JPS61146508A - Mold for molding resin - Google Patents

Abstract

PURPOSE:To produce the molded product capable of uniformly keeping the fibers on skin surfaces without irregular orientation of which restoration after molding is impossible by fitting buffer members to at least a part of molding grooves of molds. CONSTITUTION:The skins 3 preformed by vacuum molding are set in molds 11a, 11b. A parison 20 is kept between a gas spouting member 16 and both left and right molds 11a, 11b. The parison 20 is expanded, spouting compressed air from each spouting port 19 of the gas spouting member 16. The parison 20 is molded, with the skins 3, into a base molding 2 correspondingly to the surface-shapes of the molding grooves 12 of the mold 11a, 11b. The skins 3 are pressed to the molding grooves 12 of the molds 11a, 11b by flowing pressure, but because buffer members 13 are fitted into the molding grooves 12, the fibers 3a on surface side are sunk into the buffer members 13, whereby pressing force is relieved. Accordingly, the fibers 3a on the surface side do not break at their roots and also do not receive irregular permanent deformation.

Description

Detailed Description of the Invention (Field of Industrial Application) This invention relates to a resin molding mold for molding a resin molded product having a skin, and more specifically, a comparison of blow molding molds, RIM molding molds, etc. This relates to the structure of a mold that performs molding using relatively low pressure.

(Prior art) In order to give various synthetic resin molded products such as automobile interior parts and indoor equipment products an excellent appearance, and to hide defects such as scratches and unevenness on the resin surface, the surface of the molded products is coated with a layer of skin, etc. It is useful to apply wood. One of the conventional methods is to blow mold a thermoplastic resin on the back side of a fabric preformed by vacuum forming.

(Problems to be Solved by the Invention) However, when molding by the above method, for example, when using Fapritta having long hair fibers in the skin, one of the fibers may be damaged due to the pressure and temperature during molding. Sometimes one of the trees would fall down from its roots, giving it an irregular and permanent orientation. As a result, raised areas like "islands" (hereinafter referred to as "island pattern") due to local irregularities of the fibers are formed on the surface of the molded product, especially in protruding areas, resulting in an extremely unsightly appearance. Something happened.

Therefore, the present invention aims to solve the above-mentioned problems.

Structure of the Invention (Means for Solving the Problems) In order to solve the above problems, a structure is adopted in which a buffer member is attached to at least a part of the molding groove of the mold.

(Function) Therefore, when molding a molded product, even if the skin part is pressed against the mold surface due to molding pressure or temperature, the fibers on the surface are pressed by the buffer member installed in the mold. Since the pressure is relieved, the molded product will not break off at the base and become permanently deformed, so no unsightly island patterns will form on the surface of the molded product.

(Example) Next, an example in which the present invention is embodied in a blow molding mold for molding an automobile door trim will be described with reference to FIGS. 1 to 5.

As shown in Fig. 4.5, the door trim body 1 molded with this mold has a base material 2 made of polypropylene (PP).
and an outer skin 3 made of fabric having long-pile fibers 3a bonded to the surface thereof. In addition, the central part of the main body l has a protruding armrest part 5.
is integrally formed, and the outer skin 3 of the armrest portion 5
The fibers 3a have long piles (although they are formed, they have a uniform directionality. Therefore, the surface of the molded product has a uniform texture as a whole, and there are no partial island patterns etc. The overall feel is soft.Furthermore, although the armrest portion 5 is molded to protrude outward, the base material 2 and the skin 3 are firmly joined.

Next, a blow molding mold and a molding method thereof using the molding ratio of the door trim 1 constructed as described above will be described and explained with reference to FIGS. 1 to 3.

The blow molding device used in this embodiment is different from the commonly used devices, and the molding grooves 12 of the left and right pair of symmetrically formed molds 11a and 11b are made of a foam layer made of urethane resin. A buffer member 13 is attached. This buffer member 13 is formed to have a thickness of approximately 1.5 to 2 mm, and has a suitable degree of stiffness. Therefore, this buffer member 13 reduces the pressing force applied to each fiber 3a.

Inside the molds 11a, 11b are molds 11a, 1.
A gas blowing member 16 having a height and width approximately equal to 1b.
is installed. An air chamber 17 is formed inside the gas blowing member 16, and is connected to a compressed air source (not shown) through a connecting pipe 18. Further, a plurality of blow-off ports 19 for blowing out air from the air chamber 17 are provided on both sides of the gas blow-off member 16 . The gas blowing member 1
An extruder 21 is disposed above the base material 2 to heat and melt the raw material resin of the base material 2 and extrude it as an annular parison 20.

Now, when forming the door trim 1 using this apparatus, as shown in FIG. 1, the skin 3 preformed by vacuum forming is set in molds 11a and 11b. Next, the extruder 21 extrudes the cylindrical parison 20 surrounding the gas blowing member 16 until the lower ends of the parison 20 reach the lower ends of both the left and right molds 14a and 11b.

After that, both the left and right molds 111.11b are attached to the gas blowing member 16.
The parison 20 is held between the gas blowing member 16 and the left and right molds 11a and 11b by moving the parison 20 to the side. At this time,
Compressed air is blown out from each outlet 19 of the gas blowing member 16, and the parison 20 is expanded. And the same parison 20
The base material 2 is formed together with the skin 3 into a shape corresponding to the shape of the molding grooves 12 of the molds 11a and 11b.

Also, at this time, the skin 3 is applied to the mold 1 by blow pressure.
Although the fibers 3a on the front side are pressed against the molding grooves 12 of the molds 1a and 11b, since the buffer members 13 are attached to the molding grooves 12 of the molds 11a and 11b, the fibers 3a on the front side are pressed against the molding grooves 12 of the molds 11a and 11b. It sinks into the member 13 and the pressing force is relieved.

Therefore, the fibers 3a on the surface side not only do not break from their roots, but also do not undergo irregular permanent deformation.

In addition, since the skin 3 is firmly bonded to the base material 2 by mechanical anchoring or fusion, no adhesive is required.
Even the protruding armrest portion 5 can be firmly joined.

After cooling of the base material 2 is completed, two door trims 1 are obtained at the same time by opening the molds 11a and 11b and taking out the molded products. Door trim 1 with a uniform surface by cutting both ends of the molded product and brushing with steam etc.
is completed.

Therefore, with the mold 11 of this embodiment, the pressure applied to the surface of the skin 3 during blow molding can be absorbed by the buffer member 13, so that it is possible to prevent the fibers 3a of the fabritta from breaking from their roots and being permanently deformed. . Therefore, this embodiment is effective for manufacturing a resin molded product having a skin such as fabric and having an uneven shape that tends to have irregular directionality.

Furthermore, since polypropylene resin, which is one of the polyolefin resins, has no polarity and low adhesiveness, this embodiment is effective because it can provide high adhesive strength without using an adhesive.

Furthermore, since the skin 3 is bonded to the base material 2 at the same time as the blow molding, there are fewer steps (and costs are also reduced).

Note that the present invention is not limited to the above embodiments,
For example, it is also possible to embody it as follows.

(1) For the skin 3, in addition to the fabric of this embodiment, fabrics such as loop pile fabrics, velor-like fabrics, flocked fabrics, and nonwoven fabrics may be used.

(2) In addition to being attached to the entire molding groove 12 in this embodiment, the buffer member 13 may be provided only in the recessed portion of the mold 11, that is, in the portion that will become the protruding portion of the molded product.

(3) In addition to the foamed layer formed of the urethane resin of this embodiment, the buffer member 13 may also be made of synthetic resin such as polyethine or polypropylene (or may be made of the same material as the skin 3, for example, In this embodiment, a fabricator may be used.

(4) In addition to the door trim 1 of this embodiment, the present invention applies to various automobile interior parts having long-haired skins such as center pillars, front pillars, ceiling materials, instrument panels, etc.
Similarly, it is also possible to embody the present invention in a blow molding mold and a RIM molding mold for manufacturing indoor equipment products having a skin.

(5) The buffer member 13 is removable.

Effects of the Invention As detailed above, according to the present invention, a molded product can be manufactured that can maintain a uniform surface of the molded product without imparting irreversible irregular directionality to the fibers on the surface of the skin after molding. This has the excellent effect of providing a mold that can

[Brief explanation of the drawing]

1.2 shows a molding method using a blow molding mold according to an embodiment of the present invention, and FIG. 1 is a cross-sectional view showing the skin set in the blow molding mold, and FIG. Figure 2 shows the blow molding process; Figure 3 is an enlarged cross-sectional view showing the condition of the fibers on the surface of the skin during the blow molding process in Figure 2; FIG. 5 is an enlarged cross-sectional view taken along the line A-A'' in FIG. Shien 1) Hirosen Figure 2

Claims (1)

[Scope of Claims] 1. A mold for resin molding, characterized in that a buffer member (13) is attached to at least a part of the molding groove (12) of the mold (11a, 11b). 2. The mold for resin molding according to claim 1, wherein the buffer member (13) is attached to the entire surface of the molding groove (12). 3. The mold for resin molding according to claim 1 or 2, wherein the buffer member (13) is a foam layer having a thickness of about 1.5 to 21 mm. 4. Claim 1, characterized in that the buffer member (13) is made of the same material as the skin (3) of the molded product.
The mold for resin molding according to item 1, 2 or 3.