when treated in accordance with the present invention has the ability to be repeatedly extended and it will return to its non-extended shape upon release of the stretching force applied thereto in order to bring about extension. ln this connection, it is to be noted that generally fabrics can be extended or stretched up to about 6 percent of their original width and/or length. In contrast to this, fabrics treated in accordance with the invention exhibit properties of stretch as great as percent and more. For example, woolen fabrics processed in accordance with the invention exhibit properties of stretch in a range of 30 to 45 percent in comparison with a stretch factor of about 6 percent exhibited by like woolen fabrics which are not so processed, and in comparison to stretch characteristics of about 20 percent exhibited by woolen fabrics processed in accordance with known procedures for imparting a stretch thereto.

As many apparently widely different embodiments of this invention may be made without departing from the spirit and scope thereof, it is to be understood that the same is not limited to the specific embodiments thereof except as defined in the appended claims.

I claim:

1. Apparatus for producing fabric having stretch characteristics comprising a plurality of rolls for conducting fabric into a first tank of chemical reagent, a second tank of reagent, a pair of squeeze rolls at least one of which is partially immersed in said second tank, a control roll constructed and arranged to apply tension on fabric delivered from said squeeze rolls, a plurality of successive enclosed treatment zones located after said control roll, the first of said treatment zones having a sealed entrance vestibule to receive fabric each said treatment zone having located therein a plurality of rolls at least some of which are positioned above the others, motive means to drive at least those in the first zone at a first peripheral speed, devices driving rolls in at least one successive treatment zone at a higher peripheral speed, thereby providing progressively increased tension on fabric as it is advanced over said rolls and into successive zones, steam headers located in at least one successive treatment zone, flexible seals located at the exit of each zone constructed and arranged to permit the passage of fabric while maintaining the internal conditions in each zone substantially constant, a liquid seal located after the last of said successive treatment zones through which fabric passes to an exit vestibule, a first washing tank, a control roll constructed and arranged to apply tension on fabric delivered to said washing tank, a second washing tank and a pair of exit squeeze rolls, at least one of said squeeze rolls being partially immersed in said second washing tank.

2. Apparatus for producing a fabric having stretch characteristics comprising means for applying a modifying agent to a fabric, a plurality of successive enclosed treatment zones located after said means for applying a modifying agent, the first of said zones having a sealed entrance vestibule to receive said fabric, each of said treatment zones having located therein a plurality of rolls at least some of which are positioned above the others and at least one of which is a driven roll, means to drive said driven rolls so that peripheral roll speed increases in each successive zone thereby progressively increasing the tension on said fabric as it is advanced into successive zones, means located in each treating zone for regulating the temperature thereof, seals located at the exit of each zone constructed and arranged to permit the passage of fabric while maintaining the internal condition in each zone substantially constant and means for washing said fabric after said successive treatment zones.

i t t i I.