JPH08244935A - Warp preventing method for conveyor belt - Google Patents

Abstract

PURPOSE: To effectively prevent a warp in a belt main body after vulcanization molding, improve a trough properly and a straight property which are essential characteristics for a conveyor belt and to effectively prevent meandering in the overall length of the conveyor belt. CONSTITUTION: An upper face covering rubber layer 6 and a lower face covering rubber layer 7, whose thicknesses are different from each other, are laminated on the upper face and the lower face of a core body canvas reinforcing layer 5, and then, they are integrally molded. A ratio of the thickness T of the upper face covering rubber layer 6 to the thickness (t) of the lower face covering rubber layer 7 is approximately 3:1. In the belt main body 4, an ultrahigh molecular weight polyethylene sheet 8 is integrally molded by means of thermal fusion on the surface or inside of the covering rubber layer 7 on the opposite side to side on which a warp is generated. In the ultrahigh molecular weight polyethylene sheet 8, a molecular weight is a million or more, and a thickness of the sheet is 0.05-1.00mm.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for preventing warping of a conveyor belt, and more particularly to a method of integrally forming an ultra high molecular weight polyethylene sheet in the cover rubber layer on the opposite side where the conveyor belt warps or on the surface of the cover rubber. The present invention relates to a method for preventing the warp of a conveyor belt, which is provided on a conveyor belt to prevent the warp of the belt body.

[0002]

2. Description of the Related Art A conventional conveyor belt is shown in FIG.
As shown in FIG. 3, an endless belt body 4 is wound around a drive pulley 1 and a driven pulley 2 which are arranged at a predetermined interval via a plurality of guide rollers 3. As shown in FIG. 5, such a belt body 4 generally has a plurality of core body canvas reinforcing layers 5 made of a woven fabric made of nylon, polyester, vinylon and / or aromatic polyamide fibers, on the upper and lower surfaces thereof. The upper surface cover rubber layer 6 and the lower surface cover rubber layer 7 are laminated and integrally formed.

The thickness T of the upper cover rubber layer 6 on which the transported object is placed is thicker than the thickness t of the lower cover rubber layer 7 (generally, in order to have abrasion resistance and heat resistance). 3: 1
Ratio) is formed. Alternatively, the upper surface cover rubber layer 6 may be made of rubber having excellent yat resistance, and the lower surface cover rubber layer 7 may be made of different types of rubber having excellent wear resistance.

[0004]

However, when the upper surface cover rubber layer 6 and the lower surface cover rubber layer 7 of the belt body 4 have a difference in thickness as described above, or different kinds of rubber are arranged. In this case, due to the difference in heat shrinkage, the belt main body 4 has a warp S after vulcanization molding as shown by the chain line in FIG.
Occurs.

The warp of the belt main body 4 deteriorates the trough property (condition of fitting of the belt to the roller) and the straightness which are necessary characteristics of the conveyor belt, and causes one of the causes of meandering of the conveyor belt. The present invention has been devised in view of such conventional problems, and a belt main body in which an upper surface cover rubber layer and a lower surface cover rubber layer have a difference in thickness, or an upper surface cover rubber layer and a lower surface cover. In a belt body in which the rubber layer is made of different kinds of rubber, it is possible to effectively prevent the warp of the belt body after vulcanization and molding, and to improve the trough property and straightness which are the required characteristics of the conveyor belt. It is an object of the present invention to provide a method for preventing warping of a conveyor belt which can effectively prevent meandering along the entire length.

[0006]

In order to achieve the above object, the present invention aims to integrally form an ultrahigh molecular weight polyethylene sheet on the cover rubber layer side opposite to the side where the conveyor belt warps. It is a summary. The ultra-high molecular weight polyethylene sheet is integrally formed on the surface of the cover rubber layer on the opposite side where the warp of the conveyor belt occurs by heat fusion, or when the conveyor belt is vulcanized and formed, the conveyor belt does not warp. It is possible to embed it in the side cover rubber layer and integrally mold it by heat fusion.

The ultra high molecular weight polyethylene sheet has a molecular weight of 1,000,000 or more and a thickness of 0.05 mm to 1.00 mm. Further, the upper surface cover rubber layer and the lower surface cover rubber layer can be formed by using different materials or the same material. Further, according to the present invention, an upper surface cover rubber layer is laminated on the upper surface of the core canvas reinforcing layer, and the lower surface of the core canvas reinforcing layer has a molecular weight of 1,000,000 or more and a thickness of 0.05 mm to 1.00 mm. It is also possible to integrally form a molecular weight polyethylene sheet by heat fusion.

[0008]

The present invention is constructed as described above, and the belt main body in which the upper surface cover rubber layer and the lower surface cover rubber layer have a thickness difference, or the upper surface cover rubber layer and the lower surface cover rubber layer are provided. In a belt main body made of different rubber, an ultra-high molecular weight polyethylene sheet is interposed and integrally formed on the opposite cover rubber layer side where the warp of the conveyor belt occurs, so that the belt caused by the difference in heat shrinkage rate. The warp of the main body is suppressed with an ultra-high molecular weight polyethylene sheet, which makes it possible to improve the trough property and straightness that are required characteristics of the conveyor belt, and it is possible to effectively prevent meandering in the entire length of the conveyor belt. is there.

[0009]

Embodiments of the present invention will be described below with reference to the accompanying drawings. The same components as those in the conventional example are designated by the same reference numerals and the description thereof will be omitted. FIG. 1 is a sectional view of a belt main body 4 showing a first embodiment of the present invention, in which four layers of core body canvas reinforcing layers are formed of a woven fabric made of nylon, polyester, vinylon and / or aromatic polyamide fiber or the like. 5, upper and lower cover rubber layers 6 having different thicknesses
And the lower surface cover rubber layer 7 are laminated and integrally molded.

In this embodiment, the thickness T of the upper surface cover rubber layer 6 and the thickness t of the lower surface cover rubber layer 7 are formed at a ratio of about 3: 1. On the surface of the lower surface cover rubber layer 7 on the opposite side where the belt body 4 warps,
The ultra high molecular weight polyethylene sheet 8 is integrally formed by heat fusion. This ultra high molecular weight polyethylene sheet 8
Is a sheet having a molecular weight of 1,000,000 or more and a thickness in the range of 0.05 mm to 1.00 mm.

It is also possible to mold the upper cover rubber layer 6 and the lower cover rubber layer 7 by using different materials or the same material. FIG. 2 is a sectional view of a belt main body 4 showing a second embodiment of the present invention, in which an ultra high molecular weight polyethylene sheet 8 is embedded in a lower cover rubber layer 7 and is a conveyor belt. The ultra-high molecular weight polyethylene sheet 8 is embedded in the lower cover rubber layer 7 at the time of vulcanization molding and integrally molded by heat fusion (about 140 ° C. to 180 ° C.).

Further, FIG. 3 is a sectional view of a belt body 4 showing a third embodiment of the present invention. In this embodiment, two ultra high molecular weight polyethylene sheets 8a and 8b having different thicknesses are attached to a top cover rubber. The surface of the layer 6 and the lower surface cover rubber layer 7 are integrally molded by heat fusion. That is, the thickness T
A relatively thin ultra high molecular weight polyethylene sheet 8a is integrally formed on the surface of the thick upper cover rubber layer 6 by heat fusion. An ultrahigh molecular weight polyethylene sheet 8b having a thickness thicker than that of the cover rubber layer 6 side is integrally formed by heat fusion to prevent the belt body 4 from warping.

Further, in the case of this embodiment, since the surface of the upper cover rubber layer 6 on which the material to be conveyed is placed is covered with the ultra high molecular weight polyethylene sheet 8a, adhesion of cake and the like can be prevented and the It is possible to improve wear resistance and heat resistance. Next, Ultra High Molecular Weight Polyethylen sheet
e: hereinafter referred to as UHMWPE) warp of the belt body 4 when integrally formed on the surface of the upper surface cover rubber layer 6 of the belt body 4 and integrally formed on the surface of the lower surface cover rubber layer 7. Table 1 below shows an example of an experiment in which the above are compared. [Conditions of experiment]. Sample preparation specifications (No.1, No.2, No.3) when ultra-high molecular weight polyethylene sheet (UHMWPE) is integrally molded on the surface of the upper cover rubber layer of the belt body. Dimensions: length 350 to 400 mm, 4 reinforcing layers, thickness of ultra high molecular weight polyethylene sheet 0.130, 0.250 to 0.400 mm (using Sakushin Kogyo NULIGHT), thickness of top cover rubber layer 5.0
mm, thickness of bottom cover rubber layer 2.0 mm Vulcanization condition: Vulcanizing press 148 ° C × 20 minutes (pressure 20 Kgf / cm ² ) Mold shape 350 × 400 × 9.5 mmt Cooling method Remove from press and place weight on it cooling
(21.2 Kgf). Sample preparation specifications (No.4, No.5, No.6) when an ultra-high molecular weight polyethylene sheet (UHMWPE) is integrally molded on the surface of the lower cover rubber layer of the belt body. Dimension: Length 350-400 mm, Reinforcement layer 4 layers, Ultra high molecular weight polyethylene sheet thickness 0.130,0.250,0.400 mm (Nulite made by Sakushin Kogyo) Upper cover rubber layer thickness 5.0 mm, Lower cover rubber layer Thickness 1.0mm Vulcanization condition: Vulcanizing press 148 ℃ × 20min (Pressure 20Kgf / cm ² ) Mold shape 350 × 400 × 8.5mmt Cooling method Remove from press, put weight on it
(21.2 Kgf)

[0014] In FIG. 5, the warp S of the belt body after vulcanization is shown. As for the warp S of the belt body in Table 1, (+) indicates concave warp, and (−) indicates convex warp.

As a result of the above-mentioned experiment, regarding the warp of the belt body after vulcanization, the ultra high molecular weight polyethylene sheet (UHMW
It was found that the degree of warp (concave) differs depending on the arrangement of PE). That is, it was found that when UHMWPE was arranged on the surface of the upper surface cover rubber layer 6, the warp (concave shape) was large.

Further, when UHMWPE was placed on the surface of the lower cover rubber layer 7, it was found that the warp (concave shape) was small due to being restrained by the four core canvas reinforcing layers 5. Regarding the effect of UHMWPE thickness on warpage, the top cover rubber layer 6
According to the thicknesses of the lower cover rubber layer 7 and the lower cover rubber layer 7, an arbitrary thickness is set and used. Also, the ultra-high molecular weight polyethylene sheet (UHMWPE) and UHMWPE are used as the top cover rubber layer 6
And the adhesiveness with the lower surface cover rubber layer 7 was good.

According to the present invention, on the side of the lower surface cover rubber layer 7 on the opposite side where the warp of the conveyor belt occurs as described above,
By integrally molding with the interposition of the ultra high molecular weight polyethylene sheet 8, the warpage of the belt body 4 caused by the difference in heat shrinkage is prevented.
By this, it is possible to improve the trough property and straightness which are the required characteristics of the conveyor belt, and it is possible to effectively prevent the meandering in the entire length of the conveyor belt.

[0018]

As described above, the present invention provides a conveyor belt in which the upper cover rubber layer and the lower cover rubber layer are laminated on the upper and lower surfaces of the core body canvas reinforcing layer to be integrally molded. By forming an ultra-high molecular weight polyethylene sheet integrally on the side of the cover rubber layer on the opposite side where warpage occurs, the warp of the belt body is suppressed by the ultra-high molecular weight polyethylene sheet after vulcanization molding and the warpage is effective. It is possible to prevent and improve the trough property and straightness which are required characteristics of the conveyor belt, and it is possible to effectively prevent the meandering in the entire length of the conveyor belt.

[Brief description of drawings]

FIG. 1 is a sectional view of a belt body showing a first embodiment of the present invention.

FIG. 2 is a sectional view of a belt body showing a second embodiment of the present invention.

FIG. 3 is a sectional view of a belt body showing a third embodiment of the present invention.

FIG. 4 is an explanatory view of a conventional conveyor belt.

5 is an enlarged sectional view taken along the line AA of FIG.

[Explanation of symbols]

1 Drive Pulley 2 Driven Pulley 3 Guide Roller 4 Belt Body 5 Core Body Canvas Reinforcing Layer 6 Top Cover Rubber Layer 7 Bottom Cover Rubber Layer 8 Ultra High Molecular Weight Polyethylene Sheet T Top Cover Rubber Layer Thickness t Bottom Cover Rubber Layer Thickness Warp of S belt body

Claims (6)

[Claims] 1. A method of preventing warpage of a conveyor belt, comprising stacking an upper surface cover rubber layer and a lower surface cover rubber layer on the upper and lower surfaces of a core canvas reinforcing layer, and integrally molding the same. Side cover rubber layer side, an ultra-high molecular weight polyethylene sheet is interposed to integrally mold, and a method for preventing warpage of a conveyor belt. 2. The ultra high molecular weight polyethylene sheet,
The heat-welding integrally molding is performed on the surface of the cover rubber layer on the opposite side where the warp of the conveyor belt occurs.
Conveyor belt curl prevention method described in. 3. The ultra high molecular weight polyethylene sheet,
The method of preventing warpage of a conveyor belt according to claim 1, wherein the conveyor belt is embedded in a cover rubber layer on the opposite side where warpage of the conveyor belt occurs during vulcanization molding, and integrally molded by heat fusion. 4. The ultra high molecular weight polyethylene sheet comprises:
The method for preventing warpage of a conveyor belt according to claim 1, wherein a sheet having a molecular weight of 1,000,000 or more and a thickness of 0.05 mm to 1.00 mm is used. 5. The method of preventing warpage of a conveyor belt according to claim 1, wherein the upper cover rubber layer and the lower cover rubber layer are formed of different materials or the same material. 6. An upper cover rubber layer is laminated on an upper surface of the core canvas reinforcing layer, and an ultra high molecular weight having a molecular weight of 1,000,000 or more and a thickness of 0.05 mm to 1.00 mm on the lower surface of the core canvas reinforcing layer. A method for preventing warpage of a conveyor belt, which comprises integrally molding a polyethylene sheet by heat fusion.