JPH0529723U - Mold - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a mold capable of obtaining a molded product having a predetermined function in addition to the original performance of plastics without impairing the original performance of plastic and without increasing the manufacturing cost. The purpose is to. [Structure] At least a part of an inner peripheral surface of a molten resin flow path from a sprue to a cavity is formed by a porous sintered metal having desired fine pores, and a liquid path serving as a flow path for a desired liquid agent is provided inside a mold. It is provided such that the sintered metal and the outside of the mold are communicated with each other through this liquid path.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a mold used for injection molding a plastic molded product.

[0002]

[Prior Art]

 Plastic materials are used in various fields due to their excellent corrosion resistance and moldability, but depending on the application, in addition to the original performance of plastic materials, mold resistance, antistatic properties, and UV removal properties are also present. In some cases, such functions and coloring may be required.

Therefore, a mixed raw material is prepared in which a liquid material such as a mildew proofing agent, an antistatic agent, an ultraviolet absorber, and a coloring agent is mixed in advance with a plastic raw material as a main raw material, and the mixed raw material is molded into a desired shape. By such a manufacturing method, a molded product having a desired function added to the original performance of plastic is obtained.

[0004]

[Problems to be solved by the device]

 These liquid agents are relatively expensive, and generally, if they exist only in the surface layer portion of the molded product, they can fully exert their functions. It is included in the whole. Therefore, the cost of the molded product becomes very high, and by mixing these liquid agents, the physical properties inherent to the plastic may be impaired.

In view of such circumstances, the present invention provides a molded product having a predetermined function in addition to the original performance of the plastic, without impairing the original performance of the plastic and without increasing the manufacturing cost. The purpose is to provide a mold that can

[0006]

[Means for Solving the Problems]

 In order to achieve such an object, the mold according to the present invention forms at least a part of the inner peripheral surface of the molten resin flow path from the sprue to the cavity with a porous sintered metal having desired fine pores. A liquid passage serving as a flow passage for a desired liquid agent is provided inside the die, and the sintered metal and the outside of the die are communicated with each other through the liquid passage.

Not only the fixed mold side provided with the sprue but also a part of the inner wall surface of the core of the movable mold (particularly the part facing the gate) is formed of a sintered metal, and this sintered metal is also formed. You may make it the structure which connects a liquid path. The sintered metal used in the present invention is not particularly limited, but examples thereof include iron type and stainless type. The diameter of the fine holes is preferably about 5 to 200 μm.

It is preferable that the liquid agent is supplied in a constant amount in conjunction with the timing of injection of the molten raw material by interlocking a pressure pump (liquid agent pump) with a molding machine stroke.

[0009]

[Action]

 According to the above configuration, after the fixed mold and the movable mold are combined in the same manner as in the conventional injection molding, the desired plastic molten raw material is injected into the cavity through the sprue and, at the same time, the desired function is imparted. The possible liquid agent is sent to the liquid path by the pressure of the pump. The liquid agent reaching the end of the liquid passage is blocked by the sintered metal, but since the sintered metal is porous, it oozes out from the liquid passage side to the resin flow passage side through the fine pores in the sintered metal. Then, the exuded liquid agent is supplied from the spool into the cavity so as to surround the molten raw material. The molten resin injected into the cavity together with the liquid agent is filled in the cavity in a state where the liquid agent is distributed only near the surface due to its fluidity. Therefore, the obtained molded product has the desired liquid agent distributed only in the surface layer.

[0010]

【Example】

 Hereinafter, the present invention will be described in detail with reference to the drawings showing an embodiment thereof. FIG. 1 shows a cross section of one embodiment of a mold according to the present invention as seen from the side. As shown in the figure, this mold 1 is formed by combining a sprue 2 provided on a fixed mold 1a with a sprue bush 3 and a sintered metal ring 4 provided so as to abut on the tip thereof. Has been done. In addition, a sintered metal plate 6 is fitted into a core portion 1c of the moving mold (core mold) 1b which faces the cavity 5. Liquid paths 7 and 8 are connected to the sintered metal ring 4 and the sintered metal plate 6, respectively. The liquid paths 7 and 8 pass through the inside of the fixed mold 1a or the moving mold 1b, respectively, and the other ends thereof face the outside.

In the figure, 9 is a locate ring, 10 is an air supply passage, 11 is an O-ring, 12 is a fixed side mounting plate, 13 is a moving side mounting plate, and 14 is a parting line. The mold 1 is configured as described above, and a molded product 15 having a desired function can be obtained as follows. That is, first, similar to normal injection molding, the molten resin is injected into the cavity 5 through the sprue 2, and in conjunction with this, the desired liquid agent is supplied from the liquid agent pump (not shown) to the liquid passages 7 and 8. Through the sintered metal ring 4 and the sintered metal plate 6.

The liquid agent sent to the sintered metal ring 4 exudes through the fine holes to the sprue 2 side, and the liquid agent sent to the sintered metal plate 6 exudes into the cavity 5 and melts. A certain amount is filled in the cavity 5 together with the resin. Then, after separating the movable mold 1b from the fixed mold 1a, compressed air is supplied to the air supply passage 10 by a compressor (not shown) or the like, and the molded product 15 is removed from the movable mold 1b by the air pressure. A molded product (a container in this embodiment) 15 is completed by. Although not shown, the core portion 1c of the air supply passage 10 is provided with an air valve or an air slit so that the resin injected into the cavity 5 does not flow into the air supply passage 10.

In the obtained molded product 15, the liquid agent is distributed in the cavity 5 only in the vicinity of the surface of the molten resin due to the fluidity of the molten resin. Therefore, the molded product 15 is composed only of plastic excluding its surface layer, and the original physical properties of the plastic are secured. Moreover, the effect of the liquid agent is fully exerted.

The mold according to the present invention is not limited to the above embodiment. For example, in the above-mentioned embodiment, the mold for obtaining a single molded product was used, but the structure as described above can be applied to a mold for multiple production. Further, in that case, the peripheral wall of the runner portion may be formed of sintered metal.

[0015]

[Effect of the device]

 Since the mold according to the present invention is configured as described above, it is possible to easily obtain a molded product in which the required liquid agent is distributed only on the surface. That is, since the liquid agent is not distributed throughout the resin constituting the molded article but only on the surface, the obtained molded article has the effect of adding the liquid agent without impairing the original performance of the resin. Further, since it is not necessary to add an extra liquid agent, the amount of the liquid agent used can be minimized, and the manufacturing cost can be reduced. Furthermore, since the step of previously mixing the liquid material with the plastic raw material is unnecessary, the productivity can be improved.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an embodiment of a mold according to the present invention.

[Explanation of symbols]

 1 Mold 2 Sprue 4 Sintered Metal Ring 5 Cavity 6 Sintered Metal Plate 7 Liquid Channel 8 Liquid Channel 15 Molded Product

Claims (1)

[Scope of utility model registration request] 1. At least a part of an inner peripheral surface of a molten resin flow path from a sprue to a cavity is formed of a porous sintered metal having desired fine pores, and a liquid path serving as a desired liquid agent flow path is formed in a mold. A mold which is provided inside and communicates the sintered metal with the outside of the mold through this liquid path.