JPH044110A - Prevention of ooze of foamed resin in mold - Google Patents

Abstract

PURPOSE:To reduce the oozing part of foamed resin and obviate the finishing process of final product by securing a thin metal piece plate with elasticity at a constant width to the proximity of the oozing entrance part of an upper mold or a lower mold such that the oozing entrance part is covered completely. CONSTITUTION:Immediately under the tip-end line periphery of a lower mold in the oozing part 3 of the lower mold of a mold comprising an upper mold 1 and a lower mold 2, a metal strip-shaped thin mold plate 4A is secured as a thin metal mold plate 4 by a vis 5. The location of the vis is made right under 0.5 - 1 cm of the tip-end line periphery of the lower mold and vis holes are made at every interval of 2 - 5 cm. The constant width of entire covering of a oozing entrance part in the whole mold circumference of the thin metal mold plate is 2 - 20 mm. And, the thickness of the thin metal mold plate is preferably 0.1 - 1 mm should it be elastic. For the thin metal piece plate, any one of aluminum foil, iron plate, and copper plate can be available and it should be durable for a long period use.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for producing molded products by injecting a synthetic resin mixture into a mold.

[Conventional technology]

Conventionally, the protruding parts of the upper and lower molds were designed to fit together as precisely as possible. If this is not sufficient, the fitting part between the upper and lower molds can be made uneven or have peaks and valleys to reduce protrusion.

[Problem that the invention seeks to solve]

Traditionally, molds used to manufacture foamed products have gradually become looser at the fitting between the upper and lower molds due to the foaming pressure of the synthetic resin mixture, resulting in poor dimensional accuracy of the final product. (the thickness of the material becomes thicker), the number of exposed areas increases, and the loss of raw materials also increases. Apart from this, cavities and electrical equipment may be formed around the protruding parts of the product, causing defects. In addition, the additional step of cutting the protruding portion using scissors or the like in the final finishing process adds a negative factor of increased cost.

The inventor attempts to solve the above problems.

■Ensure the accuracy of the fitting part.

■Minimize the protruding part as much as possible.

■Eliminating the finishing process of the final product.

[Means for Solving the Problem] The inventor has arrived at the present invention as a result of intensive research into minimizing the protruding portion generated from the fitting portion between the upper mold and the lower mold.

That is, the content of the present invention is a method for producing a predetermined foam product by injecting a synthetic resin mixture into a mold consisting of an upper mold and a lower mold. Place an elastic thin metal plate around the mold clamping part of the resin protrusion part or the inlet entrance part to cover the entire surface of the inlet part with a constant width so that the inlet part of the resin part is completely covered. Due to the tightening of the upper mold to the lower mold and the foaming pressure of the synthetic resin mixture, the thin metal plate comes into close contact with the clamping part or fitting part of the mold at the protruding part, and the synthetic resin mixture It is characterized in that the liquid does not come out from the protruding part. This is a method for preventing foamed resin extrusion from molds, and more specifically, the fastening section of the upper mold or lower mold is fixed so that the extrusion entrance part is completely covered with a constant width over the entire surface of the extrusion entrance part. Alternatively, a method for removing a foamed resin from a mold is characterized in that a notch or a triangular section is provided at a portion of a thin metal plate fixed around an entrance for inserting a metal mold into pressure contact with a curved surface of the mold.

Apart from the above-mentioned method, there is a method of fixing a thin metal plate to the fastening/fitting part of the upper mold or the lower mold, and a method of fastening/fitting the upper mold and the lower mold.
The present invention also includes a method of preventing the synthetic resin mixture from flowing out from the bulging part by pressing the tip of the thin metal plate against the fitting part with the edge of the contact line of the tip of the upper mold and the lower mold.

[Embodiment]

The details of the present invention will be explained with reference to the drawings.

FIG. 1 is a schematic cross-sectional view for explaining the present invention, showing a lower mold tip edge (not shown) of a protruding portion 3 of a lower mold of a mold consisting of an upper mold 1 and a lower mold 2. A state in which a thin metal strip plate 4A as a thin metal plate 4 is fixed directly below with screws 5 is shown. The position of the screw is 0.5 to 1 cm directly below the tip line edge of the lower mold.
m, drill screw holes 5 every 2 to 5 cm. The fixed width of the entire surface covering the inlet of the metal thin plate around the mold is 2.
~20mm.

Further, the thickness of the thin metal plate is preferably 0.1 to 1 mm as long as it is elastic. The thin metal plate may be aluminum foil, iron plate, or copper plate, as long as it can withstand long-term use (approximately 1,000 times).

FIG. 2 is a partially enlarged cross-sectional view of the fitting part of the upper mold 1 and lower mold 2 of the mold, and shows a state in which an L-shaped strip metal thin plate 4B is fixed to the lower mold fastening part 2A with screws 5. . The angle of inclination (not shown) of the L-shaped strip-shaped metal thin plate covering portion 4C of the cut-out entrance portion is set so as to be in close contact with the maximum width when the upper mold and the lower mold are finished fitting. In other words, the inner angles of the L-shaped thin metal strip are made obtuse angles so that the covering portion of the protruding portion of the thin metal plate is not crushed when the upper mold is fastened to the lower mold.

FIG. 3 is a partially enlarged sectional view showing the state when the upper mold and the lower mold are fitted, and as the width of the thin metal plate fitting contact surface IB of the upper mold increases, the thickness of the thin metal plate increases. The illustration shows that the entrance/exit portion covering portion 4C is elastically expanded and both are in close contact with each other. The tight contact between the metal thin plate fitting contact surface and the metal extrusion inlet covering portion prevents the synthetic resin foaming liquid from flowing out.

FIG. 4 is a partially enlarged sectional view showing the fitting of the upper mold and the lower mold.
An L-shaped strip metal thin plate 4B is screwed to the fastening part IA of the upper die 1, and the metal thin plate has an opening covering part 4C.
The inner angle of is an obtuse angle and is pressed and expanded in advance so as not to be crushed by the fastening portion 2A of the lower mold. The synthetic resin mixture is prevented from being dispensed by the tight fit between the thin metal plate insert/exit O portion covering portion and the lower die metal thin plate fitting contact surface.

FIG. 5 is a partially enlarged cross-sectional view showing the fitting of the upper mold and the lower mold, and the metal strip-like thin plate 4A is at the tip of the lower mold @ directly below the kneading edge 6B.
It is screwed at ~5mm.

FIG. 6 is a partially enlarged cross-sectional view showing the fastening and fitting of the metal band-like thin plate 4A screwed directly below the tip edge of the upper mold and the lower mold. The synthetic resin mixture is prevented from overflowing by the tight fit between the thin metal strip plate and the fitting contact surface IB of the upper metal thin plate.

FIG. 7 is a partially enlarged cross-sectional view showing a fitted state of the metal strip-like thin plate 4A screwed directly above the tip line edge 6A of the lower mold and the upper mold. The metal strip plate may be attached to either the upper mold or the lower mold, depending on the shape of the mold, and is fitted tightly to prevent release.

FIGS. 8 and 9 are partially enlarged cross-sectional views showing the state of fastening of the fastening part covering thin metal strip plate 4E screwed to the innermost parts of the fastening parts of the upper mold and the lower mold. .

Similarly, Fig. 10 shows a screw secured to the flat front of the protruding part of the clamping part 2A of the lower mold, and Fig. 11 shows a screw secured to the innermost part of the clamping part IA of the upper mold. FIG. 12 is a partially enlarged new view showing the fastening of the thin aluminum strip plate 4E for covering the fastening part with screws to the flat front of the protruding part of the fastening part IA of the upper mold. The prevention of leakage using the thin metal plate fixed to the fastening portions of the upper mold and the lower mold is suitable for preventing leakage when the fastening portions of the upper mold and the lower mold are flat plates.

In FIGS. 13 and 14, the upper mold fastening part and the lower mold fastening part are not in close contact with each other over the entire surface, but the upper mold tip contact line edge 6A
This is a partial enlarged sectional view of the method of fastening with the edge of the lower mold tip contact line edge 6B, showing the fastening part IA of the upper mold and the fastening part 2A of the lower mold.
The tip of each thin metal strip plate (tip line edge) 4D is tightened around the mold to prevent the synthetic resin mixture from spilling out. In this case, the thin metal strip plate 4A screwed to the upper die and the thin metal strip plate 4A screwed to the lower die are fastened and overlapped by the tip contact line edges 6A and 6B. Due to linear adhesion due to the elasticity of thin metal plates,
Prevents the release of I@mixed liquid made from synthetic resin. The tip 4D of the thin metal strip plate 4A is the tip contact line of the mold! 6A, 6B
It is designed to penetrate further into the synthetic resin foam 8 (not shown) by 1 to 10 mm.

Fig. 15 is a partially enlarged sectional view of the case where the entrance of the protruding part 3 is added around the product in the shape of a triangular prism, and shows the tips of the protruding parts of the fastening parts IA and 2A of the upper and lower dies. The tip has a slanted part (not shown) and is machined by cutting 5 to 10 mm so that a small screw can be secured thereto. Metal strip-shaped thin plate 4
From the center to the tip of A, the upper and lower molds come into close contact when they are fastened, preventing the synthetic resin foaming liquid from flowing out.

FIG. 16 is a partially enlarged cross-sectional view for explaining the present invention in detail, using a thin metal strip plate 4A screwed directly under the tip line edge 6B of the lower mold, in which the liquid synthetic resin mixture is While foaming, the gas 7 is applied to the covered portion 4C of the exposed portion of the thin metal plate.
and the thin metal plate fitting contact surface IB of the upper die 1. The synthetic wood WI mixture foams and fills the space between the upper mold 1 and the lower mold 2, but does not come out together with the gas. Therefore, hollowing and cracking of the product can be prevented.

Figure @11 is a partially enlarged cross-sectional view showing correction using the hammer 9 when the inclination of the thin metal plate protrusion covering portion 4C becomes gentle and the protrusion becomes incompletely covered. The present invention aims at long-term use (approximately 1.000 times) by utilizing the elasticity and reversibility of the thin metal plate 4, and long-term use is possible by correcting it with a hammer.

FIGS. 18, 19, and 20 are partially enlarged cross-sectional views showing the mold shape adaptability of the L-shaped metal thin plate 4B.
Figure 18 shows a triangular thin metal plate notch 11 provided in the metal thin plate fixing part 4F, and Figure 3119 shows a metal thin plate triangular section 12 provided in the metal thin plate protrusion covering part 4C.
FIG. 20 shows the cut portion (not shown) of the triangular section 12 of the thin metal plate fixed with adhesive. The metal thin plate conforms to the curved surface inside the mold, cuts or triangular sections are cut as necessary, and adhesive is used to prevent spillage.

Note that a soft polyurethane resin is mainly used as the synthetic tree W mixed solution. The synthetic resin mixture is injected into the mold from a stirrer, becomes a foaming liquid after about 10 seconds, and is fixed as a foam in 1 to 2 minutes.

〔effect〕

When products were foamed with a urethane resin mixture using the L-shaped metal flake plate 4B according to the present invention, the number of defective products was reduced to less than 1/7 of 9111, with 5 out of 100 products being defective. In addition, the product's cracks and air pockets may be destroyed.
. ■Hardened core does not come out. ■An additional effect was that there was no need for edge cutting, and the additional effect of the thin metal plate was that ■if it was deformed beyond its plastic limit, it could be returned to its original shape with a hammer or the like.

[Brief explanation of drawings]

FIG. 11 is a schematic sectional view for explaining the present invention. 4! FIG. J2 and FIG. 3 are partially enlarged cross-sectional views showing the covering of the inlet of the L-shaped band-shaped thin metal plate fixed to the lower mold fastening part. FIG. 4 is a partially enlarged cross-sectional view showing the covering of the protruding entrance portion of the L-shaped thin metal plate fixed to the upper mold fastening portion. FIGS. 5 and 6 are partially enlarged cross-sectional views showing the covering of the protruding entrance portion of the thin metal strip plate fixed directly below the leading edge of the lower mold. FIG. 7 is a partially enlarged cross-sectional view showing the covering of the inlet portion of the aluminum band-shaped sheet plate fixed above the upper mold tip line. Figures w8 and 9 are partially enlarged cross-sectional views showing the covering of the upper and lower mold fastening parts by the thin metal strip plate fixed to the lower mold fastening part. Figure 1 O, Figure 11 and! ! Figure 1.2 is a partially enlarged cross-sectional view showing the covering of the upper and lower mold fastening parts by the thin metal strip plate fixed to the upper mold or lower mold fastening parts. Figures 13 and 14 show that the upper and lower molds are not fastened by surfaces, but by the elasticity of the upper mold tip contact line edge, the lower mold tip contact line edge, and the metal strip-like thin plate plates fixed to the upper and lower molds. FIG. 3 is a partially enlarged cross-sectional view showing prevention of dissipation and overflow of the synthetic resin mixture. FIG. 15 is a partially enlarged cross-sectional view showing a fastening portion covering of a thin metal band plate fixed to the oblique portions of the upper mold and the lower mold when the entrance of the protruding portion is added in the shape of a triangular prism around the product. FIG. 16 is a partially enlarged sectional view showing gas dissipation and prevention of overflow of synthetic resin mixture according to the present invention. FIG. 17 is a partially enlarged cross-sectional view showing a method of correcting the covered portion of the thin metal plate. FIGS. 18, 19, and 20 are partially enlarged cross-sectional views showing a method of imparting adaptability to the shape of a mold to an L-shaped strip-shaped thin metal plate. 1. Upper mold LA, upper mold fastening part 1B, upper mold thin metal plate fitting contact surface 2, lower mold 2A, upper mold fastening part 2B, lower mold metal 1 piece plate fitting contact surface 3, protrusion part 4. Metal thin flake plate 4^, Metal thin flake plate Academic information Metal thin flake plate Metal thin flake plate Extrusion entrance part Covering part Metal strip shaped thin plate plate Tip part Fastening part Covering metal strip thin flake plate Metal thin flake plate Fixing part Metal thin plate Fixed screw upper mold tip contact line edge Lower mold tip contact line edge Foamed gas synthetic resin foam (foam) Hammer Screw hole in thin metal plate Notch in thin metal plate Triangular section of metal thin plate Mold

Claims (4)

[Claims] (1) In a method for producing a specified foam product by injecting a synthetic resin mixture into a mold consisting of an upper mold and a lower mold, the protruding portion of the synthetic foam resin in at least one of the upper mold and the lower mold An elastic thin metal plate is fixed to the mold clamping part or around the upper mold inlet in a constant width over the entire surface of the upper mold part, so that the upper mold part is completely covered. The foamed resin of the mold is characterized in that the thin metal plate is brought into close contact with the protruding part by tightening to the lower mold and the foaming pressure of the synthetic resin mixture, so that the synthetic resin mixture does not overflow from the protruding part. How to prevent bulging. (2) The fastening part of the upper mold or the lower mold, so that the upper mold and the lower mold are fastened and fitted, so that the entire peripheral surface of the fitted protrusion part is completely covered with a constant width at the protrusion entrance part; Or, the foamed resin extrusion of a mold according to claim 1, characterized in that a cut or a triangular section is provided at the part of the metal thin piece fixed around the extrusion inlet and pressed against the curved surface of the mold. How to prevent it. (3) Claim 1, characterized in that a thin metal plate is fixed to the fastening/fitting part of the upper mold or the lower mold to prevent the synthetic resin mixture from overflowing from the protruding part. Method for preventing extrusion of foamed resin from a mold as described in Section 2. (4) By pressing the tips of the two thin metal plates fixed to the fastening/fitting parts of the upper and lower molds with the contact line edges of the upper and lower molds, the synthetic resin mixture is A method for preventing foamed resin from extruding from a mold according to claim 1, characterized in that overflowing from an extruding portion is prevented.