JPS61193835A - Method of loading foamable thermoplastic resin particle - Google Patents

Abstract

PURPOSE:To loading a cavity uniformly and completely with raw material particles, by clamping a stationary mold and a movable mold having an assistant mold that can be moved forward and backward, and filling a cavity that is being expanded by the backward movement of the assistant mold with foamable thermopolastic resin particles. CONSTITUTION:After a stationary mold 1 and a movable mold 2 are clamped together, a first assistant mold 3 and a second assistant mold 4 are arranged as shown, and when raw material particles are loaded from a loading machine together with air, the air is discharged through sliding surfaces between the movable mold 2 and the first assistant mold 3 and sliding surfaces between the first assistant mold 3 and the second assistant mold 4, and the cavity 6 is filled uniformly with the raw material particles. Then the second assistant mold is kept fixed, and the first assistant mold 3 is retracted to suck the raw material particles. Thereafter, when the retraction of the first assistant mold 3 is topped and at the same time the filling of the raw material articles is stopped, the filling of the expanding cavity with the raw material particles is completed.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention is a method of filling a mold for foam molding with expandable thermoplastic resin particles or pre-expanded particles obtained by pre-expanding the particles (hereinafter referred to as raw material particles). This relates to a method for manufacturing cylindrical shaped bodies, pillar shaped bodies, pot-shaped partially hollow molded bodies, etc. (prior art) Conventional 1 Molding a foamed body in a foam molding mold As a method of filling raw material particles for molding, a fixed mold and a movable mold are not brought into close contact with each other, a certain gap (for example, 2 to 3 mm) is provided, and the raw material particles are filled into the cavity together with air. (For example, Japanese Patent Application Laid-Open No. 49-66765).

(Problems to be Solved by the Invention) Although air circulation is good in the conventional method, when molding a complex shape, there is a problem that the raw material particles cannot be uniformly and completely filled in each part inside the cavity. .

Therefore, one problem that the present invention aims to solve is to uniformly and completely fill the raw material particles into the cavity.

(Means for solving the problem) After clamping a fixed mold and a movable mold equipped with an auxiliary mold that can freely move forward and backward, raw material particles are filled into the cavity that is expanding due to the retreat of the auxiliary mold. be.

(effect) The above means works as follows.

The raw material particles continue to be filled into the cavity that is being expanded by the retreat of the auxiliary mold, and then the filling of the raw material particles is completed as the auxiliary mold stops retreating (Example) Examples of the present invention will be described below. The explanation will be based on the drawings shown.

The drawing shows a mold for foam molding used in the present invention, which consists of a fixed mold 1, a movable mold 2, and a first auxiliary mold 3 and a second auxiliary mold 4, which are attached to the movable mold 2 and can move forward and backward. A filler 5 communicating with a raw material hopper (not shown) is attached to the mold 1, and the first auxiliary mold 3 and the second auxiliary mold 4 are moved back to fill the molded cavity 6 with raw material particles (not shown). It can be filled.

Between the sliding surfaces of the movable mold 2 and the first auxiliary mold 3, there is a 3 to 30)L
A gap of m is formed, which allows air to pass freely through the gap, but does not allow raw material particles (not shown) to pass through.

After clamping the fixed mold 1 and the movable mold 2, the first auxiliary mold 3 and the second auxiliary mold 4 are arranged as shown in the drawing, and the filling machine 5 is placed.
When more raw material particles (not shown) are filled with air,
Air is discharged from the gap between the sliding surfaces of the movable mold 2 and the first auxiliary mold 3 and between the sliding surfaces of the first auxiliary mold 3 and the second auxiliary mold 4, and the raw material particles (not shown) are After uniformly filling the cavity 6, the second auxiliary mold 4 is held fixed, and the raw material particles (not shown) are sucked and filled while the first auxiliary mold 3 is moved back. Thereafter, when the filling of the raw material particles (not shown) is stopped as the first auxiliary mold 3 stops retracting, the filling of the raw material particles (not shown) into the expanding cavity is completed.

Next, a specific example will be explained in detail.

Using the foam molding mold for forming the hollow molded body shown in the drawing, the cavity 6 is filled with pre-expanded polystyrene particles having a pre-expanded particle density of 0.02 g/ce, and then the second auxiliary mold 4 is used. When the pre-expanded polystyrene particles were suctioned and filled into the expanding cavity while the first auxiliary mold 3 was moved back 200 m at a rate of 10 III/sec, the pre-expanded particles were uniformly and completely filled. A partially hollow molded product in the shape of a pot was molded.

(Effect of the invention) The present invention produces the following effects.

Since the raw material particles are filled while retracting the auxiliary mold, there is no possibility that the raw material particles are filled too much or too little.
A cylindrical or columnar cavity having an arbitrary length can be uniformly and completely filled with raw material particles.

[Brief explanation of the drawing]

The drawing is a sectional view of a foam molding die used in the present invention. 1... Fixed type 2... Mobile type 3... First auxiliary type 4... Second auxiliary type

Claims (1)

[Claims] After the fixed mold and the movable mold equipped with an auxiliary mold that can move forward and backward are clamped, expandable thermoplastic resin particles or pre-expanded particles obtained by pre-foaming the particles are placed in the cavity which is being expanded by the retreat of the auxiliary mold. A method for filling expandable thermoplastic resin particles, characterized by filling the particles with.