JPS6047386B2 - waterproof sewing thread - Google Patents

Description

[Detailed Description of the Invention] Conventionally, in waterproof products such as raincoats, raincoats, anoraks, and jets, the fabric has been given sufficient waterproofness. Because the needle hole was formed by penetrating the fabric, water did not leak from the fabric, but water leaked from the seam, that is, the needle hole, which caused problems.

For this reason, various methods for preventing water leakage have been devised and implemented. For example, the following methods are known. Glue waterproof tape with adhesive resin on the back side of the first seam along the seam.

Apply resin to the back or front side of the second seam.

The product is sewn using hot-melt thread that melts at its melting point in combination with regular sewing thread made of cotton or synthetic fibers, and is heat-treated after sewing to close the needle hole.

However, these methods have various drawbacks, and no satisfactory method has yet been found.

For example, methods 1 using a waterproof tape and 2 applying a resin have the disadvantage that the texture near the seams becomes hard and elasticity is inhibited. In addition, when hot melt thread 3 is used in combination with general sewing thread, the hardening of the texture near the seams is less than with the waterproof 7° method, but the hot melt thread melts due to heat treatment, As a result, only the sewing thread remains, that is, thread fraying occurs, and as a result, there is a risk that the needle hole, which has been blocked to some extent by the sewing thread, will widen by the melted hot melt thread, and the sewing performance is also insufficient. As described above, there is no satisfactory seam waterproofing method that does not harden the texture near the seams.

The present invention has been made based on research on these points, and aims to provide sufficient waterproofness without hardening the texture near the seams. That is, in the present invention, a low melting point resin powder with a major diameter of 150 microns or less is attached to the surface and inside of a general sewing thread made of cotton or synthetic fibers in an amount of 5 to 30% of the weight of the sewing thread, and after sewing a waterproof fabric, the resin powder is This seam waterproofing method is characterized by sealing the needle hole by heat treatment at a temperature higher than the melting point of the thread.This method eliminates the so-called thread fraying that occurs after heat treatment when hot melt thread is used. , the size of the needle hole covered by the sewing thread does not change. Therefore, when hot melt yarn is used, the waterproof effect of the present invention is considerably improved, hardening of the texture is avoided, and sewability is considerably improved. Preferred as the low melting point resin powder in the present invention is a polymer with a melting point of 120°C or less, and the shape can be arbitrary such as spherical, ellipsoidal, cubic, etc., but it is preferably spherical, and its longest major axis is 150 microns or less, preferably 10 to 100 microns is suitable;
If the diameter is larger than 50 microns, so-called yarn fraying occurs, which is undesirable when hot melt yarn is used.

Further, the amount of adhering resin is suitably 5 to 30%, preferably 7 to 15%; if it is less than 5%, the waterproofing effect is small, and if it is more than 30%, so-called thread fading occurs and high waterproofness cannot be obtained. Therefore, if the low melting point resin powder with a long diameter of 150 microns or less is attached to the sewing thread in an amount of 5 to 30% based on the weight of the sewing thread, the highly waterproof sewing thread of the present invention can be manufactured. Note that the measurement of the amount of the low melting point resin powder attached to the sewing thread is determined by the following calculation formula. The resin powder adheres to the sewing thread while maintaining its powder shape.

Although it is not necessary for the original shape to remain intact, each particle of the powder can be independently identified by microscopic observation.
Therefore, the boundary can be distinguished from both the sewing thread and other adjacent powder.

Powders and powder and sewing thread are bonded together without using a binder. Of course, a binder may be present. This prevents the waterproof sewing thread from hardening, and therefore, the texture of the waterproof fabric sewn using this sewing thread is prevented from hardening near the seams. In manufacturing the waterproof sewing thread of the present invention, the sewing thread to which the low melting point resin powder is attached can be made of cotton or synthetic fibers such as polyester or nylon, but synthetic fibers such as polyester or nylon are preferably used. It's good to do that.

Regarding the yarn form, both short fibers and long fibers are possible, but in order to attach the low melting point resin powder, short fibers must be twisted, or long fibers must be crimped by processing such as false twisting. A form with a large yarn space is desirable.
The method of attaching the low melting point resin powder to the sewing thread is not particularly limited, but a simple method is, for example, to prepare an aqueous dispersion solution of the low melting point resin powder and immerse the sewing thread in the solution. At this time, it is necessary to mix a dispersant, such as an emulsifier containing a polyolefin oxide group, to uniformly disperse the low melting point resin powder.Also, in order to improve the adhesion of the low melting point resin powder to the sewing thread, a sizing agent, For example, it is desirable to add a small amount of a polyacrylic acid derivative or the like to the dispersion. The concentration of the aqueous dispersion solution of the low melting point resin powder may be changed as appropriate in relation to the amount of adhesion to the sewing thread. Further, higher waterproofness can be obtained by using the waterproof sewing thread of the present invention after being treated with water repellent, but at this time, low melting point resin powder is mixed into the water repellent aqueous solution to uniformly distribute the low melting point resin powder. The most preferable method is to disperse the sewing thread in the water and then immerse the sewing thread in the water. After attaching the low melting point resin powder to the sewing thread as described above, heat treatment is performed at a temperature higher than the melting point of the resin powder to completely fix the resin powder to the sewing thread. Just do waxing and oiling. The waterproof sewing thread of the present invention can be used for lockstitching, double chainstitching, or single chainstitching without any particular restrictions.For lockstitching or double chainstitching, the sewing thread of the present invention can be used as both the upper and lower threads. However, even if the sewing thread is used only for the upper thread or the lower thread and a regular sewing thread is used for the other thread, the waterproof effect can be sufficiently maintained.

At this time, the waterproof effect will be further improved if the general sewing thread is treated with a water-repellent finish. If the waterproof sewing thread of the present invention is sewn and then heat treated at a temperature higher than the melting point of the low melting point resin powder adhering to the sewing thread, the resin powder will dissolve and close the needle hole, improving waterproofness.

Next, examples will be shown. Example 1 Nylon-6 twisted processed yarn A 100 denier yarn was used as the core yarn, and two more of the same yarn was used to perform double covering on SZ.

This thread was immersed in the following emulsion aqueous solution. The aqueous emulsion solution was prepared by mixing powder of a low melting point polyamide resin with a major axis of 10 to 80 microns and a melting point of 115° C. in a fluorine water repellent (Note 1) so that the weight of the resin was 8%. After soaking the covering system in this, take it out and
It was heat-treated at °C for 2 minutes to obtain a waterproof sewing thread with a resin adhesion of 8%. This thread was sewn under the following conditions. Sewing type Lockstitch method One-sided presser foot stitch (see Figure 1).

In FIG. 1, 1 is sewing thread and 2 is waterproof cloth.

) [Stock] Bottom thread Waterproof sewing thread [Phase] Top thread Nylon-66 sewing thread #40 (Note 2)
Sewing thread with fluorine-based water repellent finish 5 sewing machine needles #11 6 Number of stitches 4 stitches/cm 7 Sewing fabric Water pressure resistance 1000 Twt Sewn under conditions of waterproof fabric or higher in the water column, and after heating thoroughly with an iron at 150 degrees Celsius, water pressure resistance was measured.

The results are shown in Table 1. In Example 1, sewing threads with different sizes of low-melting point resin powder and sewing threads with different amounts of resin attached were created. Example 2 A #50 sewing thread was manufactured using polyester spun yarn and immersed in the following emulsion aqueous solution.

The emulsion aqueous solution is a mixture of a fluorine-based water repellent (Note 1) and a polyurethane-based low melting point resin with a major axis of 90 to 140 microns and powder with a melting point of 120°C so that the resin weight is 15%. , take out the sewing thread after soaking, 1
A heat treatment was performed at 50°C for 2 minutes to obtain a waterproof sewing thread with a resin adhesion of 13%. This thread was sewn under the same conditions as Example 1, changing the lower thread of the sewing machine to the sewing machine thread of Example 2.
After sufficiently heating with an iron at 0°C, water pressure resistance was measured.
The results are shown in Table 1. As a comparison of Examples 1 and 2,
Sewing thread (Comparative Example 1) in which polyamide filament mesh 00 denier thread with a melting point of 115 low C is aligned with the sewing thread used in Example 1 before adhering to the low melting point resin powder on the sewing machine bobbin thread (Comparative Example 1), and the sewing machine upper thread , Both bobbin threads are nylon-66 sewing thread #4
0 (Note 2) using water-repellent water-repellent sewing thread (Comparative Example 2) was prepared, and each was thoroughly heated with an iron at 150'C, and then the water pressure resistance was measured.

(Note 1) FP-200 manufactured by Nicca Chemical Co., Ltd. (Note 2) Unilon 0 manufactured by Kanagawa Co., Ltd. As is clear from Table 1, the waterproof sewing thread of the present invention has extremely high waterproofness (water pressure resistance) compared to others. In good condition.

Next, the water pressure resistance of the resin powders produced in Example 1 with different sizes and with different amounts of adhesion was measured.

(1) The size of the resin powder is changed (2) The amount of resin adhered is changed 5 to 30% shows the best waterproof property.

[Brief explanation of drawings]

FIG. 1 is a schematic explanatory diagram showing the sewing method (one-sided press-stitch) of the first embodiment. 1...Sewing thread, 2...Waterproof cloth.

Claims (1)

[Claims] 1. A waterproof sewing thread, characterized in that a low melting point resin powder having a major diameter of 150 microns or less is attached to the sewing thread in an amount of 5 to 30% by weight based on the weight of the sewing thread while maintaining the shape of the powder.