JP2021025190A - Sewing thread and method for processing sewing thread - Google Patents

Abstract

To provide a sewing thread that is used for sewing a flexible container or sneakers and improved for suppressing torque and preventing generation of torsion and to provide a method for processing the same.SOLUTION: The outside of a synthetic fiber multifilament twisted yarn (the multifilament may be a raw yarn or a textured yarn) as a core yarn A is single-covered or double-covered with multi-layered fusible yarns B, C (the multi-layered structural yarn comprises a low melting point part in a surface layer part and a high melting point part in an inner layer part) . The low melting point part is subjected to a heating and cooling processing (a heating and melting treatment and a cooling and solidifying treatment) to maintain the shape. Thus, functions to prevent generation of torque and untwisting frays when being cut are imparted uniformly in a longitudinal direction.SELECTED DRAWING: Figure 1

Description

The present invention relates to a sewing thread using a multifilament of a synthetic fiber or a twisted thread of a cotton thread as a core thread, and suppresses the torque of the sewing thread used for sewing a flexible container, a sneaker, etc., which requires particularly high strength, and twists the thread. The present invention relates to thread processing that prevents the occurrence of threads and prevents untwisting and fraying of the cut end at the time of thread cutting to improve the workability of sewing work.

Sewing threads using synthetic fiber multifilaments are widely used as sewing threads for high-strength sewn products such as sewing of flexible containers and sneakers. In order to prevent thread entanglement during high-speed sewing with a sewing machine or the like, the sewing thread is required to suppress the twisting habit of the thread and improve the convergence of the thread entanglement and the linearity of the thread. In addition, it is necessary to prevent untwisting of the cut end at the time of thread breakage to improve work efficiency and maintain the quality of the sewn product. Sewing threads having these functions are used as suitable sewing threads in both the fields of clothing and industrial materials.

The sewing thread used in sewing with a sewing machine is strongly required to have straightness and convergence of the thread by high-speed hand movement. As a method for preventing the twisting of the sewing thread in order to satisfy this requirement, a method of adhering a resin to a thread made of a spun thread or a multifilament thread which can be twisted or aligned by a dipping method, a spray method, a coating method, etc. A method in which all molten yarns are mixed and spun yarns are twisted and then melted and solidified by heat processing by heating with a heater to fix them, or all molten yarns are mixed or entangled and then heat-processed. A method of fusing in the inner layer portion and the like are known (Patent Documents 1 to 15). Here, the fully molten yarn means a yarn in which the entire cross section of the filament melts at the same temperature from the surface layer portion to the inner layer portion of the filament.

Japanese Unexamined Patent Publication No. 2-99638 Japanese Unexamined Patent Publication No. 46-013955 Japanese Unexamined Patent Publication No. 48-001999 Japanese Unexamined Patent Publication No. 49-002944 Japanese Unexamined Patent Publication No. 49-031941 Japanese Unexamined Patent Publication No. 49-002944 Japanese Unexamined Patent Publication No. 53-130350 JP-A-59-071452 Japanese Unexamined Patent Publication No. 09-251123 Japanese Unexamined Patent Publication No. 10-269598 Japanese Unexamined Patent Publication No. 11-352369 Japanese Unexamined Patent Publication No. 2005-352179 Jinshinsho 48-047949 Jinshinsho 50-024844 Jinshinsho 63-03062

In the method using all molten yarn proposed in the prior art, since the entire resin of the molten yarn is melted, it is difficult to make the molten state uniform in the longitudinal direction of the yarn, and the fibers inside the yarn are mutual. The degree of melting and the fusion state of the fibers constituting the yarn differ depending on the adhesion state of the yarn and the mixed state of the blended resin yarn. Further, in the melting by heating with a heater, the heat is sparse and the melting state of the resin is non-uniform, resulting in non-uniform function in the length direction of the yarn.

Further, the method of adhering the resin by the dipping method or the like has a problem that the load on the environment is large due to the treatment of waste liquid and the like, and the mechanical equipment becomes expensive.

The present invention has been made to solve the above-mentioned problems of the prior art, and is a sewing thread using a multifilament of synthetic fiber or a twisted thread of cotton thread as a core thread, particularly a flexible container requiring strength. Improved technical means to suppress the torque of sewing thread used for sewing sneakers, etc. to prevent the occurrence of twisting, and to prevent untwisting and fraying of the cut end at the time of thread cutting to improve the workability of sewing work. The challenge is to get it.

In order to solve the above problems, the inventor of the present invention has a multi-layer structure polyester yarn or polyethylene yarn having a low melting point portion in the surface layer portion and a high melting point portion in the inner layer portion (hereinafter referred to as "multi-layer fusion yarn"). After winding a multi-layer fusion yarn around the core yarn by a covering method, we have developed a technology to heat and melt only the low melting point part to perform cooling and fixing treatment.

That is, the outer side of the synthetic fiber multifilament twisted yarn (the multifilament may be a raw yarn, a processed yarn, or a aligned state) is single-covered or double-covered with a multi-layer fusion yarn as a core yarn, and then a low melting point portion. Is heat-cooled (heat-melting treatment and cooling-fixing treatment) to maintain the shape of the sewing thread and prevent the generation of torque and the untwisting and fraying of the cut end. With this method, the molten state of the resin can be kept uniform in the length direction, twisting of the yarn is prevented, linearity is maintained, and the function of preventing yarn fraying can be imparted to the entire longitudinal direction of the yarn on average. it can.

According to the present invention, in sewing threads used for sewing industrial materials, the torque of the sewing threads is suppressed to prevent the occurrence of twisting, the untwisting and fraying of the cut end at the time of thread cutting is prevented, and the workability at the time of high-speed sewing work by a sewing machine is prevented. Can be improved.

Partially enlarged view of the first embodiment Part of the drawing substitute photograph of FIG. Partially enlarged view of the second embodiment Part of the drawing substitute photograph of FIG.

As a first embodiment, a twisted yarn using three 1000 denier yarns of ester is used as a core yarn A, and a double cover method using a covering machine is used to coat 50 deniers of a double-layer fused yarn with a coated bobbin yarn B. The layer fusion yarn 50 denier is wound around the coating upper yarn C, and then heated to a temperature equal to or higher than the melting point of the surface layer portion of the coating bobbin yarn B and the coating upper yarn C and lower than the melting temperature of the inner layer portion by heating the surface layer. The yarn obtained by melting only the portion and then cooling is shown in FIGS. 1 and 2.

The synthetic fiber to be the core yarn A is not limited to the twisted yarn, and for example, one or a plurality of polyester raw yarns and false twisted yarns may be drawn and used.

The stretchable false twisted yarn is aligned to form the core yarn A, the coated bobbin yarn B is the elastic false twisted yarn, and the coated upper yarn C is the multi-layer fusion yarn. By performing a heating and cooling process in which only the coating upper yarn is melted and cooled and solidified after the covering process, the vertical elongation of the core material A and the shape retention of the fused resin C are made uniform in the longitudinal direction of the yarn. It is also possible to obtain a sewing thread which is provided and has elasticity and elasticity with respect to tension in the longitudinal direction.

As a second embodiment, a double-covered method is used in which a core yarn D using four false-twisted nylon 360 denier, a false-twisted ester 50 denier as a coated bobbin yarn E, and an ester multi-layer fused yarn 50 denier as a coated upper yarn F. The sewing threads of the second embodiment obtained by the covering process and then the heating and cooling process of melting and solidifying only the surface layer portion of the coating upper thread F are shown in FIGS. 3 and 4.

A Core yarn made of ester twisted yarn B Coated bobbin yarn made of ester multi-layer fused yarn C Coated upper yarn made of ester multi-layer fused yarn D False twisted nylon core yarn E Coated bobbin yarn made of false twisted ester F ester Coated upper yarn consisting of multi-layer fused yarn

Claims (4)

A core yarn composed of natural fibers or synthetic fibers and a monofilament or multifilament having a structure in which the surface layer portion has a low melting point and the inner layer portion has a high melting point are wound and coated on the core yarn, and only the surface layer portion having a low melting point is covered. A sewing thread that is heated, melted, cooled, and fused to the core thread. A core yarn having elasticity, a coated bobbin yarn wound around the core yarn, and a coated upper yarn wound on the outside of the coated bobbin yarn in the opposite direction to the coated bobbin yarn are provided. The bobbin yarn is a synthetic yarn having elasticity, the coating upper yarn is a monofilament or multifilament having a low melting point on the surface layer portion of the filament and a high melting point portion on the inner layer portion, and only the surface layer portion having the low melting point is heated and melted. A sewing thread that has been post-cooled and fused to the core thread and the coated bobbin thread. A coating yarn made of monofilament or multifilament having a structure in which the surface layer portion of the filament has a low melting point and the inner layer portion has a melting point higher than the low melting point is wound around a core yarn composed of natural fibers or synthetic fibers by a double cover method. Sewing in which the surface layer portion of the coated yarn is fused to the core yarn and the coated yarn by heating the yarn to a temperature equal to or higher than the low melting point and lower than the high melting point to melt and cool only the surface layer portion. Thread processing method. A fusion yarn consisting of a synthetic yarn having elasticity by a double cover method on a core yarn having elasticity and a monofilament or multifilament having a structure in which the surface layer portion of the filament has a low melting point and the inner layer portion has a melting point higher than the low melting point. Is wound so that the synthetic yarn is in a lower layer than the fused yarn, and the obtained yarn is heated to a temperature equal to or higher than the low melting point and lower than the high melting point to melt and cool only the surface layer portion. , A method for processing a sewing thread, wherein the surface layer portion of the fusion thread is fused to the core thread and the synthetic fiber thread.