JP2020001322A - Molded body and method for manufacturing the same - Google Patents

Abstract

To provide a molded body, being a molded body to which a skin member is attached, and properly provided with a mark for a consumer.SOLUTION: According to the present invention, a molded body provided with a resin sheet, and a skin member attached to the same, is provided. A surface on the skin member side is a design surface. The design surface includes a mark region provided with a mark configured by a recessed portion and a protruded portion. The skin member correspondent to the recessed portion is impregnated with a resin of the resin sheet.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a molded article used for an interior member of an automobile, and a method for producing the molded article.

  As a molding technique of an automobile interior member such as a door trim, Patent Document 1 discloses a technique in which a single foamed resin sheet is reheated to a softened state and arranged between a pair of split molds. There is disclosed a technique in which a foamed resin sheet is secondarily foamed by vacuum-suctioning the foamed resin sheet to form a thick portion in a foam molded article.

JP 2001-310380 A

  As described above, the integrally molded article used as an automobile interior member may be provided with a mark (caution mark) for calling some attention to a surface (design surface) visually recognized by a consumer. However, when the skin member is mounted on the design surface, the adhesion mark or the like causes a problem that the caution mark is easily peeled from the skin member.

  The present invention has been made in view of such circumstances, and it is an object of the present invention to provide a molded body to which a mark for a consumer is appropriately provided even if the molded body has a skin member mounted thereon.

  According to the present invention, a resin sheet and a molded body provided with a skin member mounted on the resin sheet, wherein the surface on the skin member side is a design surface, and the design surface is configured by a concave portion and a convex portion. A molded product is provided in which the skin member including a mark region with a mark and corresponding to the concave portion is impregnated with a resin of the resin sheet.

  In the present invention, since the mark area having the mark constituted by the concave portion and the convex portion is formed on the design surface of the molded body, the mark does not separate as in the case where an adhesive or the like is used. In addition, since the skin member is impregnated with the resin in the concave portion in the mark area, the fall of the hair of the skin member during the formation of the concave portion is fixed, and the visibility can be prevented from lowering with time.

Hereinafter, various embodiments of the present invention will be exemplified. The embodiments described below can be combined with each other.
Preferably, the thickness of the convex portion of the mark area is smaller than the thickness of a general area outside the mark area on the design surface.
Preferably, the resin sheet is a foamed resin sheet.
In another embodiment of the present invention, the method includes an arranging step and a molding step. In the arranging step, a resin sheet and a skin member are arranged between a first mold and a second mold. The resin sheet and the skin member are formed by the first mold and the second mold, and the concave portion and the convex portion are formed on one of the opposing surfaces of the first mold and the second mold. A mark forming portion including a mark portion, and in the molding step, by pressing the skin member and the resin sheet by the mark forming portion, a mark area provided with a mark constituted by a concave portion and a convex portion is provided. A method is provided for forming
Preferably, the resin sheet is a foamed resin sheet, and the method further comprises an expansion step, wherein in the expansion step, the space is provided between the first mold and the second mold. The first mold and the second mold are brought close to each other, and the resin sheet is expanded into the space by suctioning the resin sheet under reduced pressure from both the first mold and the second mold that are close to each other. .

FIG. 1A is a perspective view of a molded body 24 according to the embodiment of the present invention. FIG. 1B is an enlarged view of a dotted line part in FIG. 1A. FIG. 1C is a cross-sectional view taken along line XX in FIG. 1A. One example of a foam molding machine 1 that can be used in the production of a molded body 24 is shown. 3A and 3B are perspective views of the first mold 21 and the second mold 22. FIG. FIG. 3C is an enlarged view of a dotted line part in FIG. 3B. FIG. 3 is a view showing an arrangement of a first mold 21, a second mold 22, a foamed resin sheet 23, and a skin member 28. FIG. 5 is a diagram illustrating a state where the foamed resin sheet 23 is suctioned under reduced pressure by a first mold 21 from the state of FIG. 4. FIG. 6 is a diagram showing a state in which a first mold 21 and a second mold 22 are brought closer to each other from the state of FIG. 5. FIG. 7 is a diagram illustrating a state where the foamed resin sheet 23 is suctioned under reduced pressure by a second mold 22 from the state of FIG. 6. FIG. 4 is a view showing a state where a molded body 24 is taken out from a first mold 21 and a second mold 22.

  Hereinafter, embodiments of the present invention will be described. Various features shown in the embodiments described below can be combined with each other. In addition, the invention is independently established for each characteristic item.

1. Molded body 24
With reference to FIGS. 1A to 1C, a molded body 24 according to an embodiment of the present invention will be described. The molded body 24 includes a foamed resin sheet 23 and a skin member 28, and has a concave cross section. The expansion ratio of the foamed resin constituting the molded body 24 can be, for example, 1.5 to 6 times, but is not limited to this example.

  The skin member 28 is mounted on the design surface D of the molded body 24. In an example, the skin member 28 is formed of a nonwoven fabric having air permeability, and specific examples thereof include nylon fibers, cellulose fibers, and aramid fibers, but are not limited thereto.

  On the design surface D, as shown in FIG. 1B, there is formed a mark area D1 to which a mark composed of the concave portion 5 and the convex portion 7 is attached. The mark area D1 is configured such that a predetermined mark is visually recognized by the shapes of the concave portion 5 and the convex portion 7.

  More specifically, the concave portion 5 forms a line indicating the contour of the mark and the internal shape thereof. The convex portion 7 forms a region surrounded by the concave portion 5. Thus, the mark area D1 is formed from the concave portions 5 and the convex portions 7. The design surface D further has a general area D2 as an area outside the mark area D1.

  As shown in FIG. 1C, the mark area D1 is configured to have a smaller thickness than the general area D2. That is, the thickness of the concave portion 5 and the convex portion 7 is smaller than that of the general region D2. Further, the concave portion 5 is configured to have a smaller thickness than the convex portion 7. As described above, by forming the concave portion 5 and the convex portion 7 so as to have a thickness smaller than that of the general region D2 on the design surface D, visibility of the mark indicated by the mark region D1 is secured.

  The resin of the foamed resin sheet 23 is impregnated in the concave portion corresponding portion 29 corresponding to the concave portion 5 in the skin member 28. Since the resin is impregnated in the skin member 28 corresponding to the concave portion 5 in the mark area D1, hair fall in the concave portion corresponding portion 29 generated at the time of forming the concave portion 5 is fixed, and the gloss is made by the impregnated resin. appear. Thereby, the visibility of the mark area D1 formed on the design surface D is improved.

2. Configuration of Foam Molding Machine 1 With reference to FIG. 2, a description will be given of a foam molding machine 1 that can be used for performing a method of manufacturing a molded body 24 according to an embodiment of the present invention. The foam molding machine 1 includes a resin supply device 2, a T-die 18, a first mold 21, and a second mold 22. The resin supply device 2 includes a hopper 12, an extruder 13, an injector 16, and an accumulator 17. The extruder 13 and the accumulator 17 are connected via a connecting pipe 25. The accumulator 17 and the T-die 18 are connected via a connecting pipe 27.
Hereinafter, each configuration will be described in detail.

<Hopper 12, extruder 13>
The hopper 12 is used for charging the raw material resin 11 into the cylinder 13a of the extruder 13. The form of the raw material resin 11 is not particularly limited, but is usually in a pellet form. The raw material resin is, for example, a thermoplastic resin such as a polyolefin, and examples of the polyolefin include low-density polyethylene, linear low-density polyethylene, high-density polyethylene, polypropylene, ethylene-propylene copolymer, and a mixture thereof.

  The raw material resin 11 is put into the cylinder 13a from the hopper 12, and then melted by being heated in the cylinder 13a to become a molten resin. Further, it is transported toward the tip of the cylinder 13a by the rotation of a screw arranged in the cylinder 13a. The screw is arranged in the cylinder 13a, and conveys the molten resin while kneading it by rotation. A gear device is provided at the base end of the screw, and the screw is driven to rotate by the gear device. The number of screws arranged in the cylinder 13a may be one, or may be two or more.

<Injector 16>
The cylinder 13a is provided with an injector 16 for injecting a blowing agent into the cylinder 13a. The foaming agent injected from the injector 16 includes a physical foaming agent, a chemical foaming agent, and a mixture thereof, and is preferably a physical foaming agent. As the physical foaming agent, use is made of an inorganic physical foaming agent such as air, carbon dioxide, nitrogen gas, and water, and an organic physical foaming agent such as butane, pentane, hexane, dichloromethane, and dichloroethane, and further, a supercritical fluid thereof. be able to.

  As the supercritical fluid, it is preferable to use carbon dioxide, nitrogen, or the like. For nitrogen, the critical temperature is 149.1 ° C. and the critical pressure is 3.4 MPa or more. It can be obtained by setting it to 7.4 MPa or more. Examples of the chemical blowing agent include those which generate carbon dioxide gas by a chemical reaction between an acid (eg, citric acid or a salt thereof) and a base (eg, baking soda). The chemical blowing agent may be supplied from the hopper 12 instead of being injected from the injector 16.

<Accumulator 17, T-die 18>
The foamed resin obtained by melt-kneading the raw material resin and the foaming agent is extruded from the resin extrusion port of the cylinder 13 a and injected into the accumulator 17 through the connecting pipe 25. The accumulator 17 includes a cylinder 17a and a piston 17b slidable therein, and the foamed resin can be stored in the cylinder 17a. Then, by moving the piston 17b after the foamed resin is stored in the cylinder 17a by a predetermined amount, the foamed resin is pushed out from the slit provided in the T-die 18 through the connecting pipe 27, and hangs down, thereby forming the foamed resin sheet 23. Form.

<First and second molds 21 and 22>
The first mold 21 and the second mold 22 will be described with reference to FIGS. 3A to 3C. The first mold 21 is configured as a concave mold that forms a cavity 21b on the facing surface 21a. On the other hand, the second mold 22 is configured as a convex mold that forms the core 22b on the facing surface 22a. The first mold 21 and the second mold 22 are arranged such that the cavity 21b and the core 22b face each other.

  A pinch-off portion 21c is provided at a peripheral end of the facing surface 21a of the first mold 21 so as to surround the cavity 21b. Further, a pinch-off portion 22c is provided at a peripheral end of the facing surface 22a of the second mold 22 so as to surround the core 22b. When the first mold 21 and the second mold 22 are brought close to each other, as shown in FIG. 6, the pinch-off portion 21c and the pinch-off portion 22c come into contact with each other, and the facing surface 21a and the facing surface 22a form a closed space S. It is configured to:

  As shown in FIG. 3B, a mark forming portion 20 is formed on the facing surface 22a of the second mold 22. Although the details will be described later, in the process of manufacturing the molded body 24, the mark forming section 20 presses the foamed resin sheet 23 and the skin member 28 housed in the closed space S so that the design surface D of the molded body 24 is A mark area D1 is formed.

  As shown in FIG. 3C, the mark forming part 20 includes a concave part forming part 20a and a convex part forming part 20b. The concave portion forming portion 20a is configured to protrude from the convex portion forming portion 20b with reference to the facing surface 22a. In this way, when the foamed resin sheet 23 and the skin member 28 accommodated in the closed space S are pressed in the step of manufacturing the molded body 24, the concave part 5 is formed in the molded body 24 by the concave part forming part 20a. Then, the convex portion 7 is formed by the convex portion forming portion 20b.

  In the present embodiment, the mark forming section 20 is formed of a member different from the second mold 22. By doing so, it is possible to change the mark applied to the molded body 24 only by changing the shape of the mark forming section 20. However, the present invention is not limited to this example, and the second mold 22 and the mark forming section 20 may be formed integrally.

  As shown in FIG. 2, the first mold 21 and the second mold 22 are provided with a large number of reduced pressure suction holes 21d and 22d. Although the details will be described later, the foamed resin sheet 23 housed in the closed space S is suctioned under reduced pressure from the suction holes 21d and 22d, so that the facing surface 21a of the first mold 21 and the facing surface of the second mold 22 are opposed to each other. The foamed resin sheet 23 can be shaped into a shape along the surface 22a.

3. Manufacturing Method of Molded Body 24 With reference to FIGS. 4 to 8, a method of manufacturing the molded body 24 according to the embodiment of the present invention will be described. The method of this embodiment includes an arrangement step, a molding step, an expansion step, and a finishing step. The details will be described below.

(1) Arranging Step In the arranging step, as shown in FIG. 4, one foamed resin sheet 23 formed by extruding a molten foamed resin from the slit of the T-die 18 and hanging it down is formed into a first mold 21 and a second mold 21. It is arranged between the two molds 22. A skin member 28 is further arranged on the second mold 22 side.

  Here, the foamed resin sheet 23 hung down from the T-die 18 is cooled to room temperature before molding and is not solidified, and the solidified foamed resin sheet 23 is not heated before molding. Immediately after being extruded from the slit, the foamed resin sheet 23 has a substantially uniform temperature as a whole, and is gradually cooled from the surface by the atmosphere while being suspended.

  The foamed resin sheet 23 has such a property that the temperature is increased toward the center in the thickness direction and the viscosity is reduced, because the foamed resin sheet 23 is less susceptible to the cooling by the air toward the center in the thickness direction. The thickness of the foamed resin sheet 23 is not particularly limited, but is, for example, 0.5 to 5 mm, and preferably 1 to 3 mm.

(2) Forming Step In the forming step, the first suction step and the mold proximity step are performed in this order. In the first suction step, as illustrated in FIG. 5, the foamed resin sheet 23 is suctioned by the first mold 21 under reduced pressure. Thereby, the foamed resin sheet 23 is shaped into a shape along the cavity 21 b of the first mold 21.

  In the mold approaching step, as shown in FIG. 6, the first mold 21 and the second mold 22 are brought close to each other. As described above, when the first mold 21 and the second mold 22 are brought close to each other, the pinch-off portion 21c provided on the first mold 21 and the pinch-off portion 22c provided on the second mold 22 come into contact with each other. Thus, a closed space S surrounded by the facing surface 21a and the facing surface 22a is formed. The volume of the closed space S is not particularly limited, but is preferably 1.1 to 4.0 times the volume of the foamed resin sheet 23. The portions of the foamed resin sheet 23 and the skin member 28 outside the closed space S are burrs 23a and burrs 28a.

  At this time, the skin member 28 and the foamed resin sheet 23 are pressed by the mark forming portion 20 formed on the facing surface 22a of the second mold 22, thereby forming the mark area D1. As described above, the concave portion forming portion 20a is configured to protrude from the convex portion forming portion 20b, and the skin member 28 in contact with the concave portion forming portion 20a is impregnated with the resin of the foamed resin sheet 23. It becomes.

  Here, preferably, the height of the recess forming portion 20a in the protruding direction is configured to be equal to the thickness of the closed space S (that is, the interval between the opposed surface 21a and the opposed surface 22a). By doing so, the pressure applied to the foamed resin sheet 23 corresponding to the concave portion forming portion 20a can be increased, and the skin member 28 corresponding to the concave portion 5 of the molded body 24 (corresponding to the concave portion corresponding portion 29 in FIG. 1C). Thus, more resin can be impregnated.

(3) Expansion Step In the expansion step, as shown in FIG. 7, a second suction step of vacuum-suctioning the foamed resin sheet 23 from both the first mold 21 and the second mold 22 is performed. Thereby, the foamed resin sheet 23 is expanded in the closed space S.

  When the foamed resin sheet 23 is suctioned from both the first mold 21 and the second mold 22 under reduced pressure, the foaming of the foamed resin sheet 23 is promoted and the foamed resin sheet 23 expands. Since the foamed resin sheet 23 has the lowest viscosity near the center in the thickness direction (highest fluidity), foaming near the center in the thickness direction is particularly promoted, and the foamed resin sheet 23 expands. As a result, a molded body 24 having a structure in which the average cell diameter in the layer near the center in the thickness direction (center layer) is large and the average cell diameter in the surface layer near the surface is small. Such a molded body 24 is lightweight and highly rigid because the central layer having a large average cell diameter has a sandwich structure sandwiched between surface layers having a small average cell diameter. Here, the average bubble diameter in the entire thickness direction is, for example, 100 to 2000 μm. The average cell diameter of the surface layer is, for example, 80 to 500 μm. The average cell diameter of the central layer is, for example, 100 to 2000 μm.

(4) Finishing Step In the finishing step, as shown in FIG. 8, the first mold 21 and the second mold 22 are opened, the burrs 23a and the molded body 24 with the burrs 28a are taken out, and the burrs 23a and 28a are removed. By cutting, the molded body 24 shown in FIG. 1 is obtained. As described above, the molded body 24 in which the skin member 28 is mounted on the foamed resin sheet 23 is formed.

4. Other Embodiments The applicable range of the present invention is not limited to the above embodiment. For example, the reduced pressure suction by the first mold 21 and the second mold 22 may start the reduced pressure suction by the first mold 21 first, or may start the reduced pressure suction by the second mold 22 first. The vacuum suction by the first mold 21 and the second mold 22 may be started simultaneously. Further, the reduced pressure suction by the first mold 21 may be stopped first, the reduced pressure suction by the second mold 22 may be stopped first, and the reduced pressure suction by the first mold 21 and the second mold 22 may be performed. May be stopped at the same time. The reduced pressure suction by the first mold 21 and the second mold 22 may be started before the first mold 21 and the second mold 22 are brought close to each other, or may be started after bringing them close to each other.

  Further, the expansion step can be omitted. Further, the resin sheet is not limited to the foamed resin sheet. Further, in the above embodiment, the thickness of the convex portion 7 of the mark area D1 is smaller than the thickness of the general area D2 outside the mark area on the design surface D, but is not limited to this form. The thickness of the portion 7 may be substantially equal to the thickness of the general area D2. In this case, it is preferable to provide the reduced-pressure suction hole 22d so as to communicate with the protrusion forming portion 20b of the mark forming portion 20 provided in the second mold 22. This makes it possible to more appropriately shape the foamed resin sheet 23 into a shape along the mark forming portion 20. In these cases, the same effects as in the above embodiment can be obtained.

1: foam molding machine 2: resin supply device 5: concave portion 7: convex portion 11: raw resin 12: hopper 13: extruder 13a: cylinder 16: injector 17: accumulator 17a: cylinder 17b: piston 18: T-die 20: mark Forming part 20a: concave part forming part 20b: convex part forming part 21: first mold 21a: facing surface 21b: cavity 21c: pinch-off part 21d: reduced pressure suction hole 22: second mold 22a: facing surface 22b: core 22c: Pinch-off portion 22d: Decompression suction hole 23: Foam resin sheet 23a: Burr 24: Molded body 25: Connection tube 27: Connection tube 28: Skin member 28a: Burr 29: Depression corresponding portion

Claims (5)

A resin sheet and a molded body provided with a skin member attached thereto,
The surface on the skin member side is a design surface,
The design surface includes a mark area with a mark composed of a concave portion and a convex portion,
A molded product, wherein the skin member corresponding to the concave portion is impregnated with a resin of the resin sheet. It is a molded object according to claim 1,
A molded body, wherein the thickness of the convex portion of the mark area is smaller than the thickness of a general area outside the mark area on the design surface. The molded article according to claim 1 or claim 2,
The molded article, wherein the resin sheet is a foamed resin sheet. A method for producing a molded article, comprising:
Including an arrangement step and a molding step,
In the arranging step, a resin sheet and a skin member are arranged between the first mold and the second mold,
In the molding step, the resin sheet and the skin member are molded by the first mold and the second mold,
A mark forming part including a concave part forming part and a convex part forming part is provided on one of the opposing surfaces of the first die and the second die,
In the molding step, a method of forming a mark region with a mark formed of a concave portion and a convex portion by pressing the skin member and the resin sheet by the mark forming portion. 5. The method according to claim 4, wherein
The resin sheet is a foamed resin sheet,
The method further comprises an inflation step,
In the expanding step, the first mold and the second mold are brought close to each other so that a space is provided between the first mold and the second mold,
A method of expanding the resin sheet into the space by vacuum-suctioning the resin sheet from both the first mold and the second mold that are close to each other.