JP3700316B2 - Method of injection compression molding of laminated molded products - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for forming a laminated molded product having a thick portion because an undercut portion is formed by injection compression molding.
[0002]
[Prior art]
For example, as an instrument panel of an automobile, a laminated panel mainly composed of a synthetic resin in which a foamed layer is interposed between a core material formed of a hard resin and a skin material is used. Conventionally, in order to mold this laminated panel, as shown in FIG. 4, a pre-shaped skin 3 and a core material 9 are set in a foam molding die 8, and a foamed resin 6 is injected into this mold to core the core material. A panel in which three layers are joined by forming a foam layer between the skin and the skin.
In this molding method, it is possible to form the thick portion 6 ′ in a part of the instrument panel.
[0003]
In JP-A-7-223269, after forming a skin layer with a slush mold, a cushioning material is foam-molded on the back side, and a mold with these remaining is used as a cavity of an injection mold. In addition, a method for producing an integrated multilayer resin molded product by injection molding a core resin is described.
In this molding method, it is possible to form a complicated shape having an undercut portion like an instrument panel.
[0004]
JP-A-5-23234 discloses a molded product such as an armrest in which an outer skin layer forming an outer surface and a thermoplastic synthetic resin constituting a structure are heat-sealed.
[0005]
[Problems to be solved by the invention]
Injection compression molding (injection press molding) is suitable for molding a molded product having a large projected area, a small orientation distortion, and a high dimensional accuracy requirement like an automobile instrument panel. In this molding method, after the molding material is injected and filled into the mold, the molding is completed by applying further compressive force to the whole or part of the slightly opened mold or cavity, that is, the molding material mold. The mold is filled by an injection molding method, and shaping and curing are performed by a compression molding method.
[0006]
FIG. 5 shows a case where an instrument panel of an automobile having the thick part is formed by injection compression molding. The injection compression molding mold uses a slide mold for a fixed mold and a movable mold, and the solid line arrow in the figure indicates the mold clamping direction, and the broken line arrow indicates the mold drawing direction.
The pre-shaped skin 3 is set on the movable mold 1a and the slide mold 1b, the movable mold 1a is clamped to a slightly opened state, the core resin 5 is injected and filled into the cavity, and further compressed into the movable mold 1a. Apply force to complete the cure. At this time, a shear edge is formed on the mold matching surface S, and there is no leakage of resin to the outside of the mold.
[0007]
In the product molded by the above-described injection compression molding, the skin 3 and the core material 5 are joined and integrated, but sink marks are generated in the thick part 5 ′ of the core material 5 and the appearance quality of the product is deteriorated. .
Moreover, each said prior art does not disclose forming the thing of the shape which has a thick part by an injection compression molding method, since it becomes an undercut part like an instrument panel.
[0008]
The present invention provides a method for molding a resin laminated panel that enables molding of a laminate having a thick portion because it becomes an undercut portion by an injection compression molding method, and a molded product with excellent appearance quality can be obtained. To do.
[0009]
[Means for Solving the Problems]
In the present invention, a skin with an insert in which an insert having a shape corresponding to a thick wall portion is attached to the skin in advance, the skin with an insert is placed in a mold for injection compression molding, and then injection compression molding is performed. A method for injection compression molding of a laminated panel, wherein the skin with an insert may be formed by integrally joining an insert having a shape corresponding to a thick part when shaping the skin. An insert product having a shape corresponding to the meat portion may be separately molded and attached to each other.
In addition to the characteristics such as high dimensional accuracy based on injection compression molding, it is possible to prevent the occurrence of sink marks in the thick-walled part for laminated molded products that cannot be properly performed by normal injection compression molding because of the undercut. A molded product with excellent appearance quality can be obtained.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows an embodiment of the present invention, and FIGS. 2 and 3 are explanatory diagrams of a molding process of a partially molded product prepared in advance.
An insert product 4 having a shape corresponding to the thick-walled portion of the molded product is molded in advance with an open-cell foam, and the insert product 4 is set in a vacuum mold 7 shown in FIG. And insert product 4 are integrally joined and shaped.
[0011]
FIG. 3 shows another method for forming a partially molded product. The insert product 4 shown in FIG. 3A is formed in advance using an open-cell foam or closed-cell foam in the same manner as described above. The slash shown in 3B or the skin 3 formed into a desired shape by vacuum forming is fitted and held. The skin 3 is a single layer or a laminate.
[0012]
The injection compression molding mold shown in FIG. 1 is the same as the mold shown in FIG. 5, and the same parts are denoted by the same reference numerals. In FIG. 1A, the skin with an insert formed in advance by combining the skin 3 and the insert 4 as described above is set on the movable mold 1a and the slide mold 1b, and the movable mold 1a and the slide mold 1b are attached to the fixed mold 2. In this state, the core material resin 5 is filled in the cavity by an injection molding method. Next, as shown in FIG. 1B, the movable mold 1a and the slide mold 1b are further moved in the mold clamping direction, and a shear edge is formed on the mold-matching surface S so that there is no resin leakage to the outside. A compressive force is further applied to the inner core material resin 5 to complete shaping and curing of the filled resin.
[0013]
A laminated molded product having a thick portion with high dimensional accuracy as a whole by filling the back surface including a thick portion previously formed by combining the skin 3 and the insert 4 with the core resin 5 by an injection method. Is obtained.
The product molded by the above-described injection compression molding includes a thin-walled portion in which the skin 3 and the core material 5 are adhered, and a thick-walled portion in which the periphery of the insert 4 molded with the foam material is covered with the skin 3 and the core material 5. Since no sink marks are generated even in the thick part of the product, it looks good and becomes a molded product with excellent cushioning and impact resistance.
Moreover, the molded article excellent in recyclability is obtained by making materials, such as the outer skin 3, the insert goods 4, and the core material 5, into an olefin resin, for example.
[0014]
In the above embodiment, the molding of the instrument panel of the automobile has been described. However, the present invention is not limited to this, and the present invention is not limited to this, and is applied to the molding of laminated panels such as automobile interior parts and daily necessities that have a thick shape. it can.
[0015]
【The invention's effect】
The present invention has an undercut so that it becomes a thick wall shape, and a molded skin with an insert in which an insert product having a shape corresponding to the thick wall portion is attached to the skin in advance is formed in advance for a laminated molded product that cannot be injection-molded properly. Since this is used for injection compression molding, in addition to characteristics such as high dimensional accuracy based on injection compression molding, molded products with excellent appearance quality without causing sink marks in thick parts. can get.
[Brief description of the drawings]
FIG. 1 is a view showing a mold and a molding process according to an embodiment of the present invention.
FIG. 2 is an explanatory diagram of a manufacturing process of a preform.
FIG. 3 is an explanatory diagram of another manufacturing process of a preform.
FIG. 4 is an explanatory view of a conventional method for forming a laminated panel.
FIG. 5 is an explanatory view of a method for forming a laminated panel by injection compression molding.
[Explanation of symbols]
1a movable type 1b slide type 2 fixed type 3 skin 4 insert product 5 core resin

Claims (3)

A skin with an insert in which an insert product having a shape corresponding to a thick-walled portion that forms an undercut portion is attached to the skin is molded in advance,
The skin with the insert is placed in a mold of an injection compression molding mold having a fixed mold, a movable mold and a slide mold,
Next , after the movable mold and the slide mold are moved in the mold clamping direction to a predetermined position with respect to the fixed mold, the mold is filled with a resin as a core material by an injection molding method, Injection of a laminated molded product having an undercut portion , wherein the slide mold is further moved in the mold clamping direction with respect to the fixed mold and injection compression molding is performed by further applying a compression force to the resin in the mold. Compression molding method.   The method of injection compression molding of a laminated molded product according to claim 1, wherein a skin with an insert is used in which an insert having a shape corresponding to a thick portion is integrally joined during shaping of the skin.   The method of injection compression molding of a laminated molded product according to claim 1, wherein the skin and the insert having a shape corresponding to the thick portion are separately molded, and the skin with the insert to which both are attached is used.

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