JP4278849B2 - 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 only heats the two resin skin members from the outer surface, the temperature difference between the inside and outside of the resin skin member becomes large and the formability is lowered. . Further, since the honeycomb structure as the core material is difficult to be heated, there is a problem that the degree of adhesion between the honeycomb structure and the resin skin member is lowered.
[0005]
[Means for Solving the Problems]
In order to solve the above-mentioned prior art, the method for molding a resin panel according to the present invention is to heat and soften two thermoplastic resin sheets clamped at a peripheral edge portion by a first heating means. The mat composed of the thermoplastic resin fiber or the fiber coated with the thermoplastic resin is heated and softened by another second heating means, and then the mat is placed between the two clamped thermoplastic resin sheets. After setting between a pair of molds, the mold is closed and two thermoplastic resin sheets and a mat are overlapped and heat-sealed at the periphery of the mold, and two sheets located in the cavity of the mold. A high pressure gas was supplied from the outside between the thermoplastic resin sheets, and the thermoplastic resin sheet was pressed against the inner surface of the cavity for shaping.
[0006]
In this way, by separately heating the mat separately from the thermoplastic resin sheet, the thermoplastic resin fiber or the fiber coated with the thermoplastic resin constituting the mat and the thermoplastic resin sheet can be surely thermally fused. it can.
[0007]
Alternatively, the thermoplastic resin sheet and the fiber mat may be heated separately, and then reheated simultaneously with the fiber mat facing the two thermoplastic resin sheets. By doing in this way, two thermoplastic resin sheets and a fiber mat can be heated uniformly.
[0008]
Furthermore, it is also preferable that the heating temperature of the fiber mat is higher than the heating temperature of the thermoplastic resin sheet. By doing in this way, the back surface of the thermoplastic resin sheet which is not directly heated by the heater, that is, the surface facing the fiber mat can be effectively heated.
[0009]
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.
[0010]
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.
[0011]
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 to each other by heat, and the fiber mat 4 is in contact with the inner side surfaces of the thermoplastic resin sheets 2 and 3 and the inner side surface. Are also fused to each other.
[0012]
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.
[0013]
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.
[0014]
On the other hand, as shown in FIG. 2B, the fiber mat 4 is clamped by a frame-shaped clamper 7 and inserted between the upper and lower heaters 8 'and 8' in this state. , 8 ', the fiber mat 4 is heated. 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.
[0015]
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. In this state, the upper and lower heaters 8, Insert between 8. At this time, the fiber mat 4 is indirectly heated but 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 during the initial heating is almost maintained.
[0016]
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.
[0017]
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. .
[0018]
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.
[0019]
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.
[0020]
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.
[0021]
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.
[0022]
Further, in the above-described embodiment, the thermoplastic resin sheets 2 and 3 and the fiber mat 4 are brought to a temperature at which the thermoplastic resin sheets 2 and 3 can be blow-molded, and then the thermoplastic resin sheet 2 and the thermoplastic resin. The case where the fiber mat 4 is positioned between the resin sheets 3 and heated again in this state has been described. However, after the initial heating shown in FIGS. 2 (a) and 2 (b), if the thermoplastic resin sheets 2, 3 and the fiber mat 4 can be quickly set in the process for blow molding dies 9, 10, again. This heating may be omitted.
[0023]
【The invention's effect】
As described above, according to the method for molding a resin panel according to the present invention, since the two thermoplastic resin sheets and the fiber mat are heated independently, the fiber mat can be heated to suitable conditions, thereby The adhesion between the fiber mat and the two thermoplastic resins can be improved, and the rigidity of the resin panel can be increased. Moreover, since it heats independently, a heating time can be shortened and the resin panel can be formed efficiently by this amount.
[0024]
Since the fiber mat is made of a plastic resin fiber or a fiber coated with a thermoplastic resin, the melted state of these thermoplastic resins is appropriately controlled so as to face between two thermoplastic resin sheets. Even without using an agent, the two thermoplastic resin sheets and the mat can be firmly bonded.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a resin panel obtained by a method for molding a resin panel according to the present invention. FIG. 2 (a) is a view of heating a resin sheet, and (b) is a view of heating a fiber mat. FIG. 3 is a cross-sectional view of a process of laminating a resin sheet and a fiber mat and reheating. FIG. 4 is a cross-sectional view showing a state in which a laminate of the reheated resin sheet and fiber mat is set between molds. ] Cross-sectional view showing blow molding state [FIG. 6] Cross-sectional view showing mold release state [Explanation of symbols]
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 (2)

 Two thermoplastic resin sheets clamped at the periphery are heated and softened by the first heating means, and the mat made of thermoplastic resin fibers or fibers coated with the thermoplastic resin is heated and softened by the second heating means, Subsequently, the mat is placed between the two clamped thermoplastic resin sheets and reheated at the same time. After setting in this state between the pair of molds, the pair of molds is closed and the peripheral edge of the mold The two thermoplastic resin sheets and the mat are stacked and heat-sealed together, and a high-pressure gas is supplied from the outside between the two thermoplastic resin sheets located in the cavity of the mold so that the thermoplastic resin sheet is A method for molding a resin panel, wherein the molding is performed by pressing against an inner surface of a cavity.   The method for molding a resin panel according to claim 1, wherein the heating temperature of the fiber mat is higher than the heating temperature of the thermoplastic resin sheet.

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