US3808844A

US3808844A - Apparatus for controlling the amount of elastic stretch in stretch woolens

Info

Publication number: US3808844A
Application number: US00263795A
Authority: US
Inventors: H Oldfield
Original assignee: Worcester Textile Co
Current assignee: Worcester Textile Co
Priority date: 1972-08-19
Filing date: 1972-08-19
Publication date: 1974-05-07
Anticipated expiration: 1991-05-07

Abstract

Apparatus for controlling the amount of elastic stretch in stretch woolens having a cylindrical drum rotatably mounted on a stand. A drive roll is supported by arms pivotally mounted on vertical members which extend upwardly from the stand and there is a piston mechanism for moving the drive roll into rolling contact with the cylindrical surface of the drum. A drag roll is also supported by arms mounted on vertical members which extend upwardly from the stand and the drag roll is positioned adjacent the drive roll with their axes of rotation being parallel to each other. A drive mechanism connected to the drive roll causes the cylindrical drum to rotate and results in the fabric being passed therearound and between the drum and the drive roll. The rotational speed of the drag roll is maintained slower than that of the driving roll to produce a stretch in the warp yarns of the fabric. The amount of stretch applied to these warp yarns is varied by mechanically controlling the rotational speed of the drag roll. Primary steam conduit structure is partially mounted within the cylindrical drum with the section within said drum having a plurality of apertures in its outer wall that allows the steam to be released within said drum. This steam in turn escapes from the drum through a multitude of apertures in its cylindrical surface and then passes through the fabric which is travelling around the drum. A secondary steam conduit structure is also partially mounted within the cylindrical drum with its internal portion being in the form of a helical coil which acts to prevent condensation in the drum of the steam released therein by the primary steam conduit structure. An auxiliary bath is mounted on the stand in a position to receive the fabric after it has passed around the drive roll. Squeeze rolls are supported on the stand in a position to receive the fabric after it has been passed through the bath. By varying the amount of drag by the drag roll, the amount of permanent elastic stretch to be imparted into the woolen fabric passing through the apparatus can be varied as the permanent set is produced by the action of the steam passing through the chemically impregnated fabric.

Description

United States Patent [191 Oldfield APPARATUS FOR CONTROLLING THE AMOUNT OF ELASTIC STRETCH IN STRETCH wooLENs [75] Inventor: Howard P. Oldfield, Smithfield, R.I.

[73] Assignee: Worcester Textile Company,

Centerdale, R.I.

[22] Filed: Aug. 19, 1972 [21] Appl. No.: 263,795

Primary Examiner-Harvey C. Hornsby Assistant Examiner-Philip R. Coe Attorney, Agent, or Firm-Barlow & Barlow 57 ABSTRACT Apparatus for controlling the amount of elastic stretch in stretch woolens having a cylindrical drum rotatably mounted on a stand. A drive roll is supported by arms pivotally mounted on vertical members which extend upwardly from the stand and there is a piston mecha- [451 May 7,1974

nism for moving the drive roll into rolling contact with the cylindrical surface of the drum. A drag roll is also supported by arms mounted on vertical members which extend upwardly from the stand and the drag roll is positioned adjacent the drive roll with their axes of rotation being parallel to each other. A drive mechanism connected to the drive roll causes the cylindrical drum to rotate and results in the fabric being passed therearound and between the drum and the drive roll. The rotational speed of the drag roll is maintained slower than that of the driving roll to produce a stretch in the warp yarns of the fabric. The amount of stretch applied to these warp yarns is varied by mechanically controlling the rotational speed of the drag roll. Primary steam conduit structure is partially mounted within the cylindrical drum with the section within said drum having a plurality of apertures in its outer wall that allows the steam to be released within said drum. This steam in turn escapes from the drum through a multitude of apertures in its cylindrical surface and then passes through the fabric which is travelling around the drum. A secondary steam conduit structure is also partially mounted within the cylindrical drum with its internal portion being in the form of a helical coil which acts to prevent condensation in the drum of the steam released therein by the primary steam conduit structure. An auxiliary bath is mounted on the stand in a position to receive the fabric after it has passed around the drive roll. Squeeze rolls are supported on the stand in a position to receive the fabric after it has been passed through the bath. By varying the amount of drag .by the drag roll, the amount of permanent elastic stretch to be imparted into the woolen fabric passing through the apparatus can be varied as the permanent set is produced by the action of the steam passing through the chemically impregnated fabric.

5 Claims, 8 Drawing Figures PATENTEIJm 1 m4 SHEET 3 [IF 3 FIG.8

FIG.6

APPARATUS FOR CONTROLLING THE AMOUNT OF ELASTIC STRETCH IN STRETCH WOOLENS BACKGROUND OF THE INVENTION The invention relates to apparatus for controlling the amount of elastic stretch permanently set into stretch woolens. In the past the creases or pleats formed on treated wool fabrics by a steam press or by steaming between pleating papers has been found not to be stable. They disappeared gradually during normal wear and were lost immediately if wetted with water. The set imparted to stretched fibers and wool fabrics creased or pleated in this manner was called cohesive or temporary set. Since strained, temporarily set wool fibers and fabrics are not firmly held, they tend to assume their unstrained configuration when water enters them and the crease or pleat is then completely lost.

It has been found, however, that when strained wool fibers are treated with boiling water or steam for an extended period of time they acquire a set which is stable or permanent to subsequent wetting, even with hot water. In this case the degree of set is dependent on the time of boiling or steaming. When alkalies or reducing agents are added to the boiling water or steam the rate of permanent setting has been found to increase very rapidly.

With this knowledge available industry has proceeded to produce what is known as stretch woolens by impregnating wool fabric with an aqueous solution of monoethanolamine sulfite and then squeezing the fabric in open width to give a final wet pickup of 60 to 80 percent by weight of the dry fabric. Next having a knowledge of the amount of stretch which is desired to be imparted to the fabric, the fabric was then placed in tension warpwise which reduced the width of the fabric. This particular section of the fabric which is now under the predetermined tension was then steamed for the required period of time in order to give a permanent set to the strained wool fibers. In the past this has been a slow process since only a limited amount of the fabric could be properly stretched out and then 'steamed at a time due to the physical limitations of the equipment used at that time. In many cases this meant that a given length of the fabric had to be cut from the roll in order to be placed in 'the necessary stretched condition and this length was governed by the length of the equipment in which the steaming took place.

The stretch woolens are primarily produced as a fabric to be used in outer garments for mens and womens wear and they impart to these garments improved characteristics in bothrappearance and comfort. The elastic effect of garments made from such material makes them more comfortable and they may be made more form fitting as they accommodate themselves to bodily movements. The stretch woolen fabrics have a very high tailorability also. Garments made from this fabric SUMMARY OF THE INVENTION The operation of applicants apparatus for controlling the amount of elastic stretch permanently imparted to stretch woolens will be quickly comprehended. A preliminary step necessary for the apparatus requires that the woven woolen fabric first have been impregnated with an aqueous solution of monoethanolamine sulfite. Starting at this point the fabric is threaded first over and partially around the drag roll, then almost completely around the cylindrical surface of the steam decator drum during which the fabric passes beneath a driving roll that is positioned in rolling contact with the steam decator drum and finally back around a portion of the drive roll. At this point the fabric maybe passed next into a bath or directly through the squeeze rolls. The drive roll is rotated at a speed greater than the speed of rotation of the drag roll to place a tension warpwise upon the warp yarns. This increased stretching of the warp yarns causes the weft yarns to pull up and to have an increased crimp amplitude as they pass over and under successive transverse warp yarns. By varying the amount of difference between the speed of rotation of the drive roll and the drag roll, the amount of elastic stretch to be imparted to the fabric may be controlled. As the fabric is passing around the rotating decator drum steam is passed into the drum which escapes outwardly through the apertures in the cylindrical surface of the drum and passes through the fabric thereby imparting a permanent set to the yarn in its stretched and distorted condition. The time cycle for the fabric to rotate around the drum is predetermined to be at least the minimum amount of time which is necessary for the steaming operation to give a permanent set to the warp and weft yarns of the fabric. During the steaming process the chemicals that had been impregnated into the fabric in the aqueous solution rearrange the molecular chains of the wool fiber permanently setting the crimp of the filling yarn.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a left side elevation view of applicants apparatus for controlling the amount of elastic stretch in stretch woolens;

FIG. 3 is a plan view of applicants apparatus with the drive mechanism for the drive roll and the drag roll not shown;

FIG. 3 is a partial elevation view illustrating the decator drum and the steam conduit'structures partly in DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIGS. 1 and 2 of the drawings applicants apparatus for controlling the amount of stretch in stretch woolens is generally designated by the numeral 10. The woven woolen fabric which is to be processed through the apparatus has to be preconditioned before it is passed therethrough. When it is ready for threading into the apparatus, the fabric has already been impregnated with an aqueous solution of mono- I ethanolamine sulfite followed by a squeezing operation to provide it with the proper amount of wetness.

The preconditioned fabric W is first threaded over guide roller 12 then beneath guide bar 14 and next over guide roller 16. These guide members have their ends secured to laterallyspaced arms 18 which extend outwardly at 90 angles to vertical members 20. The vertical members 20 form a portion of stand 17. Next the fabric is directed downwardly around guide bar 22 and upwardly over and partially around drag roll 30.

Guide bar 22 is part of tensioning mechanism 21 that is secured to vertical members 20. The mechanism 21 has a shaft 23 with a worm gear 24 mounted on one end and a wheel 25 mounted on the other end for adjusting the tension on the fabric. Rotation of wheel 25 causes gear 24 to rotate pinion gear 26 mounted on shaft 27. This causes the tension bar 28 having its opposite ends connected to arms 29 to increase or lower the tension of bar 28 against the fabric as the arms are rotated upwardly and downwardly.

Screw bar 31 over which the fabric W passes on the way to drag roll 30 functions to spread the cloth out evenly before it passes on to drag roll 30. Both the drag roll 30 and screw bar 31 are supported at their opposite ends by arms 35 having one of their ends secured to vertical members 38. The fabric passes around drag roll 30 and then onto the cylindrical surface of decator drum 40. As the vfabric passing around the drum reaches the top of the drum it passes between drive roll 50 and steam decator drum 40 which are in rolling contact. It is drive roll which rotatesthe drum causing the fabric to be passed therearound it. After the fabric passes over and partially around the drive roll 50 it has. the option of being passed through the bath and then through squeeze rolls or may go directly to squeeze rolls 70 and bypass the bath. Drive roll 50 has its opposite ends mounted on laterally spaced arms 51 one of whose ends are pivotally secured on vertical members 52 by shaft 53.

When it is desired to thread the fabric under drive roll 50, a switch (not shown) is actuated to pass air through tube 54'into cylinder 55. This causes the piston rod 56 connected to a piston within the cylinder to raise arm 51 away from the cylindrical surface of drum 40. After the fabric has been threaded thereunder a second signal releases air through tube 57 into cylinder 55 causing the piston rod to draw drive roll 50 back into rolling engagement with drum 40 with the fabric pinched therebetween. The lower end of cylinder 55 is pivotally secured to bracket 58 mounted on cross member 59. The cross members in turn are supported by legs 61 with this general support structure of the apparatus also forming a part of the stand 17.

If the fabric is to be passed through bath 60, it initially passes over guide roll 62 down into the liquid within the bath and around roll 63 which holds the fabric down in the bath and then upwardly over guide roll 64. Spray pipes 65 are mounted above the path to provide a constant supply of liquid within the bath. The

ported on roller bearings 44 that are supported on the top of legs 45. Primary steam conduit 46 has its horizontal section 47 journalled within the neck sections 43 of the drum. This allows the drum to rotate while the horizontal section 47 remains stationary. Steam supplied from a source is directed inwardly through steam conduit 48 and it passes through apertures into the interior of the drum. The steam then escapes through apertures 42 and passes through the fabric traveling around the drum. It is this steaming-which sets up the permanent set of the crimps of the warp and weft yarns. A second steam conduit 49 passes into the interior of drum 40 through steam conduit 48. The portion of the steam conduit 49 within the drum is formed in the shape of a helical coil and it functions as a super heater to prevent condensation of the steam released through apertures 48 of the first steam conduit. A steam hood is mounted over said steam drum to provide a chimney through which excess steam may be vented out of the work area.

The fabric according to this invention is shown in FIGS. 5-8 as composed of warp yarns and weft yarns 90. FIGS. 5 and 6 show a fabric as woven prior to shrinkage. In this form the yarns are spaced apart a sufiicient distance to provide clearance for the shrinkage to which the fabric is subjected. In the embodiment shown the fabric is woven with a plain weave wherein the warp yarns 80 are substantially straight and the weft yarns are crimped as they pass under and over successive warp yarns.

The finished fabric after being shrunken is illustrated in FIGS. 7 and 8 wherein it will be noted that the warp and weft yarns are more closely spaced than the fabric of FIGS. 5 and 6 and the weft yarns 90 are more highly crimped, that is, there are more crimps per inch due to the greater number of warp yarns per inch in the contracted state of the fabric and they are bent more sharply as they pass under and overthe successive warp yarns.

The manner in which the method of controlling the amount of elastic stretch in stretch woolen fabrics will be most easily understood by referring to FIGS. 4-8. In FIG. 4 a schematic illustration shows the major components of applicants novel apparatus, the steam decator drum 40, drag roll 30 anddrive roll 50. Drive roll 50 is connected by chains and sprockets to motor 72 which is a variable speed motor. Rotation of drive roll 50 causes drum 40 to rotate and convey the fabric through the apparatus asdescribed previously. Drag roll 30 in a similar manner is connected by chains and sprockets to motor 74 which is also of the variable speed variety. It is to be realized that by the exercise of ordinary mechanical skill both rolls could have their rotation controlled by a single motor and still function in the same manner.

By having the drive roll rotate at a faster rate of speed than that of the drag roll the warp yarns of the fabric are caused to elongate and remove some of their crimp from their length. At the same time the weft yarns have their length shortened, and this causes the crimp in the weft yarns to increase in amplitude as the yarn is pulled up and bent more sharply as it traverses first over and then under successive warp yarns. The high shrinkage results in'increasing the number of yarns per inch and thereby produces a denser fabric. The crimp is increased in frequency due to the increased number of yarns per inch and in amplitude as the yarns are pulled up and bent more sharply in their traverse. This increased density up-grades the fabric and improves its appearance and value by an amount greatly in excess of the processing cost. g

The process also provides for stabilizing the fabric in this highly compacted and crimped state. This stabilization imparts a memory to the yarn so that when it is thereafter deformed it tends to return to its original state. The fabric is highly stretchable weftwise due to the fact that when it is tensioned, the crimp is pulled out of the yarns although the yarns do not themselves increase in actual length. When the stretching force is removed, the yarn memory causes the yarns to pull back and the crimp to be restored. The pull-back effect is equivalent to that normally produced by rubber yarns but in this case is produced by the memory effect of the wool yarn. By varying the degree of difference between the speed rotation of the drive roll and the drag roll the amount of stretch which is permanently set into the fabric by the steaming operation can be varied. For example, if there is only a small difference between the speed of the two rolls, the amount of elastic stretch permanently set into the wool fabric will be relatively small. Likewise a greater difference between their two rotational speeds will produce a greater amount of elastic stretch permanently set in to the fabric. Tension gauges or stretch meters may also be utilized to maintain quality control over the degree of elasticity pennanently set into the fabric.

What is claimed is: 1. Apparatus for controlling the amount of weftwise elastic stretch in stretch woolens comprising a cylindrical drum having closed ends and a multi tude of spaced apertures along its cylindrical surface, shaft means extending from the opposite ends of said drum,

bearing means rotatably supporting said shaft means, primary steam conduit means mounted partially within said cylindrical drum and adapted to be connected to a source of steam outside said drum, the section of said primary steam conduit means within said drum having a plurality of apertures in its outer wall that allows steam to be released within said drum which steam then escapes out of the drum through the multitude of apertures in its cylindrical surface and passes through a fabric traveling around said drum, secondary steam conduit means mounted partially within said cylindrical drum and adapted to be connected to a source of steam outside said drum whereby said secondary steam means acts to prevent condensation in the drum of the steam released therein by said primary steam conduit means, a stand,

a drive roll supported by said stand near said drum and on the woolen removal side of the drum having means for rotationally driving it, means for moving said drive roll into rolling contact with said drum whereby rotation of said drive roll causes said drum to rotate and feed a fabric around said drum, a drag roll supported by said stand on the woolen feeding side of said drum,

means for varying the rotational speed of said drag roll with respect to the rotational speed of said drive roll. V

2. Apparatus for controlling the amount of elastic stretch in stretch woolens as recited in claim 1 wherein said means for moving said drive roll into contact with said drum comprises a cylinder, a reciprocating piston therein, and a piston rod having one of its ends attached to said piston.

3. Apparatus for controlling the amount of elastic stretch in stretch woolens as recited in claim 1 wherein said drive roll and drag roll are mounted adjacent each other near the top of said cylindrical drum.

4. Apparatus for controlling the amount of elastic stretch in stretch woolens as recited in claim 1 further comprising a steam hood supported over the top of said drum.

5. Apparatus for controlling the amount of elastic stretch in stretch woolens as recited in claim 1 wherein the portion of said second steam conduit means within the cylindrical drums is in the shape of a helical coil.

Claims

1. Apparatus for controlling the amount of weftwise elastic stretch in stretch woolens comprising a cylindrical drum having closed ends and a multitude of spaced apertures along its cylindrical surface, shaft means extending from the opposite ends of said drum, bearing means rotatably supporting said shaft means, primary steam conduit means mounted partially within said cylindrical drum and adapted to be connected to a source of steam outside said drum, the section of said primary steam conduit means within said drum having a plurality of apertures in its outer wall that allows steam to be released within said drum which steam then escapes out of the drum through the multitude of apertures in its cylindrical surface and passes through a fabric traveling around said drum, secondary steam conduit means mounted partially within said cylindrical drum and adapted to be connected to a source of steam outside said drum whereby said secondary steam means acts to prevent condensation in the drum of the steam released therein by said primary steam conduit means, a stand, a drive roll supported by said stand near said drum and on the woolen removal side of the drum having means for rotationally driving it, means for moving said drive roll into rolling contact with said drum whereby rotation of said drive roll causes said drum to rotate and feed a fabric around said drum, a drag roll supported by said stand on the woolen feeding side of said drum, means for varying the rotational speed of said drag roll with respect to the rotational speed of said drive roll.