JP2000167859A - Method for integrally molding skin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for integrally molding a skin by which a manufacturing cost can be saved and a molded product integrally molded with a skin having a uniform cushioning feel can be insert-molded without the use of a large-scale processing device. SOLUTION: This method for integrally molding a skin comprises a sheet manufacturing step for obtaining an unfoamed sheet 4 with a skin 3 by superposing the skin 3 on the unfoamed sheet 10, an insertion step to arrange the unfoamed sheet 4 with the skin 3 in the cavity 51 of a mold 5, a molding step to inject a base material resin 6 into the cavity 51 to mold an insert molded product 7 and a foaming step to unload the insert molded product 7 from the cavity 51 of the mold 5 and heat the unfoamed sheet 10 to foam.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for integrally molding a skin, and more particularly to an insert molding method.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 4, in the process of integrally molding an insert material composed of a skin and a foamable resin with a base resin, a foaming agent 911 and a base resin 912 such as polypropylene are used in a step a. The mixture is mixed and extruded in an extruder 919 to obtain an unfoamed sheet 910.

[0003] Next, in step b, the unfoamed sheet 9
10, electron beam irradiation by the electron beam irradiation device 921, heating by the heater 922, and corona discharge by the corona treatment device 923 are performed. The irradiation of the electron beam is performed on the unfoamed sheet 910.
The base resin 912 in the inside is crosslinked. Heating by the heater 922 causes the unfoamed sheet 910 to foam to form the foamed sheet 91. The corona discharge smoothes the surface of the foam sheet 91. Next, in step c, the foam sheet 91
A skin 93 is laminated on the surface to form a foam sheet 94 with a skin, and cut into a desired shape by a cutter 916. Note that FIG.
, Reference numerals 918 and 917 denote a drawing roller and a rolling roller.

[0005] Next, as shown in FIG.
Insert into 1. The mold 95 includes a convex 952, a concave 953, a cavity 951 formed between the convex 952 and the concave 953, an injection device 958 for injecting the base resin 96 into the cavity 951, and a gate 954. Have. When the foamed sheet 94 with a skin is inserted into the cavity 951, the foamed sheet 91 side has the gate 95.
Insert in the direction facing 4.

Next, in the step e, the convex mold 952 and the concave mold 953 are clamped, and the gate 9 is closed by the injection device 958.
The base resin 96 is injected into the cavity 951 through 54 to form a skin integral molded product 98. Next, in step f, the mold is opened to take out the skin integral molded product 98 from the cavity 951 (FIG. 5 (f1)). As described above, a skin integral molded product 98 is obtained in which the base resin 96 is integrally molded with the skin foam sheet 94 composed of the skin 93 and the foam sheet 91 (FIG. 5 (f2)).

[0006]

However, the foam sheet 91 is soft and thick. Therefore, as shown in FIGS. 5E and 6, when the base resin 96 is insert-molded into the soft and thick foam sheet 91, the base resin and the foam of the foam sheet 91 are generated by the heat and pressure of the base resin 96. The agent begins to melt. The eluted portion 915 of the foam sheet 91
Is hard and thin, and loses cushioning properties, and impairs the cushioning feeling of the integrally molded skin 98. Further, as shown in FIG. 4, in the step b, a large-scale processing device such as an electron beam irradiation device 921, a heater 922, and a corona processing device 923 is required, and the production cost of the foam sheet 91 increases.

The present invention has been made in view of the above-mentioned conventional problems, and it is possible to reduce the production cost without using a large-scale processing apparatus and to insert-mold a skin-integrated molded product having a uniform cushioning feeling. An object of the present invention is to provide a method for integrally molding a skin.

[0008]

The present invention relates to a sheet manufacturing process for obtaining an unfoamed sheet with a skin by laminating an unfoamed sheet comprising a foaming agent and a base resin with a skin, and forming the unfoamed sheet with a skin into a mold. Inserting the base resin into the cavity to form an insert-molded product; removing the insert-molded product from the cavity; heating the insert-molded product to form the insert-molded product; And a foaming step of foaming an unfoamed sheet.

In the present invention, the most remarkable thing is that the base resin is insert-molded together with the unfoamed sheet with a skin to obtain an insert-molded product, which is molded, and then heated to form an unfoamed sheet in the insert-molded product. To foam the sheet.

In the method for integrally forming a skin of the present invention, an unfoamed sheet with a skin is insert-molded. The unfoamed sheet is thin and hard because it is an unfoamed sheet. For this reason, even when subjected to heat and pressure due to the injected base resin during the insert molding, the unfoamed sheet is less likely to melt. Since the insert molded product is heated after the insert molding to foam the unfoamed sheet, it is possible to form a skin integrated molded product lined with a foamed sheet of uniform thickness and having an excellent cushion feeling.

[0011] Further, since the foam sheet is foamed by heating the insert molded product, other processes such as corona treatment are not required in the heating step. Therefore, the heating process is simplified, and the cost of manufacturing equipment can be reduced.

It is preferable that the base resin is a resin that does not need to be crosslinked. As a result, it is not necessary to provide a special treatment for cross-linking, and it is possible to further reduce equipment costs. The above-mentioned non-crosslinking resin means a resin which has a strong restoring force against heat and pressure without cross-linking. As the resin which does not need to be crosslinked, for example, ethylene vinyl acetate resin, vinyl chloride, thermoplastic elastomer and the like can be used.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 An integrated skin forming method according to an embodiment of the present invention will be described with reference to FIGS. The skin integral molding method of this embodiment includes a sheet manufacturing process, an insert process, a molding process, and a foaming process. Hereinafter, this will be described in detail.

(A) Sheet manufacturing process First, as shown in FIG.
And prepare. As the foaming agent 11, azodicarboxylic acid amide or the like is used, and as the base resin 12, an ethylene vinyl acetate resin is used. The blowing agent 11 and the base resin 12 are charged into an extruder 19 and melt-kneaded. Next, the extruder 19
The kneaded material is extruded into a sheet form from a forming nozzle 190 provided at the lower part of the sheet, and is continuously drawn out by a draw-out roller 18 to obtain an unfoamed sheet 10.

Next, the unfoamed sheet 10 and the skin 3 are overlaid, and both are pressed by a rolling roller 17 to obtain an unfoamed sheet 4 with a skin, which is an integrated product. As the skin 3, a fabric skin is used. Next, the unfoamed sheet 4 with the skin is cut into a desired shape by the cutter 16.

(B) Insertion Step Next, as shown in FIG. 2B, a mold 5 for insert molding is prepared. The mold 5 includes a convex mold 52 and a concave mold 53.
A cavity 51 formed between the convex mold 52 and the concave mold 53; an injection device 58 for injecting the base resin 6 into the cavity 51; and a gate 54. The size of the unfoamed sheet 4 with the skin is set to cover the entire cavity surface 50 of the concave mold 53. Next, the unfoamed sheet 4 with skin
Is arranged in the cavity 51 of the mold 5. At this time, the unfoamed sheet 4 with the skin makes the skin 3 face the cavity surface 50.

(C) Molding Step After the mold 5 is clamped, the injection device 58 is used to
Then, the base resin 6 is injected into the cavity 51 of the mold 5 to form the insert molded product 7. As the base resin 6, polypropylene or the like is used.

(D) Foaming Step The insert molded product 7 is removed from the cavity 51 of the mold 5. The insert molded product 7 is heated to 200 ° C. by the heater 22 to foam the unfoamed sheet 10 to obtain the foamed sheet 1.

(E) Completion As described above, the base resin 6 is applied to the skin 3 and the foam sheet 1.
Is integrally molded to obtain a skin integral molded product 8. The obtained integrally molded skin 8 is used for, for example, interior door trim of automobiles, pillar garnish, and the like.

As described above, in the method for integrally forming the skin according to the present embodiment, as shown in FIG.
0 is unfoamed and thin and hard, so the injected base resin 6
, The unfoamed sheet 10 is less likely to melt. Therefore, as shown in FIG. 2 (e), the unmolded sheet 10 is foamed by heating the insert molded article, thereby backing the foamed sheet 1 having a uniform thickness and having an excellent cushioning feeling. Can be molded.

Further, as shown in FIG. 2 (d), when the insert molded article 7 is heated, the unfoamed sheet 10 foams, so that other processing such as corona treatment is not required in the heating step. Furthermore, since a material that does not need to be crosslinked is used as the base resin, electron beam irradiation for crosslinking is unnecessary.
Therefore, the heating process is simplified, and the cost of manufacturing equipment can be reduced.

[0022]

According to the present invention, the production cost can be reduced without using a large-scale processing apparatus.
Further, it is possible to provide a method for integrally forming a skin, which can insert-mold a integrally formed skin product having a uniform cushion feeling.

[Brief description of the drawings]

FIG. 1 is an explanatory view (a) of a method for integrally molding a skin according to a first embodiment.

FIG. 2 is an explanatory view (b) of the integral skin molding method following FIG. 1;
~ (E).

FIG. 3 is an explanatory view showing a molding step according to the first embodiment.

FIGS. 4A to 4C are explanatory views of a conventional method of integrally forming a skin.
(C).

FIG. 5 is an explanatory view (d) of the integral skin molding method following FIG. 4;
~ (F).

FIG. 6 is an explanatory view showing a molding step of a conventional example.

[Explanation of symbols]

 1. . . Foam sheet, 10. . . Unfoamed sheet, 11. . . Blowing agent, 12. . . Base resin, 16. . . Cutter, 18. . . Pull-out roller, 19. . . Extruder, 22. . . 2. heater, . . Epidermis, 4. . . 4. Unfoamed sheet with skin, . . Mold, 50. . . Cavity surface, 51. . . Cavity, 52. . . Convex, 53. . . Concave, 54. . . Gate, 58. . . Injection device, 6. . . 6. base resin; . . 7. Insert molded product, . . Skin integrated molded product,

 ────────────────────────────────────────────────── ─── Continued from the front page (72) Inventor Takahashi Hashimoto 100 Kanayama, Ichiriyama-cho, Kariya-shi, Aichi F-term (reference) in TOYOTA Auto Body Co., Ltd. 4F206 AA10 AA11 AB02 AG03 AG20 AH26 JA04 JB13 JC07 JF05 4F212 AA10 AA11 AB02 AG03 AG20 AH26 UA09 UB01 UB13 UG02 UG05

Claims (2)

[Claims] 1. An unfoamed sheet comprising a foaming agent and a base resin, a sheet manufacturing process for obtaining an unfoamed sheet with a skin by overlapping the skin, and disposing the unfoamed sheet with a skin in a cavity of a mold. An insert process for injecting a base resin into the cavity to form an insert molded product; removing the insert molded product from the cavity; heating the insert molded product to foam the unfoamed sheet; And a foaming step for forming the skin. 2. The method according to claim 1, wherein the base resin is
A method for integrally molding a skin, wherein the resin is a crosslinkable resin.