KR20070111698A - Micro cellular foaming sheet applied multi-layer of instrument panel - Google Patents

Abstract

A multi-layer instrument panel is provided to ensure complete recycle of materials, thereby preventing environmental pollution, to minimize the number of processing steps required for producing the panel, and to realize excellent cushioning effect and high-quality texture. A multi-layer instrument panel comprises: a skin layer(10) obtained by kneading ethylene propylene diene monomer rubber or ethylene octene copolymer and block polypropylene and paraffin oil into a banbury mixer or kneader to form a pelletized master batch, mixing homopolypropylene and polypropylene with the master batch, and microfoaming the resultant mixture with an inert gas and performing injection molding thereof; a foam layer(20) obtained by foaming a blend of polypropylene and low density polyethylene so as to be hot fused to one surface of the skin layer; a barrier layer(30) obtained by extruding a blend of polypropylene and low density polyethylene so as to be hot fused to the surface of the foam layer; a foam core layer(40) obtained by microfoaming a polypropylene and low density polyethylene so as to be injection molded on the surface of the barrier; and a core layer(50) obtained by injection molding a blend of polypropylene with low density polyethylene on the surface of the foam core layer.

Description

Micro cellular foaming sheet applied multi-layer of instrument panel

1 is a cross-sectional view of an instrument panel according to the prior art,

2 is a manufacturing process flow chart of the instrument panel according to the prior art,

3 is a cross-sectional view of the instrument panel according to the present invention,

Figure 4 is a flow chart of the manufacturing process of the instrument panel according to the present invention,

5 is a schematic view schematically showing a heat fusion apparatus of manufacturing an instrument panel skin according to the present invention;

Figure 6 is a schematic diagram schematically showing a single injection molding apparatus used in the micro-foaming process of the instrument panel according to the present invention.

<Explanation of symbols for major symbols in the drawings>

10: skin layer 20: foam layer

30: barrier layer 40: foam core layer

50: core layer 60: skin layer manufacturing step

61: foam layer manufacturing step 62: barrier layer manufacturing step

63: heat fusion step 64: foam core layer injection step

65: core layer injection step 70: heat fusion apparatus

80: integral injection molding machine

The present invention relates to a multi-layered instrument panel to which a micro-foaming sheet is applied. More specifically, the present invention relates to a skin layer, a foam layer, a barrier layer, a foam core layer, and a core layer. The present invention relates to a multi-layered instrument panel to which a micro-foamed sheet is micro-foamed.

In general, various parts used in the interior of automobiles, such as instrument panels, door trims, or consoles, which are installed in front of the driver's seat and passenger seat, are generally soft panel type and hard panel. Prepared in such a way.

Here, as shown in Figure 1, in the case of a soft panel (Soft panel) by using a polyurethane foam method foamed between the skin layer 100 and the core layer 300 with a polyurethane resin foam layer 200 It has the advantage of providing soft texture and luxurious image to automobile interior parts. The interior structure is composed of 3 layers of skin layer, core layer, skin layer and polyurethane foam layer. Has become a heavy structure.

Thermoplastic polyolefin resin sheets, PVC sheets, ABS sheets, etc. are used for the skin material of the interior materials for vehicles, and as the interior materials of the vehicles, product performances such as design freedom, embossing quality, tactile properties, scratch resistance, heat furnace, etc. Durability such as chemical resistance, light resistance and chemical resistance, as well as safety performance such as flame retardancy and airbag deployment are required. If the material is not suitable for the required performance, the material is not suitable for the application field.

In addition, the foam layer is mainly a foaming function by foaming the polyurethane-based resin, wrapped in the skin material to absorb the impact from the outside, and performs a function to give a soft feeling. In the case of the skin layer, as described above, since the outermost part of the molded article is configured, the skin layer directly contacts the skin of the user, thereby performing a function of improving aesthetics and feel by the design.

In the conventional vehicle panel manufacturing process, a skin layer made of a skin material is inserted into an injection mold of a core as shown in the flowchart shown in FIG. 2, and a manufacturing method of injecting a core layer or foaming a foam layer between the skin layer and the core layer is generally performed. It is used.

Looking at the conventional panel manufacturing method as described above, it is possible to recycle the skin layer, foam layer and core layer using various materials such as PVC, polyurethane and ABS / PC or polypropylene series, causing environmental pollution. Have a problem

In addition, in the case of the interior material having a triple structure, as each mold process is required, due to the complexity of processing, the production cost is increased as a result, the light weight of the product is deteriorated, and the quality is not good, so there is a problem in quality. .

In order to solve the above problems, the present invention integrates the skin layer, the foam layer, and the barrier layer sequentially by heat fusion method, injects the foam core layer on the barrier layer surface, and injects the core layer again. I would like to propose.

In addition, all the layers laminated on the instrument panel to be recycled using the same material and to minimize the manufacturing step using the integral injection molding method.

The present invention for achieving the above object is a pelletized master batch by kneading an ethylene propylene diene rubber or ethylene octene copolymer, block polypropylene and paraffin oil by mixing a Banbury mixer or kneader Next, homopolypropylene and polypropylene were mixed in the masterbatch through a twin screw extruder, and then placed in an injection molding machine to form a skin layer to be injected by fine foaming with an inert gas.

Foam layer mixed with polypropylene and low density polyethylene so as to be integrally heated and melted on one surface of the skin layer, and a barrier layer made of an extruder by mixing polypropylene and low density polyethylene so as to be integrally heated and melted onto the surface of the foam layer. , A foam core layer mixed with polypropylene and low density polyethylene so as to be injected into the barrier layer and finely foamed with an inert gas; and a core layer mixed with polypropylene and low density polyethylene so as to be injected into the surface of the foam core layer. It is done.

In one preferred feature according to the invention, the skin layer is 45 to 50% by weight of ethylene propylene diene rubber or ethylene octene copolymer, 25 to 30% by weight of block polypropylene and 20 to 25% by weight of paraffin oil. By mixing the parts and kneading at 180 ~ 200 ℃ 20 to 25 minutes to prepare a master batch, 50% by weight of this masterbatch that contains 30 to 35% by weight of homopolypropylene and 15 to 20% by weight of block polypropylene It features.

According to another preferred feature of the present invention, the skin layer further comprises 13-15% by weight of calcium carbonate powder, 0.3-0.5% by weight of lubricant and light stabilizer, and 0.1-0.2% by weight of ultraviolet absorber, respectively. It is characterized by.

In another preferred feature according to the invention, the foam layer is characterized in that 65 to 70% by weight of polypropylene and 30 to 35% by weight of low density polyethylene is included.

In another preferred feature according to the invention, the foam layer is characterized in that it further comprises 10 to 15% by weight of talc and 1 to 3% by weight of an additive of glycerol mono stearate.

According to another preferred feature of the present invention, the barrier layer is characterized in that it contains 60 to 65% by weight of polypropylene, and 35 to 40% by weight of low density polyethylene.

In another preferred feature according to the invention, the barrier layer is characterized in that it further comprises 5 to 10% by weight of talc, and 1 to 3% by weight of the clerol mono stearate.

In another preferred feature according to the invention, the foam core layer is characterized in that 70 to 75% by weight of polypropylene and 25 to 30% by weight of low density polyethylene is included.

In another preferred feature according to the invention, the foam core layer is characterized in that it further comprises 1 to 3% by weight of glycerol mono stearate and 10 to 15% by weight of talc additives.

In another preferred feature according to the invention, the core layer is characterized in that it contains 70 to 75% by weight of polypropylene, and 25 to 30% by weight of low density polyethylene.

According to another preferred feature of the present invention, the core layer is characterized by further comprising 1 to 3 parts by weight of glycerol mono stearate and 10 to 15% by weight of talc additives.

According to another preferred feature of the present invention, after mixing the polyolefin-based resin and additives through a twin screw extruder, the step of manufacturing a skin layer formed by fine foaming with an inert gas and mixing the polyolefin-based resin and additives A foam layer manufacturing step of forming a fine foam by inert gas to form a single injection molding machine, a barrier layer manufacturing step of producing a predetermined thickness using an extrusion molding machine by mixing a polyolefin-based resin and additives, the skin layer manufacturing step and foam layer production Step, heat fusion step of the skin layer, foam layer, barrier layer prepared in the step of manufacturing the barrier layer is integrated by heat fusion, the sheet integrated in the heat fusion step is mounted on the injection mold, and the polyolefin resin and additives are mixed to integrally injection Foam core layer which is injected into molding machine and finely foamed with inert gas Output stage and is characterized in that a core layer consisting of an injection step of injection by mixing a polyolefin resin and additives to the foam core layer surface inside the injection mold in the finished foam core layer injection step.

Hereinafter, with reference to the accompanying drawings will be described in detail the instrument panel of the multi-layer structure to which the micro-foaming sheet according to an embodiment of the present invention.

Figure 3 is a cross-sectional view of the instrument panel according to the present invention, Figure 4 is a flow chart of the manufacturing process of the instrument panel according to the present invention, Figure 5 is a schematic diagram schematically showing a heat fusion apparatus of manufacturing an instrument panel skin according to the present invention, Figure 6 Is a schematic diagram schematically showing a single injection molding apparatus used in the micro-foaming process of the instrument panel according to the present invention.

The instrument panel having a multi-layered structure to which the micro-foaming sheet according to the present invention is applied increases the light weight and cushioning by finely foaming the skin layer 10 and the foam layer 20, and further expands the core to the foam core layer 40 and the core layer 50. According to the configuration of each of the conventional in the instrument panel has a feature to increase the light weight by fine-foaming the core portion occupying a relatively large weight portion.

Example

The skin layer 10 forms the outermost surface of the instrument panel, which is extruded from a polyolefin resin, 40 to 50% by weight of ethylene propylene diene rubber (EPDM) or ethylene octene copolymer, and a block polypropylene 25 ~ 30% by weight of the mixture, and 20 to 25% by weight of the paraffin oil is added to a mixer such as a Banbury mixer or kneader and kneaded at 180 ~ 200 ℃ for 20 to 25 minutes to be adjusted to the appropriate size, etc. And, through this kneading process to produce a pelletized master batch (Master batch).

30% to 35% by weight of homopolypropylene, 15 to 20% by weight of block polypropylene with long-branched structure, and 13 to 15% by weight of calcium carbonate powder used as reinforcing agent in 50% by weight of the prepared master batch Mix.

In addition, 0.3 to 0.5% by weight of the lubricant is mixed to smoothly flow in the injection machine as an additive, and 0.3 to 0.5% by weight of the light stabilizer used as a resin stabilizer to prevent deterioration of the resin. Mix 0.1 to 0.2% by weight.

When the raw material for preparing the skin layer 10 is formed, the raw material is injected into the integral injection molding apparatus 80 shown in FIG. 6 to form fine foam, and the high pressure and temperature are applied to the inert gas (H2, Co2) during injection. It can be lightened by forming micropores by changing it into supercritical fluid state and then making it to 0.4 ~ 0.7mm with proper thickness through extrusion molding machine.

The foam layer 20 is intended to provide a cushioning of the instrument panel, and mixes 30 to 35% by weight of low density polyethylene (LDPE) with 65 to 70% by weight of a thermoplastic resin-based polypropylene. 10 to 15% by weight of talc and glycerol monostearate 1 to 3% by weight are further added.

The mixture of the foam layer 20 prepared as described above is introduced into the integrated injection molding apparatus 80 and the inert gas (CO 2, N 2), which is a blowing agent, is blown into the cylinder in the same manner as the foaming of the skin layer 10. The foam layer 20 can also be made by fine foaming to reduce the weight by injecting and foaming by changing to a critical state, and is manufactured to an appropriate thickness of 3 ~ 5mm by an extrusion molding machine.

Barrier layer 30 is to prevent deformation by heat transferred to the foam layer 20 in the manufacturing process, 60 to 65% by weight of polypropylene, 35 to 40% by weight of low density polyethylene is mixed with additives To protect the flexibility and heat resistance, 5 to 10% by weight of talc and 1 to 3% by weight of glycerol monostearate are added.

The mixture of the barrier layer 30 prepared as described above is introduced into an integral injection molding machine and injected into the surface of the foam layer 20. The barrier layer 30 is manufactured with an appropriate thickness of 0.2 to 0.4 mm.

The skin layer 10, the foam layer 20, and the barrier layer 30 prepared as described above are wound into a bobbin of the heat welding apparatus shown in FIG. After mounting the sheet in a mold, the core layer is injected therein. In general, the core layer is manufactured by using a rigid material such as a rigid metal sheet of a metal sheet, and the core layer is manufactured in a shape. The core layer has a problem in that the light weight is poor and the material is not excellent and the quality is lowered.

However, in the present invention, the core part is composed of the foam core layer 40 and the core layer 50, respectively, to increase the lightness and quality due to the foam core layer 40, and the skin layer 10 and the foam layer. 100 and 100% recycling is possible using the same material as the barrier layer (30).

Foam core layer 40 is injected into the barrier layer 30, 70 to 75% by weight of polypropylene and 25 to 30 parts by weight of low-density polyethylene (HDPE) of linear structure is mixed, and talc as an additive 10 to 15% by weight and glycerol mono stearate 1 to 3% by weight of the mixture in the same manner as the fine foaming method of the skin layer 10 is finely foamed and injected into the surface of the barrier layer 30 mounted on the mold.

The core layer 50 is formed to increase rigidity, such as a metal plate or a plastic series, and is injected using the same raw material as the foam core layer 40. The core layer 50 is formed by general injection without foaming. Let's do it.

The present invention configured as described above is 100% recyclable at the time of disposal as the entire panel is used as a homogeneous material, which is environmentally friendly, can increase the lightness due to fine foaming and minimize the manufacturing process by using the integral injection method.

Hereinafter, a manufacturing method according to the present invention will be described in detail with reference to FIG. 4.

First, as the skin layer manufacturing step 60, after mixing the polyolefin-based resin and additives completely through a twin screw extruder, it is put into the integral injection molding machine, and the skin layer 10 by injecting an inert gas changed into a supercritical fluid into the cylinder. After forming a micro-foam to form a micro-pores in the skin layer 10 through an extrusion molding machine.

Secondly, as a foam layer manufacturing step 61, a polyolefin-based resin and an additive are mixed and introduced into an integral injection molding machine, and the foam layer 20 is formed by fine foaming with an inert gas in the same manner as the skin layer manufacturing step 60. do.

Third, as a barrier layer manufacturing step 62, a barrier layer manufactured to a predetermined thickness is manufactured by using an extrusion molding machine generally used by mixing a polyolefin resin and an additive.

Fourth, as the heat fusion step 63 of the skin layer manufacturing step 60, the foam layer manufacturing step 61 and the barrier layer manufacturing step 62, the skin layer, the foam layer, and the barrier layer by heat fusion to integrate. Each skin layer 10, foam layer 20, and barrier layer 30 are held in the bobbin and passed through a heating roller supplied with heat from a heater to be integrated by a pressure roller.

Fifth, as the foam core layer injection step 64, the sheet integrated in the heat fusion step 63 is mounted on an injection mold, and a polyolefin resin and an additive are mixed and introduced into an integral injection molding machine to produce the skin layer (60). In the same) fine foamed with an inert gas is injected to the foam core layer 40 which is injected to the barrier layer surface.

Sixth, as the core layer injection step 65, a polyolefin-based resin and an additive are mixed on the foam core layer surface inside the injection mold completed in the foam core layer injection step 64 and injected into an integral injection molding machine to make a core layer 50 ) The instrument panel is completed.

The present invention constituted as described above is 100% recyclable by using the entire instrument panel as a homogeneous material, which is environmentally friendly, and finely foams the skin layer, the foam layer, and the foam core layer to increase the lightness of the entire panel, and also integrally injection molding. By minimizing the manufacturing process using the method, there is an advantage that can shorten the production time and significantly reduce the production cost.

The present invention configured as described above has the advantage that it is possible to recycle by using the material used as the homogeneous resin, 100% recycling without causing environmental pollution.

In addition, by inserting the integrated skin material into the injection mold and injecting the foam core layer and the core layer using the integral injection molding method, the process step can be minimized, thereby greatly reducing the production time and production cost. In addition, the core layer is composed of a foam core layer and a core layer, respectively, as the cushioning feeling is improved, thereby providing excellent material quality and high quality, and there is no need for a separate finishing process after molding.

Claims (12)

Pelletized master batches are prepared by kneading ethylene propylene diene rubber or ethylene octene copolymer, block polypropylene and paraffin oil in a Banbury mixer or kneader, and then homopolyols in the master batch. A skin layer in which propylene and polypropylene are mixed through a twin screw extruder and then put into an injection molding machine and finely foamed with an inert gas for injection; A foam layer mixed with polypropylene and low density polyethylene and foamed with an inert gas so as to be integrally heated and fused to one surface of the skin layer; A barrier layer made of an extruder by mixing polypropylene and low-density polyethylene so as to be integrally heated and fused to the foam layer surface; A foam core layer mixed with polypropylene and low density polyethylene so as to be injected onto the barrier layer and finely foamed with an inert gas; And A core layer in which polypropylene and low density polyethylene are mixed to be injected onto the surface of the foam core layer; Instrument panel having a multi-layer structure, characterized in that consisting of a fine foam sheet. The method of claim 1, wherein the skin layer, 45-50% by weight of ethylene propylene diene rubber or ethylene octene copolymer, 25-30% by weight of block polypropylene, 20-25% by weight of paraffin oil, and kneading at 180-200 ° C. for 20-25 minutes A multi-layered instrument panel applying a micro-foamed sheet, wherein the batch is prepared and 50% by weight of the masterbatch comprises 30 to 35% by weight of homopolypropylene and 15 to 20% by weight of block polypropylene. The method according to claim 1 or 2, wherein the skin layer, 13 to 15% by weight of calcium carbonate powder, 0.3 to 0.5% by weight of each of the lubricant and light stabilizer, 0.1 to 0.2% by weight of the ultraviolet absorber further comprises an instrument panel having a multi-layered foam applied. The method of claim 1, wherein the foam layer, An instrument panel having a multi-layered structure, which comprises 65 to 70% by weight of polypropylene and 30 to 35% by weight of low density polyethylene. The method according to claim 1 or 4, wherein the foam layer, 10 to 15% by weight of talc, and 1 to 3% by weight of an additive of glycerol mono stearate. An instrument panel having a multi-layer structure to which a micro-foaming sheet is applied. The method of claim 1, wherein the barrier layer, 60-65% by weight of polypropylene, and 35-40% by weight of low-density polyethylene instrument panel having a multi-layer structure, characterized in that it comprises a micro-foam sheet. The method of claim 1 or 6, wherein the barrier layer, 5 to 10% by weight of talc, and 1 to 3% by weight of the clerol mono stearate by weight of the multi-layered instrument panel applying a micro-foaming sheet characterized in that it further comprises The method of claim 1, wherein the foam core layer, An instrument panel having a multilayer structure applied with a micro-foaming sheet, comprising 70 to 75% by weight of polypropylene and 25 to 30% by weight of low density polyethylene. The method according to claim 1 or 8, wherein the foam core layer, An instrument panel having a multi-layered structure to which microbubble sheets are applied, comprising 1 to 3% by weight of glycerol monostearate and 10 to 15% by weight of talc. The method of claim 1, wherein the core layer, A multi-layered instrument panel with a micro-foamed sheet comprising 70 to 75% by weight of polypropylene and 25 to 30% by weight of low density polyethylene. The method of claim 1 or 10, wherein the core layer is An instrument panel having a multilayer structure to which a micro-foaming sheet is applied, further comprising 1 to 3% by weight of glycerol monostearate and 10 to 15% by weight of talc. (a) a skin layer manufacturing step of mixing a polyolefin resin and an additive through a twin screw extruder and then inserting it into an integral injection molding machine and forming a fine foam with an inert gas; (b) a foam layer manufacturing step of mixing the polyolefin-based resin and the additive and then adding the same to an integrated injection molding machine to form micro-foams with an inert gas; (c) a barrier layer manufacturing step of mixing the polyolefin resin and the additive to produce a predetermined thickness using an extrusion molding machine; (d) a heat fusion step of integrating the skin layer, the foam layer, and the barrier layer prepared in the skin layer manufacturing step, the foam layer manufacturing step, and the barrier layer manufacturing step by heat fusion; (e) a foam core layer injection step of mounting the sheet integrated in the heat fusion step into an injection mold, mixing polyolefin-based resin and additives, inserting into an injection molding machine, and finely foaming with inert gas for injection; And (f) a core layer injection step of injecting a mixture of a polyolefin resin and an additive into the foam core layer surface inside the injection mold completed in the foam core layer injection step; Instrument panel manufacturing method of a multi-layer structure applying a micro-foaming sheet, characterized in that consisting of.

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