JPH01156568A - Continuous shrinking of shrinkable fabric - Google Patents

Abstract

PURPOSE: To carry out a shrinking treatment excellent in uniformity in good yield by initially thermally shrinking only both selvedge parts a clothlike material and then performing a heat shrinking treatment of the whole clothlike material in a state of holding the selvedges when carrying out the shrinking treatment of the running thermally shrinkable clothlike material. CONSTITUTION: When a clothlike material having properties of shrinking by heating is continuously subjected to a shrinking treatment, the thermal shrinking treatment of only selvedge parts formed at both edges of the clothlike material is initially carried out in a first step. The thermal shrinking treatment of the whole clothlike material can then be performed while holding the selvedge parts shrunk in the first step to thereby carry out the uniform continuous shrinking treatment with a good productivity. The yield is excellent without requiring cutting and removing of the vicinities of the selvedge parts as defectives.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to a method for shrinking a cloth-like material that has the property of shrinking when heated, continuously and with a uniform shrinkage rate, and in particular, relates to a method for shrinking a cloth-like material that has the property of shrinking when heated, and in particular, relates to a method for shrinking a cloth-like material that has the property of shrinking when heated, and in particular, relates to a method for shrinking a cloth-like material that has the property of shrinking when heated, and in particular, relates to a method for shrinking a cloth-like material that has a property of shrinking when heated, and in particular, a method for shrinking a cloth-like material that has a property of shrinking when heated. The present invention relates to a method suitably used for manufacturing a conductive cloth material having a high elongation rate and made of shrunken conductive fibers.

(Prior art) In recent years, containers such as trays, containers, packages, etc. used for packaging or transporting electronic devices such as semiconductor devices, which are at risk of having their functions damaged due to the intrusion of static electricity or noise, have become increasingly popular. Filing cases used to shrink and store recording materials such as magnetic disks and magnetic cards that are sensitive to static electricity and noise are required to have antistatic properties and conductivity necessary to shield electromagnetic waves. ing. Under such circumstances, for example, Japanese Patent Application Laid-open No. 58-155917 and Japanese Patent Application Laid-Open No. 58-1
In JP 66035, a nonwoven fabric, a knitted fabric, or a woven fabric formed from a fiber mixture of conductive fibers and thermofusible fibers is laminated on a base material, and heated to a temperature higher than the melting temperature of the thermofusible fibers to melt it. By attaching the I
A method for manufacturing packaging sheets for parts such as C at low cost has been proposed.

However, in the sheet manufactured by the above-mentioned method, it is not possible to expect much elongation of the conductive cloth material itself, so when the sheet is subjected to deep drawing processing by vacuum forming or pressure forming, the notebook will not be stretched. There was a problem in that the conductive fibers in the cloth-like material were cut by the heat exchanger and the conductivity of the obtained molded product was significantly reduced.

In order to solve this problem, the applicant heat-treated a knitted fabric made of twisted yarns of conductive fibers that have been first twisted and heat-fusible fibers that have a higher heat shrinkage rate than the conductive fibers. By doing so, we have been studying a method for producing a sheet in which the conductive fibers are not easily cut even when subjected to deep drawing, by shrinking the heat-melting fibers and crimping the conductive fibers accordingly. Ta.

(Problems to be Solved by the Invention) However, when a cloth-like material that has the property of shrinking when heated as described above is heat-treated using a punching method in a heating furnace or the like, the cloth-like material shrinks unevenly. There is a problem in that it is not possible to obtain a cloth-like article of uniform quality with a desired degree of shrinkage. When continuously fed into a heating furnace, there was a problem in that shrinkage of the cloth-like material was restricted by the pin tenter and uniform shrinkage could not be obtained.

The present invention solves the above-mentioned problems of the prior art, and its purpose is to provide a method that allows a cloth-like material that has the property of shrinking when heated to be shrunk continuously and with a uniform shrinkage rate. It is about providing.

(Means for Solving the Problems) In order to achieve the above-mentioned object, the method for continuously shrinking a shrinkable fabric according to the present invention provides a method for continuously shrinking a shrinkable fabric that shrinks when heated. a first heating step of heating and shrinking only the heat-shrinkable selvage formed on the edge, and gripping the selvage that has been shrunk in the first heating step;
The method is characterized by including a second heating step of heating and shrinking the entire cloth-like article.

(Function) In the method for continuously shrinking a shrinkable fabric of the present invention, only the heat-shrinkable ears formed at both ends of the shrinkable fabric are heat-shrinked in advance, so that the fabric has no heat shrinkage. A correspondingly larger bulge is formed, and in the next heating step, the entire cloth-like material shrinks uniformly until the slack disappears.

(Example) Examples of the present invention will be described below based on a method for manufacturing a conductive cloth in which the present invention is most preferably used.

The shrinkable cloth material in the present invention Iζ is, for example, a knitted fabric knitted by a flat knitting machine using plied yarns 6 made by twisting together lament yarns 63 and heat-shrinkable IA fibers 62 made of heat-shrinkable fibers. In other words, it refers to a cloth-like material whose overall area is reduced by heat treatment, resulting in the fibers constituting it shrinking due to heat treatment.

Here, the conductive fibers include metal fibers, carbon fibers,
Examples include metal-adsorbed synthetic resin fibers, metal-plated synthetic resin fibers, and the like. Among these, metal-adsorbing synthetic resin fibers are those obtained by adsorbing copper ions on acrylic fibers and then subjecting them to reduction treatment, and these metal-adsorbing synthetic resin fibers are particularly preferred because they have excellent bending resistance.

In addition, as heat-shrinkable fibers, fibers such as polyolefin resins such as polyethylene and polypropylene, polyamide resins, polyester resins, polyacrylonitrile resins, polyvinyl chloride resins, polycarbonate resins, and polymethyl methacrylate resins are preferably used. In particular, depending on the relationship with the conductive fibers used, fibers are selected that have a higher heat shrinkage rate than that of the conductive uA fibers.

The above-mentioned conductivity l! ! 6. Twisted yarn made by twisting 4 fibers and heat-shrinkable fibers. As shown in FIG. 1 Iζ, a flat knitting machine 10
The flat knitting machine 10 continuously knits the cloth into, for example, a jersey.

The knitted fabric 60 knitted by the flat knitting machine IO has a pair of heat-shrinkable tapes 61.
61 are respectively pasted by the tape pasting device 30. This heat-shrinkable tape 61 is mainly a PVC tape,
Silicone tape or the like is preferably used.

In this way, when heat-shrinkable tapes 61 and 61 are attached to both ends of the knitted fabric 60 in the width direction immediately after knitting, not only the effects specific to the present invention as detailed below are achieved, but also
This is preferable because there is no risk of curling of both ends in the width direction, and there is no risk of shrinkage in the width direction even if the knitted fabric 60 is pulled in the welt direction of the stitches (i.e., the longitudinal direction of the knitted fabric 6G). .

In addition to pasting heat-shrinkable tape, ears can be formed, for example, by sewing both ends in the width direction of a cloth-like material into a tightly packed rubber knit made only of heat-shrinkable fibers during the knitting process. Alternatively, the ears may be formed by applying a heat-shrinkable resin thickly to both ends of the cloth in the width direction so as to fill the stitches or stitches of the cloth. The heat-shrinkable fibers are preferably vinyl chloride fibers, nylon fibers, acrylic fibers, polyester fibers, etc.
The heat-shrinkable resin is preferably a vinyl chloride resin, a nylon resin, a polyvinyl alcohol 821 resin, or the like.

The thus obtained knitted fabric 60, which is a cloth-like material having heat-shrinkability, is passed between a pair of application rollers 40, 40, except for the edges, if necessary.

The surface of each application roller 40 is wetted with, for example, a THF solvent capable of dissolving heat-shrinkable fibers, and the solvent is applied to the knitted fabric 60 tc. As a result, the stitches of the knitted fabric 60, that is, the cross-contact portions of the plied and twisted yarns are melted and integrated, and the knitted fabric 60 is prevented from deforming.

The knitted fabric 60 thus subjected to the prevention of deformation is guided by a pair of fixed rolls 51.52 and a dancer roll 53 located between the fixed rolls 51.52, and subjected to a first heating step.

In the first heating step, only the heat-shrinkable tape 61 and 61 attached to the edges of the knitted fabric 60 that has been transported is heated.
This is carried out using a heating furnace 21. The knitted fabric 60 that has undergone the first heating process has a heat-shrinkable tape 61 attached to its edges.
61 shrinks in the length direction, resulting in a state in which a large length in the feeding direction is formed as a whole.The knitted fabric 60 that has passed through the first heating process is thus transported to the second heating process.

The second heating step includes a pair of pin tenters 71 71 and a 21st heating furnace 7 disposed in a conveyance area of the pin tenters 71 .
Implemented by 0. As shown in FIG. 2, each pin tenter 71 is engaged with the contracted ear portion of the knitted fabric 60, and guides both ends thereof toward each other toward the downstream side. A second heating furnace 70 is disposed downstream of each pin tenter 71, and the second heating furnace 70 allows
The knitted fabric 60 conveyed by each pin tenter 71 is heated to a temperature at which it contracts.

When the knitted fabric 60 is heated in the second heating furnace 70, the heat-shrinkable fibers 62 of the twisted yarns 6 in the knitted fabric 60 are heat-shrinked in the axial direction, as shown in FIG. As the filament yarn 63 is made of conductive fibers twisted in a helical manner, the spacing between the helices is shrunk in the axial direction as a result of the heat shrinkage, and the filament thread 63 becomes finely crimped into a spiral shape. The knitted fabric 60 contracts as the filament yarn 63 becomes crimped, but the contraction in the width direction of the knitted fabric 60 is caused by the ears of the knitted fabric 60 being locked by each pin tenter 71. Each pin tenter 71
and 71 intervals. On the other hand, in the feeding direction, the large slack formed in the center of the knitted fabric 60 is stretched and contracted to the point where it disappears.

In other words, the shrinkage of the knitted fabric 60 due to heating in the feeding direction is defined by the degree of shrinkage of the portion of the knitted fabric 60 caused by the first heating step.

Therefore, it is recommended to use a fabric with a known shrinkage rate at a predetermined heating temperature.
This is preferable because it becomes possible to control the shrinkage rate of the knitted fabric 60 in the feeding direction.

The conductive knitted fabric 60 thus obtained is attached to a sheet-like base material made of polyvinyl chloride, for example, to form a conductive sheet, and the sheet is subjected to deep drawing.
The container is said to have an antistatic function.

The present invention has been described in detail using conductive cloth as an example, but the present invention is not only suitably used in the production of such conductive cloth, but also applicable to all types of shrinkable cloth. It can be applied to objects.

(Effects of the Invention) Since the method for continuously shrinking a shrinkable cloth material of the present invention is configured as described above, it is possible to uniformly shrink the shrinkable material in the feeding direction while transporting the shrinkable material. As a result, shrinkage work can be carried out in production.

Further, since the obtained cloth-like material is shrunk at the same shrinkage rate in the vicinity of the ears and in the center, there is no need to cut the vicinity of the ears as a defective product, and the yield of the product is excellent.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram illustrating the steps of an embodiment of the method of the present invention, Fig. 2 is a schematic plan view of the vicinity of the second heating step in Fig. 1, and Fig. 3 is an example of a shrinkable cloth material. FIG. 2 is an enlarged view of the twisted yarns constituting the conductive knitted fabric.

Claims (1)

[Scope of Claim] A method of continuously heating and shrinking a shrinkable cloth material having the property of shrinking when heated, comprising only heat-shrinkable ears formed at both end edges of the cloth material. a first heating step of heating and shrinking the cloth; and a second heating step of heating and shrinking the entire cloth while gripping the edges shrunk in the first heating step. Continuous contraction method.