JPH0353874Y2 - - Google Patents

Description

[Detailed explanation of the idea]

INDUSTRIAL APPLICATION FIELD The present invention relates to a thermocompression molded product of polyurethane foam. Conventional technology Conventionally, thermocompression molding of polyurethane foam
Polyurethane foam was cut into a plate shape suitable for molding, placed between two molds, and compressed by both molds for hot compression molding. For example, when manufacturing a sun visor for a car, prepare two pieces of urethane foam cut to 40 mm x 150 mm x 450 mm, and heat compression mold them using a pair of molds for the first piece and the second piece. The resulting pieces were put together, a bone frame was sandwiched in the middle, a rotating bearing was inserted into the upper side, the pieces were glued together, and a cloth or vinyl chloride sheet was covered to make the product. Problems to be Solved However, after compression molding urethane foam with a mold, when the molded product is taken out, its dimensions are 5 to 5.
Because it would shrink by 10%, it was necessary to make the mold larger in advance. In addition, the degree of contraction varies depending on the degree of compression. For example, if the structure is complicated and the degree of compression is increased partially, such as by creating a recess for inserting a mirror in the sun visor, the degree of contraction will vary depending on the degree of compression. It changed in different directions, and when the two pieces were put together after molding, there was a drawback that the sizes did not match. It is best to predict the degree of shrinkage in advance and create a mold, but if the structure of the molded product becomes complex,
It was difficult to predict the shrinkage rate in each direction, so it was necessary to create a mold based on a certain degree of prediction, and then modify the mold while examining the size of the molded product through trial molding. The inventors of the present invention have developed a urethane foam that reduces the shrinkage rate of the urethane foam by compression molding, so that even if the structure of the molded product becomes complex, the difference in shrinkage rate in each direction is small and there is no need to modify the mold. They developed a foam molded product. Solution: A reinforcing material made of perforated metal sheet, wire mesh, or inorganic fiber is sandwiched between polyurethane foam.
This is a polyurethane foam molded product molded by heat compression. Polyurethane foam is made of known polyols,
It is obtained by foam molding using polyisocyanate as the main raw material, using a catalyst, a blowing agent, and adding other additives as necessary. The reinforcing material preferably has a gap that allows the polyurethane foam present on both sides to adhere to each other during hot compression molding. Examples of materials with gaps include perforated metal sheets, wire meshes, meshes made of inorganic fibers, and open nonwoven fabrics. There are no particular restrictions on the metal, and iron, copper, aluminum, stainless steel, etc. can all be used. These reinforcing materials are sandwiched with flexible or semi-rigid polyurethane foam cut into plates, sandwiched between two molds heated with heaters, and compressed and hot-pressed to the desired thickness. In this way, a molded product of urethane foam with a reinforcing material present in between and a surface shape whose openings become smaller in accordance with the shape of the mold can be obtained. If additional adhesion between polyurethane foams and between reinforcements is required. It is desirable to apply an adhesive to the surface of the polyurethane foam or to the surface of the reinforcement. Effects By using the reinforcing material, shrinkage in the direction of the insertion surface of the reinforcing material can be almost eliminated, and there is no need to estimate the shrinkage in each direction and manufacture the mold. The use of reinforcement also increases the stiffness of the polyurethane foam and also makes it possible to omit a frame inserted around the periphery of the sun visor. The thermocompression molded polyurethane foam products of the present invention are not only used for sun visors, but also for bra parts, health sheets, etc.
It can also be applied to products that have traditionally been thermoformed, such as knee pads.

【table】

[Table] Example Polyurethane foam obtained according to the formulation in Table 1.
They were cut to 20 mm x 180 mm x 480 mm, and two pieces of each were prepared. Between these two polyurethane foams 1 and 2
A nonwoven fabric 3 made by aligning 200Tex glass fiber multifilaments vertically (4 pieces) and horizontally (2 pieces) and bonding them at the intersections is put in, compression molded in a mold heated to a surface temperature of 200 degrees, and after cooling, the surrounding burrs are removed. After removing it, its dimensions were measured. Formulation a and formulation b had the same dimensions after cooling. The results are shown in Table 2. Comparative example The polyurethane foam used in the example was
One piece cut to 180 mm x 480 mm was molded in the same manner as in the example except that no reinforcing material was used, and its dimensions were measured. Formulation a and formulation b had the same dimensions after cooling. The results are shown in Table 2.

【table】 [Brief explanation of the drawing]

FIG. 1 is a sectional view and a plan view of a polyurethane foam molded product produced in this example. A to K indicate the dimensions of each part, 1, 2...polyurethane foam, 3... reinforcing material.

Claims (1)

[Claims for Utility Model Registration] 1. A polyurethane foam molded product formed by heat compression with a reinforcing material made of a perforated metal sheet, wire mesh, or inorganic fiber sandwiched between polyurethane foams. 2. The molded article according to item 1, wherein the polyurethane foams and/or the polyurethane and the reinforcing material are bonded with an adhesive.