JP4278850B2 - Molding method of resin panel - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a resin panel used as an automobile bonnet, door panel, tailgate, trunk lid, trunk board, rear package tray, and the like, and a molding method thereof.
[0002]
[Prior art]
Because it has the advantages of being lightweight, not rusting, and being easy to mold, conventional resin bonnets and door panels have been proposed, and outer panels using highly rigid thermosetting resins have actually been manufactured. .
[0003]
However, thermosetting resins are highly rigid, but are difficult to recycle. For this reason, a proposal for increasing the rigidity of a panel using a thermoplastic resin that can be recycled but has low rigidity is disclosed in JP-A-8-323842. The content is that the honeycomb structure is blow-molded between two resin skin materials.
[0004]
[Problems to be solved by the invention]
Since the panel disclosed in JP-A-8-323842 heats the two resin skin members from the outer surface in a state where the core material is placed on the resin skin sheet positioned below the two resin skin members, The resin skin sheet located below hangs down due to the weight of the core material and is not shaped in the lower mold cavity, thereby making the thickness of the resin skin sheet uneven.
And when the thickness of the resin skin sheet becomes non-uniform, there will be sink marks on the surface, resulting in a problem that the rigidity is lowered and the appearance is inferior.
[0005]
[Means for Solving the Problems]
In order to solve the above-mentioned prior art, the present invention is to heat and soften two thermoplastic resin sheets and a core material at the same time or separately by clamping their peripheral portions, and then two thermoplastic resin sheets. The core material is disposed so as to be separated from the two thermoplastic resin sheets, and after being set between the pair of molds in this state, the mold is closed and two sheets are formed at the periphery of the mold. The thermoplastic resin sheet and the core material are overlapped and heat-sealed, and a high-pressure gas is supplied between the two thermoplastic resin sheets located in the mold cavity to press the thermoplastic resin sheet against the cavity inner surface. It was shaped.
[0006]
Thus, by supporting the peripheral part of the two thermoplastic resin sheets and the core material with individual clamps, the core material can be set between the molds without contacting the lower resin sheet. it can. The core material is preferably a mat made of a fiber in which a thermoplastic resin fiber or a thermoplastic resin is coated, or a fiber in which a thermoplastic resin fiber is entangled with a natural fiber.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below. First, a resin panel obtained by the method for molding a resin panel according to the present invention will be described with reference to FIG. 1. A resin panel 1 includes a fiber mat 4 between two thermoplastic resin sheets 2 and 3. It is configured to be filled.
[0008]
The thermoplastic resin sheets 2 and 3 are made of, for example, resins such as polyvinyl chloride, polymethyl methacrylate, polystyrene, polypropylene, polycarbonate, polyethylene terephthalate, polyamide, and modified polyphenylene oxide, but are not limited thereto.
[0009]
Further, as the fiber constituting the fiber mat 4, a fiber in which the surface of a fiber such as a thermoplastic resin fiber or glass fiber is coated with a thermoplastic resin or a fiber in which a thermoplastic resin fiber is entangled with a natural fiber is used. The thermoplastic resin fibers constituting the fiber mat 4 or the thermoplastic resin on the fiber surface are fused together by heat, and the fiber mat is in contact with the inner side surfaces of the thermoplastic resin sheets 2 and 3 and the inner side surfaces. The fibers constituting 4 are also fused together.
[0010]
The resin panel 1 is manufactured by blow molding. The process will be described with reference to FIGS.
First, the thermoplastic resin sheets 2 and 3 are heated to a temperature at which blow molding is possible. On the other hand, the fiber mat 4 is also heated to a temperature at which it can be deformed.
[0011]
As for the thermoplastic resin sheet, as shown in FIG. 2 (a), the thermoplastic resin sheet 2 is clamped by the frame-shaped clamper 5, and the thermoplastic resin sheet 3 is clamped by the frame-shaped clamper 6, respectively. The thermoplastic sheet is inserted between the upper and lower heaters 8 and 8 and heated. The clampers 5 and 6 have a frame shape with the same dimensions. As the heaters 8, 8, for example, those capable of rapid heating such as near infrared rays are preferable.
[0012]
On the other hand, as shown in FIG. 2B, the fiber mat 4 is clamped by the clamper 7 and inserted between the upper and lower heaters 8 ', 8' in this state, and the heaters 8 ', 8' The fiber mat 4 is heated at. The clamper 7 has a frame shape having the same dimensions as the clampers 5 and 6. As the heaters 8 'and 8', those capable of rapid heating such as near infrared rays are preferable.
[0013]
Next, as shown in FIG. 3, the clamped fiber mat 4 is positioned between the clamped thermoplastic resin sheet 2 and the clamped thermoplastic resin sheet 3, and in this state, again between the upper and lower heaters 8, 8. insert. Although the fiber mat 4 is indirect, the fiber mat 4 is heated by the heaters 8 and 8 and is placed in a sealed space formed by the thermoplastic resin sheet 2 and the thermoplastic resin sheet 3. The temperature at the time of heating is almost maintained.
[0014]
Then, when the thermoplastic resin sheets 2 and 3 are heated by the heaters 8 and 8 and softened to a state where blow molding is possible, the thermoplastic resin sheets 2 and 3 and the fibers inserted between them as shown in FIG. The mat 4 is set between the upper and lower molds 9 and 10 for blow molding.
[0015]
Next, the upper and lower molds 9, 10 are closed as shown in FIG. Then, the thermoplastic resin sheets 2 and 3 and the fiber mat 4 are stacked and pressed at the periphery of the mold to form a body, and the inner side is molded following the shape of the mold cavity 11. In addition, by making the total thickness before molding of the thermoplastic resin sheets 2 and 3 and the fiber mat 4 larger than the thickness dimension of the mold cavity 11, a product that surely follows the shape of the mold cavity 11 can be obtained. .
[0016]
Here, a compressed air supply passage 12 is formed in the lower mold 10, and a needle 13 connected to the supply passage 12 protrudes from the cavity surface. Therefore, when the upper and lower molds 9 and 10 are closed, the needle 13 breaks through the thermoplastic resin sheet 3 and enters the portion 4 of the fiber mat. Therefore, compressed air is blown through the needle 13. Then, the thermoplastic resin sheets 2 and 3 are pressed against the cavity surfaces of the upper and lower molds 9 and 10 to obtain a product that accurately follows the mold cavity shape.
[0017]
The needle 13 is preferably provided in a mold for forming the back side surface of the product in order to make a hole in the sheet. Also, the number of needles 13 may be plural, and by blowing and discharging cooling air using a plurality of needles, the internal cooling effect can be enhanced and the product dispensing cycle can be shortened.
[0018]
Thereafter, as shown in FIG. 6, the product is taken out and the product is taken out, the peripheral portion is cut, deburring and drilling is performed at a necessary portion, and the resin panel 1 shown in FIG. 1 is obtained.
[0019]
Note that the heating temperature of the fiber mat 4 alone may be set to a temperature higher than the temperature at which the thermoplastic resin sheets 2 and 3 can be blow-molded. Thereby, in the case of reheating, since the surface which faces the fiber mat 4 of the thermoplastic resin sheets 2 and 3 is also heated simultaneously, heating efficiency becomes high.
[0020]
In the above-described embodiment, the thermoplastic resin sheets 2 and 3 and the fiber mat 4 are set in advance to a temperature at which the thermoplastic resin sheets 2 and 3 can be blow-molded, and then the thermoplastic resin sheet. Although the fiber mat 4 is positioned between the thermoplastic resin sheet 3 and the thermoplastic resin sheet 3 and reheated in this state, the first heating shown in FIGS. 2 (a) and 2 (b) may be omitted. Good.
[0021]
【The invention's effect】
As described above, according to the molding method of the resin panel according to the present invention, since the two thermoplastic resin sheets and the core material are blow-molded in a separated state, the lower thermoplastic resin sheet is formed by the weight of the core material. It is possible to prevent the sagging from drooping, and consequently to prevent the thickness of the thermoplastic resin sheet from becoming uneven. Thereby, it is possible to form a resin panel having high rigidity and good appearance.
[0022]
When the core material is a mat made of plastic resin fibers or fibers coated with a thermoplastic resin, the bonding strength between the mat and the two thermoplastic resin sheets is increased, so that a resin panel with higher rigidity can be formed. it can.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a resin panel to be molded by the method for molding a resin panel according to the present invention. FIG. 2 (a) is a diagram of heating a resin sheet, and FIG. Fig. 3 is a cross-sectional view of a process in which a resin sheet and a core material are laminated and reheated in a separated state. Fig. 4 shows a state in which a laminate of a reheated resin sheet and a core material is set between molds. Cross-sectional view showing FIG. 5 Cross-sectional view showing a blow-molded state FIG. 6 Cross-sectional view showing a releasing state
DESCRIPTION OF SYMBOLS 1 ... Resin panel, 2, 3 ... Thermoplastic resin sheet, 4 ... Fiber mat, 5, 6, 7 ... Clamper, 8, 8 '... Heater, 9, 10 ... Mold, 11 ... Cavity, 12 ... Compressed air supply Passage, 13 ... needle.

Claims (3)

The two thermoplastic resin sheets and the core material are clamped at their respective peripheral portions with individual clamps, and the core material is separated from the two thermoplastic resin sheets between the two thermoplastic resin sheets. Arrange and heat soften the two thermoplastic resin sheets and the core at the same time ,
After setting between the pair of molds in this state, the mold is closed and the two thermoplastic resin sheets and the core material are overlapped and heat-sealed at the periphery of the mold and positioned in the mold cavity. A method for molding a resin panel, wherein a high pressure gas is supplied between two thermoplastic resin sheets and the thermoplastic resin sheet is pressed against an inner surface of a cavity to be shaped. Two thermoplastic resin sheets and a core material are individually heated and softened by clamping each peripheral portion with an individual clamp.
Next, the core material is disposed so as to be separated from the two thermoplastic resin sheets between the two thermoplastic resin sheets, and the two thermoplastic resin sheets and the core material are simultaneously reheated,
After setting between the pair of molds in this state, the mold is closed and the two thermoplastic resin sheets and the core material are overlapped and heat-sealed at the periphery of the mold and positioned in the mold cavity. A method for molding a resin panel, wherein a high pressure gas is supplied between two thermoplastic resin sheets and the thermoplastic resin sheet is pressed against an inner surface of a cavity to be shaped. 3. The method of molding a resin panel according to claim 1 , wherein the core material is a mat made of a plastic resin fiber, a mat made of a fiber coated with a thermoplastic resin, or a natural fiber entangled with a thermoplastic resin fiber. A method for molding a resin panel, characterized in that the mat is made of fiber.

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