Method of Manufacturing Raschel Lace Knitted Fabric

Abstract

A method of manufacturing a Raschel lace knitted fabric. In a knitting step, a Raschel knitted fabric is knitted by inserting an insertion yarn made of the same type of material as a first chain stitch yarn into a chain stitch weave which is knitted by feeding the first chain stitch yarn made of a meltable material and a second chain stitch yarn having a higher melting temperature than the first chain stitch yarn from different beams to individual reeds. Heat treatment is performed for a treatment time in which the second chain stitch yarns and a weft passage yarn remain as yarns, at a temperature equal to or lower than the melting temperature of the second chain stitch yarn and equal to or higher than the melting temperature of the meltable material, in a state where the Raschel knitted fabric is stretched.

What is claimed is: 
     
         1 . A method of manufacturing a Raschel lace knitted fabric, which obtains the Raschel lace knitted fabric by executing the following steps:
 a knitting step of knitting a Raschel knitted fabric by feeding a plurality of chain stitch yarns each forming a chain stitch weave extending in a knitting direction, a weft passage yarn which is knitted in a knitted fabric weft direction between a plurality of chain stitch weaves formed by the chain stitch yarns, and a thermal melting yarn exhibiting weldability by being partially or entirely melted by being heated, to a Raschel knitting machine, and   a heat treatment step of heat-treating the Raschel knitted fabric which is obtained through the knitting step,   wherein in the knitting step,   a plurality of chain stitch weaves are knitted in which a meltable yarn portion made of thermally weldable polyurethane which is a meltable material which is partially or entirely melted by being heated is set to be a first chain stitch portion, a poorly-meltable yarn portion made of a poorly-meltable material having a higher melting temperature than the meltable material is set to be a second chain stitch portion, the first chain stitch portion and the second chain stitch portion are provided in the same chain stitch weave, and a surface of the first chain stitch portion is in an exposed state, and   a Raschel knitted fabric is knitted in which the weft passage yarn is set to be a poorly-meltable yarn made of a poorly-meltable material having a higher melting temperature than the meltable material, and an insertion yarn made of a polyurethane material is inserted into the chain stitch weave, and   wherein in the heat treatment step,   heat treatment to heat the Raschel knitted fabric obtained through the knitting step at a temperature equal to or lower than melting temperatures of the poorly-meltable material and the weft passage yarn and equal to or higher than a melting temperature of the meltable material in a knitted fabric tensioned state where a contact portion between the first chain stitch portion and the insertion yarn is formed is executed for a treatment time in which each of the poorly-meltable yarn portion, the weft passage yarn, and the insertion yarn remains as a yarn, so that a Raschel lace knitted fabric in which the insertion yarn is welded to the chain stitch weave is obtained.   
     
     
         2 . The method of manufacturing a Raschel lace knitted fabric according to  claim 1 ,
 wherein a first chain stitch yarn which is made of the meltable material and is a filament yarn and a second chain stitch yarn made of the poorly-meltable material are fed from different beams to individual reeds, and the first chain stitch portion and the second chain stitch portion are knitted in the same chain stitch weave by the first chain stitch yarn and the second chain stitch yarn, respectively, and   the insertion yarn is inserted into the chain stitch weave which is formed by the first chain stitch yarn and the second chain stitch yarn, so that a Raschel knitted fabric is knitted, and   wherein in the heat treatment step,   heat treatment to heat the Raschel knitted fabric obtained through the knitting step at a temperature equal to or lower than the melting temperatures of the second chain stitch yarn and the weft passage yarn and equal to or higher than the melting temperature of the first chain stitch yarn is executed for a treatment time in which each of the second chain stitch yarn, the weft passage yarn, and the insertion yarn remains as a yarn, thereby obtaining a Raschel lace knitted fabric.   
     
     
         3 . The method of manufacturing a Raschel lace knitted fabric according to  claim 2 ,
 wherein the first chain stitch yarn is a yarn that is thinner than the insertion yarn,   a surface of the insertion yarn is melted in the heat treatment in the heat treatment step, and   the first chain stitch yarn is welded to the surface of the insertion yarn.   
     
     
         4 . The method of manufacturing a Raschel lace knitted fabric according to  claim 2 , wherein the first chain stitch yarn is thinner than the insertion yarn. 
     
     
         5 . The method of manufacturing a Raschel lace knitted fabric according to  claim 2 , wherein a first reed to which the first chain stitch yarn is fed is located further on the front side than a second reed to which the second chain stitch yarn is fed, in a front-back direction of the Raschel knitting machine. 
     
     
         6 . The method of manufacturing a Raschel lace knitted fabric according to  claim 2 , wherein the second chain stitch yarn is a nylon yarn. 
     
     
         7 . The method of manufacturing a Raschel lace knitted fabric according to  claim 2 ,
 wherein a first chain stitch yarn feeding amount adjustment mechanism which adjusts yarn feeding tension by adjusting a yarn feeding amount in a first chain stitch yarn feeding part from a beam for feeding the first chain stitch yarn to a first reed is provided, and   a second chain stitch yarn feeding amount adjustment mechanism which adjusts yarn feeding tension by adjusting a yarn feeding amount in a second chain stitch yarn feeding part from a beam for feeding the second chain stitch yarn to a second reed is provided.   
     
     
         8 . The method of manufacturing a Raschel lace knitted fabric according to  claim 2 ,
 wherein the first chain stitch yarn is a thermally weldable polyurethane yarn having a thickness in a range of 17 to 156 dtex and a melting temperature in a range of 150° C. to 180° C.,   the second chain stitch yarn is a nylon yarn having a thickness in a range of 33 to 78 dtex and a melting temperature of 200° C.,   the insertion yarn is a polyurethane yarn having a thickness in a range of 156 to 310 dtex and a melting temperature in a range of 190° C. to 220° C., and   in the heat treatment step, the Raschel knitted fabric obtained through the knitting step is heat-treated for a time in a range of 30 to 90 seconds at a temperature within a heating temperature range of 190° C. or more and 200° C. or less.   
     
     
         9 . The method of manufacturing a Raschel lace knitted fabric according to  claim 1 ,
 wherein in the knitting step,   a conjugate yarn having the meltable yarn portion and the poorly-meltable yarn portion in a single yarn is fed to a single reed to be knitted into a chain stitch weave having the first chain stitch portion and the second chain stitch portion, and the insertion yarn is inserted into the chain stitch weave, thereby knitting the Raschel knitted fabric.   
     
     
         10 . The method of manufacturing a Raschel lace knitted fabric according to  claim 1 ,
 wherein in the knitting step,   a chain stitch weave having the first chain stitch portion, the second chain stitch portion, and the insertion yarn is knitted on the entire Raschel knitted fabric.   
     
     
         11 . The method of manufacturing a Raschel lace knitted fabric according to  claim 1 ,
 wherein in the knitting step,   a yarn different from the insertion yarn is inserted into the chain stitch weave which is formed by the first chain stitch portion and the second chain stitch portion, as a floating insertion yarn in a knitted form in which a part of the yarn floats on a back surface of the Raschel knitted fabric.   
     
     
         12 . The method of manufacturing a Raschel lace knitted fabric according to  claim 3 , wherein a first reed to which the first chain stitch yarn is fed is located further on the front side than a second reed to which the second chain stitch yarn is fed, in a front-back direction of the Raschel knitting machine. 
     
     
         13 . The method of manufacturing a Raschel lace knitted fabric according to  claim 4 , wherein a first reed to which the first chain stitch yarn is fed is located further on the front side than a second reed to which the second chain stitch yarn is fed, in a front-back direction of the Raschel knitting machine. 
     
     
         14 . The method of manufacturing a Raschel lace knitted fabric according to  claim 3 , wherein the second chain stitch yarn is a nylon yarn. 
     
     
         15 . The method of manufacturing a Raschel lace knitted fabric according to  claim 4 , wherein the second chain stitch yarn is a nylon yarn. 
     
     
         16 . The method of manufacturing a Raschel lace knitted fabric according to  claim 5 , wherein the second chain stitch yarn is a nylon yarn. 
     
     
         17 . The method of manufacturing a Raschel lace knitted fabric according to  claim 3 ,
 wherein a first chain stitch yarn feeding amount adjustment mechanism which adjusts yarn feeding tension by adjusting a yarn feeding amount in a first chain stitch yarn feeding part from a beam for feeding the first chain stitch yarn to a first reed is provided, and   a second chain stitch yarn feeding amount adjustment mechanism which adjusts yarn feeding tension by adjusting a yarn feeding amount in a second chain stitch yarn feeding part from a beam for feeding the second chain stitch yarn to a second reed is provided.   
     
     
         18 . The method of manufacturing a Raschel lace knitted fabric according to  claim 4 ,
 wherein a first chain stitch yarn feeding amount adjustment mechanism which adjusts yarn feeding tension by adjusting a yarn feeding amount in a first chain stitch yarn feeding part from a beam for feeding the first chain stitch yarn to a first reed is provided, and   a second chain stitch yarn feeding amount adjustment mechanism which adjusts yarn feeding tension by adjusting a yarn feeding amount in a second chain stitch yarn feeding part from a beam for feeding the second chain stitch yarn to a second reed is provided.   
     
     
         19 . The method of manufacturing a Raschel lace knitted fabric according to  claim 5 ,
 wherein a first chain stitch yarn feeding amount adjustment mechanism which adjusts yarn feeding tension by adjusting a yarn feeding amount in a first chain stitch yarn feeding part from a beam for feeding the first chain stitch yarn to a first reed is provided, and   a second chain stitch yarn feeding amount adjustment mechanism which adjusts yarn feeding tension by adjusting a yarn feeding amount in a second chain stitch yarn feeding part from a beam for feeding the second chain stitch yarn to a second reed is provided.   
     
     
         20 . The method of manufacturing a Raschel lace knitted fabric according to  claim 6 ,
 wherein a first chain stitch yarn feeding amount adjustment mechanism which adjusts yarn feeding tension by adjusting a yarn feeding amount in a first chain stitch yarn feeding part from a beam for feeding the first chain stitch yarn to a first reed is provided, and   a second chain stitch yarn feeding amount adjustment mechanism which adjusts yarn feeding tension by adjusting a yarn feeding amount in a second chain stitch yarn feeding part from a beam for feeding the second chain stitch yarn to a second reed is provided.