JPH06190936A - Method for forming bent / crimped portion on the periphery of automobile ceiling material - Google Patents

Abstract

(57) [Summary] [Purpose] Manufacturing cost can be reduced and workability is good.
Provided is a method for forming a bent / press-bonded portion on the periphery of an automobile ceiling material. [Constitution] A modified polyolefin film is melted by heating the periphery of an automobile ceiling material comprising a core material having a modified polyolefin film on both sides and a skin material bonded to the core material via a foam layer, and then melting the modified polyolefin film. A bent or crimped portion at the periphery of an automobile ceiling material, characterized in that the periphery is bent in a folded or curled shape with the core material inside and the bent portion is pressure-bonded to the ceiling material base by the modified polyolefin melt. It is a forming method.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molded ceiling material for vehicles such as automobiles, and more particularly to a method for forming a bent / crimped portion on the periphery of an automobile ceiling material.

[0002]

2. Description of the Related Art The basic structure of a thermoformable composite sheet used for a vehicle ceiling material is a core material, a foam laminated on one side thereof, and a skin material laminated on the one side ( See, for example, JP-A-63-287639). Conventional core material is made of cardboard, resin felt, glass fiber reinforced thermoplastic resin sheet, etc., as a terminal treatment of the front and rear portions of the ceiling material, generally after stripping the required peripheral edge of the core material, The peripheral edge of the ceiling material was treated by bending the remaining peripheral edge of the skin material into a folded shape and adhering the folded part to the core material with a double-sided tape and a thermosetting hot melt film or an adhesive.

[0003]

However, in the above processing method, it is inevitable that the manufacturing cost is increased due to the equipment for improving the peeling weight of the core material, and the core material is bent in a folded shape. Since the peripheral edge of the skin material needs to be adhered to the core material with an adhesive or the like, the work of processing the peripheral edge of the ceiling material becomes very troublesome.

In view of the above points, an object of the present invention is to provide a method of forming a bending / crimping portion at the periphery of an automobile ceiling material, which can reduce the manufacturing cost and has good workability.

[0005]

The method for forming a bent / press-bonded portion at the periphery of an automobile ceiling material according to the present invention has been devised to achieve the above object, and a core material having a modified polyolefin film on both sides and , A modified polyolefin film is melted by heating the peripheral edge of an automobile ceiling material composed of a skin material adhered to a core material via a foam layer, and then the folded or curled shape with the peripheral material inside the core material. The modified polyolefin melt is pressure-bonded to the base of the ceiling material.

The present invention will be described in detail below.

The core material is, for example, a mixed fiber non-woven fabric or a mat-like material mainly composed of inorganic fibers and thermoplastic resin fibers, and the inorganic fibers are bound by the thermoplastic resin.

As the inorganic fibers constituting the mat-like material of the core material, for example, glass fibers, rock wool, etc. are often used. The length of the inorganic fibers is preferably 5 to 250 mm, and more preferably 50 to 150 mm in length, and the inorganic fibers having a distribution of 70% by weight or more are used from the viewpoint of forming the mat-like material. The thickness of the inorganic fiber is
From the viewpoint of bending strength and thickness recoverability of the obtained thermoformed core material, it is preferably 5 to 20 μm, and more preferably 7
˜13 μm.

Further, as the thermoplastic resin fiber constituting the core material, a resin which is easily melted and bound to the glass fiber is preferable, and for example, a fiber made of a resin such as polyethylene, polypropylene or polystyrene is used. The length and thickness of the thermoplastic resin fiber are preferably such that they can be easily mixed with the above-mentioned inorganic fiber to form a mat-like material. Specifically, the length is preferably 5 to 200 mm, more preferably 20 to 100 mm. Thickness is 5
˜70 μm, more preferably 15 to 40 μm.

With respect to the mixing ratio of the inorganic fibers and the thermoplastic resin fibers, when the ratio of the inorganic fibers is small, the heat resistance of the obtained thermoformable core material is lowered, and when the ratio is large, the joint portion between the inorganic fibers is decreased and the mechanical fibers are mechanical It is preferable to set the weight ratio of the inorganic fiber and the thermoplastic resin to be in the range of 5: 1 to 1: 5 because the mechanical strength, that is, the rigidity is reduced.

As a method for producing the mat-like material, any method may be adopted. Generally, the above-mentioned inorganic fiber and thermoplastic fiber are supplied to a card machine, defibrated and needle punched to give a mat. To produce a product. The needle punch is preferably 2 to 10 per cm ² for the purpose of improving the mechanical strength of the mat-like material and the resulting thermoformable core material.
The number of hits is 0, more preferably 10 to 50.

The density of the mat-like material becomes heavier as the mat-like material increases, and the mechanical strength of the mat-like material decreases as the mat-like material becomes smaller. Therefore, the density is preferably 0.01 to 0.2 g / cm ³ . The weight of the mat-like material is preferably 300 to 1500 g / m ² , and more preferably 500 to 800 g / m ² in order to obtain mechanical strength.

The thermoplastic resin used for binding the inorganic fiber is one which is easily impregnated in the mat-like material in a molten state and is also bound to the glass fiber. Examples of such a thermoplastic resin include polyethylene,
Thermoplastic resins such as polypropylene, ethylene-vinyl acetate copolymer, saturated polyester and modified products thereof (for example, maleic anhydride-modified polyethylene) are used.

The modified polyolefin films provided on both sides of the core material are such that they are melted by heating the peripheral edge of the ceiling material described later, and the bent portion of the ceiling material is pressed against the ceiling material base by this melt. Examples of such a film include low density polyethylene, linear low density polyethylene, high density polyethylene, polypropylene, and a mixture thereof.

The foam layer interposed between the core material and the skin material is made of crosslinked polyolefin foam, soft urethane foam or the like. The polyolefin resin forming the base material of the expandable polyolefin resin composition includes homopolymers of olefin monomers such as ethylene, propylene, butene-1: ethylene vinyl acetate copolymer, ethylene propylene copolymer, ethylene vinyl chloride copolymer. Copolymers based on olefins such as polymers and ethylene-acrylic acid copolymers: Blocks, random blocks and random copolymers of one polyolefin resin with another polyolefin resin: chlorinated polyethylene, chlorinated polypropylene Substituted polyolefins such as: A polyolefin-based polyolefin blended with another resin such as an ethylene-vinyl acetate copolymer or polyvinyl chloride, or a rubber such as chloroprene rubber.

As the foaming agent, azodicarbonamide,
An organic decomposition type foaming agent such as dinitrosopentamethylenetetramine, allophanic acid amide, p, p′-oxybisbenzenesulfonyl hydrazide, or an inorganic decomposition type foaming agent such as sodium bicarbonate can be appropriately used. Among these, azodicarbonamide or the one based on it is preferable. In order to accelerate the decomposition of the foaming agent, known decomposition aids such as zinc oxide and zinc stearate may be added as appropriate.

The amount of the foaming agent added is the polyolefin resin 1
It is 10.0 to 35.0 parts by weight, preferably 20.0 to 30.0 parts by weight, relative to 00 parts by weight. When the amount of the foaming agent added is less than 10.0 parts by weight with respect to 100 parts by weight of the polyolefin resin, the crosslinked product in a molecularly fixed state cannot be sufficiently expanded by the three-dimensional network,
Therefore, the desired expansion ratio cannot be obtained. On the other hand, if the amount of the foaming agent added exceeds 35.0 parts by weight, the cell membrane is broken due to an increase in internal pressure, and conversely the magnification is reduced. The expandable polyolefin resin composition includes an antioxidant, a heat stabilizer,
Additives such as a metal damage inhibitor, an ultraviolet absorber and a pigment can be added as necessary.

The method for producing a polyolefin resin foam according to the present invention includes, for example, adding a metal hydroxide, a foaming agent and isopropyltriisostearoyl titanate to a polyolefin resin, and optionally adding a crosslinking aid and various additives. Agent, petroleum resin, etc. are added, and the resulting mixture is kneaded to form a foamable polyolefin resin composition, and the composition is formed into a required shape such as a sheet by a T die by a melt extrusion method, The obtained molded product is crosslinked by irradiation with ionizing radiation, and then heated to decompose the foaming agent to foam, thereby forming a foam.

As the skin material, knit, polyvinyl chloride leather, TPO (thermoplastic polyolefin elastomer), non-woven fabric or the like is appropriately used.

In order to integrally form the core material and the skin material into an automobile ceiling material, for example, both surfaces of a core material made of a mixed fiber non-woven fabric or a mat-like material whose main materials are inorganic fibers and thermoplastic resin fibers are used. Laminate the modified polyolefin film,
A skin material is laminated on the obtained composite substrate through a crosslinked polyolefin foam layer composed of a polyethylene / polypropylene mixture, and the obtained laminate is placed between a male mold and a female mold, and heated and pressed to the front part. And the rear part is shaped into the required shape. This pressurization is performed so that the core material has a thickness of 1 to 2 mm.

After subjecting the thus obtained automobile ceiling material to trimming, piercing, etc., the peripheral edge of the ceiling material on the core material side is heated to melt the modified polyolefin film. This heating is performed at a temperature within the plasticizing region where the core material and the modified polyolefin film can be folded during the next pressure bonding. The heating location may be the entire ceiling material or the front and rear portions thereof. This heating is carried out, for example, at a required position of the core material, preferably 350 to 350 coming from a hot air blower.
It is performed by applying hot air of 390 ° C.

Then, the heating peripheral edge of the ceiling material is bent in a folded or curled shape with the core material inside, and then this bent portion is further pressure-bonded to the ceiling material base by the modified polyolefin melt. The bending of the ceiling material and the subsequent crimping of the bent portion are performed using, for example, a pair of processing tools each having a concave groove portion having a substantially U-shaped cross section at its tip. The concave groove portion of one of the processing tools has a shape that follows the front shape of the ceiling material, and the concave groove portion of the other processing tool has a shape that follows the rear shape of the ceiling material.

The bending of the ceiling material and the subsequent crimping of the bent portion are preferably performed in separate steps using a bending tool and a crimping tool. In each step, the bending and crimping of the ceiling material can be performed by, for example, arranging the front portion and the rear portion of the ceiling material in the respective concave groove portions of the facing processing tool having the above-described configuration, and pressing the processing tool against the ceiling material. Done. It is essential that the heating of the core material and its bending and pressure bonding are performed instantaneously.

[0024]

EXAMPLES Next, the present invention will be specifically described with reference to Examples.

I) Manufacturing of ceiling material In FIG. 1, a modified polyolefin film (2) is attached to both sides of a core material (1) made of a mixed fiber non-woven fabric or a mat-like material mainly composed of inorganic fibers and thermoplastic resin fibers. The cross-linked polyolefin foam layer is formed on one side of the obtained composite substrate.
The skin material (4) is laminated via (3), the resulting laminate is placed between the male mold (5) and the female mold (6), and the front and rear parts are heated and pressed to form the desired shape. Shape into. This pressurization is performed so that the core material has a thickness of 1 to 2 mm.

The core material (1) is a mixed-fiber non-woven fabric or a mat-like material mainly composed of inorganic fibers and thermoplastic resin fibers,
Inorganic fibers are bound by a thermoplastic resin. The inorganic fiber is glass fiber and has a length of 50 to 150.
mm fiber has a distribution of 70% by weight or more and a thickness of 7 to 1
3 μm. The thermoplastic resin fiber is polyethylene fiber, the length is 20 to 100 mm, and the thickness is 15
Is about 40 μm. The mat-like material is manufactured by supplying inorganic fibers and thermoplastic fibers to a card machine, defibrating the fibers, and performing needle punching at 10 to 50 points per cm ² .

The thermoplastic resin used to bind the inorganic fibers is polyethylene.

The modified polyolefin film preferably has a weight per unit area of 120 to 150 g / m ² .

The foam layer is a crosslinked product of a blend of polyethylene and polypropylene. This is the addition of a metal hydroxide, a foaming agent, and isopropyltriisostearoyl titanate to the above polyolefin-based resin, a crosslinking aid, various additives and petroleum resin, and the resulting mixture is kneaded. To obtain a foamable polyolefin-based resin composition, and the composition is molded into a desired shape such as a sheet by a T-die by a melt extrusion method, the obtained molded product is crosslinked by irradiation with ionizing radiation, and then heated. A foam is obtained by decomposing a foaming agent to foam.

The skin material is made of knit.

Thus, the automobile ceiling material (7) shown in FIG.
Is obtained.

Ii) Formation of Bending / Crimping Portion After subjecting the obtained automobile ceiling material to trimming, piercing, etc., as shown in FIG. 3, the front portion of the ceiling material (7) on the core material side ( 7a) and rear part (7b) come from the hot air blower 35
The modified polyolefin film of the core material is melted by heating with hot air of 0 to 390 ° C. (8) in FIG. 3 is an outlet of the hot air supply device.

Next, as shown in FIG. 4, the heated front part (7a) and rear part (7b) are treated with a pair of bending tools.
Using (9), bend the core material inward with the core material inside. The bending tool (9) has a groove with a U-shaped cross section at the tip.
(9a), the groove of one of the processing tools has a shape along the front portion of the ceiling material, and the groove of the other processing tool has a shape along the rear portion of the ceiling material.

For the bending of the ceiling material, the front part (7a) and the rear part (7b) of the ceiling material (7) are arranged in the concave grooves of these processing tools (9) respectively, and the processing tools (9 ) Is pressed against the ceiling material (7).

Then, the bent portion (10) of the ceiling material (7) is heated again with hot air of 350 to 390 ° C. coming from the hot air blower,
As shown in Fig. 5, the heated bending part (10) of the ceiling material (7)
Is pressed against the ceiling material base with a crimping tool that operates with an air cylinder.

In this way, the bent portion of the ceiling material (7) is pressure-bonded to the base of the ceiling material with the core material inside, and the modified polyolefin melt is pressure-bonded to form the bent / pressure-bonded portion (11) on the periphery of the ceiling material.

[0037]

According to the method of forming a bending / crimping portion according to the present invention, the required peripheral edge of the core material is stripped off and the remaining peripheral edge of the skin material is bent back like a conventional end treatment of a ceiling material. Since the method of adhering the folded part to the core material is not adopted, the manufacturing cost does not increase due to equipment etc. for improving the peeling weight of the core material, and the peripheral edge of the skin material bent in a folded shape is used as the core. Since it is not necessary to adhere the material to the material with an adhesive or the like, the work of processing the peripheral edge of the ceiling material can be greatly simplified.

Further, in the method of the present invention, the work efficiency can be improved by heating the core material and bending and crimping the core material instantaneously.

In addition, since the peripheral edge of the ceiling material after heating is bent with the core material inward, even if the type of skin material is changed, the crimping of the bent portion is the adhesion of the core materials, and the adhesive effect is does not change.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a molding die for a ceiling material.

FIG. 2 is a plan view of a ceiling material.

FIG. 3 is a cross-sectional view showing a heating step of the core material.

FIG. 4 is a cross-sectional view showing a bending step of the ceiling material.

FIG. 5 is a cross-sectional view showing a step of pressure-bonding a ceiling material.

[Explanation of symbols]

 (1) ... Core material (2) ... Modified polyolefin film (3) ... Crosslinked polyolefin foam layer (4) ... Skin material (5) ... Male type (6) ... Female type (7) ... Ceiling material (7a) ... Front part (7b)… Rear part (8)… Blowout port (9)… Bending tool (9a)… Concave groove (10)… Bend (11)… Bending and crimping part

Claims (1)

[Claims] 1. A modified polyolefin film is melted by heating the periphery of an automobile ceiling material comprising a core material having modified polyolefin films on both sides and a skin material bonded to the core material via a foam layer. Next, bending and crimping on the periphery of the ceiling material for automobiles, characterized in that the periphery is bent with the core material inside to be folded or curled, and the bent portion is pressure-bonded to the base of the ceiling material with the modified polyolefin melt. Forming method.