JPS5822351B2 - Method of manufacturing lightweight conveyor belt made of thermoplastic resin - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention has a total thickness of 1 mm to 1.5 mm including the core canvas.
The present invention relates to a method of manufacturing a lightweight conveyor belt made of thin thermoplastic resin.

A well-known conveyor belt is usually made of a thermosetting material such as natural rubber, styrene/butadiene rubber, and multiple layers of core canvas, and its total thickness is 3 m.
7IL or higher.

However, the reason why the thickness is 3 mm or more is due to restrictions in the manufacturing method.

Next, to explain the manufacturing method, the thermosetting resin material is formed into a thin sheet-like body using a calender, and this and adhesive-treated canvas are alternately stacked to form a laminate, and this laminate is then processed. The conveyor belt is drawn into a vulcanizing press equipped with an upper heating plate and a lower heating plate that can be pressurized, and vulcanized by heating under pressure to produce the required conveyor belt.

However, since the conveyor belt uses a thermosetting material, it naturally hardens during vulcanization.

Therefore, if the thickness of the laminate that is the object to be pressurized is thick (3 mm or more), the pressure of the vulcanizing press will sufficiently act on the laminate, making it possible to uniformly apply the required pressure. , it is possible to obtain a conveyor belt with the required thickness without uneven thickness.

However, at this time, the thickness of the laminate is small (1 to 1.5
mm), it becomes difficult to apply pressure uniformly, and when a belt with a total thickness of 1.5 mm and a width of 500 mm is manufactured, the difference in thickness at both ends in the width direction is 0.2 to 0.3 mm, i.e. Thickness unevenness of 10% or more occurred, and when it was actually run on a roller, an extreme meandering motion occurred, making it impossible to put it to practical use.

In view of the above circumstances, the total thickness is small (1 to 1.5 m).
rrt) Kokichi has been proposed to use thermoplastic resin materials (thermoplastic urethane, polyvinyl chloride, thermoplastic rubber, etc.) that plasticize when heated instead of thermosetting materials as materials for lightweight conveyor belts. Ta.

However, when this material is manufactured using a conventional press, the thermoplastic resin material naturally becomes plasticized when heated, and the pressing force from the press easily escapes, and the pressing force is not transmitted sufficiently. The adhesive force between the canvas and the resin material is insufficient, and methods such as increasing the pressure or heating temperature may be considered as a way to solve this problem.
According to this, it is difficult to regulate the thickness due to the protruding phenomenon, and there is also the problem that the resin material adheres to the surface of the hot plate, so that it cannot be put to practical use at all.

Therefore, as the next manufacturing method, as shown in FIG. 1, heating rolls 12 that rotate in opposite directions with a required gap are placed opposite each other, and a thin thermoplastic resin sheet 3 is formed in the gap.
Next, the adhesive-treated canvas 4, then the resin sheet 3 similar to the above, and then the same canvas 4 as above are successively stacked one on top of the other, and the laminate is pulled in, and the laminate is heated with heating rolls 1 and 2. A manufacturing method has been proposed in which the resin sheet 3 and the canvas 4 are bonded to each other at the same time as they are plasticized, pressurized, and rolled to a predetermined thickness.

However, according to this method, the area for adjusting the thickness is limited to an extremely narrow area of the line contact surface between the heating rolls, so it is significantly affected by the state of the laminate (for example, the state of plasticization, etc.), and the thickness cannot be adjusted to a specified thickness. It is difficult to form the resin sheet and it is uneven, and the heating from the heating roll to the laminate is instantaneous, and combined with the small pressing area, the adhesive force between the resin sheet and the canvas is extremely low. It has the disadvantage of being small,
This also cannot be put to practical use.

The present invention was made in view of the following points, and its gist is that there is a heating roll having a right circular outer circumferential surface, and that the roll is moved by a moving steel band that is stretched around the roll in an arc shape. Between the heating roll surface and the moving steel band, a soft material such as paper is placed on the side in contact with the heating roll surface, then a thinly molded thermoplastic resin sheet, then adhesive-treated canvas, and then A laminate of thermoplastic resin sheets similar to those described above, then canvas, etc. similar to those described above, is drawn in, and the laminate is heated and plasticized with heating rolls in □, and then a steel band is formed. The thickness is adjusted by the pressing force applied to the heating roll side, and the thermoplastic resin sheet and the canvas are bonded together by using the movement of the steel band and the shearing force generated between the driven heating rolls.

; Next, this will be explained in detail.

In FIG. 2, reference numeral 5 denotes a heating roll whose outer peripheral surface is a right circle, and has heating means such as electric heating inside.

A steel band 6 is attached to the heating roll 5 in an arc shape.

This steel band 6 is an endless arcuate steel band, for example, as shown in the figure, it is a moving steel band that is stretched between a guide roll 7.8 and a drive roll 9, and is moved by the rotation of the drive roll 9. The structure is such that the pressing force of the steel band 6 against the heating roll 5 can be adjusted by driving the roll 5 and changing the position of the drive roll 9.

Therefore, the surface of the heating roll 5 and the steel band 6
In between, there is a sheet of soft material such as paper 10 on the side in contact with the surface of the heating roll 5, then a thinly molded thermoplastic resin sheet 11, then an adhesive-treated canvas 12, then a resin sheet 11 similar to the above, and then The canvas 12 and the like similar to those described above are stacked one after another alternately to form a laminate JA, which is then drawn in.

The drawn laminate A is plasticized by heating from the heating roll 5 between the heating roll 5 and a steel band 6 passed over the heating roll 5 in an arc shape, and at the same time, by the pressing force of the steel band 6 against the heating roll 5 side. ;Adjust it to the specified thickness,
Furthermore, when the movement of the steel band 6 is transmitted to the heating roller 5 through the laminate A, the resin sheet 11 and the canvas 12 are bonded together by the shear force generated within the laminate A, and a lightweight thermoplastic resin composite is formed. The company manufactures ruts.

According to the manufacturing method of the present invention 2, thermoplastic resin sheet 11
A shearing force is generated within the laminate A to bond the canvas 12 and the resin sheet 11 into the canvas 12, thereby heating the resin sheet 11 to a high temperature and promoting plasticization. Since the adhesive strength can be increased even without the resin sheet 11 being relatively hard, this treatment is possible.

This makes it possible to increase the pressing force of the steel band 6 against the heating roll 5 side when adjusting the thickness.
In addition, since the high pressure force is absorbed by the soft material sheet 10 such as paper that is placed along the laminate A, even in the laminate A with a small total thickness (1 mm to 1.5 mm). The pressing area of the steel band 6 that can apply uniform pressure and can be passed over the heating roll 5 in an arc shape during pressurization is extremely small, and the heating area from the heating roll 5 to the laminate A is also small. , it is easier to obtain a lightweight conveyor belt made of thermoplastic resin and having a more uniform predetermined thickness.

Actually, as shown in Fig. 3, the above method was used to create a fabric with two layers of core canvas (made of polyester), a total thickness of 1.5 mm, and a belt width of 5 mm.
A lightweight conveyor belt made of 00mm thermoplastic resin (urethane) was manufactured, and the thickness was 1.487fLm to 1.5mm.
It is within the range of 2mm variation, extremely accurate, and the adhesive strength between the canvas and resin sheet is 15-17kg/2.5
cIrL width was obtained, confirming that the method of the present invention is extremely effective.

[Brief explanation of the drawing]

FIG. 1 is a schematic side view illustrating a conventional method, FIG. 2 is a schematic side view illustrating the present invention, and FIG. 3 is a sectional view of a product targeted by the present invention. 1.2...Heating roll, 3...Resin sheet, 4...
・Canvas, 6... Steel band, 7, 8... Guidance roll, 9... Drive roll, 10... Soft material sheet,
11...Thermoplastic resin sheet, 12...Canvas, A.
...Laminated body.

Claims (1)

[Claims] 1. There is a heating roll whose outer circumferential surface is a right circle, and the roll is arranged so as to be driven by a moving steel band that is stretched around the heating roll in an arc shape, and the heating roll surface is located between the heating roll surface and the moving steel band. A sheet of soft material such as paper is placed on the side in contact with the material, then a thinly molded thermoplastic resin sheet, then an adhesive-treated canvas, then a thermoplastic resin sheet similar to the above, and then a canvas similar to the above, etc. Alternately stacked laminates are drawn in, the laminate is heated with a heating roll to plasticize it, and the thickness is adjusted by the pressing force of the steel band toward the heating roll, and the thickness is adjusted between the movement of the steel band and the driven heating roll. A method for manufacturing a lightweight conveyor belt made of thermoplastic resin, characterized by bonding a thermoplastic resin sheet and canvas using shearing force generated in the process.