JPS6031643B2 - Continuous board making method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is a method of sealing the vicinity of both ends with gaskets, and disposing a raw material at the joint end of one of the two endless belts between the opposing belt surfaces of two endless belts running at the same speed. Regarding the continuous plate manufacturing method, a liquid raw material such as a liquid polymerizable compound is supplied from the supply section, polymerized by heating as it moves along the belt surface, and a plate-shaped product is obtained from the Sekiguchi machine on the other belt. This invention relates to a continuous plate making method with improved means.

Recently, the low manufacturing cost of the opposed belt type continuous sheet manufacturing method has been recognized, and conventionally, sheets are made by assembling cells from two pieces of tempered glass and injecting liquid raw materials between the tempered glasses.
BACKGROUND ART There is a growing demand for producing colored resin plates, which have been produced in small quantities in a wide variety of products using the so-called glass cell casting method, using an opposed belt type continuous plate manufacturing method.

These colored resin plates must meet the demand for a wide variety of products and small quantities, and most of the continuous production of one product ranges from a few machines to several hundreds of products in length. At this time, producing one or several to several low defective products every time the product is changed has a serious impact on the product rollout.
．． In order to obtain a plate-like polymer product with uniform thickness using a continuous plate-making machine with two endless belts arranged one above the other, it is necessary to generate internal hydraulic pressure to support the weight of the upper belt.
This must be controlled from the outside with a suitable belt surface external holding mechanism to maintain an appropriate distance between the belt surfaces, that is, the thickness of the polymerizable compound. In order to simply generate internal liquid pressure in the polymerizable compound between the belt surfaces, methods have been proposed to raise the position of the raw material supply V, such as making the belt sloped or, in extreme cases, making it vertical. ing. In addition, when running an endless belt almost horizontally, there are methods such as forcibly feeding the raw material with a metering pump and pinching the belt surface with an appropriate force using an appropriate belt surface external holding mechanism. When the liquid raw material supplied between the belt surfaces faces each other with an appropriate gap and flows back through this gap due to the liquid pressure, the size of the gap, the viscosity of the liquid raw material, the hydraulic pressure, the running speed of the endless belt, etc. By apparently stopping the tip of the backflow in this gap due to equilibrium, leakage can be virtually prevented, and the liquid raw material can be injected without leakage without any sliding between the injection means and the belt surface. As a device that can do this, it has been proposed to press fit in a space narrower than the distance between gaskets for sealing near both ends between opposing belt surfaces. Furthermore, as in Japanese Patent Publication No. 51-3-23, a syringe mounting device has been proposed which regulates the positional relationship between the upper belt main pulley and the running direction of the belt and is movable toward the middle of the belt. The present invention is a further improvement on these, and although the raw material injection device that has been proposed can move in the direction of the belt, the type of liquid raw material
For example, when switching from A-color to B-color liquid raw material, stop the opposing belt type continuous plate making machine and the supply of A-color liquid raw material, then switch to the B-color liquid raw material injection device, then start the plate-making machine and B-color liquid raw material. It is necessary to start injecting the raw material, and the belt is stopped while polymerization is already in progress, so the pressure applied from the outer surface of the belt by the belt surface external holding mechanism becomes substantially stronger, and the raw material, which is in a flowable state, is The disadvantage was that the thickness varied, resulting in a large number of defective products.

The present invention provides an improved continuous board manufacturing method that overcomes these drawbacks.

The gist of the present invention is that the endless belt is formed by two opposing surfaces that run opposite each other, and gaskets that are sandwiched between both belt surfaces near both ends of the belt and run to follow the running of the belt. In a continuous plate manufacturing method in which a liquid raw material is injected into a space where a liquid raw material is heated and polymerized and solidified, the raw material supply section is provided with at least two raw material injection means, and each of the raw material injection means is arranged so as to cross over a belt. It is characterized by being movable along the rails or guides provided, and furthermore, when switching raw materials, the remaining liquid of the raw materials whose supply has been stopped to the raw material supply section can escape from the rails or guides to prevent them from dripping. It is a continuous board making method.

In the present invention, the endless belt is made of metal such as steel or stainless steel, and in order to obtain a plate-like product with an excellent surface appearance, it is carefully polished and has a thickness of 0.1 to 3, especially 0. .5 to 2 ribs is preferred.

In the drawing, 1 and 1' are endless belts,
It is tensioned by main pulleys 2 and 3 and 2' and 3', and a predetermined tension is applied.

The main pulleys 2 and 2' are provided with hydraulic cylinders, and by changing the oil pressure, the tension of the belt can be changed. There is also a method of adjusting the belt tension using a mechanical method such as a spring. Although it is preferable to increase the belt tension in order to improve the shape of the belt and improve the thickness accuracy of the plate-shaped object, the belt tension is generally operated at 3 to 15 k9/rail. The belt is made to travel by driving the main pulley 3', and its meandering is adjusted by adjusting the angles of the main pulleys 2 and 3, and 2' and 3'.

The angle of the main pulley IJ is adjusted by changing hydraulic pressure or other mechanical methods. This can also be achieved by adjusting the meandering of the belt by changing the angle of the rolls 12, 12' brought into contact with the back surface of the belt. The gasket, numbered 13 in the drawings, runs along the running of the belt while being sandwiched near both ends of the opposing belt, and prevents the liquid raw material from leaking to the outside of the belt.

Gaskets manufactured using soft trade polyvinyl chloride, polyethylene, ethylene-vinyl acetate copolymer, polyurethane, and other materials are used.
It is preferable to use a material having the properties described in Japanese Patent No. 7-49823, for example, a material having a hollow circular cross section. What is the heating polymerization solidification section?
This refers to the first heating polymerization zone 5 and 5', the second heating polymerization zone 8 and 8', the heat insulation zone 9, and the cooling zone 10 shown in FIG.

Spray devices 7 and 7' are installed in the first heating and polymerization belts 5 and 5' for applying hot water to the back surface of the belts 1 and 1' to heat them. However, in order to avoid increasing the size of the continuous plate making apparatus and increase productivity, it is preferable to polymerize as rapidly as possible, and a temperature of 65 to 95 qC is used.

4, 4' and 6, 6' indicate roller groups that support the belt from the back side. The roller group is arranged in the polymerization belt so that at least the liquid raw material does not leak to the outside from the space formed by the opposing gasket.

The belt sag between adjacent rollers due to the hydraulic pressure of the liquid raw material, the repulsion force of the gasket, etc., but as the amount of this swivel increases, the thickness accuracy of the plate-like object deteriorates. The method of solving these problems is to reduce the sagging of the belt as described above, but it is preferable to narrow the spacing between the rollers and increase the tension of the belt. For this purpose, the arrangement interval of the rollers (distance between the centers of adjacent rollers) is approximately 20 to 10 ratios. The rollers are set so that even when the liquid raw material polymerizes and contracts, it moves following this and does not separate from the back surface of the belt. In addition to rollers, there are other ways to support the belt.
It is also possible to use the mechanism described in Publication No. 8. In the second heating polymerization zone 8, 8', the plate-like material is heated to 100 qo or more to remove residual monomer from the plate-like material.

A far infrared heater is used here, and a hot air stove may be provided. The heat insulation zone 9 and the cooling zone 10 are set to appropriate conditions in order to obtain a plate-like product of good quality.

11 is a roller for supporting the belt 1' on the belt castle.

The raw material supply section refers to a band that supplies liquid raw materials to a space formed by an opposing belt and a gasket, that is, a heating polymerization solidification section, through a raw material injection means at a constant flow rate using a metering pump.

A polymerization initiator, auxiliary agents, dyes and pigments, etc. are mixed or dissolved in the liquid raw material. The raw material injection means is a means for injecting the liquid raw material into the space formed by the opposing belt and the gasket.The raw material injection means is a means for injecting the liquid raw material into the space formed by the opposing belt and the gasket. The present invention is characterized in that the tip of the raw material outlet portion is movable, and will be described below with reference to the drawings.

In FIGS. 2 and 3, 1 and 1' are upper and lower belts, 2 and 2' are upper and lower main pulleys, respectively, and the raw material supply section is provided with two raw material injection means at the front and rear in the belt running direction. shows. 21, 21' are paths, 22, 22
′ indicates the rear swash plate-shaped raw material outflow part.

The liquid raw material A is supplied onto the lower belt 1' from the path 21 through the raw material outlet 22, and the liquid raw material B flows through the raw material outlet 22' from the route 21' and is supplied onto the lower belt 1'. Figures 4 and 5 show an embodiment in which the raw material feeder shed is equipped with two stacked raw material injection means, 21 and 21' are paths, and 22 and 22' are slanted plate-shaped raw material outlet parts. The liquid raw material A flows through the path 21 over the oblique plate-shaped raw material outlet 22 and is injected between the opposing belts 1 and 1', and the liquid raw material B passes through the path 21' and flows over the oblique plate-shaped raw material outlet 22. It flows through the outflow portion 22' and is injected between the facing belts 1, 1'.

Reference numerals 23 and 23' denote rails, and both of the raw material injection means can be moved along these rails, allowing them to escape from the raw material injection section.

This also applies to the embodiments of FIGS. 2 and 3. Therefore, when changing from liquid raw material A to liquid raw material B, it is possible to carry out the change very reliably and with a high yield. FIGS. 6 and 7 show still other embodiments.

The raw material outlet portions 22, 22' for the liquid raw materials A, B have a tubular shape, and the respective paths 21, 21' are supported by a guide 27, and their tips are bent to form the raw material outlet portions 22, 22'.

The paths 21, 21' are rotatably supported by a guide 27,
When the raw material outlet portions 22, 22' are facing downward, that is, facing the belt surface, they are in an injection state, and when they are facing upward, they are in an injectable state. This ensures that the raw material injection is stopped. Next, an example will be described.

Example 1 The continuous plate making machine shown in FIG. 1 with a specific rudder of 150 in the belt and a length of 66 ribs in the first heated polymerization zone 5, 5' was charged with the injection shown in FIGS. 2 and 3. The inside of the sloping plate-shaped raw material outlet portions 22, 22' is scraped 30 degrees using a means, and the distance between this tip and the surface of the lower endless belt 1' is uniformly 2.
I got 0 skin.

As gaskets for sealing near both ends, wall thickness 0.6
A hollow circular cross-section made of polyvinyl chloride and containing a weight part of dibutyl phthalate 6 and having an outer diameter of 8 ribs was fed along a lower endless belt 1' so that its inner diameter was 140 mm. Liquid raw material A has a polymerization rate of 20% by weight,
Mix and dissolve 500 ppm of azobismethylvaleronitrile as a polymerization initiator, 100 ppm of an ultraviolet absorber, and 2 cape Pm of dioctyl sulfosuccinate as a stripping agent in 8 poise methyl methacrylate at room temperature, and use a metering pump to dissolve the mixture every minute. The endless belt was fed at a constant rate of 8.2 k9, and the endless belt was run at a speed of 2.5 k9 per minute. was set. In this state,
The length of the backflow of liquid raw material directly below the end of the raw material outlet is approximately 5
0 side, the liquid raw material gradually spread in the belt running direction, reached the gasket position near both side ends at about 2.3 skins, and filled the space between the opposing belts. In this state, 80 q0 of overflow water is sprayed onto the back of the belt in the first heating polymerization zone, and then in the second heating polymerization zone, it is heated to 13,000 q0 with an infrared heater, cooled with cold air, and then the belt is heated to a thickness of 2 q0. I took out a transparent plate of willow.
Two to three seconds before stopping the supply of the liquid raw material A, a raw material similar to the liquid raw material A except that it contains 0.2% by weight of titanium oxide is supplied as the liquid raw material B through the other raw material outlet, and the liquid raw material After stopping the raw material supply, the raw material A injection means was removed by moving the straight raw material outlet part on the rail. Thereafter, polymerization was carried out under the same conditions to obtain a white plate-like material. At the time of switching, there were only three plate-like objects in which both colorless and transparent materials and white materials were mixed. Example 2 The same liquid raw material A was poured into the same continuous plate making apparatus as in Example 1 using the injection means shown in FIGS. The gap between the end of the belt and the belt surface was increased by two lengths.

In this state, the length of the backflow of the liquid raw material directly below the end of the raw material outflow part is about 4 degrees, and the liquid raw material in the belt running direction reaches the gasket position near both ends at about 2.5 degrees. , filling the space between the opposing belts. Next, the same liquid raw material B as in Example 1 was started to be supplied from the other raw material outlet 2 seconds before the combination of the liquid raw material A was stopped, and the injection means for the liquid raw material A was started immediately after the raw material supply stopped. Rotate the outflow part diagonally upward from the belt surface direction and guide 27
It was removed from. Thereafter, when the supply of liquid raw material B was continued, the length of the plate-like material in which colorless and transparent materials and white materials were mixed at the time of switching was 4.

[Brief explanation of the drawing]

FIG. 1 is a front view of an apparatus for implementing the present invention, FIGS. 2 and 3, 4 and 5, and 6 and 7 are a front view and a plan view of the main parts, respectively. . 1, 1'...Upper, lower belt, 2, 2', 3, 3'...
・Main pulley, 4, 4'...Roller group, 5, 5'
...First heating polymerization band, 6,6'...
Roller group, 13...Gasket, 14...
... Plate-shaped product, 21, 21' ... Route, 22,
22'... Raw material outflow section, 23, 23'... Rail, 24
, 24'...Pith, 25, 25'...Handle,
26... Trolley, 27... Guide. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7

Claims (1)

[Claims] 1. Formed by two opposing surfaces of endless belts that run opposite each other, and gaskets that are sandwiched between both belt surfaces near both ends of the belt and run to follow the running of the belts. In a continuous plate manufacturing method in which a liquid raw material is injected into a space and heated to polymerize and solidify, the raw material supply section is provided with at least two raw material injection means, each of which is disposed so as to cross over a belt. It is characterized in that it is movable along a rail or guide, and furthermore, when switching raw materials, it is made to be able to escape from the rail or guide so that residual liquid of the raw material whose supply has been stopped to the raw material supply section does not drip. Continuous board making method. 2. The sequence according to claim 1, characterized in that the raw material injection means has a raw material outlet part whose tip is movable so that the residual liquid of the raw material does not drip into the raw material supply part when the raw material supply is stopped. Board making method.