JP3049705B2 - Molding method for vehicle interior materials - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming an interior material for a vehicle, and more particularly, to an interior base material used for a molded ceiling, a door trim and other interior materials for a vehicle. The present invention relates to a method of molding an interior material for a vehicle comprising a skin material joined to a surface side of a vehicle.

[0002]

2. Description of the Related Art Conventionally, molded ceilings for vehicles and the like, door trims and other interior materials are formed by joining a skin material to a ceiling base material, an interior base material, and the like. Some of these ceiling base materials and interior base materials use a foamed polypropylene base material (hereinafter referred to as a PP base material).

As shown in FIG. 4, a conventional interior material 1 such as a molded ceiling for a vehicle is formed of an interior substrate 2 and a skin material 3 joined to the surface side of the interior substrate 2. The interior base material 2 is made of a PP base material, and the skin material 3 is made of a nonwoven fabric or the like. In addition, the skin material 3 can also be formed from a cloth-made skin such as a tricot on the front side and wadding such as slab urethane laminated on the back side of the skin.

[0004] In the case where the interior base material 2 made of the PP base material of the conventional interior material 1 and the skin material 3 are joined, the surface temperature of the PP base material is heated to 220 to 240 ° C, and the foamed material is heated and foamed. And press-molded at room temperature to be integrated.

[0005]

When the interior base material 2 made of the PP base material of the conventional interior material 1 shown in FIG. 4 and the skin material 3 are joined, the surface temperature of the PP base material is set to 220 to 240. ° C
Is heated and foamed, laminated on the skin material 3 and press-molded at room temperature, but tension is applied so that the skin material 3 does not wrinkle. A cell of a certain PP base material is crushed, and molding cannot be performed along the R shapes 22a and 23a due to the unevenness of the lower die 22 and the upper die 23 in a deep drawing portion of the PP base material, and the skin material 3 and the upper die 23 A gap 5 was generated between them, and a sharp R shape could not be obtained, and the thickness of the interior base material 2 became thin, and there was a possibility that the strength was reduced. Further, not only in the deeply drawn portion of the PP base material, but also in the flat surface portion of the general surface, since the interior base material 2 is cooled and shrunk by 10 to 15% after molding, there is a possibility that the strength is reduced.

An object of the present invention is to eliminate the risk that cells of an interior base material made of a PP base material in a molten and foamed state during press molding are crushed, and a sharp R-shape is formed in a deep drawing portion of the PP base material. An object of the present invention is to provide a method of forming an interior material for a vehicle, which can be molded, does not have a possibility of reducing the thickness of the interior base material, and can improve the strength.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and a method for forming an interior material for a vehicle according to the first aspect of the present invention includes an interior base material and a surface side of the interior base material. In the method for molding a vehicular interior material comprising a skin material to be joined, the interior base material is formed from a foamed polypropylene base material, and the foamed polypropylene base material and the skin material are heated to a molding temperature of the foamed polypropylene base material. In this state, press molding is performed integrally with a press molding die, and then the air inside the press molding die is evacuated to expand the cells of the expanded polypropylene base material.

[0008] The method of molding an interior material for a vehicle according to claim 2 is a method of molding an interior material for a vehicle comprising an interior substrate and a skin material bonded to a surface side of the interior substrate. A base material is formed from a foamed polypropylene base material, a nonwoven fabric for preventing drawdown during heating is laminated on the back surface of the foamed polypropylene base material, and the foamed polypropylene base material, the nonwoven fabric and a skin material are molded into a foamed polypropylene base material at a molding temperature. In this state, the press-molding unit is used to perform press-molding in a heated state, and then the air inside the press-molding unit is evacuated to expand the cells of the foamed polypropylene base material.

According to a third aspect of the present invention, there is provided a method of molding an interior material for a vehicle, wherein the expansion of the cells of the expanded polypropylene base material due to the evacuation of the air inside the press forming die is performed after the integrated press forming by the press forming die. This is performed after a lapse of up to 30 seconds.

According to the method for molding an interior material for a vehicle according to the first aspect of the present invention, the foamed polypropylene base material and the skin material are integrated by a press mold while the foamed polypropylene base material is heated to a molding temperature. Press-molded, then the air inside the press mold is evacuated and the cells of the expanded polypropylene base are expanded, so even if the cells of the expanded polypropylene base are temporarily compressed by press forming, It is stretched again by evacuation, the thickness of the foamed polypropylene base material increases, and sharp R-shaped molding can be performed.

According to the method for molding an interior material for a vehicle according to the second aspect of the present invention, the nonwoven fabric for preventing drawdown during heating is laminated on the back surface of the foamed polypropylene base material. Even if the base material is heated to the molding temperature, there is no danger of the foamed polypropylene base material being drawn down, and the back side of the foamed polypropylene base material is pressed when the back surface of the foamed polypropylene base material is integrally pressed by a press mold. Even if the cell is temporarily compressed by press molding, it is stretched again by evacuation, the thickness of the expanded polypropylene base material increases, and a sharp R-shaped molding can be performed.

Further, according to the method of molding an interior material for a vehicle according to claim 3 of the present invention, the expansion of the cells of the foamed polypropylene base material due to the evacuation of the air inside the press mold is controlled by the press mold. 5-30 after integral press molding by
Since it is performed after the lapse of seconds, the temperature of the foamed polypropylene base material decreases, without vacuuming in the state of excessive melting,
Cell destruction can be prevented, sharp R-shaped molding can be performed, and the thickness of the interior base material increases and the strength improves.
The peeling of the skin material and the interior base material can be prevented, and the feel and appearance can be improved.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a method for forming a vehicular interior material according to the present invention will be described in detail with reference to the drawings. 1 and 2
(A) and (b) show an outline of an embodiment of a method of forming an interior material for a vehicle according to the present invention. In the present embodiment, a case where the invention is applied to a molded ceiling for a vehicle as an interior material is shown. However, the present invention is not limited to this.

As shown in FIG. 1, the interior material 11 is
2 and a skin material 1 laminated on the surface side of the interior base material 12.
3 is formed. The interior substrate 12 is made of a secondary or post-expanded polypropylene (PP) substrate, and the PP substrate contains 5 to 20% by weight of glass fiber. The PP substrate has a basis weight of 700 to 1000 g / m ² ,
The foam thickness is 3.5 to 5.0 mm, and the foam thickness is 4 to 5 times that of the raw material.

The skin material 13 is made of a non-woven fabric or the like, for example, a PET non-woven fabric having a basis weight of 100 to 200 g / m ^2.
Is used. The nonwoven fabric may be a PP nonwoven fabric, a PE nonwoven fabric, a nylon nonwoven fabric, an acrylic nonwoven fabric, or the like, or may be formed from a cloth skin such as a tricot on the front side and wadding such as slab urethane laminated on the back side of the skin. A skin material can also be used.

While the PP base material is heated to the molding temperature, the interior base material 12 and the skin material 13 made of the PP base material are integrally press-formed by a room-temperature press mold 21. The back surface side of the skin material 13 is impregnated to form the interior base material 12 and the skin material 13 in a joined state.

The lower mold 22 and the upper mold 23 of the press mold 21 are formed in a vacuum mold, and a plurality of air discharge holes 25 are formed at positions corresponding to the R shapes 22a and 23a due to the unevenness of the lower mold 22 and the upper mold 23. Are formed, and a vacuum pump 27 is provided so as to communicate with the plurality of air discharge holes 25.

Next, a method of forming the interior material 11 will be further described with reference to FIGS. 2 (a) and 2 (b). The PP substrate 12 is heated by a heating furnace or the like. When the surface temperature of the PP base material 12 is 2
After heating to 20 to 240 ° C., it is inserted between the lower mold 22 and the upper mold 23 of the press mold 21 at room temperature of 20 to 50 ° C.

A skin material 13 made of a PET non-woven fabric is clamped on the upper mold 23 of the press mold 21 at room temperature. By clamping the lower mold 22 and the upper mold 23 of the press mold 21, the front side of the heated and melted PP base material 12 impregnates the back side of the skin material 13 made of PET nonwoven fabric,
Impregnated and joined.

Next, after integral press molding by the press mold 21, after 5 to 30 seconds, preferably 10 to 15 seconds,
After a lapse of seconds, the vacuum pump 27 of the press mold 21 is operated to release the air inside the press mold 21 to the air discharge holes 2.
5 is evacuated to expand the cells of the PP substrate 12.

If the evacuation is performed before the elapse of 5 seconds after the integral press molding, the cells of the PP substrate 12 are in a state of being heated and melted. After the elapse of 31 seconds or more, the PP base material 12 is excessively cooled, and the expansion of the cell cannot be sufficiently obtained.

FIG. 3 shows a different embodiment of the present invention. In this embodiment, a nonwoven fabric 15 for preventing drawdown during heating is laminated on the back surface of the PP base material 12. Is the same as in the above-described embodiment.

Accordingly, the PP base material 12, the non-woven fabric 15 and the skin material 13 are integrally press-formed by a room-temperature press mold 21 while the PP base material 12 and the non-woven fabric 15 are heated to a forming temperature. By evacuating the air inside the press mold 21 by operating the vacuum pump 27, the cells of the PP substrate 12 can be expanded.

In the embodiment shown in FIG. 3, the air discharge hole 25 for evacuating the air inside the press mold 21 is made of PP.
It is formed not only at the deep drawing portion of the base material 12 but also at a position corresponding to the flat surface portion of the general surface, so that the cells of the flat surface portion of the PP base material 12 can be expanded.

[0025]

The above is the method of the embodiment of the method for forming an interior material for a vehicle according to the present invention. According to the method for forming an interior material for a vehicle according to the first aspect of the present invention, the interior base material is used. Is formed from a foamed polypropylene base material, and the foamed polypropylene base material and the skin material are integrally press-formed by a room-temperature press mold in a state where the foamed polypropylene base material is heated to a molding temperature. The air of the foamed polypropylene base material is expanded by evacuating the air of the foam, and the cells of the foamed polypropylene base material are stretched by evacuation, the thickness of the foamed polypropylene base material is increased, and a sharp R-shaped molding is performed. Can be.

According to a second aspect of the present invention, a nonwoven fabric for preventing drawdown during heating is laminated on the back surface of the foamed polypropylene base material, and the foamed polypropylene base material and the nonwoven fabric and the skin material are laminated. While the foamed polypropylene base material is heated to the molding temperature, the foamed polypropylene base material is press-molded integrally with a press mold at room temperature, and then the air inside the press mold is evacuated to expand the cells of the foamed polypropylene base material. Therefore, it is possible to prevent the foamed polypropylene base material from being drawn down when the foamed polypropylene base material is heated, and after the press molding, the cells of the foamed polypropylene base material are stretched by evacuation to reduce the thickness of the foamed polypropylene base material. Increased and sharp R-shaped molding can be performed.

According to a third aspect of the present invention, the expansion of the cells of the expanded polypropylene base material due to the evacuation of the air inside the press mold is performed after the integrated press molding by the press mold. , After 5 to 30 seconds, the temperature of the foamed polypropylene base material is lowered, and the cell is prevented from being destroyed without being evacuated in the state of being excessively melted. Can,
The thickness of the interior base material is increased, the strength is improved, the peeling of the skin material and the interior base material is prevented, and the feel and appearance can be improved.

According to the present invention, there is no fear that cells of the interior base material made of the foamed polypropylene base material in the melt-foamed state during press molding are crushed. Shape can be formed,
There is no fear that the thickness of the interior base material is reduced, and a method of molding a vehicle interior material that can improve strength can be obtained.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional view showing a method of forming an interior material for a vehicle according to the present invention, which is formed by press forming at room temperature and then evacuating.

FIGS. 2A and 2B show a method of forming an interior material for a vehicle according to the present invention, in which FIG. 2A is a cross-sectional view showing a state in which an interior base material and a skin material are laminated, and FIG. Sectional drawing of the state pulled.

FIG. 3 shows a different embodiment of a method for molding a vehicular interior material according to the present invention.
FIG. 3 is a partial cross-sectional view in a state where vacuum has been drawn.

FIG. 4 is a partial cross-sectional view showing a conventional method for forming an interior material for a vehicle.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Interior material 12 Interior base material 13 Skin material 15 Nonwoven fabric 21 Press mold 22 Lower mold 23 Upper mold 25 Air exhaust hole 27 Vacuum pump

Continued on the front page (51) Int.Cl. ⁷ Identification code FI B29L 31:58

Claims (3)

(57) [Claims] 1. A method for molding a vehicular interior material comprising an interior substrate and a skin material bonded to a surface side of the interior substrate, wherein the interior substrate is formed from a foamed polypropylene substrate, The polypropylene base material and the skin material are integrally press-formed with a press mold while the foamed polypropylene base material is heated to the molding temperature, and then the air inside the press mold is evacuated to form a cell of the foamed polypropylene base material. A method for molding an interior material for a vehicle, comprising: 2. A method for molding a vehicular interior material comprising an interior base material and a skin material bonded to a surface side of the interior base material, wherein the interior base material is formed from a foamed polypropylene base material. A nonwoven fabric for preventing drawdown during heating is laminated on the back surface of the polypropylene base material, and the foamed polypropylene base material and the nonwoven fabric and the skin material are integrally press-formed by a press mold while the foamed polypropylene base material is heated to a molding temperature. Then, the air inside the press mold is evacuated to expand the cells of the foamed polypropylene base material, thereby molding a vehicle interior material. 3. The method according to claim 1, wherein the expansion of the cells of the foamed polypropylene base material by evacuation of the air inside the press mold is performed 5 to 30 seconds after integral press molding by the press mold. The method of molding an interior material for a vehicle according to claim 1 or claim 2.