JPS6282010A - Manufacture of foamed molded article - Google Patents

Abstract

PURPOSE:To enable manufacture of a foamed molded article whose surface is smooth by controlling a leak of a foaming agent cast with pressure through an opening part and notched part provided to a panel material in a formed state, by blockading the opening part and notched part with a sheet made of synthetic resin prior to loading of a molding tool with a core material panel. CONSTITUTION:An opening part 2 and notched part 3 of a core material panel 1 are blockaded with protrusions 14, 15 by putting the core material panel 1 over a protrusion mold 13 on a vacuum molding device 12. Then a void part 16 of the vacuum molding device 12 is depressurized by putting a heated square thermoplastic resin sheet 5 over the core material panel, 1 a shower of cooling water is sprayed from the upper part of the sheet and a fixed shape retention is maintained by fusing a resin sheet 5 to the surface of the core material panel 1. The core material panel 1 is released from a protrusion mold 13 part after cooling of the sheet 5, the whole surface of the core material panel is covered by the resin sheet 5 while the opening part 2 and notched part 3 are being blockaded with a part of the resin sheet 5 and a panel material 4 to which preprocessing has been applied and having a sheetlike flange 6 is completed. The skin material 8 is fitted to a bottom force 9, and the panel material 4 to the top force 10; and liquid foaming raw materials 7 are cast on the inside of the skin material 8.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention relates to a method for manufacturing a foam molded product, and more specifically, a core panel, a foam raw material, and an outer skin if necessary are placed in a cavity of a half-shaped mold. Regarding the manufacturing method of a foam molded product having a three-layer structure of a panel layer, a foam layer, and a skin layer, specific examples of this foam molded product include automobile interior parts such as instrument panel pads, console box nuts, and foam. The present invention relates to a method of manufacturing a foamed molded product in which openings and cutouts for various parts are formed in the molded product.

(Prior art) Foam molded products, specifically instrument panel pads, which are automobile interior parts, are formed with openings and cutouts for mounting parts such as speedometers, radios, and air outlet valves. Conventionally, a vacuum forming method or a slush molding method is used to form an opening and A core panel with a notch formed therein is loaded with a foaming raw material into a cavity formed by combining a pair of upper and lower molds, and the foaming raw material is foamed between the skin material and the core panel. (-Me, the so-called integrated foam molding method to integrate these, or the above-mentioned skin material is cut out, and a core panel with openings and notches formed in advance between the mold cavities and a foaming raw material are loaded, A foam molding method that uses so-called integral skin foam is widely adopted, in which a foam layer is formed by the foaming action of the foaming raw material, and a relatively dense skin layer (skin) is integrally formed in the area that comes into contact with the mold surface. has been done.

(Problems to be Solved by the Invention) In automobile interior parts such as the above-mentioned instrument panel band, the core panel material is inevitably Whether it is an integral molding method or a molding method using integral skin foam, there is a drawback that the urethane foam, which is the foamed material, tends to leak out from these openings and notches provided in advance.

In order to eliminate this drawback, a method has been adopted in which paper, adhesive tape, etc. are used to mask the opening of the core panel, the notch extending to the edge of the panel and the skin, or the joint between the notch and the mold. However, although these are very labor-intensive operations, the foam material was not perfect in terms of preventing leakage.

For this reason, the urethane foam leaking onto the back side of the foam molded product must be removed from the panel material after molding.
In addition to the masking work described above, a release agent was applied to the back of the panel material in advance to facilitate the removal of the urethane foam, and after molding, the leaked urethane foam was scraped off using a hand hook or the like. was. However, all of these methods require a large amount of man-hours, and there is also a lot of loss due to urethane leakage.

In addition, when urethane foam leaks, the density inside the foam near the leakage point decreases, resulting in a difference in surface hardness between the molded product and other parts, and the relationship between the amount of shrinkage and As a result, the smoothness of the surface of the molded product was impaired, and in severe cases, cavities were created inside the molded product.

The present invention solves the above-mentioned problems inherent in the conventional method of manufacturing foam molded products, suppresses the leakage of the press-injected foam material from the openings and notches formed in the panel material, and
The purpose of the present invention is to provide a method for producing a vine by producing a foam molded product with a smooth surface.

(Means for Solving the Problems) In order to achieve this object, the present invention has the following configuration. That is, the present invention includes a core panel formed in advance and having a notch extending over the opening and the edge, and at least a foaming material loaded into a cavity formed by combining a pair of upper and lower molds. In the manufacturing process of a foam molded product having a three-layer structure of a skin layer, a foam layer, and a panel layer, prior to loading the core panel into the mold, the opening and the notch of the core panel are is characterized in that it is closed in advance with a synthetic resin sheet.

(Example) Next, a specific example of the present invention will be described as an example of an instrument panel band, which is one of the interior parts of an automobile.
This will be explained using drawings.

FIG. 1 is a perspective view of a core panel with openings and notches closed with resin sheets, and FIG. 3 is a perspective view of a core panel material that has been subjected to skin material, foamed raw material, and preliminary processing according to the present invention. FIG. 3 is a cross-sectional view of a loaded mold.

The core spring /I/ (1) which is subjected to preliminary processing is
As shown in Figure 4, synthetic resins such as ASG (acrylic nitrous styrene resin mixed with glass chips), ABS resin, and Dilarc (trade name of ALCO, a copolymer of styrene and maleic anhydride) Or a metal plate,
For example, it is formed from a steel plate, and the molded body has an opening (2) (end) for mounting a speedometer, radio, air outlet, accessory case, etc., and a notch (3) extending to the edge of the molded body. is formed.

Next, the opening (2) and the notch (
Core panel (1) that closes 3) with a resin sheet (5)
The details of the preliminary processing will be explained below. The vacuum forming apparatus (2) shown in FIG.
When the bottom of the core panel (1) is on the surface of the panel (1),
A protrusion α that closes the opening (2) and notch (3) of the
9 is prominently placed. The inside of the vacuum forming device 02 is the sixth
As shown in the figure, the device (
A plurality of suction holes α penetrating through the surface side of the device 02 are drilled over the entire surface of the device 02, and the inside of the cavity OQ of the device 02 is connected to an appropriate suction device (not shown) so as to be able to reduce the pressure. ing.

The core panel (1) is attached to the convex α3 on this vacuum forming device (2).
), and the opening (2) and notch (3) of the core panel (1) are closed with the protrusion α409 (see FIGS. 7 and 8).

In addition, when the opening (to) of the core body panel (1) cannot be sufficiently closed with only the protrusion α9 on the convex shape 03 of the device, or the core body panel (1) has a recess instead of the opening. or when you want to obtain a core panel material that has undergone multiple quality pre-processing using a single vacuum forming machine, the shape of the opening of the core panel can be adjusted as shown in Figure 9. Insert the matched insert 01 into the opening from the outside of the panel in advance to close the armpit.

Next, a rectangular thermoplastic resin sheet 1 (5) that is sufficiently larger than the surface area of the core panel (1) is heated to 120 to 180°C.
, for example, a resin sheet such as a polyvinyl chloride sheet, an ionomer resin sheet made from modified polyethylene, or a hnylidene chloride resin sheet is placed over the core panel (1), and the cavity αG of the vacuum forming device (2) is heated to the atmospheric pressure. 745mmH
After reducing the pressure to . 1) Fuses to the surface and maintains a certain shape (No. 10)
(see figure). Note that the core spring /l/ (1) is a heavy film A S
When the resin sheet (5) is made of G resin, ABS resin, or Dilarc, and the resin sheet (5) is a thermoplastic resin with a thickness of 30 μm to 500 μm as described above, the above-mentioned fusion work can be performed without using any special adhesive force. , it is possible to obtain sufficient adhesive strength for use in automobile instrument panel bands.

However, if the materials of the core panel (1) and the resin sheet (5) are different from each other (for example, when a steel plate is used for the core panel (1)), there may be a gap between the sheet and the core panel. When sufficient adhesive strength cannot be expected, it is desirable to apply adhesive to the core panel in advance.Also, when a particularly strong adhesive strength is required between the core panel and the sheet,
Even in the case of the resin core spring 1v (1) and the thermoplastic resin sheet (5) as exemplified above, it is desirable to interpose an adhesive between them.

Also, depending on the special shape of the convex α3 of the vacuum forming device, the position of the suction hole αη, etc., the degree of vacuum on the inner surface of the resin sheet (5) may partially decrease, and its adhesive strength may partially deteriorate. However, if there is such a concern, it is desirable to use an adhesive to reinforce and bond the thermoplastic resin sheet in advance after it has been formed.

After the thermoplastic resin sheet (5) is sufficiently cooled, the core panel (1) is removed from the convex part 03 of the vacuum forming device @, and the surface of the core panel (1) shown in Fig. 1 is The opening (2) and notch (3) are covered with a resin sheet (5).
A pre-processed panel material (6) which covers the entire surface of the core panel while being partially closed, and has a sheet-like flange (6) with the periphery of the sheet extending outward from the periphery of the core panel. 4) is completed.

In the above-described embodiment, the resin sheet was provided to prevent the resin sheet from sinking into a concave shape at the protrusion α(A) 09, the opening (2) of the core body panel (1), etc. However, if there is no particular problem when inserting the pre-processed panel material (4) into the mold even if a depressed state remains on the sheet at the relevant part, these protrusions Q4) as and The nest 09 becomes unnecessary.

Opening (2) and cutout (3) of core panel (1)
A panel (O (4)) that has undergone preliminary processing to close the
This can also be done using the means detailed below.

That is, after applying adhesive to the entire surface of the core panel (1),
This core spring 1v(i) is inserted into a sufficiently large heat-shrinkable resin tube, and steam or the like is injected onto the surface of the tube to heat-shrink the tube, and the resin is applied to both sides of the core panel. The tubes are brought into close contact with each other, and the opening or notch of the core panel is closed with a resin sheet to obtain a pre-processed panel material (4) (not shown). Thereafter, a sheet flange (6) made of a resin sheet is attached to the peripheral edge of the core panel in an overhanging manner.

In addition, if the open areas of the openings and notches in the core panel are small, or if there are many openings, there is no risk of foam material such as urethane foam leaking from these openings, and the opening area is very limited. If there is a risk of foam material leaking only from an opening or notch, seal only the opening or notch where leakage is likely to occur, and apply a thermoplastic resin sheet of the size of a temple to the armpit area. paste,
Furthermore, a resin sheet may be attached to the peripheral edge of the core panel to form a sheet-like flange extending from the peripheral edge of the core panel (not shown).

After completing the panel material (4) that has undergone preliminary processing, the third
As shown in the figure, PVC resin (polyvinyl chloride), A
BS resin, a mixture of PVC resin and ABS resin or P
VC resin and foamed PVC, ABS resin and foamed PP, ABS
A skin material (8) with a thickness of 0.5 to 5.0 mm is made of a thermoplastic resin single sheet or composite sheet made of resin and foamed PE, etc., while the upper mold αO is subjected to the preliminary processing described above. The treated panels and material (4) were attached to the inner surface of the skin material (8) attached to the lower mold (9), and a liquid foaming material made of polyurethane (an example of the composition of which is shown in Table 1 below) was applied to the inner surface of the skin material (8) attached to the lower mold (9). After injecting 7), the upper and lower molds α0 (
9) and the overhanging end edge α of the sheet-like flange (6) and skin material (8) of the panel material (4) loaded into the cavity formed by the combination of the upper and lower molds.
By overlapping the material in the upper and lower molds over the entire circumference of ℃, the charging material in the upper and lower molds takes on the shape of a bag, and the ζ trowel foaming raw material (7) in the bag part is foamed.
Subsequent curing progresses, and a three-layer foam molded product is manufactured using the so-called integral molding method, consisting of a skin layer, a foam layer, and a panel layer via a resin sheet, without leakage of the foam material. .

Table-1 (Blend of urethane foaming raw materials) (Parts by weight) EI) 240 (Mitsui Nisso Urethane) 70 parts POP
31-28 (Mitsui Nisso Urethane) 30 parts triethanolamine 10 parts water
3 parts triethylenediamine 0.3 parts silicone
Part 0,5 Crude MDI
78.7 parts Also, instead of the above molding method, specifically without using the skin material (8) in the above process,
By utilizing a so-called integral skin foam, a foam molded article having a three-layer structure can be produced without leakage of the foam material.

That is, in the same way as in the previous embodiment, the upper mold is loaded with the panel material that has been pre-processed as described above, while the lower mold is injected with the same liquid foaming raw material as described above. and the sheet-like flange that protrudes from the periphery of the panel material,
Through this sheet-like flange part, the inside of both the upper and lower mold cavities is made into a substantially sheathed shape, and as the injected foaming raw material foams and hardens, a relatively high-density skin layer (skin) is formed in contact with the lower mold surface. A foam molded product having a three-layer structure consisting of a foam layer integrally formed on the surface side and a panel layer with a resin sheet interposed therebetween is obtained. During this foaming operation, the presence of a sheet-like flange extending over the periphery of the panel member (4) has the effect of enhancing the effect of closing the upper and lower molds to prevent leakage of the foam material.

(Effects of the Invention) The present invention provides an indispensable opening in a core panel, which is an essential component in the construction of a foamed molded product, and a cutout along the edge of the panel, which is a leakage point of the foamed material that expands inside the mold. By sealing the notches with a resin sheet before molding the foam molded product, leakage of the foam material from the chain parts can be effectively prevented. It is economical and eliminates the need to remove leaked foam material that adheres to the surface of the product after the molding process, which reduces the product value. It is highly effective in preventing contamination of connected products and also in improving the surface smoothness of the products.

In addition, when the opening of the core panel is closed, the outer periphery of the resin sheet that covers the entire surface of the panel is intentionally extended beyond the periphery of the panel material, so that the periphery of the panel material that has undergone preliminary processing is removed. By forming a sheet-like flange in advance on the mold and placing the flange on the edge of the mold where the upper and lower molds are overlapped during molding, the cavity formed by the combination of the upper and lower molds can be sealed more tightly. By forming the foam material into a bag-like shape with a high temperature, accidental leakage of the foam material can be effectively prevented in this respect as well. In addition, the entire surface of the core panel is covered with a resin sheet, or the core panel is inserted into a large resin tube, and a heat-softened sheet is used to cover the core panel surface ζ simultaneously and integrally. Since the openings and notches in the body panel can be closed, the closing operation can be carried out extremely quickly.

In addition, as a secondary effect of the present invention, the resin t-t fused to the core panel surface may cause the migration of harmful substances from the foam layer to the panel layer, or from the panel layer to the foam layer, such as the reaction of foamed urethane. It is expected to have the effect of preventing amine, which is commonly used as a catalyst, from migrating from the foam layer to the panel layer and preventing the panel material from being contaminated by the amine.

[Brief explanation of drawings]

Figure 1 is a perspective view of a pre-processed panel material with openings and notches closed, and Figure 2 is A-A in Figure 1.
3 is a cross-sectional view of the mold loaded with molded article material, FIG. 4 is a perspective view of the core panel product, FIG. 5 is a perspective view of the vacuum forming device, and FIG. A sectional view taken along the line B-B in FIG.
Figure 7 is a perspective view just before the core panel is placed on the vacuum forming device, Figure 8 is a sectional view taken along the line C-C in Figure 7 when the core panel is placed on the vacuum forming device, and FIG. 9 is a perspective view immediately before the resin sheet is placed on the core panel, and FIG. 10 is a sectional view of the panel material subjected to preliminary processing on the vacuum forming apparatus taken along line D--D in FIG. 9. In the figure, (1)...core panel, (2)...opening,
(3) Notch, (4) Pre-processed panel material, (5) Thermoplastic resin sheet, (6) Sheet flange, (7) Foaming raw material , (8)...
Skin material, (9)...lower mold, 00...upper mold, 0℃...
- Indicates the edge of the skin material.

Claims (6)

[Claims] (1) A core panel that is pre-molded in a cavity formed by combining a pair of upper and lower molds and has a notch extending over the opening and the edge, and at least a foaming raw material is loaded to form a skin layer and foam. In the manufacturing process of a foam molded product having a three-layer structure of a layer and a panel layer, the opening and notch of the core panel are made of synthetic resin in advance before loading the core panel into the mold. A method for producing a foam molded product, characterized in that it is closed with a sheet. (2) Cover the entire surface of the core panel with a thermoplastic resin sheet, adhere the sheet to the panel using a vacuum forming method, close the openings and notches of the panel, and cover the peripheral edge of the resin sheet. The method for producing a foam molded product according to claim 1, wherein the sheet-like flange is formed by leaving the flange projecting from the periphery of the panel. (3) The core panel is inserted into a large heat-shrinkable resin tube, and the opening and notch of the panel are closed by heat shrinkage of the tube, and a sheet-like flange is formed around the periphery of the panel. A method for producing a foam molded product according to item 1. (4) The foamed molded product according to claim 2 or 3, wherein when the upper and lower molds are combined, a sheet-like flange provided on the peripheral edge of the core panel is interposed between the overlapping peripheral edges of both molds. manufacturing method. (5) The method for manufacturing a foam molded product according to one of claims 1 to 4, wherein the core panel is formed of a synthetic resin plate. (6) The method for manufacturing a foam molded product according to one of claims 1 to 4, wherein the core panel is formed of a metal plate.