JP2807543B2 - Manufacturing method of diaphragm holder for membrane filter plate - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for manufacturing a diaphragm retainer for a membrane filter plate, and more specifically, to a method of passing a solution or a chemical that corrodes a metal, and squeezing the material. The present invention relates to a method for manufacturing a diaphragm retainer of a membrane type filter plate which is required to have good property and chemical resistance.

(Prior art and its problems) Conventionally, a presser for fixing and attaching a membrane type filter plate plate and a diaphragm at a peripheral portion of a stock solution supply port is exposed to a strongly acidic chemical solution and repeatedly subjected to tightening pressure. Those made of stainless metal such as steel or titanium alloy or those made of highly rigid plastic have been used.

However, the above-mentioned stainless steel presser has sufficient mechanical strength, but has a disadvantage in chemical resistance and is expensive. On the other hand, the above-mentioned plastic presser has poor chemical resistance. However, even if satisfied, there is a problem in mechanical strength.

Further, since the presser is made of a material different from that of the diaphragm, there is a problem that the presser bites into the diaphragm and is torn, or a deformation of the presser causes a gap to cause liquid leakage or the like.

(Means for Solving the Problems) The present invention is a method for manufacturing a diaphragm presser for a membrane filter plate for solving the above problems, and the gist of the invention is that a diaphragm is provided at a peripheral portion of a liquid supply port of the membrane filter plate. A method for manufacturing a flange-shaped presser for fixing the presser to a filter plate, wherein a pellet of a polyolefin-based thermoplastic elastomer is filled in a recess of a lower mold for molding the presser, and A ring-shaped metal core having a hole to be loosely fitted to the protruding core provided at a position corresponding to the bolt hole is overlaid on the pellet, and then the flat part between the protruding cores, A die for a membrane-type filter plate characterized by disposing a plate-like body of a polyolefin-based thermoplastic elastomer in an amount sufficient for coating, then closing an upper mold for molding, and heating and pressing. This is a method for manufacturing an afram retainer.

 Hereinafter, embodiments of the present invention will be specifically described with reference to the drawings.

FIG. 1 is a half perspective view of a lower mold for molding used in the present invention, and FIGS. 2 (a), 2 (b), and 3 (c) show the molding order of the periphery of a bolt hole of a holding tool according to the method of the present invention. FIG. 3 is a sectional perspective view, FIG. 3 is a half perspective view of a core metal used in the present invention, FIG. 4 is a perspective view showing a state in which a periphery of a bolt hole of a retainer is formed, and FIG. FIG. 6 is a schematic plan view showing a plate-shaped body arranged on a mold, and FIG. 6 is a partially cutaway perspective view showing a holding member obtained by the present invention.

The lower mold for molding (hereinafter referred to as "lower mold") used in the present invention is shown in a half perspective view in FIG.
A protruding core C fastened by a core stopper C ″ from the back is disposed at a position corresponding to the bolt hole of the holding tool inside,
Recesses D 'and D' into which the packing D is fitted are formed inside and outside the recess A ', respectively.

As shown in the side sectional view of FIG. 2 (b), the upper mold has a through-hole portion in which the projecting core C is loosely fitted in correspondence with the position of the projecting core C, as shown in the side sectional view of FIG. When B 'is formed and the mold is closed, the thickness of the film formed on the surface of the holding member between the core metal 3 and the protruding core C and between the core metal 3 and the lower mold A and the upper mold B. Is formed, and the packing D seals both sides of the concave portion A '.

Polyolefin-based thermoplastic elastomer (hereinafter, referred to as "elastomer") for forming a coating of the holding member according to the present invention.
Is obtained by blending or partially cross-linking a polyolefin resin such as polypropylene and an ethylene-propylene copolymer rubber or an ethylene-propylene non-conjugated diene copolymer rubber, and the diaphragm of a membrane filter plate. It is an elastic material of the same material with excellent corrosion resistance and chemical resistance.

 Hereinafter, the present invention will be described in the order of manufacturing steps.

First, as shown in the side sectional view of FIG. 2 (a), the elastomer pellet (hereinafter referred to as "pellet") 2 covers the pedestal C 'of the projecting core C in the recess A' of the lower mold A. As shown in the perspective views of FIGS. 2 (b) and 4, a half-ring piece 21 of the same quality as the pellet 2 is projected on the pellet 2 deposited on the pedestal C '. 3. Then, as shown in a half perspective view in FIG. 3, the bolt 3 'is aligned with the protruding core C, and the core metal 3 is placed on the pellet 2, and thereafter the protruding portion is formed. Inside the core C, inside the bolt hole 3 ′ of the cored bar 3 (the side opposite to the half-ring piece 21), insert the pellet 2
A spacer 22 made of polypropylene or the like having a melting temperature slightly higher than that of the pellet 2 is sandwiched therebetween so as to keep the gap between the bolt hole 3 ′ and the protruding core C constant, Prevent displacement.

As shown in the schematic plan views of FIGS.
In the flat portion 3 "between the bolt holes 3 ', 3', a plate-like body 23 made of cut rice cake is placed.

Thereafter, the upper mold B is lowered, the mold is closed, and the temperature is 190-2.
Molding under the conditions of 00 ° C., pressure of 0.5 to 1 kg / cm ² , and pressing time of 15 minutes, and cooling for about 10 minutes, as shown in FIG. 2C, the entire outer surface of the core bar 3 is made of an elastomer. Thickness 1-3mm
Is formed integrally.

The burr formed in the gap between the through-hole portion B 'of the upper mold B and the upper part of the protruding core C is cut off after the mold is opened to obtain a product.

In the above press molding, the pellets 2 in the outer peripheral direction of the upper surface of the pedestal C 'of the projecting core C in which the molten elastomer easily overflows.
By placing the half-ring piece 21 on the top, a coating having a predetermined thickness is obtained, and a gap between the bolt hole 3 ′ and the inner surface of the protruding core C is formed.
By interposing a spacer 22 made of polypropylene or the like having a melting point slightly higher than that of the elastomer, the displacement of the core metal 3 during press molding can be suppressed.

According to the above-described molding method, the pellets 2 arranged in the recesses A 'of the lower mold A are melted, and the bolts of the cored bar 3 are formed around the projecting core C, that is, as shown in a partially cutaway perspective view in FIG. An integral coating is formed on the entire lower surface of the metal core 3 including the inner wall portion of the hole 3 ', and a flat portion 3 "on the upper surface between the bolt holes 3', 3 'of the metal core 3.
Is melted during pressing to form an integral film on the entire upper surface of the core bar 3. When the upper die B is opened, the core bar 3 having the liquid supply port 4 is formed. A flange-shaped diaphragm retainer 1 whose entire outer surface is covered with an elastomer coating 24 is obtained.

(Effects of the Invention) The present invention has the above configuration, and thus has the following effects.

That is, according to the present invention, an integral coating is formed on the lower outer surface of the core metal by pellets of a selected chemical resistant elastomer of the same material as the diaphragm of the membrane filter plate filled in the concave portion of the lower mold for molding. In addition to being able to be formed, an integral coating can be formed on the upper outer surface of the core metal by the elastomer plate-shaped body disposed on the upper surface between the bolt holes of the core metal.

In particular, since a coating having a desired thickness can be formed around the bolt hole where it is difficult to form a coating, the obtained holding member is made of a metal core having high rigidity and mechanical strength, and a resistive material integrally attached to the metal core. Combination with a coating with excellent chemical properties satisfies all the characteristics required for the presser.Even if it digs into the diaphragm and damages it as in the past, it creates a gap due to deformation and leaks liquid. Problems such as arising could be solved.

[Brief description of the drawings]

FIG. 1 is a half perspective view of a lower mold for molding used in the present invention, and FIGS. 2 (a), 2 (b), and 3 (c) show the molding order of the periphery of a bolt hole of a holding tool according to the method of the present invention. Shown in cross section, third
Fig. 4 is a half perspective view of a metal core used in the present invention, Fig. 4 is a perspective view showing a state in which the periphery of a bolt hole of a presser is formed, and Fig. 5 is a plate-like shape arranged on a lower mold. The body is shown in a schematic plan view, and FIG. 6 is a perspective view, partially cut away, of the retainer obtained according to the invention. 1… Holder, 2… Pellets, 21… Half-ring piece, 22…
Spacer, 23 plate-like body, 24 coating, 3 core metal,
3 ': bolt hole, A: lower mold, A': recess, B:
... Upper mold, B '... Through hole, C ... Projecting core

Claims (1)

(57) [Claims] 1. A method of manufacturing a flange-shaped presser for fixing a diaphragm to a filter plate at a peripheral portion of a liquid supply port of a membrane filter plate, comprising: a recess of a lower mold for forming the presser. After filling the polyolefin-based thermoplastic elastomer pellets, a ring-shaped metal core having a hole for loosely fitting into a protruding core disposed at a position corresponding to the bolt hole of the presser is placed on the pellet. Overlay, then, on the flat part between the protruding cores, place a plate-like body of polyolefin-based thermoplastic elastomer sufficient to cover the upper part of the presser, then close the upper mold for molding, and press A method for producing a diaphragm retainer for a membrane filter plate, comprising: