WO1998028482A1

WO1998028482A1 - Bonded sewing thread

Info

Publication number: WO1998028482A1
Application number: PCT/US1997/023434
Authority: WO
Inventors: James O. Threlkeld
Original assignee: Threlkeld James O
Priority date: 1996-12-20
Filing date: 1997-12-19
Publication date: 1998-07-02
Also published as: AU5612098A

Abstract

A thread for sewing as well as a process for making the same which includes application of an aqueous polyester bonding agent as well as a dye in a metering area (53) with applicators (54, 59) followed by setting of the bonding agent and the dye with a drying operation which includes a first pair of heated rolls (74) and a second pair of heated rolls (80).

Description

BONDED SEWING THREAD Background of the Invention

The present invention relates broadly to threads used in textile construction, primarily sewing, and, more particularly, to a bonded thread for sewing. Thread used in forming textiles, including garments, needs to have a certain strength to withstand the rigors of industrial sewing. Many of the threads are fibrous in that they are formed from a plurality of individual fiber elements which define a filament body of an elongate sewing thread. Often, some of the fibrous elements project from the sewing thread body and can become entangled in machinery during high-speed sewing operations. This loose fiber entanglement can cause thread breakage which can slow production and add to the cost of producing garments. Accordingly, one of the remedies applied includes the application of a bonding agent which coats the thread and defines a smooth outer surface thereof to prevent random fibrous projections. This technique is applied whether the thread is a single filament or is composed of multifilaments which may be twisted or otherwise treated prior to sewing.

Typically, the bonding agent is formed from an insoluble nylon resin carried in a methyl alcohol-based solution. This bonding agent is typically applied in a bath and then set using a hot air oven which results in a film-like coating on the fiber. Once of the problems with this technique is that it is relatively slow and therefore expensive. Additionally, the bath and hot air oven typically take up an inordinate amount of space. Summary of the Invention

It is accordingly an object of the present invention to provide a bonded sewing thread which is inexpensive to produce and may be produced rapidly. It is further an object of the present invention to provide such a sewing thread which experiences lower elongation and is stronger than previous bonded sewing threads.

It is yet another object of the present invention to provide such a sewing thread which results in better dye quality and lower shrinkage than the prior bonded threads. To that end, a thread for sewing includes at least one fibrous filament having a bonding agent applied thereto to prevent individual fibers from projecting from the surface of the at least one filament, thereby reducing the risk of breakage during sewing, the bonding agent being a coating of aqueous polyester set to the at least one filament by heat. It is preferred that the thread include a bundle of filaments interlaced with the at least one filament to form a filament bundle with the filament bundle having the bonding agent applied thereto.

It is further preferred that the thread be dyed using a dye mixed with the aqueous polyester bonding agent. Further, the fiber bundle preferably includes a twist applied thereto prior to application of the bonding agent.

Since the aqueous polyester bonding agent possesses properties which are superior to the nylon resin known in the prior art, a specialized machine and method are preferably used to form the bonding sewing thread to take advantage of the special properties associated therewith. The thread made according to the special process is a thread for sewing having a bonding agent applied thereto to prevent individual fibers for projecting from the surface thereof, thereby reducing the risk of breakage during sewing, the thread being formed in a continuous, in-line treating process for traveling filaments with the thread comprising at least one fibrous filament caused to travel along a travel path and an aqueous polyester bonding agent applied to the at least one filament using a metering applicator disposed along the travel path with the polyester bonding agent being heat set to the at least one fibrous filament using heated rolls disposed along the travel path downstream of the metering applicator as the at least one fibrous filament having the aqueous polyester bonding agent applied thereto is caused to travel thereacross. Preferably, the at least one fibrous filament includes at least one additional fibrous filament associated therewith to form a filament bundle, the association occurring along the travel path prior to application of the bonding agent. A release agent may be applied to the fibrous filament prior to contact of the fibrous filament with the heated rolls, with the heated rolls being heated to a temperature of less than 150/C. Preferably, the filament bundle includes a twist imparted thereto by a twist application assembly prior to application of the aqueous polyester bonding agent.

The present invention further includes a method for forming bonded sewing thread using a textile machine which defines a thread travel path. The method includes the steps of providing at least one fibrous filament for movement along the thread travel path, causing the at least one fibrous filament to travel along the travel path using an assembly for imparting movement to the at least one fibrous filament associated with textile machines; applying a predetermined quantity of aqueous polyester bonding agent to the at least one fibrous filament using a metering applicator associated with the textile machine along the travel path as the at least one fibrous filament moves therealong; applying heat to the at least one fibrous filament using at least one pair of heated rolls mounted to the textile machine downstream from the applicator with the heated rolls having the at least one fibrous filament trained therearound and winding the at least one fibrous filament on a winder associated with a textile machine to form a package of bonded sewing thread.

The method preferably further includes the step of applying a release agent to the at least one fibrous filament prior to heat application and the step of applying heat to the at least one fibrous filament includes applying heat at a temperature of less than 150/C on a first pair of rolls and applying heat at a temperature of greater than 220/C on a second pair of heated rolls mounted to the textile machine. Alternately, the step of applying heat to the at least one fibrous filament may include applying heat at a temperature in a range of 150/C to 160/C on a first pair of rolls and applying heat at a temperature of greater than 220/C on a second pair of heated rolls mounted to the textile machine. Preferably, the step of providing at least one fibrous filament includes providing at least one additional fibrous filament in an interlaced relationship with the at least one fibrous filament to form a multifilament bundle for application of the aqueous polyester bonding agent thereto. The method preferably further comprises the step of providing an assembly for imparting a twist to the fibrous bundle to form a twisted filament bundle for application of the aqueous polyester bonding agent thereto. Alternately, the twist may be applied to the at least one fibrous filament. Finally, the method preferably includes the step of mixing a dye with the aqueous polyester bonding agent for application to the at least one fibrous filament to obtain a dyed, bonded sewing thread. By the above, the present invention provides a method for producing a bonded sewing thread, the bonded sewing thread itself and the bonded sewing thread produced according to the method which results in a bonded sewing thread having better dye qualities, lower shrinkage and lower elongation and which is less expensive and faster to produce. Brief Description of the Drawing, s

Fig. 1 is a perspective view of the bonded sewing thread according to the preferred embodiment of the present invention being formed on a textile machine configured for producing bonded sewing thread according to the present invention. Detailed Description of the Preferred Embodiment Turning now to the drawings and, more particular, to Fig. 1, a bonded thread for sewing is formed on a textile machine indicated generally at 10 which includes a generally rectangular upstanding body 12 including a superstructure 14 and a subframe 16 mounted thereto which are supported on feet 15. While this is the preferred configuration for the textile machine for forming the bonded sewing thread, it will be appreciated by those skilled in the art that the essential components of the machine may be fitted in several different configurations depending on available space and whether all of the operations which will be described presently are to be performed.

A filament supply is illustrated generally at 20 and includes a pair of rolled filament packages 22,28 supported on rotatable platforms 25,30 which in turn may be supported on a spindle 31. As will also be appreciated by those skilled in the art, the present invention is adaptable for forming a thread from a single filament or from a plurality of filaments which are interlaced forming a filament bundle. Additionally, the filaments, whether a monofilament or a filament bundle, may be formed with a twist which is accomplished by driving the rotatable packages 22,28 in rotation as indicated by arrows in Fig. 1. The assembly for driving the filament platforms 25.30 is not shown, yet it is well within the skill of those of ordinary skill in this art to drive platforms into rotation. For example, if a single filament were used from the first package 22, driven at 15,000 rpm, three twists per inch would occur. Additionally, other twist characteristics may be imparted by altering the speed of rotation of the filament package 22. In order to achieve an interlaced twisted filament bundle, a second filament 32 is fed through the hollow core of a spindle on which the first filament package 22 is mounted to emerge therefrom and it has the first filament 26 laced thereabout. If both platforms 25,30 are driven into rotation, a twist will be imparted to the resulting fibrous filament bundle with results in a tightly twisted traveling filament bundle 33. This filament bundle 33 is fed through a yarn guide 18 onto the remainder of the textile machine 10.

The textile machine 10 defines a travel path along which the filament or filament bundle 33 may travel for processing. Initially, it may be desirable to draw the filaments prior to any other processing. To that end, drawing rolls 36,38,40,42 are provided around which the filament 33 may be trained. From the drawing rolls 36,38,40,42, and proceeding downstream, a yam guide 44 is provided for aligning the yarn prior to its entry into a metering area 53. It may be desirable to wash the filament bundle 33 and, to that end, a washing area is provided in the form of a box 46 including a detergent and water mixture fed from a supply 52 through supply lines 56. Further, dye or other treatment liquid may be applied through applicator 54 from a supply container 56. Alternately, and as will be seen in greater detail hereinafter, me dye may be mixed with the bonding agent. Downstream from the first applicator 54, a second metering assembly 58 is provided. This metering assembly 58 includes a metering applicator 59 and a supply tube 61 which is fed from a supply hose 64 by a pump 67 which draws from a supply of aqueous polyester bonding agent 72. In order to heat set the bonding agent onto the thread, a first pair of heated rolls 74 is provided including a first heated roll 76 and a second heated roll 78. From there, the final heating step is provided through additional contact heat from a second pair of heated rolls 80 including a first heated roll 82 and a second heated roll 84. A shroud 81 may be placed over these rolls 82.84 in order to help conserve and contain the heat generated thereon. Finally, the filament bundle 33 encounters a winding assembly 86 including a first guide roll 88 and a cantilevered guide pin 92. A surface winder including a drive roll 91 is provided to drive a thread package 90 into rotation as it is wound. All of the aforesaid components are arranged in a vertical array along the superstructure 14 of the textile machine 10 except for the pump 67 and the aqueous polyester resin supply container 72 which are mounted to the subframe 16. Once again, it should be emphasized that the aforesaid components are arranged in a neat, compact package for continuous in-line thread production operations. Nevertheless, it will not deviate from the present invention to arrange the components in any number of ways to suit the individual applications of those practicing the invention.

The operation of the present invention will now be explained. Initially, it will be noted that the operation is described with regard to a multifilament bundle, but it will be appreciated that a single, monofilament may be used with equal success with the monofilament being drawn from a single filament package on a single rotatable platform. Further, if it is not desired to impart a twist to the filament, there is no need to rotate the rotatable platform and the filament is merely drawn from the package.

Initially, and with respect to a multifilament bundle, a first filament 32 is drawn from its associated filament package 28 and fed axially through the hollow spindle supporting the other rotatable platform 25. As it is drawn through the center and outwardly beyond the other package 22, a filament 26 from the other package 22 is interlaced therewith and the associated filament bundle 33 is fed through the first yarn guide 18 and trained around all four draw rollers 36,38,40,42 if the filament is to be drawn. If not, it will be trained in avoidance of the draw rollers and fed through the second yarn guide 44 into the washing assembly 46 where the filament bundle is washed. From there, it goes through the first applicator 54 where some form of treatment liquid may or may not be applied. The bonding agent is then applied in the following metering assembly 58. The aqueous polyester bonding agent from container 72 is pumped using pump 67 through line 64 and is metered onto the yarn in the metering applicator 59. From there, the filament bundle is trained around the first heated roll pair 74. It has been determined that, if the first heated roll pair 72 is heated to a range of 150/C to 160/C or even above, a release agent is unnecessary. A release agent is a silicon oil or other type of lubricant which acts as a barrier between the heated rolls and the filament bundle to prevent the filament bundle from sticking to the rolls as the rolls are rotated with the thread traveling thereacross. As may be appreciated, if the filament bundle were to stick to the rolls, the process would fail. Therefore, typically, if the heated rolls are heated in the range of 100/C to 120/C, a release agent is necessary to prevent such sticking. One of the advantages to the aqueous polyester bonding agent applied to the sewing thread of the present invention is that, if the first heated roll pair is heated beyond 150/C, the aqueous carrier provides a steam layer between the filament bundle and the rolls 76,78 to prevent sticking, thus eliminating the need for a release agent. In the past, one of the problems associated with heating the first roll pair to a high temperature to remove the aqueous carrier prior to the ultimate heat set was that the aqueous carrier would flash to steam and cause splattering of its base component, be it dye or bonding agent, resulting in an uneven coating. An unusual result achieved with the polyester bonding agent of the present invention is that the first heated roll pair can be heated dramatically to temperatures greater than 150/C without splatter and without a release agent which results in a uniform coating on the resulting sewing thread. Further, the thread may be dyed with a dye being mixed in the bonding agent.

From the first pair of heated rolls 74, the filament bundle 33 is trained around the second pair of heated rolls 80 which is heated to a temperature of greater than 230/C. This final heating provides the final set of the bonding agent to the filament bundle resulting in the bonded sewing thread. Finally, the thread is wound onto a package 90 using a surface winding assembly 86. This is also the assembly that provides the primary driving movement of the thread through the device. Other driving forces are imparted to the filament bundle from the draw rolls 36,38,40,42, the first pair of heated rolls 74 and the second pair of heated rolls 80. The resulting thread package is then complete and ready for sewing and is produced at a much more rapid pace than was previously possible with bath dyes and hot air oven drying. By the above, the present invention provides a bonded sewing thread using an aqueous polyester bonding agent, resulting in a thread which has a lower elongation factor, a better dye quality and a lower shrinkage and which is less expensive to produce than the prior thread.

It will therefore be readily understood by those persons skilled in the art that the present invention is susceptible of a broad utility and application. Many embodiments and adaptations of the present invention other than those herein described, as well as many variations, modifications and equivalent arrangements, will be apparent from or reasonably suggested by the present invention and the foregoing description thereof, without departing from the substance or scope of the present invention. Accordingly, while the present invention has been described herein in detail in relation to its preferred embodiment, it is to be understood that this disclosure is only illustrative and exemplary of the present invention and is made merely for purposes of providing a full and enabling disclosure of the invention. The foregoing disclosure is not intended or to be construed to limit the present invention or otherwise to exclude any such other embodiments, adaptations, variations, modifications and equivalent arrangements, the present invention being limited only by the claims appended hereto and the equivalents thereof.

Claims

I claim:

1. A thread for sewing comprising at least one fibrous filament having a bonding agent applied thereto to prevent individual fibers from projecting from a surface of said at least one filament thereby reducing the risk of breakage during sewing, said bonding agent being a coating of aqueous polyester set to said at least one filament by heat.

2. A thread for sewing according to claim 1 and further comprising a plurality of filaments interlaced with said at least one filament to form a filament bundle, said filament bundle having said bonding agent applied thereto.

3. A thread for sewing according to claim 1 wherein said thread is dyed using a dye mixed with said aqueous polyester bonding agent.

4. A thread for sewing according to claim 2 wherein said fiber bundle includes a twist applied thereto prior to application of said bonding agent.

5. A thread for sewing having a bonding agent applied thereto to prevent individual fibers from projecting from a surface thereof, thereby reducing the risk of breakage during sewing, said thread being formed in a continuous, in-line treating process for traveling filaments, said thread comprising: at least one fibrous filament caused to travel along a travel path; an aqueous polyester bonding agent applied to said at least one filament using a metering applicator disposed along said travel path, said polyester bonding agent being heat set to said at least one fibrous filament using heated rolls disposed along said travel path downstream of said metering applicator as said at least one fibrous filament having said aqueous polyester bonding agent applied thereto is caused to travel thereacross.

6. A thread for sewing according to claim 5 wherein said at least one fibrous filament includes at least one additional fibrous filament associated therewith to form a filament bundle, said association occurring along said travel path prior to application of said bonding agent.

7. A thread for sewing according to claim 5 and further comprising a release agent applied to said at least one fibrous filament prior to contact of said at least one fibrous filament with said heated rolls with said heated rolls being heated to a temperature of less than 150°C.

8. A thread for sewing according to claim 6 wherein said filament bundle includes a twist imparted thereto by a twist application assembly prior to application of said aqueous polyester bonding agent.

9. A method for forming a bonded thread for sewing using a textile machine which defines a thread travel path comprising the steps of : providing at least one fibrous filament for movement along the thread travel path; causing said at least one fibrous filament to travel along the travel path using means for imparting movement to said at least one fibrous filament associated with said textile machine; applying a predetermined quantity of aqueous polyester bonding agent to said at least one fibrous filament using a metering applicator associated with said textile machine along said travel path as said at least one fibrous filament moves therealong; applying heat to said at least one fibrous filament using at least one pair of heated rolls mounted to said textile machine downstream from said applicator, said heated rolls having said at least one fibrous filament trained therearound; and winding said at least one fibrous filament on a winder associated with said textile machine to form a package of bonded sewing thread.

10. A method for forming a bonded sewing thread according to claim 9 wherein said method further includes the step of applying a release agent to said at least one fibrous filament prior to heat application and said step of applying heat to said at least one fibrous filament includes applying heat at a temperature of less than 150° C on a first pair of rolls and applying heat at a temperature of greater than 220° C on a second pair of heated rolls mounted to said textile machine.

11. A method for forming a bonded sewing thread according to claim 9 wherein said step of applying heat to said at least one fibrous filament includes applying heat at a temperature in a range of 150°C to 160°C on a first pair of rolls and applying heat at a temperature of greater than 220°C on a second pair of heated rolls mounted to said textile machine.

12. A method for forming a bonded sewing thread according to claim 10 wherein said step of providing at least one fibrous filament includes providing at least one additional fibrous filament in an interlaced relationship with said at least one fibrous filament to form a multifilament bundle for application of said aqueous polyester bonding agent thereto.

13. A method for forming a bonded sewing thread according to claim 12 and further comprising the step of providing means for imparting a twist to said fibrous bundle to form a twisted filament bundle for application of said aqueous polyester bonding agent thereto.

14. A method for forming a bonded sewing thread according to claim 9 and further comprising the step of providing means for imparting a twist to said at least one fibrous fⁱlament to form a twisted filament for application of said aqueous polyester bonding agent thereto.

15. A method for forming a bonded sewing thread according to claim 9 and further comprising the step of mixing a dye with said aqueous polyester bonding agent for application to said at least one fibrous filament to obtain a dyed, bonded sewing thread.