JPH0448816Y2 - - Google Patents

Description

[Detailed explanation of the idea] [Industrial application field] This idea relates to a top plate for a laboratory bench.

[Prior Art] Since laboratory benches are used for various experiments, their top plates are required to be strong and have excellent heat resistance and chemical resistance.

Due to various restrictions on the conditions of use or the location of the laboratory bench, it is generally placed on the top plate A, as shown in Figure 2.
It is manufactured separately into a mounting stand B on which the top plate is placed.
The structure is such that it is fixed to the wooden part of the top plate A from the mounting base B side using wood screws 8, 8, etc. at the installation location.

A wooden plate-shaped core material 5 is used as a conventional top plate for a laboratory bench.
A top plate 6 made by baking inorganic paint on an asbestos cement board at high temperature is placed on top, and a metal or synthetic resin rim that also serves as a decorative plate is placed around the sides of the top plate 6 and the plate-shaped core material 5. There is a structure with 7 attached.

Since this top plate has a structure in which a separate edge 7 is attached to the edge, spilled chemicals, water, etc. may enter through the joint, causing the surface to warp or the internal core material to corrode. As a result, the service life is shortened, so there was an idea to solve this problem by molding the edge part of the top plate integrally with the center part using synthetic resin (for example, a patent application filed by the same applicant (Sho 62-278484).

The synthetic resin integrated top plate based on this concept does not allow spilled chemicals, water, etc. to enter through the edges of the conventional top plate, causing the surface to warp or the interior to corrode, and therefore has a long service life. Although it has the advantages of
In order to make it possible to attach the synthetic resin-integrated top plate to the mounting stand B at the installation location, it is necessary to fit a wooden core into the back of the synthetic resin-integrated top plate.

[Problem that the invention aims to solve] The work of fitting a wooden core to the back of a synthetic resin-integrated top plate is a very troublesome and inefficient work when carried out on-site.

Therefore, when creating a synthetic resin-integrated top plate, the inventors came up with the idea of molding a wooden core at the same time and making it into one piece, and they have conducted extensive experiments and studies.

Initially, when a plate-shaped core material is inserted as a core and its top and side surfaces are molded with synthetic resin to make it an integral piece, the thermal expansion and contraction of the synthetic resin and the thermal expansion and contraction of the plate-shaped core material during the molding process. I encountered a problem where a crack occurred due to the difference.

The purpose of this invention is to create a structure that prevents spilled chemicals, water, etc. from entering the inside by molding the edge part of the top plate integrally with the center part using synthetic resin, and then inserting a plate-shaped core material into the edge part of the top plate. To provide a top plate for a laboratory bench which does not cause cracks in the molded resin when it is integrally formed by inserting it as a core and molding its top and side surfaces with synthetic resin.

[Means for solving the problem] In order to facilitate the work of attaching the top plate to the stand, this invention uses a plate-shaped core material that can be easily fixed using wood screws etc. on the inside of the bottom surface of the top plate. .

In addition, in order to prevent the mold resin from cracking during the resin molding process, the sides of the plate-shaped core material are covered with elastic members to alleviate the difference between the expansion and contraction of the synthetic resin and the wooden framework during synthetic resin molding. I decided to let them do it.

Furthermore, in order to improve adhesion by the outer mold resin layer, the upper surface of the plate-shaped core material and the peripheral side surface of the elastic member are covered with an air-impermeable member.

[Function] By providing an elastic member around the side surface of the plate-shaped core material, the difference between the thermal expansion and contraction of the synthetic resin during synthetic resin molding and the thermal expansion and contraction of the wooden framework can be alleviated, and the occurrence of cracks in the molded resin can be prevented. can.

After the synthetic resin mold layer is formed on the outside,
The plate-shaped core material is compressed and fixed in a predetermined position by the compressive force of the elastic member due to contraction during formation of the mold resin layer.

By covering the top surface of the plate-shaped core material and the outer circumferential side surface of the elastic member with an air-impermeable material, it is possible to prevent moisture, gas, etc. generated from the plate-shaped core material from entering the mold resin during resin molding, and to prevent molding. It can prevent the generation of bubbles in the resin and prevent the adhesive strength of the mold resin from decreasing.

[Example] Next, an example of this invention will be described.

Plywood 1 cut into predetermined dimensions is used as a plate-shaped core material.

In addition to the above-mentioned plywood, the plate-shaped core material may be any other material as long as it has a surface at least on the upper and peripheral parts excluding the lower part, is plate-shaped as a whole, and can be screwed with wood screws etc. For example, a plate-shaped core material made of foam may be used, and the material thereof is not particularly limited.

An elastic member is attached to the peripheral side of the plywood 1, for example, with a foaming rate.
It is wrapped with 50% ethylene fluoropylene terpolymer 2 (hereinafter abbreviated as EPT).

In addition to the above-mentioned EPT with a foaming rate of 50%, the elastic member is
It has an elastic modulus lower than that of the mold resin when molded with synthetic resin, and can withstand heating temperatures (approximately 150℃).
The material may be any material as long as it has low penetration of synthetic resin during molding, such as an elastic member made of silicone rubber with a foaming rate of 20 to 80%, an elastic member made of rubber-modified foamed epoxy resin, etc., and the material is not particularly limited. It's not a thing.

Wrap it around the circumferential side of this plywood 1 with a foaming rate of 50%.
An air-impermeable member, such as an aluminum thin plate 3, is attached to cover the outer peripheral surface of the EPT 2 and the upper surface of the plywood 1.

The air-impermeable member may be any material other than the aluminum thin plate described above, as long as it does not allow gas to pass therethrough and can withstand the heating temperature during synthetic resin molding, and is not particularly limited.

Next, the plywood 1 covered with the aluminum thin plate 4 is
The process of molding the upper surface part and the peripheral side part with synthetic resin will be explained.

First, EPT with a foaming rate of 50% is wrapped around the circumference of plywood around the lower surface of the upper die of a mold, and the outer circumference of the EPT and the top of the plywood are covered with a thin aluminum plate and temporarily fixed. Next, the upper mold is fitted to a lower mold having an inner peripheral surface larger than the outer surface of the plywood, which is covered with a thin aluminum plate temporarily fixed to the lower surface of the upper mold, and the plywood, etc. is housed in the upper mold and the lower mold, and the A liquid synthetic resin having high strength, heat resistance, and chemical resistance, such as an epoxy resin for molding, is injected into the mold, and the synthetic resin liquid is hardened. Then,
The upper surface and peripheral side surface of the plywood covered with the thin aluminum plate are firmly adhered with epoxy resin, and a mold layer 4 of a predetermined shape of epoxy resin is formed around the plywood. This can be taken out from the mold and subjected to finishing processing if necessary to obtain a top plate for a laboratory bench.

In addition to the above-mentioned epoxy resin for molding, synthetic resins with high strength, heat resistance, and chemical resistance include polyester resins, urethane resins, acrylic resins, etc., and these resins can be used by adding fillers as appropriate. be able to.

In the molding process of the epoxy resin mentioned above, the sum of the linear expansion and contraction rate when the epoxy resin is cured and the linear expansion and contraction rate when it is cooled to room temperature is about 0.3 to
The distortion caused by this shrinkage is alleviated by the EPT 2 with a foaming rate of 50% wrapped around the circumferential side of the plywood, so that no cracks occur in the epoxy resin mold layer 4. The shrinkage force generated in the process of forming mold layer 4 with epoxy resin is the foaming rate.
Since 50% of the EPT 2 is elastically contracted and the elastic compressive force is applied to the plywood 1, the plywood 1 is crimped and fixed in a predetermined position.

In addition, when curing the above epoxy resin, the temperature is approximately 150°C.
When the temperature rises to a certain extent, the wooden framework will absorb more moisture,
Although gases are emitted, this moisture and gas are blocked by the aluminum thin plate and do not flow into the epoxy resin mold layer, which prevents deterioration of the adhesion between the epoxy resin and the aluminum thin plate, and the whole is firmly bonded and integrated. It becomes a top plate.

[Effects of the invention] As described above, the top plate for a laboratory bench according to this invention is easy to install on-site, does not cause cracks on the surface, has high strength, and has excellent heat resistance and chemical resistance. There is no need to worry about spilled chemicals, water, etc. getting inside.

[Brief explanation of the drawing]

FIG. 1 is a perspective sectional view illustrating an embodiment of this invention, and FIG. 2 is a sectional view illustrating a conventional example. A...Top plate part, B...Base part, 1, 5...Plywood respectively, 2...Wrapped EPT with a foaming rate of 50%, 3
... Aluminum thin plate, 4 ... Epoxy resin mold layer, 6 ... Surface plate, 7 ... Edge, 8 ... Wood screw.

Claims (1)

[Scope of utility model registration request] By covering the sides of the plate-shaped core material with an elastic member, and further covering the top surface and the outer peripheral side surface of the elastic member with an air-impermeable material, the area around the top surface and side surface has high strength, heat resistance, and chemical resistance. A top plate for a laboratory table, characterized by being molded from a synthetic resin having the following characteristics.