JPS6132722A - Preparation of perforated rubber sheet having no burr - Google Patents

Abstract

PURPOSE:To obtain the titled sheet in good workability, by holding a base rubber sheet between a frame body provided with perforation forming projections and a hot press platen through a release sheet and carboard under pressure to apply press molding thereto before peeling off the release sheet and the cardboard. CONSTITUTION:A base green rubber sheet 4 is placed on the top parts 9 of a large number of perforation forming projections 3 provided to a frame body 2 and a release sheet 6 and cardboard 7 are subsequently placed on said rubber sheet 4 in a superposed state. Further, a heated press platen 5 is fallen onto the cardboard 7 and the aforementioned base green rubber sheet 4 is held between the heated press platen 5 and the frame body 2 through the aforementioned release sheet 6 and the cardboard 7 to apply press molding to said rubber sheet 4. Thereafter, the aforementioned heated press platen 5 is removed, and the aforementioned release sheet 6 and cardboard 7 are peeled off to obtain the desired rubber sheet.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a method for manufacturing a porous rubber sheet (screen) used for sieving crushed stone, ore, etc.
The present invention relates to a method for producing a porous rubber sheet (screen) that leaves almost no particles attached to the product during its production and requires almost no post-processing such as puffing.

(Prior art) The conventional technology involves manufacturing a porous rubber sheet (porous rubber screen) by pressing a raw raw rubber sheet between a goo provided with a large number of hole-forming protrusions and a flat surface of a molding press pressure plate. A release sheet such as a cloth sheet or a vulcanized rubber sheet is interposed between the materialized rubber sheet and the pressure plate, and the cloth sheet or vulcanized rubber sheet is peeled off after vulcanization is completed. There is a method to obtain a porous rubber screen without paris (for example,
(Inventions described in Japanese Patent Publication No. 9-34474 and Japanese Patent Publication No. 52-10478).

(Problem to be solved by this invention) However,
The above-mentioned conventional technology has the following problems. In other words, release sheets such as cloth sheets and vulcanized rubber sheets have too much elasticity, so wrinkles and unevenness tend to form on the surface of the final screen, resulting in uneven thickness.
When the product is actually used, the part that comes into contact with the screen support frame is a point contact, and this unevenness causes phenomena such as uneven wear and cutting. In addition, if the thickness of the firmness that occurs between the release sheet and the top surface of the hole-forming protrusion is thin (0
, 1 to 0.2 fl), the adhesive strength between the release sheet and the Paris exceeds the strength of the Paris itself, so the firmness is relatively easy to peel off when the release sheet is peeled off, but the Paris may be removed depending on the weight and shape of the product. When it becomes partially thick, it becomes difficult to remove the paris, and the paris often remains on the edges of the holes in the screen product, making its removal cumbersome. These particles are usually removed by puffing, but since rubber is an elastic material, depending on the direction of polishing, there are parts where the particles are cut and parts where they are not. In other words, the edges of the edges that form the main body are cut, but the edges cannot be cut in the direction from the main body to the edges. Furthermore, if a rubber material that is easily puffed is used, the durability of the screen itself will be reduced. Furthermore, according to the method of punching holes using a punch, if the tip of the punch does not hit the hole surface at right angles and accurately, a small amount of holes will remain in the shape of a flange at the edge of the hole, and if there are many holes, the punch will It is difficult to accurately insert the hole into the hole, and if the punch itself is made smaller, it still leaves a flange-shaped hole at the edge of the hole. Removing these particles was a very labor-intensive and time-consuming task.

(Means for solving the above-mentioned problems) The present invention was invented in view of the above-mentioned problems, and it is possible to produce this kind of porous rubber screen without leaving almost any particles attached to the product. The present invention aims to provide a method for manufacturing a porous rubber screen that hardly requires any puff removal means such as subsequent puffing treatment.

Hereinafter, the configuration of the present invention will be explained.

That is, the gist of the present invention is to provide a method for manufacturing a porous rubber sheet by pressing a raw rubber sheet between a frame provided with a large number of hole-forming protrusions and a flat surface of a pressure heating plate. A release sheet and cardboard are interposed between the material raw rubber sheet and the pressure heating plate, and after the material raw rubber sheet is pressure-molded, the pressure and heating plate is unloaded, and the release sheet and cardboard are separated. This is a method for manufacturing a porous rubber sheet, which is characterized by peeling it off.

Next, one embodiment of the present invention will be described based on the accompanying drawings.

Figure 1 is a cross-sectional view of the porous rubber sheet just before manufacturing.
1 is a press hot plate, 2 is a frame placed on the press hot plate 1,
Reference numeral 3 denotes a hole-forming projection provided on the frame 2, and 5 a pressurizing heat disposed such that it can move up and down so as to approach or separate a flat surface parallel to the top 9 of the hole-forming projection 3. Show the board. In these devices, the material rubber sheet 4 is placed on the top 9 of the hole forming projection 30 of the frame 2, and then,
A release sheet 6 and cardboard 7 are placed on top of this. In addition,
12 is a lower mold for fixing the hole-forming projection of the frame.

Then, as shown in FIG. 2, by lowering the pressure heating plate 5, the raw rubber sheet 4 is pressed between the frame 2 and the release sheet 6 and the cardboard 7. (The raw rubber compressed by the pressure heating plate 5 and the frame body 2
A gap 10 is formed between the top 9 of the frame 2 and the release sheet 6 by biting into the gap 8 that exists between them, but due to the pressing force of the cardboard, which has both moderate rigidity and moderate elasticity, it can be made thinner. It becomes a layer. Note that it is not necessary to use only one piece of cardboard; it may be more effective to use two or more pieces of paper, taking into account various conditions such as the degree of pressure on the pressure plate, vulcanization conditions, and the thickness of the product to be manufactured. becomes. Next, as shown in FIG. 3, after unloading the pressure heating plate 5, the release sheet 6 and the cardboard 7 are peeled off as shown in the figure, so that the Paris edition is attached to the back side of the release sheet 6. urge

In addition, if the back side of the release sheet is made with a finely uneven surface 11 as shown in Fig. 4, the particles will bite into the uneven surface well.
The binding force with the release sheet increases and becomes stronger than the strength of Paris itself, making it especially optimal. The material for the release sheet is appropriately selected from materials with good release properties, such as polyester, Tetron, Teflon, and release paper.

(Example) In the above-described method for manufacturing a porous rubber sheet of the present invention, a cardboard with a thickness of one crane is used as the cardboard, a polyester sheet (0.1M) whose one side is sandblasted is used as the release sheet, As raw rubber material, rubber with particularly good abrasion resistance was used.

The surface pressure of the pressure heating plate is 30 kg/ca, and the hole size is 25
A porous rubber screen measuring m square, 1500 m in length and 600 mm in length was manufactured.

The pores of the obtained porous rubber screen had no particles at all.
All of the particles were attached to the back side of the release sheet that had been peeled off.

(Effects) In the method for manufacturing the porous rubber screen of the present invention constructed as described above, cardboard and a release sheet are interposed between the pressure heating plate and the material raw rubber sheet, and in particular, since the cardboard is interposed, Due to the appropriate rigidity and pressing force of cardboard,
The area around the barrier formed between the pressure heating plate and the top of the hole-forming protrusion of the frame becomes a thinner layer, which reduces the binding force between the release sheet and the barrier when peeling off the release sheet and cardboard. The strength is far greater than the strength of the sheet itself, and when the sheet is peeled off, the firmness can be completely attached to the back surface of the sheet and then peeled off.

In addition, thick paper such as cardboard has extremely low heat shrinkage and good dimensional stability compared to rubber etc., so it is not affected by the heat during pressure vulcanization and does not wrinkle. The surface of the porous rubber screen will not be uneven. In particular, even if a single piece of cardboard cannot sufficiently prevent the occurrence of wrinkles due to changes in the pressure of the pressurizing plate and other manufacturing conditions, using multiple sheets of cardboard, such as two or three sheets, can prevent wrinkles. It is more effective as it can completely prevent the occurrence of

Furthermore, since the back side of the release sheet has minute irregularities formed, when the release sheet and cardboard are peeled off, the binding force between the release sheet and the release sheet is greater than the strength of the burr itself. , you can definitely strip Paris.

Furthermore, since almost no debris remains in the pores of the resulting porous rubber screen, there is no need to remove debris using puffs or punches, and no debris remains in the holes of the frame, improving work efficiency. Extremely good. and again,
The resulting product porous rubber screen has no particles in the pores, so the sieving efficiency is improved, and the product surface has no unevenness or wrinkles (it is flat, so there is no point contact with the screen support frame, Since there is surface contact, there are no problems such as abnormal wear or cutting, and the durability of use is improved.

[Brief explanation of the drawing]

Figure 1 is when the present invention is being carried out (immediately before manufacturing a porous rubber sheet)
FIG. 2 is an explanatory diagram of the present invention when the pressurizing and heating plate is pressurized, and FIG. 3 is an explanatory diagram of the present invention when the pressurizing and heating plate is depressurized. FIG. 4 is a partially enlarged sectional view of the release sheet used in the present invention. DESCRIPTION OF SYMBOLS 1... Press heating plate, 2... Frame body, 3... Hole forming protrusion, 4... Material raw rubber sheet, 5... Pressure heating plate, 6
...Release/mold sheet, 7...Cardboard, 8...Gap, 9
...Top, 10...Paris, 11...Uneven surface, 12
...Lower mold.

Claims (1)

[Claims] In a method of manufacturing a porous rubber sheet by pressing a raw raw rubber sheet between a frame provided with a large number of hole-forming projections and a flat surface of a pressurizing and heating plate, there is a gap between the raw raw rubber sheet and the pressurizing and heating plate. , production of a porous rubber sheet characterized by interposing a release sheet and cardboard, press-molding a raw rubber sheet, unloading the pressure heating plate, and peeling off the release sheet and cardboard. Method.