JP4112673B2 - Manufacturing method of resin molded products - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for manufacturing a resin molded product, and more particularly to a method for manufacturing a resin molded product having an insert inside.
[0002]
[Prior art]
Conventionally, a resin molded product having an insert inside is known. Such a resin molded product can be obtained by previously placing an insert corresponding to the shape of the molded product in a molding die and then injecting an injection resin into the molding die.
[0003]
[Problems to be solved by the invention]
When manufacturing a resin molded product having an insert as described above, it is necessary to place an insert corresponding to the shape of the molded product in the molding die in advance. However, in this case, the insert must be disposed at a predetermined position in the molding die, and the fact is that the degree of freedom in the molding operation is limited.
[0004]
The present invention has been made in view of the above points, and an object of the present invention is to provide a method for producing a resin molded product that can greatly improve the degree of freedom of molding work.
[0005]
[Means for Solving the Problems]
The present invention comprises an injection resin and a soft mesh material provided on the injection resin, the mesh material comprising an electromagnetic shielding fiber, the electromagnetic shielding fiber comprising a synthetic resin core material, and a core material. In a method of manufacturing a resin molded product having a large number of linear bodies composed of a metal layer covering an outer surface, a synthetic resin core on the negative side of an open mold and a metal layer covering the outer surface of the core A step of arranging a mesh of electromagnetic shielding fibers having a number of linear bodies having holes, a step of clamping a molding die, and injecting an injection resin into the molding die to form a mesh And a step of pressing the product against the negative side of the molding die and penetrating the injection resin into the hole of the mesh-like product , wherein the mesh-like product is located on the negative side of the injection resin. It is a manufacturing method.
[0006]
According to the present invention, the flexible mesh material previously disposed in the molding die is deformed following the shape in the molding die when the molding die is clamped. Moreover, since the mesh-like object has moderate unevenness on the surface, the adhesion between the injection resin and the mesh-like object is improved.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
1 to 4 are views showing a resin molded product and a manufacturing method thereof according to the present invention. As shown in FIG. 1, the resin molded product 10 includes an injection resin 12 and a soft electromagnetic shielding fiber (mesh-like material) 11 disposed on one side of the injection resin 12. Among these, the electromagnetic wave shielding fiber 11 shields electromagnetic waves as an insert, and specifically, from a mesh-like porous fiber comprising a large number of linear bodies 15 as shown in FIGS. 4 (a) and 4 (b). It has become.
[0008]
Each linear body 15 includes a core material 15a made of a synthetic resin, for example, polyester, and a metal layer 15b covering the outer surface of the core material 15a. The metal layer 15b has no copper or nickel on the outer surface of the core material 15a. It is formed by electrolytic plating. In addition, the linear body 15 may be comprised from the glass core material 15a and the metal layer 15b which covers the outer surface of this glassy core material 15a, and even if the linear body 15 is comprised only from a metal core material. good.
[0009]
As the injection resin 12, a general-purpose heat-type resin can be used. For example, PC, HIPS, PS, PP, PE, ABS, PVC, nylon and the like can be used.
[0010]
Furthermore, by using the injection resin 12 having transparency and the electromagnetic wave shielding fiber 11 has a desired light transmittance, it is possible to obtain a resin molded product 10 having excellent electromagnetic wave shielding characteristics and transparency as a whole. .
[0011]
Next, a method for producing a resin molded product having such a configuration will be described.
First, as shown in FIG. 2, a molding die 1 having a fixed die 2 provided with a gate 2a and a movable die 3 is prepared. Next, in a state where the fixed mold 2 and the movable mold 3 are opened, the electromagnetic wave shielding fiber 11 is unwound from the unwinding roll 5 and between the fixed mold 2 and the movable mold 3 (molding mold). 1 in the cavity 7).
[0012]
At this time, the electromagnetic wave shielding fiber 11 disposed in the cavity 7 of the molding die 1 is held in a state in which no tension is applied between the unwinding roll 5 and the winding roll 6.
[0013]
Next, as shown in FIG. 3, the movable mold 3 approaches the fixed mold 2, and the fixed mold 2 and the movable mold 3 are closed (clamped).
[0014]
At this time, since the electromagnetic wave shielding fiber 11 disposed in the cavity 7 of the molding die 1 is soft and not tensioned, the electromagnetic wave shielding fiber 11 is connected to the fixed mold 2 in the cavity 7. Deformation follows the shape of the cavity 7 between the movable mold 3. In this way, the electromagnetic shielding fiber 11 deformed into a desired shape can be arranged at a predetermined position in the cavity 7.
[0015]
When the fixed mold 2 and the movable mold 3 are clamped, the electromagnetic shielding fiber 11 is sandwiched between the fixed mold 2 and the movable mold 3 above and below the cavity 7.
[0016]
Next, the injection resin 12 is injected into the cavity 7 from the gate 2a of the fixed mold 2 and is pressed by the injection resin to press the electromagnetic wave shielding fiber 11 to the movable mold 3 side.
[0017]
In this case, since the electromagnetic wave shielding fiber 11 has porosity, it has moderate unevenness on the surface. For this reason, the adhesiveness between the electromagnetic wave shielding fiber 11 and the injection resin 12 can be improved by the injection resin 12 entering the concave and convex portions of the electromagnetic wave shielding fiber 11. Since the electromagnetic shielding fiber 11 is a mesh-like porous fiber, a part of the injection resin 12 passes through the hole of the electromagnetic shielding fiber 11 in the cavity 7 and flows to the movable mold 3 side. For this reason, compared with the case where the film through which the resin does not penetrate is arranged in the cavity 7 of the molding die 1, the injection resin can be sufficiently distributed in the cavity 7 even if the cavity 7 has a complicated shape. The degree of freedom of the shape of the resin molded product can be increased.
[0018]
In this way, a resin molded product 10 is obtained in the cavity 7 of the molding die 1. Thereafter, the electromagnetic shielding fiber 11 is broken by a cutter (not shown) by the shape of the resin molded product 10, and the electromagnetic shielding fiber 11 is further wound by the winding roll b.
[0019]
Thus, according to this Embodiment, the resin molded product 10 which has an electromagnetic wave shielding characteristic can be manufactured easily and simply.
[0020]
In addition, in the said embodiment, although the example which used the electromagnetic wave shield fiber 11 as a mesh-shaped object of the resin molded product 10 was demonstrated, it may not be restricted to this but a synthetic resin nonwoven fabric may be used instead of the electromagnetic wave shield fiber 11. Alternatively, a synthetic resin film having a large number of holes may be used.
[0021]
Moreover, although the example which fractured | ruptured the electromagnetic shielding fiber 11 after producing the resin molded product 10 was demonstrated, the cutter was provided in the fixed mold 2 and the movable mold 3, and the type | mold of the fixed mold 2 and the movable mold 3 is provided. The electromagnetic shielding fiber 11 may be broken in advance at the time of fastening.
[0022]
【Example】
Next, specific examples of the present invention will be described.
In this embodiment, a case (resin molded product 10) is manufactured using the electromagnetic shielding fiber 11.
[0023]
Such an electromagnetic shielding fiber 11 can be produced by a linear body 15 in which a metal layer 15b is formed by electrolessly plating nickel and copper on a polyester core material 15a.
[0024]
Next, the electromagnetic wave shielding fiber 11 was placed in the molding die 1, and the injection resin 12 was injected into the cavity 7 of the molding die 1 to obtain a resin molded product 10.
[0025]
Specific manufacturing conditions are as follows.
The used molding die 1 corresponds to a 100 × 100 × 15 box-shaped resin molded product 10.
[0026]
The molding machine used was J350 EPU (350 tons of mold clamping) manufactured by Nippon Steel Works, and the electromagnetic shielding fiber 11 cut to 150 × 300 was fixed to the upper part of the movable mold 3, and the lower part of the electromagnetic shielding fiber 11 was free. It was set in the state of.
[0027]
The following three types of injection resins were used.
Polycarbonate (PC)
High impact polystyrene (HIPS)
Heat-resistant polypropylene (heat-resistant PP)
[0028]
Next, the properties of the resin molded product 10 will be described.
The molding condition of the resin molded product 10 was completely the same as that of a normal resin molded product without any harmful effects caused by the electromagnetic shielding fiber 11. Moreover, as for the contact | adherence condition of the electromagnetic wave shield fiber 11 and the injection | emission resin 12, as seen from the microscope, the injection | emission resin 12 entered between the electromagnetic wave shield fiber 11, it was in the situation where it bite, and both were completely contact | adhered.
[0029]
The flat electromagnetic shielding fiber 11 has good followability with respect to the molded product 10 having a depth of 10 mm, and the followability is almost 100% in a state where there is no obstacle around. Even when the injection pressure and temperature of the resin were changed, the electromagnetic shielding fiber 11 was not damaged.
[0030]
【The invention's effect】
As described above, according to the present invention, when the molding die is clamped, the soft mesh-like product can be deformed following the shape in the molding die. For this reason, it is not necessary to prepare in advance an insert having a shape that matches the shape in the molding die. Moreover, since the adhesiveness between the injection resin and the mesh-like object can be improved, it is not necessary to provide another adhesive or the like between the injection resin and the mesh-like object.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a resin molded product according to the present invention.
FIG. 2 is a schematic view showing a state where a molding die is opened in the method for producing a resin molded product according to the present invention.
FIG. 3 is a schematic view showing a state in which a molding die is closed in the method for producing a resin molded product according to the present invention.
FIG. 4 is a view showing an electromagnetic wave shielding fiber.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Molding die 2 Fixed die 3 Movable die 7 Cavity 10 Resin molding 11 Electromagnetic wave shield fiber 12 Injection resin

Claims (2)

An injection resin and a soft mesh material provided on the injection resin, the mesh material is made of an electromagnetic shielding fiber, and the electromagnetic shielding fiber is a synthetic resin core material and a metal covering the outer surface of the core material In the method for producing a resin molded product having a large number of linear bodies composed of layers,
An electromagnetic shielding fiber mesh material having a large number of linear bodies having holes, which is composed of a synthetic resin core material and a metal layer covering the outer surface of the core material, is arranged on the negative side of the open mold. Process,
A process of clamping the mold,
Injecting the injection resin into the molding die, pressing the mesh-like material against the negative side of the molding die, and penetrating the injection resin into the holes of the mesh-like material;
And the mesh-like product is positioned on the negative side of the injection resin .   When the mold is clamped, the mesh-like object is held in the mold without applying tension, and the mesh-like object is deformed following the shape in the mold. Item 2. A method for producing a resin molded product according to Item 1.

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