JPS6124186B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to canvas fabrics woven from fibers such as polyester, nylon, or vinylon (hereinafter simply referred to as canvas) and thermoplastic resin sheets (hereinafter simply referred to as resin sheets) such as vinyl chloride resin or polyurethane resin. A relatively thin layer (1 mm to 1.5
mm) It relates to a method for manufacturing a lightweight thermoplastic resin belt (hereinafter simply referred to as a belt).

Conventionally, such belts are manufactured by using a roto-cure device, which is well known as a continuous manufacturing device for rubber belts, and a thin sheet of molten resin is placed on canvas between a roll and a steel band that moves on the roll surface. A plurality of unwelded laminates of canvas and resin sheets stacked in a shape are sandwiched and moved so that the resin sheets and canvas are alternately positioned, and the resin sheets are heated to a temperature higher than the welding temperature to sufficiently soften and unweld them. There is a known method for manufacturing a belt by pressurizing a welded laminate to allow the resin of the resin sheet to sufficiently penetrate between the stitches of the canvas, and then cooling the welded laminate.

However, such a manufacturing method not only requires a large amount of capital investment, but also requires a large amount of equipment and space, and even if existing equipment is used, a large amount of money is required to replace the steel band, resulting in high manufacturing costs. be.

In addition, since the belt obtained by such a manufacturing method is manufactured by sandwiching the laminate between the steel band and the roll surface and heating and pressurizing it, the roll has almost no flexibility, but the steel band is flexible. Because of its flexibility, the pressure applied to the laminate is uneven in the width direction, resulting in deformation of the weave density of the canvas. This method has the disadvantage that only a belt with an uneven thickness, which has a raised wall thickness (causing a crown phenomenon), can be obtained, which causes belt meandering.

The present invention was developed in view of the above, and an object of the present invention is to provide a belt manufacturing method that can produce belts with good thickness accuracy and little change in canvas weaving density at a lower cost. In order to achieve this object, the present invention is to manufacture a belt by the method described in the claims.

The belt manufacturing method of the present invention will be explained in detail below with reference to an embodiment of the drawings. In the drawings, A is a preheating roller, B and C are heating rollers, D and E are cooling rollers, and rollers A, B, and C are Each internally heated to 150 to 180℃ using steam or hot water, etc.
The rollers D and E are each internally cooled to, for example, 50 to 100°C by cooling water. The rollers are arranged adjacent to each other in the order of A, B, C, D, and E, and in the illustrated embodiment, the preheating roller A rotates counterclockwise, the heating roller B rotates clockwise, and the heating roller C rotates counterclockwise. , the cooling roller D rotates clockwise, and the cooling roller E rotates counterclockwise, so that the circumferential speeds of the respective rollers are the same.

The preheating roller A and the cooling roller D are provided so that they can be braked, and the heating distance of the preheating roller A can be arbitrarily changed according to the thickness of the belt to be heated, so the position on the circumference of the heating roller B can be arbitrarily changed. It is provided. The distance between heating roller B and cooling roller D can also be changed depending on the thickness of the belt. Further, the size of each roll is not particularly limited, but preferably heating rollers B and C have a large diameter, and preheating roller A and cooling rollers D and E have a diameter smaller than that of heating rollers B and C. Good.

Also, the gap between the preheating roller A and the heating roller B is set at a distance that is slightly thicker than the thickness of the product belt, and the gap between the heating roller B and the heating roller C, and the gap between the heating roller C and the cooling roller D are set apart. The gap between cooling rollers D and E is adjusted to be equal to the thickness of the product belt.

Further, the surface of each roller is finished, for example, by plating, in order to make the belt surface more mirror-like, and the surface is made thick so that a uniform temperature distribution can be maintained.

Note that a patterned roller may be used as the cooling roller E to provide a pattern on the belt surface.

Reference numeral 1 denotes a belt, and the belt 1 is made of a laminate made of a canvas and a resin sheet pasted together.

To manufacture a belt according to the present invention, first, one or more unwelded laminates 2 and 3 of canvas and resin sheets are stacked one on top of the other so that the resin sheets and canvas are alternately positioned, and the unwelded laminates of uneven thickness are formed. 2,3
In the first step, the unwelded laminates 2 and 3 are moved along the circumferential surface of the preheating roller A as the roller rotates, and the unwelded laminates 2 and 3 are preheated to a temperature slightly lower than the welding temperature of the resin of the resin sheet. Through this process, the unwelded laminates 2 and 3 of uneven thickness are brought into an ironed state by the heat of the outer surface of the roller, and heated uniformly.

Next, in a second step, the unwelded laminates 2 and 3 preheated in the first step are passed between a preheating roller A and a heating roller B, and precompressed to a thickness slightly thicker than the product belt. By this step, the thicknesses of the unwelded laminates 2 and 3, which have uneven thicknesses, can be made substantially uniform.

Next, in the third step, the pre-pressed unfused laminates 2 and 3 are moved along the circumferential surface of the heating roller B as the roller rotates to a temperature close to the welding temperature of the resin (approximately 150 to 160°C). Heat to ℃). Through this process, the thickness of the unwelded laminates 2 and 3, which have uneven thicknesses, is pre-compressed to a nearly constant thickness in the second step, and the canvas and resin sheet are blended together, making the heating of the laminate more uniform. It can be done.

Next, in the fourth step, the unwelded laminates 2 and 3 heated in the third step are passed between heating rollers B and heating rollers C, and are pressed to the thickness of the product and welded. By this means, it is possible to sufficiently penetrate the resin between the stitches of the canvas and obtain good adhesion.

Next, in the fifth step, the heated, pressurized and welded laminate is transferred along the circumferential surface of the heating roller C to maintain the pressed thickness and heating state, and the canvas and resin sheet of the heat-welded laminate are transferred. Complete welding so that no unwelded parts remain.

Next, in the sixth step, the surface state of the welded laminate is stabilized by passing between the heating roller C and the cooling roller D of the next step. By this means, the surface of the welded laminate is cooled slightly below the resin temperature.
The surface unevenness disappears and the surface becomes smooth and wrinkle-free.

Next, in the seventh step, the cooling roller D is cooled to a temperature lower than the welding temperature of the resin by being transferred along the circumferential surface of the cooling roller D. By this means the welded laminates are joined together.

In this way, in the present invention, the resin sheet and the canvas are preheated in the first step so that they become somewhat soft but still have some hardness, and in the second step the resin sheet and the canvas are pressurized to make their mutual contact surfaces familiar. In the three steps, the resin in this state is uniformly heated to the welding temperature, that is, it is heated gradually and evenly heated to the inside, and in the fourth step, the resin is pressure welded, so that good adhesion can be obtained. Furthermore, in the fifth step, the welding temperature is maintained for a certain period of time to complete the welding so that no unwelded parts remain. If this welded laminate is cooled as it is, wrinkles may occur on the surface of the resin sheet, so it is passed between a heating roller C and a cooling roller D to stabilize the surface condition while being cooled, and then further cooled by a cooling roller D. to fix the state.

By sequentially carrying out such a method using a roller, the present invention makes it possible to manufacture a resin belt with a good surface condition and a uniform thickness at a low cost.

[Brief explanation of the drawing]

The drawings show an embodiment of the manufacturing method of the present invention. 1... Belt, 2, 3... Unwelded laminate of canvas and resin sheet, A... Preheating roller, B, C... Heating roller, D, E... Cooling roller.

Claims (1)

[Scope of Claims] 1. A method for manufacturing a thermoplastic resin belt in which a belt is manufactured by thermally welding an unwelded laminate of a thermoplastic resin sheet and canvas together by applying heat and pressure, comprising: (i) Preheating roller A rotating the welded laminate
(ii) moving the unwelded laminate preheated in step (i) to a temperature slightly lower than the welding temperature of the thermoplastic resin sheet while moving it along the circumferential surface of the thermoplastic resin sheet; and a heating roller B, which is placed adjacent to the preheating roller A and a heating roller B rotating in the opposite direction, to apply prepressure and make the thickness uniform; (iii) the step of (ii); A step in which the unwelded laminate pre-pressed in the step is moved along the circumferential surface of heating roller B and heated to the welding temperature of the thermoplastic resin sheet; The unwelded laminate is passed between a heating roller B and a heating roller C, which is placed adjacent to the heating roller B and is rotating in the opposite direction to the heating roller B, to press the unwelded laminate to the thickness of the product. , a step of welding; (v) a step of moving the laminate welded in step (iv) along the circumferential surface of the heating roller C to maintain the pressurized thickness and heating state; vi) Following step (v), the surface of the welded laminate is passed between the heating roller C and the cooling roller D, which is disposed adjacent to the heating roller C and is rotating in the opposite direction. (vii) Following the step (vi), the welded laminate is placed on a cooling roller D.
A method for manufacturing a thermoplastic resin belt, comprising the steps of: transporting the belt along its circumferential surface and cooling it to a temperature lower than the welding temperature.