JPH10156849A - Manufacture of laminate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To raise durability of a certain part of a laminate since an expansion ratio is small while the expansion ratio of the other part of the laminate is large and a sufficient soft feeling is obtained. SOLUTION: A base material 30 is supported with either of a top force 20 or a bottom force 10, and a molding face 21 wherein a surface layer 32 of a skin 31 is formed, is formed on the other side. Further, an interval between a surface 30a of the base material at the nearest position of both forces and a molded face has a value varying according to the place. A sheet like molten resin laminate 31 wherein a front side molten resin layer 32m and an inside molten resin layer 33m which is not unfoamed though a foaming agent forming a foamed layer 33 is contained, while they have respectively specific thickness, are integrally superimposed, is supplied so as to cover almost the whole of the bottom force. The top force 10 and the bottom force 20 are stopped under a state wherein they come near to each other to the nearest position. The molten resin laminate 31 is filled between a front surface of the base material and the molding face 31 by foaming an inside molten resin layer 33m containing the foaming agent, and each molten resin laminate material 31 is cooled.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminate used for door trim of vehicles, interior materials of vehicles, interior materials of houses, exterior materials of furniture, and the like, and particularly to production of laminates having a soft-feel outer surface. About the method.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 4, for example, as shown in FIG. 4, a laminate of a preformed porous woody base material 1 and a flexible synthetic resin is formed into a thin sheet. A flexible sheet-like foam layer 2a on the back surface of the molded skin layer 2b
Was prepared. First, the base material 1 once dried by spraying an adhesive on the surface is set on a vacuum forming die 5, and then a skin material 2 held around by a holding frame 3.
Is heated by a far-infrared heater or the like to be softened and lowered to come into contact with the substrate 1 and the upper outer peripheral portion of the vacuum forming die 5, and to apply a negative pressure from the vacuum source 7 to the suction pipe 6 provided in the vacuum forming die 5. The skin material 2 was suctioned through the many thin tubes 6 a branched from the suction pipe 6 and the porous base material 1, and adhered to the entire surface of the base material 1.

Alternatively, as disclosed in Japanese Patent Application Laid-Open No. 8-34024, in a method for manufacturing a door trim, a porous base material and a foamable molten resin for forming a skin material are placed between a pair of molds. Press the upper part of the door trim so that the upper part is thicker than the lower part, and then separate the two molds so that the separation distance of the upper part is longer than the lower part, and the upper part of the upper part is compared with the lower part of the door trim. There is also a method of forming a skin material including a foam layer in which the molten resin is foamed and cured, and a skin layer cured without foaming so that the thickness is larger. The foamable molten resin forms a foamed layer on the porous substrate side because the cooling rate is slow, and forms a skin layer on the surface side that does not foam because the cooling rate is fast in contact with the mold.

[0004]

In the first prior art described above, it is necessary to prepare in advance a skin material in which a separately formed sheet-like skin layer and a foam layer are adhered to each other. However, there is a problem that the working environment is deteriorated because the molding device and the bonding device are required and the adhesive is used. In the case of door trim, it is required to increase the foaming ratio in the upper half where the hands and arms touch, so that a sufficient soft feeling can be obtained, and to reduce the foaming ratio in the lower part where the feet hit, to increase durability. However, the first prior art cannot respond to such a situation.

In the second prior art, it is not necessary to form the skin material in advance, and it is possible to meet the demand for changing the expansion ratio depending on the location to some extent. After pressing so that the upper part is thicker than the lower part, the two molds are separated so that the separation distance of the upper part is longer than that of the lower part, so there is a problem that a special manufacturing device is required. . Also, a foamed layer foamed and cured from the same molten resin due to the difference in cooling rate,
Because it forms a cured skin layer without foaming,
It is difficult to increase the expansion ratio of the foamed layer without foaming the skin layer, and thus there is a problem that a sufficient soft feeling cannot be obtained.

The present invention solves these problems by increasing the expansion ratio in a portion of the skin material to give a sufficient soft feeling, and reducing the expansion ratio in the other portion to increase durability. It is another object of the present invention to provide a method for producing a laminate having high productivity.

[0007]

According to the method of manufacturing a laminate according to the present invention, a preformed base material is covered with a skin composed of a foam layer and a surface layer to produce a laminate having a soft touch outer surface. The upper mold and the lower mold are
One of them supports the base material and the other forms a molding surface for molding the surface layer of the skin, and the distance between the surface of the base material and the molding surface at the closest position of both molds varies depending on the location. It is assumed that In the present invention, a sheet-like molten resin laminate in which a front-side molten resin layer forming a surface layer and a foaming agent forming a foamed layer, each having a predetermined thickness, and an unfoamed inner molten resin layer are integrally laminated. A molten resin supply step of supplying the body so as to cover almost the entire lower mold, a mold clamping step of stopping the upper mold and the lower mold in a state of approaching each other to the closest position, and inner melting including a foaming agent The method includes a foaming step of foaming the resin layer to fill the molten resin laminate between the surface of the base material and the molding surface, and a cooling step of cooling each molten resin laminate. According to the present invention as described above, the foaming ratio of the foamed layer is large in the portion where the distance between the surface of the base material and the molding surface is large at the closest position of both molds, and the foaming layer is foamed in the portion where the space is small. Magnification decreases.

[0008] The present invention is a substrate-side molding die in which a lower die has a support surface for supporting the lower surface of the substrate on the upper surface, and an upper die in which a molding surface for molding the surface of the surface layer is formed on the lower surface. It is a material-side molding die, and in the molten resin supply step, the molten resin laminate is preferably supplied so as to cover almost the entire upper side of the lower mold and the base material supported thereon with the inner molten resin layer facing down. . In this case, the base material may simply be placed on the support surface of the lower mold.

Further, in the present invention, it is preferable that a heater is provided in at least one of the lower mold and the upper mold, and in the foaming step, the molten resin laminate is heated by the heater to foam it. This heater is preferably an electric heater provided along the forming surface on which the surface layer is formed.

The molten resin laminate is supplied in a direction orthogonal to the extrusion port above the lower die while simultaneously extruding the front side molten resin layer and the inner molten resin layer from the slit-shaped extrusion port of the supply die of the extruder. It is better to move it.

According to the present invention, the distance between the surface of the base material and the molding surface in a state where the laminated body is a door trim of an automobile and both dies are in the closest position is a part in the upper half part in the use state of the door trim. It is good to make it large and to make it small in the lower half. In the upper half of the door trim, the gap between the surface of the base material and the molding surface at the closest position of both molds is large, so that the expansion ratio of the foam layer is large. In the lower half of the door trim, the gap is small, The expansion ratio decreases.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIGS. 1 to 3, an embodiment in which a method of manufacturing a laminate according to the present invention is applied to manufacture of a door trim of an automobile will be described. The door trim A manufactured according to the present invention has an armrest portion A at an intermediate portion in the vertical direction.
a (see FIG. 3), in which the surface of a rigid base material 30 formed in advance is covered with a skin 31.
The base material 30 is a porous material having air permeability. The crushed wood fibers are mixed with a phenol resin of about 7% as a binder into a fibrous material and hot-pressed into a plate of approximately constant thickness with irregularities. Things. The skin 31 is formed by integrally superposing a surface layer 32 on the front side and a foam layer 33 on the base 30 side. The manufacturing apparatus used in this embodiment includes a lower mold (base-side molding die) 10 attached to a lower fixed-side mold support member (not shown) and an upper movable-side mold support member (not shown). An upper die (skin-side molding die) 20 and a supply die (resin supply device) 35 for supplying the molten resin sheet 31m are provided.

As shown in FIGS. 1 to 3, a support surface 11 for supporting the back surface of the base material 30 formed in advance as described above is formed on the upper surface of the lower mold 20. An outwardly-facing step portion 11a whose planar contour matches the contour of the door trim is formed. The upper mold 20 supported by the movable mold support member can approach and separate from the lower mold 10 from above. FIG. 1 shows a separated state, and FIGS. 2 and 3 show a closest approach state. A molding surface 21 for molding the surface of the skin 31 that covers the surface of the substrate 30 is formed on the lower surface of the upper mold 20. The inward step 21a formed on the upper die 20 along the outer periphery of the molding surface 21 has a slight gap when the two dies 10, 20 are in the closest position as shown in FIGS. The lower die 10 can be fitted to the outwardly facing step 11a.

As shown mainly in FIGS. 2 and 3, when the dies 10 and 20 are in the closest positions, the surface 30a of the base 30 supported on the support surface 11 of the lower die 10 and the upper die 2
The gap between the 0 molding surfaces 21 is large in a portion corresponding to an upper half portion which is higher than the armrest portion Aa in the use state of the door trim A (slightly higher left half in the figure), and is lower than the lower half. The portion corresponding to the half portion (slightly right half in the figure) is smaller. The interval between the lower half portions is slightly larger than a later-described molten resin laminate 31m.

A heater 25 is provided along the molding surface 21 of the upper mold 20 to generate heat when energized by a power supply 26. The heater 25 is formed, for example, by forming a thin-film ceramic insulator layer so as to cover the molding surface 21 and forming a thin-film resistor layer made of titanium nitride or the like thereon. It generates heat when energized through the switch. A grain pattern (a fine uneven pattern) is formed on the surface of the insulator layer, and a grain pattern is formed on the surface of the resistor layer correspondingly.

As shown in FIG.
A supply die 35 which projects over the lower mold 10 supporting the base material 30 in a state where 0 is separated upward, and two supply pipes 36 for supplying a synthetic resin material in a molten state to be the skin 31 to the supply die 35. (Supplying a synthetic resin material to be the surface layer 32 and the foamed layer 33, respectively. FIG. 1 shows only one of them). The material of the surface layer 32 and the foam layer 33 which are the skin 31 is a polyolefin synthetic resin (for example, polypropylene), and the material of the foam layer 33 is a foaming agent (for example, azodicarbonamide).
Is kneaded.

Next, a manufacturing method according to this embodiment will be described. First, in a state where the upper mold 20 is separated upward, the supporting surface 11 of the lower mold 10 is set to normal temperature (for example, 20 ° C.).
The substrate 30 previously formed is placed on the substrate. In the subsequent molten resin supply step, as shown in FIG. 1, the molten surface layer 32 supplied to the supply die 35 via the supply pipe 36 from the extruder for an injection molding machine capable of measuring and extruding the resin, and The material of the foam layer 33 (the temperature is 110 to 210
° C) is a plastically rich two-layer sheet-like molten resin laminate 31 composed of a front-side molten resin layer 32m and an unfoamed inner molten resin layer 33m that are joined together and integrally laminated.
m and is extruded from an elongated slit-shaped extrusion port 35 a of the supply die 35. Each molten resin layer 32m, 3
The thickness of 3 m is, for example, 0.5 mm, and the width and length are slightly larger than the base material 30. This molten resin laminate 3
1 m is supplied so that the inner molten resin layer 33 m side is turned down so as to cover almost the entire upper side of the lower mold 10 and the base material 30 placed thereon.

In the subsequent mold clamping step, the upper mold 20 is
The upper mold 20 is stopped when it reaches the closest state shown in FIG. In this closest approach,
Surface 30a of substrate 30 supported by lower mold 10 and upper mold 20
Is 3 mm at the upper half of the door trim A and 1.5 mm at the lower half.
Therefore, the surface of the front side molten resin layer 32m and the molding surface 2
1 have gaps S of about 2 mm and about 0.5 mm, respectively. During this mold clamping step, the molten resin laminate 3 protruding outside from the outward step 11a of the lower mold 10
Unnecessary portions of 1 m are provided by the two step portions 11a and 21 fitted to each other.
It is cut off by the shearing action of a. The molten resin laminate 3
As for the outward and inward step portions 11a and 21a used for cutting the unnecessary portion of 1 m, the lower die 10 side may be an inward step portion and the upper die 20 side may be an outward step portion. Alternatively, instead of such shearing by the step portions that are fitted to each other, a pressing blade provided downward along the outside of the molding surface 21 of the upper die 20 is pressed against the flat surface of the outer periphery of the lower die 10. You may.

In the foaming process following the mold clamping process, the power supply 26
From the heater 25 to generate heat. As a result, the molding surface 21 of the upper mold 20 is rapidly heated, and the molten resin laminate 3 is heated.
1m reaches 150 ° C. in about 30 seconds and the inner molten resin layer 33
m starts foaming, and heats it for 1 minute to complete foaming, and then stops energization. Due to this foaming, the molten resin laminate 31 m is filled between the surface 30 a of the base material 30 and the molding surface 21 of the upper mold 20, and the surface of the front-side molten resin layer 32 m contacts the molding surface 21 of the upper mold 20. 32m of molten resin layer
Is transferred to the surface of the mold. The gap S is large in the upper half portion of the door trim A, and the front side molten resin layer 32m is sufficiently foamed before coming into contact with the molding surface 21, so that the inner side molten resin layer 33m has a foaming ratio of about 5, In the lower half part, the front side molten resin layer 32m
Immediately comes into contact with the molding surface 21, so that the foaming ratio stops at about 2. Since each of the molten resin layers 32m and 33m has considerably large viscosity, the foam does not move along the surface 30a of the base 30.

When the power supply to the heater 25 is stopped, the process shifts to a cooling step, and the temperature of the molten resin laminate 31m sharply drops due to heat transfer to the inside of the upper mold 20. After about 30 seconds, the temperature of the molding surface 21 is reduced to about 40 ° C., and when the molten resin layers 32 m and 33 m are hardened, the upper die 20 is raised to take out the door trim A. In the door trim A thus obtained, since the foaming ratio of the foamed layer 33 is about 5 in the upper half, a sufficient soft feeling is obtained, and the foamed layer 3 is obtained in the lower half.
Since the expansion ratio of No. 3 is about 2, sufficient durability can be obtained.

In the above-described embodiment, the substrate-side molding die supporting the substrate 30 is the lower die 10, and the substrate 30 is the lower die 1
It is easy to carry out since it only needs to be placed on zero and no special holding means is required. However, the present invention may be practiced with the substrate-side molding die as the upper die 20, and in that case, the substrate 30 may be held on the upper die 20 by vacuum suction or the like.

In the above-described embodiment, the electric heater 25 provided on the molding surface 21 of the upper mold 20 which is the skin mold is used.
By heating the molten resin laminate 31m close to this, the inner molten resin layer 33m is foamed, so that the heating efficiency is good, and since the heating is only in the vicinity of the molding surface 21, the cooling step following this is performed promptly. Therefore, the molding cycle can be shortened. However, the heater is not limited to the electric type, and steam may be passed through a pipe formed in the mold.
Further, it may be provided in the lower mold, or may be provided in both upper and lower molds.

[0023]

According to the present invention, since the front side molten resin layer forming the surface layer and the inner side molten resin layer forming the foam layer are separate, the thickness and density of the surface layer are affected. In addition, the expansion ratio of the foam layer can be set to a desired value. Also, in the portion where the distance between the surface of the base material and the molding surface at the closest position of both molds is large, the expansion ratio of the foam layer is large, so that a sufficient soft feeling can be obtained. Since the foaming ratio becomes small, sufficient durability can be obtained, and the portion where the space is large and the portion where the space is small can be arbitrarily arranged.

According to the lower mold used as the substrate-side molding die and the upper mold used as the skin material-side molding mold, the substrate only needs to be placed on the support surface of the lower mold. The implementation is easy because no special holding means is required.

If at least one of the lower mold and the upper mold is provided with a heater and is heated by this to foam the inner molten resin layer, the foaming is surely performed.
If this heater is an electric heater provided along the molding surface of the mold for molding the surface layer, the inner molten resin layer is efficiently heated, and the heating is performed only in the vicinity of the molding surface. Is performed promptly, and the time required for manufacturing can be reduced.

When the laminate is used as a door trim of an automobile, the distance between the surface of the base material and the molding surface in a state where both dies are in the closest position is large in the upper half part in the use state of the door trim, If it is small in the half part, the expansion ratio of the foam layer is large in the upper half of the door trim touched by hands and arms, and a sufficient soft feeling is obtained, and the foam layer is in the lower half of the door trim where the foot hits Has a small expansion ratio, so that the durability is improved.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a state in the middle of a molten resin supply step in one embodiment of a method for manufacturing a laminate according to the present invention.

FIG. 2 is a cross-sectional view showing a state at the end of a mold clamping step in the embodiment shown in FIG.

FIG. 3 is a cross-sectional view showing a state at the end of a foaming step in the embodiment shown in FIG.

FIG. 4 is a diagram showing an example of a method for manufacturing a laminate according to a conventional technique.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... Lower mold, 11 ... Support surface, 20 ... Upper mold, 21 ... Molding surface, 25 ... Heater, 30 ... Base material, 30a ... Surface, 31 ...
Skin, 31m ... Molten resin laminate, 32 ... Surface layer, 32m
... front side molten resin layer, 33 ... foam layer, 33m ... inner molten resin layer, 35 ... supply die, 35a ... extrusion port.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI B29L 31:30

Claims (6)

[Claims] 1. A method for producing a laminate having a soft-feel outer surface by covering a preformed base material with a skin composed of a foam layer and a surface layer, wherein the upper mold and the lower mold are any one of them. One side supports the base material,
On the other hand, a molding surface for molding the surface layer of the skin is formed, and the distance between the surface of the base material and the molding surface in a state where both dies are at the closest position has a different value depending on a location. A sheet-shaped molten resin laminate in which a front-side molten resin layer forming the surface layer and a foaming agent forming the foamed layer, each having a predetermined thickness, and an unfoamed inner molten resin layer are integrally laminated. Supplying a molten resin so as to cover almost the entirety of the lower mold, a mold clamping step of stopping the upper mold and the lower mold in a state of approaching each other to the closest position, and a foaming agent. A foaming step of foaming the inner molten resin layer and filling the molten resin laminate between the surface of the base material and the molding surface; and a cooling step of cooling each of the molten resin laminates. Of producing a laminated body. 2. The lower mold is a substrate-side molding die having a support surface for supporting the lower surface of the substrate formed on the upper surface, and the upper die is formed with a molding surface for molding the surface of the surface layer on the lower surface. A skin material side forming die, wherein in the molten resin supplying step, the molten resin laminated body covers the lower mold and the base material supported thereon on the lower mold with the inner molten resin layer facing down. The method for producing a laminate according to claim 1, wherein the laminate is supplied. 3. A heater is provided in at least one of the lower mold and the upper mold, and in the foaming step, the molten resin laminate is heated by the heater and foamed. The method for producing a laminate according to claim 1. 4. The heater according to claim 3, wherein the heater is an electric heater provided along the molding surface on which the surface layer is molded.
The method for producing a laminate according to the above. 5. The supply of the molten resin laminate is performed by simultaneously extruding the front-side molten resin layer and the inner molten resin layer from a slit-shaped extrusion port of a supply die of an extruder and moving the supply die above the lower die. The method for producing a laminate according to any one of claims 1 to 5, wherein the method is performed by moving the laminate in a direction orthogonal to the extrusion port. 6. The laminated body is a door trim of an automobile, and a gap between a surface of the base material and a molding surface in a state where the two dies are in a closest position is an upper half in a use state of the door trim. The method of manufacturing a laminate according to any one of claims 1 to 5, wherein the part to be a part is large, and the part to be a lower half is small.