JPH0691659A - Conveyor belt for vulcanizing waterproof sheet - Google Patents

Abstract

PURPOSE:To efficiently vulcanize rubber sheet without scrapping a rubber sheet patterned at a joint as a defective product by covering, with a covering member, the joint where both end parts of a conveyor belt body are sewn together. CONSTITUTION:A conveyor belt 1 to be used for continuously vulcanizing a waterproof sheet has a structure that a joint 4 of both end parts of a conveyor belt body 2 sewn together is covered with a covering member 3. Therefore, the joint 4 of the conveyor belt body 2 lapped and sewn together by a sewing machine will not be in contact with a rubber sheet directly. The trace of the joint 4 in the rubber sheet is very slight comparing with prior art one having stitching. Accordingly, a rubber sheet having excellent appearance can be obtained, and it is almost the same as one which is patterned at other part than the joint 4 also with respect to tensile strength and tensile extension percentage.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a conveyor belt used for continuous vulcanization of a waterproof sheet, and more particularly to improvement of a joint portion of a conveyor belt body.

[0002]

2. Description of the Related Art A rubber waterproof sheet is provided with a cloth pattern on its surface in order to improve its appearance and to prevent slipping when walking on the waterproof sheet. Then, as one of the methods for providing such a pattern, as disclosed in JP-A-57-17233, in a continuous vulcanizer, a vulcanization can is sandwiched between conveyor belts and a rubber sheet is passed through the vulcanization can. A method of forming a pattern at the same time as the sulfurization is usually used.

In this method, an unvulcanized rubber sheet is passed from one side of a vulcanizing can while being sandwiched from both sides. At this time, pressure is applied by the rolls, and the vulcanized, that is, uncured rubber sheet is patterned with the cloth pattern of the conveyor belt. Then, after that, it is heated and vulcanized while being sandwiched between the conveyor belts, and cured with the pattern attached.
By the way, the conveyor belt used as described above has an endless belt shape, and always has a joint portion. Conventionally, as shown in FIG. 5, the joint portion wraps the end portion of the conveyor belt, and the sewing machine is used at a plurality of places. It was formed by sewing.

[0004]

However, in the case where the above-mentioned joining portion is used, the pattern of the sewing machine sewing or the belt step is attached to the pattern of the portion of the rubber sheet which the joining portion contacts, and the joining portion is also formed. Since it is thicker than other parts, if it is patterned at the joint, the pattern becomes a deeper pattern than the pattern attached at other parts, and the rubber sheet at that part is substantially thin. As a result, the thickness becomes uneven, and the quality of the waterproof sheet is inferior in terms of physical properties and appearance, resulting in a defective product.

Therefore, in order to reduce the ratio of such defective products to the whole, it is conceivable to lengthen the conveyor belt. However, although the ratio decreases, the defective products do not disappear, and a fundamental solution is provided. I couldn't say that. The present invention addresses the above situation and improves the structure of the joint portion of the conveyor belt to suppress the deterioration of the appearance and physical properties even if the rubber sheet is patterned at the joint portion of the conveyor belt, and the defective product It is an object to provide a conveyor belt for a waterproof sheet that does not meet the requirements.

[0006]

SUMMARY OF THE INVENTION The present invention is directed to a conveyor belt used for continuous vulcanization of a waterproof sheet to achieve the above object, in a joint portion of a conveyor belt in which both ends of a conveyor belt body are sewn together. It is characterized by covering the cover member. Further, for the reason to be described later, the thickness of the cover member that covers the joint portion of the waterproof sheet vulcanizing conveyor belt is set to be larger than the thickness of the conveyor belt body, and the cover member that covers the joint portion of the conveyor belt body. It is preferable that the material includes thermoplastic fibers, and that the cover member that covers the joint portion of the conveyor belt body is heat-sealed to the conveyor belt body.

[0007]

According to the present invention, in the conveyor belt used for continuous vulcanization of the waterproof sheet, the structure is such that the joint portion of the conveyor belt body in which both ends of the conveyor belt body are sewn together is covered with the cover member. The lapped and sewn joint does not come into direct contact with the rubber sheet, and after the joint of the rubber sheet is much shallower than the one with conventional seams, the appearance of the rubber sheet is good The obtained waterproof sheet has almost the same strength as tensile strength and tensile elongation as compared with the patterned one except for the joint portion, and a good quality waterproof sheet can be obtained.

[0008]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a plan view of a joint portion 4 of a waterproof sheet vulcanizing conveyor belt 1 of the present invention, and FIG. 2 is A of FIG.
FIG. 2 is a conveyor belt main body for waterproof sheet vulcanization, 3 is a cover member, and the conveyor belt main body 2
Is one that can withstand the temperature when vulcanizing rubber, its strength,
Polyamide, aromatic polyamide, which is excellent in durability and is not stretched or cut during use, is preferably made of polyamide, aromatic polyamide,
Textiles such as polyester and polyphenylene sulfide may be mentioned. Further, the fibers are not limited to those woven alone, and may be a mixed woven fabric or a mixed-spun fabric in which two kinds of fibers are mixed.

The cover member 3 for covering the conveyor belt main body 2, like the conveyor belt main body 2, can withstand the vulcanization temperature, has excellent strength and durability, and does not stretch or cut during use. However, in the case of the cover member 3, it is preferable that the cover member 3 is different from the conveyor belt main body 2 and can be easily processed by heat, and a belt-shaped body made of fibers such as polyphenylene sulfide, polyamide, and polyester is used. Aromatic polyamide fibers are fibers that are difficult to process by heat, but in some cases, as a material of the cover member 3, a cloth woven or blended with the above-described fibers that are easily processed by heat is used. Since it can be heat-cut, it is possible to prevent the thread from being frayed at the end portion of the cover member 3 when it is cut into a predetermined width used as the cover member 3.

When the cover member 3 is attached to the conveyor belt body 2, it can be sewn using the thread 6, but as the cover member 3, polyphenylene sulfide,
It is also possible to use a film having a textured pattern on the surface of polyether ether ketone or the like. When such a film is used or when a cover member 3 containing a thermoplastic fiber is used, the film shown in FIG. Cover member 3 as shown
Can be heat fused to the conveyor belt body 2. Furthermore, even if the cover member 3 does not have thermoplasticity, it can be bonded to the conveyor belt main body 2 using an adhesive.
Then, the seam of the thread does not appear at the joint portion 4, and the surface can be made smoother.

When the cover member 3 is woven or mixed-spun with an aromatic polyamide, it is preferable that the proportion of thermoplastic fibers such as polyphenylene sulfide is 40% or more. When a wide woven fabric is formed into a predetermined strip, it can be cut by heat, and a smooth end can be obtained without fraying the fibers at the cut end, and a step at the joint 4 can be obtained. And pattern disturbance can be minimized.

The structure of the joint portion 4 will be specifically described. Both ends of the conveyor belt main body 2 are overlapped and sewn together with a thread 5 made of an aromatic polyamide fiber, and the joint portion 4'is in contact with the rubber sheet. The cover member 3 is arranged so as to cover the joint portion 4 ', and the end portion of the cover member 3 in the longitudinal direction of the waterproof sheet vulcanizing conveyor belt 1 is sewn to the conveyor belt body 2 with the thread 6 made of aromatic polyamide fiber.

As the thread 5 for sewing the end portions of the conveyor belt main body 2 to each other, it is preferable to use a thread of about 20 to 30 made of aromatic polyamide fiber, and if it is thinner than 30 thread, the cutting may occur due to insufficient strength. However, if it is thicker than 20th, processing becomes difficult, which is not preferable. Normally, the 20th one is used. Further, as the thread 6 for sewing the cover member 3, a thread made of the same aromatic polyamide fiber is used, but it is preferable that the thread 6 has a thickness of about 40 to 50 count, and if it is thinner than 50 count, the fixing strength of the cover member is increased. If it is thicker than 40th, the pattern attached to the waterproof sheet will be deep and the physical properties of the waterproof sheet will be deteriorated, which is not preferable. Normally, the one having about 40th is used.

The thickness of the cover member 3 is preferably substantially the same as or thicker than the thickness of the conveyor belt main body 2. The thickness of the conveyor belt body 2 is usually 0.6 to
Since the thickness is about 0.7 mm, the thickness of the cover member 3 is 0.7 to
Those of 0.8 mm are used. The waterproof sheet vulcanizing conveyor belt 1 as described above is used in the following device. In FIG. 4, the waterproof sheet vulcanizing conveyor belt 1 of the present invention is used. An unvulcanized rubber sheet 7 which is a continuous vulcanizing device for waterproof sheets, advances toward the vulcanizing can 8 from the right side in the drawing, but before entering the vulcanizing can 8, the upper waterproof sheet vulcanizing conveyor It is sandwiched between the belt 1a and the lower waterproof sheet vulcanizing conveyor belt 1b.

When sandwiched between the upper and lower waterproof sheet vulcanizing conveyor belts 1a, 1b, the rubber sheet 7 is still in an unvulcanized state and is deformed, so that the waterproof sheet vulcanizing conveyor belt 1a,
The pattern of fibers 1b is applied to the rubber sheet 7. The rubber sheet 7 advances through the vulcanization can 8 while being sandwiched between the upper and lower conveyor belts 1a and 1b for waterproof sheet vulcanization, and is heated and pressurized to be vulcanized. The rubber sheet 7 has a uniform pattern of the fabric of the waterproof sheet vulcanizing conveyor belt 1, but the pattern of the joining portion 4 at the joining portion 4 of the waterproof sheet vulcanizing conveyor belt 1 is different from the other portions. However, the pattern was uneven only in that part. The pattern of the joint portion 4 is not only non-uniform as compared with the other portions, but also has a deep pattern, so that the rubber sheet 7 often has poor appearance and poor strength at that portion.

However, by using the waterproof sheet vulcanizing conveyor belt 1 in which the joint portion 4 of the waterproof sheet vulcanizing conveyor belt 1 is joined using the cover member 3 as described above, It is possible to obtain a sheet which has less non-uniformity and can be prevented from being defective in appearance, and which can satisfy the standard values in terms of physical properties.

An example in which a rubber sheet obtained by the waterproof sheet vulcanizing conveyor belt 1 of the present invention and a rubber sheet obtained by a conventional conveyor belt are compared in terms of physical properties and appearance will be shown. The conveyor belt main body 2 uses Technora (made by Teijin Ltd.) which is a filament yarn of aromatic polyamide as warp and Conex (made by Teijin Ltd.) which is spun yarn of aromatic polyamide as weft (1000D / 1 ×).
20S / 4) / (92 × 61 pieces / 5 cm) woven fabric, and the cover member 3 is the waterproof sheet vulcanizing conveyor belt 1
Conex (made by Teijin) is used for the yarn in the longitudinal direction of
A yarn of polyphenylene sulfide fiber was used as the yarn in the width direction (20S / 4 × 200D / 5) / (61 × 92 yarns /
5 cm) woven fabric. Nomex (manufactured by Teijin Ltd.) 20 count yarn 5 by overlapping the ends of the conveyor belt body 2
Are sewn together, the cover member 3 is arranged so as to cover the joint portion 4'of the surface of the conveyor belt body 2 that is in contact with the rubber sheet, and the end portion of the cover member 3 is Nomex (made by Teijin Ltd.) 4
I sewed it with 0 count thread 6. After that, the rubber sheet was vulcanized by a vulcanizing can according to a predetermined procedure, and the sample was subjected to patterning at the joint portion 4 of the vulcanized rubber sheet according to JIS K630 (vulcanized rubber physical test method). Made, physical properties (tensile stress M at elongation 300%
₃₀₀ , tensile strength at break T _B , elongation at break E _B ) and depth of uneven pattern of the vulcanized rubber sheet in contact with the joint 4 of the waterproof sheet vulcanizing conveyor belt 1. It was measured. The results are shown in Table 1 as an example.

Conventional waterproof sheet vulcanizing conveyor belt 1
As No. 1, Conex (manufactured by Teijin Ltd.) was used for both warp and weft (20S / 6 × 20S / 6) / (90 × 3)
(0 piece / 5 cm) was used and the ends were overlapped and sewn with Nomex (manufactured by Teijin Ltd.) 20th thread 12.
Then, the waterproof sheet vulcanizing conveyor belt 11 is used to vulcanize the rubber sheet by a vulcanizing can according to a predetermined procedure, and a sample is prepared at the joint portion 4 of the vulcanized rubber sheet where the pattern is formed. , Physical properties (tensile stress M ₃₀₀ at 300% elongation, tensile strength T _B at cutting, elongation E _B at cutting) and vulcanization in contact with the joint 13 of the waterproof sheet vulcanizing conveyor belt 11. The depth of the non-uniform pattern of the rubber sheet was measured. The results are shown in Table 1 as Comparative Example 1. Further, with respect to the rubber sheet patterned at the portion other than the joining portion 4 of the waterproof sheet vulcanizing conveyor belt 1, samples were prepared in the same manner as described above and the physical properties were measured. The results are shown in Table 1 as Comparative Example 2.

[0019]

[Table 1]

As shown in Table 1 above, compared to the rubber sheet vulcanized by the conventional waterproof sheet vulcanizing conveyor belt 11, the one using the waterproof sheet vulcanizing conveyor belt 1 of the present invention is a waterproof sheet. The depth of the non-uniform pattern at the joint portion 4 of the vulcanizing conveyor belt 1 is shallow, and the joint portion 4 of the waterproof sheet vulcanizing conveyor belt 1 proposed in the present invention is not so different from other portions. You can see that it is finished more uniformly.

[0021]

The waterproof sheet vulcanizing conveyor belt of the present invention has a structure in which the joint portion of the conveyor belt main body is overlapped with the conveyor belt main body and sewn together, and then covered with a cover member. Even with the attached rubber sheet, the pattern is shallower than the one patterned at the joint of the conventional tarpaulin vulcanizing conveyor belt, and can be said to be closer to the pattern where other uniform patterns are attached. Since it is possible to obtain a rubber sheet with better physical properties than conventional ones even if the mechanical properties are measured, it is not necessary to discard the rubber sheet patterned by the joints as a defective product and it is an efficient rubber sheet. The sheet can be vulcanized.

[Brief description of drawings]

FIG. 1 is a plan view of a main part of a waterproof sheet vulcanizing conveyor belt according to the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a plan view of a main part according to another embodiment of the waterproof sheet vulcanizing conveyor belt of the present invention.

FIG. 4 is a cross-sectional view of a vulcanizing apparatus in which the waterproof sheet vulcanizing conveyor belt of the present invention is used.

FIG. 5 is a plan view of a main part of a conventional waterproof sheet vulcanizing conveyor belt.

[Explanation of symbols]

 1 Waterproof Sheet Vulcanizing Conveyor Belt 2 Conveyor Belt Main Body 3 Cover Member 4 Joint 5 Thread 6 Thread 7 Rubber Sheet

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI technical display location B29K 105: 24 B29L 7:00 4F (72) Inventor Yoshitaka Higashida 4-chome, Hamazoe-dori, Nagata-ku, Kobe No. 21 Mitsuboshi Belting Co., Ltd.

Claims (7)

[Claims] 1. A conveyor belt for waterproof sheet vulcanization, in which an unvulcanized rubber sheet is carried into a continuous vulcanizing can during continuous vulcanization of a waterproof sheet, at a joint portion of a conveyor belt in which both ends of a conveyor belt body are sewn together. A conveyor belt for vulcanizing a waterproof sheet, characterized by covering a cover member. 2. The conveyor belt for waterproof sheet vulcanization according to claim 1, wherein the thickness of the cover member covering the joint portion of the conveyor belt is set to be substantially equal to the thickness of the conveyor belt. 3. The material of the cover member with which the joint portion of the conveyor belt is covered contains a thermoplastic fiber.
Conveyor belt for vulcanization of the waterproof sheet described. 4. A conveyor belt for vulcanization of a waterproof sheet according to claim 3, wherein the thermoplastic fiber is polyphenylene sulfide. 5. The waterproof belt vulcanizing conveyor belt according to claim 3, wherein the cover member covering the joint portion of the conveyor belt is heat-sealed to the conveyor belt body. 6. The conveyor belt for waterproof sheet vulcanization according to claim 1, wherein the cover member covering the joint portion of the conveyor belt is sewn to the main body of the conveyor belt. 7. The conveyor belt for vulcanization of a waterproof sheet according to claim 6, wherein the thread for sewing the cover member covering the joint portion of the conveyor belt to the conveyor belt main body has a thickness of 40 to 50.