JP2022127106A - Method for manufacturing foam molded products and automobile interiors - Google Patents

Abstract

To improve the quality of foam molded products.SOLUTION: In the method for manufacturing the foam molded product 20 of the present disclosure, a paper auxiliary sheet 50 is addressed to the pair of inner faces 32 (sheet 40 addressed to the inner faces 32) of the foam molding die 30. The lower end of the auxiliary sheet 50 is sandwiched between the inner side 32 and the cover member 45, and the upper end protrudes above the foam molding die 30. When the polyurethane foam 20X foaming in the foam mold 30 adheres to the auxiliary sheet 50, the auxiliary sheet 50 is pulled up in accordance with the progress of foaming of the polyurethane foam 20X.SELECTED DRAWING: Figure 6

Description

TECHNICAL FIELD The present disclosure relates to methods for manufacturing foamed molded articles.

Conventionally, as a method for producing this type of foam-molded product, there is known a method in which a raw material for foamed resin is poured into a mold and foamed (see, for example, Patent Document 1).

JP 2009-253053 A (paragraph [0058], FIG. 2(a))

In the above-described conventional method for producing a foam-molded product, it is required to improve the quality of the foam-molded product.

In one aspect of the invention, which has been made to solve the above problems, a surface member is arranged in advance on the inner surface of a foaming mold, and a raw material of a foamed resin is foamed in the foaming mold, and the foamed resin is the above-mentioned A method for producing a foam-molded product, comprising the step of moving the surface member upward relative to the foam mold in accordance with the progress of foaming of the foamed resin when the surface member is adhered to the surface member.

(A) Perspective view of an automobile provided with the ceiling panel of the present disclosure, (B) Cross-sectional view near the roof of the automobile Cross section of ceiling panel Perspective view of foam molded product Cross section of foam mold Sectional view of a foaming mold in which polyurethane foam is foamed Sectional view of a foaming mold in which polyurethane foam is foamed Sectional view of a foaming mold in which polyurethane foam is foamed Sectional view of a foaming mold in which polyurethane foam is foamed Cross-sectional view of a foaming mold according to a modification Cross-sectional view of a foaming mold according to a modification Cross-sectional view of a foaming mold according to a modification Cross-sectional view of a foaming mold according to a modification Sectional drawing of the belt conveyor which concerns on a modification

FIG. 1 shows a ceiling panel 100 corresponding to the interior parts of an automobile. The ceiling panel 100 is attached to the underside of the roof 91 of the automobile 90 and constitutes the ceiling of the passenger compartment of the automobile 90 .

As shown in FIG. 2, the ceiling panel 100 includes a foam sheet 11, a pair of glass fiber sheets 12, a backing material 14 (for example, a laminate of polypropylene film and polyethylene terephthalate nonwoven fabric), and a skin material 16 (for example, , polyethylene terephthalate fiber) are laminated. Among them, the foam sheet 11 is made of rigid polyurethane foam or semi-rigid polyurethane foam, and is manufactured from a foam molded article 20 (see FIG. 3) formed by forming a block of rigid polyurethane foam or semi-rigid polyurethane foam. The foam-molded product 20 is formed by foaming a polyurethane raw material 20Z (corresponding to the “foam resin raw material” in the claims) in the foam mold 30 . The method for manufacturing the foam molded product 20 will be described in detail below.

First, a sheet 40 is laid on a rectangular foaming mold 30 shown in FIG. 4A. The sheet 40 may have a configuration in which a single sheet 40 is folded into a box shape and fitted into the foaming mold 30, or a plurality of sheets having shapes matching the bottom surface 31 and the inner side surface 32 of the foaming mold 30 may be used. A configuration in which the sheets 40 are assigned to each other may also be used. Hereinafter, the foaming mold 30 on which the sheet 40 is laid is simply referred to as the "foaming mold 30".

Among the pair of opposing inner side surfaces 32 of the foaming mold 30, for example, a position at a height of about 1/3 from the bottom surface 31 (between the bottom surface 31 and a height of about 1/3 from the bottom surface 31) The cover member 45 is fixed (see FIG. 4B). The cover member 45 has a belt-like shape extending between both ends of the inner surface 32 in the horizontal direction, and the lower portion 45A is attached to the inner surface 32 of the foaming mold 30 (the sheet 40 applied to the inner surface 32). there is A portion above the middle portion in the vertical direction of the cover member 45 is inclined away from the inner side surface 32 as it goes upward. In addition, as shown in FIG. 4B, the upper portion may be bent with respect to the lower portion 45A and may extend linearly, or may be gently curved and extended from the lower portion 45A. After gently curving from the lower portion 45A, the tip portion may hang down.

Then, as shown in FIG. 4B, paper auxiliary sheets 50 (" (corresponding to "surface member" and "paper sheet") are assigned. Similarly to the cover member 45, the auxiliary sheet 50 extends between both horizontal ends of the inner surface 32 of the foaming mold 30, its lower end is sandwiched between the inner surface 32 and the cover member 45, and its upper end is It protrudes upward from the foaming mold 30 . The foaming mold 30 is prepared as above.

Next, as shown in FIG. 5A, a polyurethane raw material 20Z is injected into a foaming mold 30 and foamed to form a polyurethane foam 20X. As the foaming of the polyurethane foam 20X progresses, the upper portion of the polyurethane foam 20X passes over the cover member 45 and adheres to the auxiliary sheet 50 as shown in FIG. 5(B). At this time, the cover member 45 is pushed by the foaming polyurethane foam 20X and approaches the inner surface 32 of the foaming mold 30 .

After that, as shown in FIG. 6, the auxiliary sheet 50 is pulled up according to the progress of foaming of the polyurethane foam 20X that is further foamed. The operation of pulling up the auxiliary sheet 50 may be performed, for example, by an operator visually confirming that the upper surface of the polyurethane foam 20X has risen, and as the upper surface of the polyurethane foam 20X rises, the operator grasps the upper end of the auxiliary sheet 50 by hand and pulls it up. . Further, as shown in FIG. 7, a detector 35 (a camera, a laser, or the like) that detects the upper surface of the polyurethane foam 20X and a work robot 36 that grips the upper end of the auxiliary sheet 50 are used. The working robot 36 may be controlled to pull up the auxiliary sheet 50 according to the degree of rise.

As shown in FIG. 8, when the polyurethane foam 20X finishes foaming and hardens, the sheet 40 is removed from the foam mold 30, and the foam molded product 20 in the state shown in FIG. 3 is completed. Note that the sheet 40, the cover member 45, and the auxiliary sheet 50 are omitted in FIG. The foamed molded product 20 is formed into a rectangular parallelepiped shape by cutting off the outer side surface portion 20A to which the sheet 40 is fixed and the bulging upper portion 20B, and then sliced vertically to be used as the foamed sheet 11. - 特許庁

By the way, in this type of foam-molded product, the rise of the outer edge attached to the inner surface 32 (the sheet 40 attached to the inner surface 32) of the foam mold 30 during foaming of the polyurethane foam 20X causes the inner surface 32 and the , the foam cells of the outer side surface portion 20A may collapse due to the shear stress generated between the outer edge portion and the central portion, resulting in non-uniform foam cells. In addition, if many foam cells are crushed, it is necessary to cut off the outer side surface portion 20A largely, and there is a problem that the yield is lowered.

On the other hand, according to the method for manufacturing the foam molded product 20 of the present embodiment, the auxiliary sheet 50 previously placed on the inner surface 32 of the foam mold 30 is pulled up according to the progress of foaming of the polyurethane foam 20X. Since the outer edge portion adhering to the auxiliary sheet 50 rises as the central portion rises, shear stress is less likely to occur. As a result, the collapse of the foam cells is suppressed, and the foam cells are less likely to become uneven, so the quality of the foam molded product 20 is improved. Moreover, the cut off portion of the outer side surface portion 20A can be reduced, and the yield is improved.

Further, when the auxiliary sheet 50 is placed on the inner side surface 32 of the foaming mold 30, the lower end of the auxiliary sheet 50 is sandwiched between the cover member 45 and the inner side surface 32. The polyurethane foam 20X is prevented from entering between 50 and the inner surface 32 (the sheet 40 applied to the inner surface 32). Moreover, since the cover member 45 is inclined away from the inner side surface 32 as it goes upward, the auxiliary sheet 50 can be easily inserted from above between the cover member 45 and the inner side surface 32 .

Moreover, when the foam mold 30 does not have a lid as in the manufacturing method of the present embodiment, the upper surface of the foam molded product has a mountain shape with a large center bulge due to stagnation in the rise of the outer edge of the polyurethane foam 20X. However, according to the manufacturing method of the present embodiment, the outer edge portion attached to the auxiliary sheet 50 rises in accordance with the rise of the central side portion, so the expansion of the upper surface of the foam molded product 20 is less than conventional. can also be made smaller. In addition, since the height of foaming is made uniform, the overall height is lower than that of a foamed molded product having a mountain-shaped upper surface.

As a result, the cut off portion of the upper portion 20B of the foam molded product 20 can also be reduced, thereby further improving the yield. In addition, when the upper surface of the foam-molded product is mountain-shaped, stacking the foam-molded products on top of each other makes the foam-molded products unstable. 20 can be stacked and stored because the upper portion 20B bulges small, and the area of the storage space for the foam molded product 20 can be reduced.

Even foam-molded products with mountain-shaped upper surfaces can be stacked by placing them along the walls of storage containers. Since the overall height is lower than that of mountain-shaped foam-molded products, more foam-molded products 20 can be stacked in the same space.

[Other embodiments]
(1) The configuration may be such that the height of the auxiliary sheet 50 is maintained and the foaming mold 30 is lowered together with the sheet 40 . Even in this case, the auxiliary sheet 50 rises relative to the foam mold 30, thereby suppressing the shear stress generated between the outer edge portion and the central portion.

(2) The indicator for pulling up the auxiliary sheet 50 may be the passage of time instead of the rise of the upper surface of the polyurethane foam 20X. In particular, when manufacturing a plurality of foam molded products 20 under the same conditions, correlation data between the passage of time and the rise of the upper surface of the polyurethane foam 20X is measured in advance, and the auxiliary sheet 50 is pulled up based on the correlation data. may be configured.

(3) As shown in FIG. 9, the foaming mold 30 may be configured with a lid 30F. In this case, it is conceivable to provide a slit 30S for pulling up the auxiliary sheet 50 between the side wall 30A of the foaming mold 30 and the lid 30F.

(4) As shown in FIG. 10, a slit 30S is also provided between the side wall 30A and the bottom wall 30B of the foaming mold 30 in addition to between the side wall 30A of the foaming mold 30 and the lid 30F. The configuration may be such that the auxiliary sheet 50 wound in a shape is sequentially delivered between the upper and lower slits 30S.

(5) As shown in FIG. 11, a float 51 floating on the polyurethane foam 20X may be attached to the auxiliary sheet 50 so that the auxiliary sheet 50 rises as the upper surface of the polyurethane foam 20X rises.

(6) In the above embodiment, the auxiliary sheet 50 and the cover member 45 are made of paper, but they may be made of synthetic resin such as vinyl or polyurethane.

(7) The foaming mold 30 may not be covered with the sheet 40 and the polyurethane raw material may be directly injected. In this case, it is preferable to apply a release agent (which may be liquid or solid such as wax) inside the foaming mold 30 .

(8) In the above embodiment, the foaming mold 30 has a rectangular shape in plan view, but is not limited to this, and may have a circular shape in plan view, for example.

(9) In the above-described embodiment, the auxiliary sheet 50 is arranged on the pair of inner side surfaces 32 facing each other of the foam molding die 30. It may be arranged on the inner surface 32 .

(10) The polyurethane foam 20X may be foamed while the lower end of the auxiliary sheet 50 is exposed in the foaming mold 30 without using the cover member 45 .

(11) As shown in FIG. 12, a plurality of auxiliary sheets 50 are arranged on the inner side surface 61 of the foaming mold 30 so that the inner side is positioned upward, and the outer auxiliary sheet 50 (that is, the lower side is A configuration may be adopted in which the rising is stopped from the positioned auxiliary seat 50). According to this configuration, when the lower portion of the polyurethane foam 20X is already cured, the portion fixed to the auxiliary sheet 50 is prevented from being forcibly moved upward and peeled off. The plurality of auxiliary sheets 50 may all start rising at the same time, or may be constructed such that the auxiliary sheets 50 on the outer side (that is, the auxiliary sheets 50 located on the lower side) are sequentially lifted. may

(12) As shown in FIG. 13, a configuration may be adopted in which the foamed resin is continuously foamed on the belt conveyor 60 . In this case, the auxiliary sheet 50 is applied to a pair of inner side surfaces 61 facing each other across the belt conveyor 60, and the auxiliary sheet 50 is moved obliquely upward relative to the transfer direction of the belt conveyor 60. may be It is conceivable that the auxiliary sheet 50 is wound in a roll and is successively fed out.

(13) The foamed molded product 20 may be made of a foamed resin other than polyurethane.

Although specific examples of the technology included in the claims are disclosed in the specification and drawings, the technology described in the claims is not limited to these specific examples. Various modifications and changes of the examples are included, and a part of specific examples is also included.

<Appendix>
Hereinafter, the first to ninth aspects of the invention extracted from the above-described embodiments will be described while showing effects and the like as necessary.

[First aspect]
A surface member is arranged in advance on the inner surface of a foaming mold, and a raw material for a foamed resin is foamed in the foaming mold,
Manufacture of a foam-molded product, comprising a step of moving the surface member upward relative to the foam mold according to the progress of foaming of the foam resin when the foam resin adheres to the surface member. Method.

In the conventional method for manufacturing foam-molded products, the rise of the portion of the foamed resin adhering to the inner surface of the foam-molding mold (outer edge) during foaming does not coincide with the rise of the central portion due to friction with the inner surface. The foam cells may become non-uniform due to the shear stress generated between the outer edge portion and the central portion, which may cause the foam cells to collapse.

On the other hand, according to the first aspect of the invention, the surface member is arranged in advance on the inner surface of the foaming mold, and the surface member is moved to the foaming mold according to the progress of foaming of the foamed resin. Therefore, shear stress is less likely to occur between the outer edge portion and the central portion. As a result, the collapse of the foam cells is suppressed, and the foam cells are less likely to become non-uniform, thereby improving the quality of the foam-molded product.

[Second aspect]
The method for manufacturing a foam-molded product according to the first mode, wherein the surface member is raised in accordance with the rise of the upper surface of the foamed resin.

The configuration may be such that the foaming mold is lowered with respect to the surface member, or the configuration may be such that the surface member is raised relative to the foaming mold as in the second aspect of the invention.

[Third aspect]
The method for manufacturing a foam-molded product according to the first aspect or the second aspect, in which a cover member fixed to the foam mold and sandwiching the lower end portion of the surface member between itself and the inner surface is provided.

According to the third aspect of the invention, since the lower end of the face member is sandwiched between the inner surface and the cover member, it is possible to prevent the foamed resin from entering between the face member and the inner surface.

[Fourth aspect]
The method for manufacturing a foam-molded product according to the third aspect, wherein the cover member is inclined away from the inner surface as it goes upward, and is pushed by the foamed resin to approach the inner surface.

According to the fourth aspect of the invention, since the cover member is inclined away from the inner surface as it goes upward, it becomes easier to arrange the surface member.

[Fifth aspect]
A sheet is laid on the foaming mold,
The method for manufacturing a foam-molded article according to the third aspect or the fourth aspect, wherein the cover member is fixed to the sheet.

As in the fifth aspect, the foaming mold may be covered with a sheet.

[Sixth aspect]
The foaming mold has a rectangular shape in plan view,
The method for manufacturing a foam-molded product according to any one of the first to fifth aspects, wherein the surface member is arranged on at least a pair of inner side surfaces facing each other among four inner side surfaces of the foam mold. .

[Seventh aspect]
continuous foaming with the foaming mold having an upper surface of a belt conveyor and a pair of the inner surfaces facing each other;
The method for producing a foam-molded article according to the first aspect, wherein the surface member is moved obliquely along the transfer direction of the belt conveyor.

The first aspect of the invention may be applied to a method of foaming a foamed resin in a foaming mold having a rectangular shape in plan view as in the sixth aspect, or may be applied to a method of foaming a foaming mold as in the seventh aspect. It may be applied to a method of foaming a foamed resin on a belt conveyor that constitutes a part.

[Eighth aspect]
The method for producing a foam-molded article according to any one of the first to seventh aspects, wherein the surface member comprises a paper sheet.

The surface member may include a paper sheet as in the eighth aspect, may be a synthetic resin film, or may be a thinly sliced resin foam.

[Ninth aspect]
A method for producing an interior trim for an automobile, comprising a step of slicing a foam-molded product produced by the method for producing a foam-molded product according to any one of the first to eighth aspects.

REFERENCE SIGNS LIST 11 foam sheet 20 foam molded article 20X polyurethane foam 20Z polyurethane raw material 30 foam mold 32 inner surface 40 sheet 45 cover member 50 auxiliary sheet

Claims (9)

A surface member is arranged in advance on the inner surface of a foaming mold, and a raw material for a foamed resin is foamed in the foaming mold,
Manufacture of a foam-molded product, comprising a step of moving the surface member upward relative to the foam mold according to the progress of foaming of the foam resin when the foam resin adheres to the surface member. Method. The method for manufacturing a foam-molded product according to claim 1, wherein the surface member is raised in accordance with the elevation of the upper surface of the foamed resin. 3. The method of manufacturing a foam-molded product according to claim 1, further comprising a cover member fixed to the foam mold and provided with a cover member sandwiching a lower end portion of the surface member between itself and the inner surface. 4. The method of manufacturing a foam-molded product according to claim 3, wherein the cover member is inclined away from the inner surface as it goes upward, and is pushed by the foamed resin to approach the inner surface. A sheet is laid on the foaming mold,
5. The method of manufacturing a foam molded product according to claim 3, wherein the cover member is fixed to the sheet. The foaming mold has a rectangular shape in plan view,
6. The method of manufacturing a foam-molded product according to claim 1, wherein the surface member is arranged at least on a pair of opposing inner surfaces among four inner surfaces of the foam mold. continuous foaming with the foaming mold having an upper surface of a belt conveyor and a pair of the inner surfaces facing each other;
2. The method for manufacturing a foam molded product according to claim 1, wherein the surface member is moved obliquely along the transport direction of the belt conveyor. 8. The method for producing a foam molded product according to any one of claims 1 to 7, wherein the surface member comprises a paper sheet. 9. A method for manufacturing interior parts of an automobile, comprising a step of slicing a foam-molded product manufactured by the method for manufacturing a foam-molded product according to any one of claims 1 to 8.

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