JPH11320738A - Laminate sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laminate sheet without losing a cushion property of a foam even by receiving a pressure and a heat of injecting a core material at the time of molding. SOLUTION: A plurality of extruders for kneading and melting resins mixed with predetermined different amounts of a foaming agent and an assistant are provided for the laminate sheet 21. A first resin is extruded in a sheet-like state by the first extruder to form a first unfoamed sheet part 23a. An electron beam irradiation unit 25d for irradiating an electron beam and a heater 25e for heating to foam it are mounted at the part 23a to provide a first foaming chamber 25. A second resin is extruded in a sheet-like state to an upper side of a first foam layer 231 formed by transferring the part 23a in the chamber 25, crosslinked, foamed to form a second foaming chamber 26 for foaming a second foam layer 232. Further, foam layers 233, 234 are sequentially molded in a multilayer to the upper surfaces of the further formed layers 231, 232.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an extruder for kneading and melting an olefin resin mixed with a foaming agent and an auxiliary agent to extrude a sheet-like unfoamed sheet portion. Provide a foaming furnace to form a foamed sheet by heating,
Provide a heating roll to further heat and melt one side of the foam sheet, pressed against the back of the separately formed skin,
The present invention relates to an integrally formed laminate sheet.

[0002]

2. Description of the Related Art Hitherto, as this kind, those shown in FIGS. 4 to 7 have been known.

[0003] That is, FIG. 4 shows a state in which the skin 1A constituting the laminate sheet 1 is formed by the calender roll forming machine 2.

[0004] The skin 1A is charged with a PP resin or EPDM into a blender 3 and preliminarily mixed, then kneaded with a Banbury mixer 4 and a mixing roll 4A, and then heated with a heating roll 5 to form a plurality of skins. It is sent to a calendar roll forming machine 2 equipped with a roll. Then, the roll is rolled into a sheet between a plurality of rolls, subjected to embossing by the subsequent embossing rolls 6, then transferred between the cooling drums 7 and cooled, and the skin thickness is inspected by the thickness gauge 8a. When the winding amount reaches a predetermined length, the skin 1A is formed by cutting with a slitter 8b.

[0005] FIG. 5 shows an unfoamed sheet portion 1B to be a foamed sheet 11B constituting the laminated sheet 1, which is extruded by an extruder 12;
Shows the state of extrusion and molding.

[0006] The unfoamed sheet portion 1B is supplied with a chemical foaming agent from an hopper 13 into an olefin-based resin.
4B, and the drive motor 14a drives the screw 14c.
Is kneaded and melted in a kneading section 14 for rotating the T-die 15
Extruded to a predetermined thickness in the form of a sheet from the unfoamed sheet part 1
B is formed.

FIG. 6 shows the epidermis 1A formed in FIG. 4 and FIG.
2 shows a state in which the laminated sheet 1 is formed by joining the unfoamed sheet portion 1B formed in the step (1).

That is, in the hot air foaming step, the unfoamed sheet portion 1B formed in FIG. 4 is transferred to the heating furnace 16, and the preheating is performed by the preheating heater 16a. The foaming agent which is kneaded is foamed by heating to form the foamed sheet 11B.

The foam sheet 11B is heated by the heating roll 17 to melt one side in the skin bonding step, and the skin 1A transported toward the foam sheet 11B is also heated by the heating roll 17 and the back side is melted. Is done.

[0010] Then, the both surfaces fused with each other are joined by applying pressure by a pressing roll 18 to be wound up or made into a fixed size, and cut in a subsequent cutting step by a slitter 8b to form a laminate sheet 1. You.

FIG. 7 shows a molded article 111 formed by injection molding or press injection molding (generally called SPM) of the core material 19 using the laminated sheet 1 formed in FIG. The cross section of the main part is shown.

On the lateral side, the compression hardness of each layer of the molded article 111 is represented by an image.

As described above, the resin for the core material 19 is melted and injected from a gate (not shown) through the sprue 19a.
The core material 1 collides with the foamed surface of the laminate sheet 1 under high heat and high pressure and flows while melting (n thickness) the foamed surface.
9 is formed.

[0014]

However, in the laminate sheet 1 described above, one layer of the foamed sheet 11
B, the foamed surface is thinned by heat and pressure in the pressure portion 19b, and the foamed surface is largely melted and the foamed sheet 19 is thinned. Tend to be large)
There was a problem that the cushioning property was reduced and the feel was lost.

When the expansion ratio is reduced to improve the heat resistance and pressure resistance, the compression hardness is increased and the feel is reduced, so that the texture of the molded article 111 is inferior. That is, there was a problem that either the feel or the heat resistance had to be sacrificed.

It is an object of the present invention to provide a laminate sheet which does not lose the cushioning properties of the foam even when subjected to injection pressure or high heat of the resin for the core material when molding a molded article.

[0017]

In order to achieve the above-mentioned object, the invention according to claim 1 is to knead and melt an olefin resin mixed with a foaming agent and an auxiliary agent to form a sheet-like resin. An extruder for extruding the foamed sheet portion is provided, a foaming furnace for heating the unfoamed sheet portion to form a foamed sheet is provided, and a heating roll for further heating and melting one side of the foamed sheet is provided, and separately formed. A plurality of extruders for kneading and melting respective resins mixed with different predetermined amounts of foaming agents and auxiliaries are provided on a laminated sheet formed integrally by pressing on the back surface of the outer skin, and first from the first extruder. The first resin is extruded from a nozzle into a sheet to form a first unfoamed sheet portion, and an electron beam irradiation device for irradiating the first unfoamed sheet portion with an electron beam, and a heater for heating and foaming are installed. First foam A chamber is provided, and the second resin is extruded into a sheet, crosslinked and foamed on the upper side of the first foamed layer formed by transferring the unfoamed sheet portion in the first foamed chamber to form the second foamed layer. A second foaming chamber to be formed is provided, and a foaming layer can be sequentially formed into a multilayer on the upper side of the foaming layer thus formed.

According to a second aspect of the present invention, in the laminate sheet according to the first aspect, the foaming agent is heated so as to be foamed in each of the foaming chambers so that each foaming layer has a predetermined foaming ratio. It is characterized by being regulated by the mixing ratio.

According to a third aspect of the present invention, there is provided the laminate sheet according to the first aspect, wherein the resin extruded in a sheet shape from the nozzle is rotatable so as to be transferred to a predetermined thickness. It is characterized by having provided.

According to a fourth aspect of the present invention, there is provided an extruder for kneading and melting an olefin-based resin mixed with a foaming agent and an auxiliary agent and extruding a sheet-shaped unfoamed sheet portion. Provide a foaming furnace for heating the part to form a foamed sheet, provide a heating roll for further heating and melting one side of the foamed sheet, press against the back surface of a separately formed skin, and form a laminated sheet integrally In the extruder, at the tip of the extruder is provided a die having a built-in radial branch, provided with a mixing unit having a built-in parallel flow path connected to the branch, provided with a mixing means of a foaming agent in the mixing unit, Providing each discharge section having a built-in laminated flow path connected to the parallel flow path, providing a laminated nozzle for discharging the laminated flow paths to positions shifted from each other and laminating them in a multilayer sheet form, and forming an unfoamed multilayer sheet When In the electron beam irradiation device for irradiating electron beam on the unfoamed multilayer sheet being conveyed is provided, it is characterized in that a foaming chamber to further heating.

According to a fifth aspect of the present invention, in the laminate sheet according to the fourth aspect, the mixing means includes a mixing port for mixing a predetermined amount of the blowing agent into each of the parallel flow paths. A plurality of hoppers for the foaming agent reaching the mixing ports are provided, and a mixer is attached to a rear portion of the flow path of each of the mixing ports.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION

[0023]

Embodiment 1 Embodiment 1 of the laminate sheet of the present invention will be described with reference to FIGS.

FIG. 1 is an explanatory diagram showing a cross section of a forming process of a laminate sheet.

FIG. 3 is an explanatory view of a molded article formed by using a laminate sheet.

In FIG. 1, reference numeral 21 denotes a laminate sheet.
Are joined and they are integrated. In addition, foam 23
Is a foam layer in which the first foam layer 231 to the fourth foam layer 234 are multilayered.

The forming process of the laminate sheet 21 is as follows.
The foaming stage is composed of a foaming stage and a skin joining stage. First, in the foaming stage, a smooth and rotatable belt conveyor 24 is provided, and the first to fourth foaming chambers 25 and 26 are located above the belt conveyor 24. , 27, 28,
Each of the foaming chambers 25, 26, 27, and 28 is provided with an electron beam irradiation device 25d and a heater 25e.

In the vicinity of the front of each electron beam irradiation device 25d, there is provided a nozzle 25c connected to each of a plurality of resin extruders.

Further, a thickness control roll 30 and a heating roll 31 are provided behind the fourth foaming chamber 28.

In the subsequent skin bonding stage, a skin 22 roll is positioned above the heating roll 31.
It is mounted so that it can be sent downward as indicated by the arrow.

Pressing rolls 32 are provided at narrower intervals so that the outer skin is sandwiched by the heating rolls 31 and the back side is melted, and the pressing is continuously applied to the foam.

The skin and the foam are transferred and joined between the pressing rolls 32 while receiving the pressing. And
When passing between the pressing rolls 32, the foam 23 is restored to a predetermined thickness.

Subsequently, a cooling / transfer roll 33 is provided. Subsequently, a slitter 34 is provided to cut the laminate sheet to a predetermined size.

Of course, the laminate sheet is wound into a predetermined length to form a roll and then slit to cut the laminate sheet.
It may be transported or stored.

As described above, the laminate sheet 21 formed by joining the foam 23 composed of the multilayer foam layers 231, 232, 233 and 234 having different foam densities and the skin 22 is used. The molding state when the molded article 20 is molded will be described mainly with reference to FIG.

FIG. 3 is a cross-sectional view of a main part of the molded product, and the lateral side shows the compression hardness of each foam layer constituting the molded product.

That is, when the molten resin (about 180 ° C.) for the core material 19 is injected from the sprue 19 a, it hits the first foamed layer 231 which is the lowermost surface of the laminate sheet 21, and in the horizontal direction in FIG. Flow to spread.

At this time, since the first foaming layer 231 has a low foaming ratio and a high compression hardness, the surface of the resin for the core material 19 is only melted (m) to serve as an adhesive layer. As in the conventional example shown in FIG. 7, the foamed layer 231 is melted (n) and cut off, so that the foamed layer does not become thin.

Thus, the high-foamed foam layers 232, 233 and 234 after the second foam layer 232 are also protected, so that the cushioning property as it was during foam molding can be maintained.

In the case of injection molding, which is high-pressure molding, the molded product 20 is different from press injection molding, which is low-pressure molding.
Only the first foamed layer 231 may be formed into a thin solid sheet without hardly foaming to form a multilayer.

[0041]

EXAMPLES Further, as a result of forming a laminate sheet under the following conditions, an extremely good feel was obtained without losing cushioning property in molding a molded article. ● Resin used: Laminate sheet material ・ Skin: TPE (hard segment = PP resin soft segment = EPDM) ・ Foam layer: PP / PE blend molded article ・ Core material: PP composite material ● Expansion ratio ・ First foam layer: 0 ５5 times ・ Second foam layer: 4 to 10 times ・ Third foam layer: 8 to 12 times ・ Fourth foam layer: 10 to 18 times In the present embodiment, four foam layers are used. It is also conceivable to find a good feel by increasing or decreasing the foam layer while adjusting the expansion ratio.

[0042]

Embodiment 2 Embodiment 2 of the foam for laminate sheet of the present invention will be described with reference to FIGS. 2 and 3. FIG.

FIG. 2 is an explanatory view showing a molded state of a foam for a laminate sheet.

In FIG. 2, reference numeral 44 denotes an extruder for kneading and melting an olefin-based resin 43A fed from a hopper 45, and reference numeral 46 denotes a die 46 assembled with a tip 44a of the extruder 44 via a breaker plate 46b. Dice 4
The inside of 6 is radially formed with a branch channel 46a to diverge the extruded resin.

47 is mounted on the die 46, and the die 4
6. A mixing section having a parallel branch channel 47c connected to the sixth branch channel 46a. The mixing section 47 has a mixing port 47e opened to the parallel branch channel 47c so that a predetermined amount of a foaming agent can be charged from the outside. A blowing agent hopper 47d is mounted.

At the rear of the flow path of the mixing port 47e, a mixer 47f (mainly a static mixer) is shown.
Is inserted.

At the rear end of the kneading section 47, a laminating nozzle 48 is assembled.

The lamination nozzle 48 has a lamination flow path 4 inside.
8g, and the lamination flow path 48g is a parallel branch flow path 4
7c, and goes to the discharge port 48h.
At h, the parallel branch channels 47c are integrally laminated to discharge and transfer the unfoamed multilayer sheet 431.

The transferred unfoamed sheet portion 431 is
It is transported below an electron beam irradiation device for electron beam irradiation provided for crosslinking.

Subsequently, it is transported in a foaming chamber having a preheater and a hot air nozzle provided for foaming.

The foamed sheet foamed in the foaming chamber is cooled and wound up in a roll to complete the molding.

The formed foam sheet is joined to a separately formed skin in the same manner as in the first embodiment to form a laminate sheet.

Other configurations, operations, and examples are the same as those of the first embodiment, and thus description thereof will be omitted.

[0054]

As described above, according to the first aspect of the present invention, a laminate sheet in which one kind of foam sheet and a skin are conventionally bonded is combined with a foam sheet having various foaming ratios. Can form a multi-layer foam,
It becomes a foam that can respond to the injection pressure and heat of the core material during molding.

Therefore, a molded article having a good touch can be obtained without losing the cushioning properties of the foam even after molding.

According to the second aspect of the present invention, the expansion ratio of each foam layer of the foam can be freely selected, and the first foam layer has pressure resistance and pressure resistance.
By having a heat-resistant function and the foam layer placed on it has a high foaming function and a touch function, it is compared with the conventional one where the foaming ratio of the foam sheet was lowered for pressure resistance and heat resistance and the touch was sacrificed. In addition, the expansion ratio can be freely set, and a foam having a good feel can be obtained.

According to the third aspect of the present invention, the feed speed of the belt can be freely adjusted.

Therefore, the belt feeding can be adjusted to the foaming speed, and a foam sheet of stable quality can be formed.

According to the invention of claim 4, the foamed multilayer sheet can be formed by one extruder. Therefore, the apparatus is simplified and the formation of the foam is inexpensive.

According to the fifth aspect of the present invention, a blowing agent can be homogeneously mixed into a resin to be melt-extruded.

Accordingly, a foam having a stable quality can be obtained.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram illustrating a cross-section illustrating a forming process of a laminate sheet according to Embodiment 1 of the present invention.

FIG. 2 is an explanatory diagram showing a molded state of a foam according to a second embodiment of the present invention.

FIG. 3 is a fragmentary cross-sectional view of a molded article according to Embodiments 1 and 2 of the present invention.

FIG. 4 is an explanatory view showing a molded state of a skin according to a conventional example.

FIG. 5 is an explanatory view showing a molding state of an unfoamed sheet portion according to a conventional example.

FIG. 6 is an explanatory view showing a molding state of a laminate sheet according to a conventional example.

FIG. 7 is a sectional view of a main part of a molded product according to a conventional example.

[Explanation of symbols]

 21 Laminated sheet 23a Unfoamed sheet part 231 First foamed layer 232 Second foamed layer 233 Third foamed layer 234 Fourth foamed layer 25 First foaming chamber 25c Nozzle 25d Electron beam irradiation device 25e Heater 26 Second foaming chamber

────────────────────────────────────────────────── ─── Continued on the front page (51) Int.Cl. ⁶ Identification code FI B32B 31/14 B32B 31/14 C08J 7/00 305 C08J 7/00 305 // B29K 23:00 105: 04 105: 24 B29L 9 : 00

Claims (5)

[Claims] An extruder for kneading and melting an olefin-based resin mixed with a foaming agent and an auxiliary agent and extruding a sheet-shaped unfoamed sheet portion is provided, and the foamed sheet is heated by heating the unfoamed sheet portion. A foaming furnace to be formed is provided, and a heating roll for further heating and melting one side of the foamed sheet is provided, and the foamed sheet is pressed against a back surface of a separately formed outer skin to form a different amount of foam in a integrally formed laminated sheet. A plurality of extruders for kneading and melting each resin mixed with an agent and an auxiliary agent are provided. First, the first resin is extruded from a nozzle into a sheet shape from a nozzle to form a first unfoamed sheet portion. (1) An electron beam irradiator for irradiating an electron beam to an unfoamed sheet portion and a heater for heating and foaming are provided to provide a first foaming chamber, and the unfoamed sheet portion moves through the first foaming chamber. Then formed A second foaming chamber for extruding the second resin into a sheet, cross-linking and foaming to form a second foaming layer is provided on the upper side of the formed first foaming layer, and sequentially above the foaming layer thus formed,
A laminated sheet characterized in that a foamed layer can be formed into a multilayer. 2. The laminate sheet according to claim 1, wherein each of the foam layers heated and foamed in each of the foam chambers is regulated by a mixing ratio of the foaming agent so as to have a predetermined foaming ratio. . 3. The laminate sheet according to claim 1, further comprising a rotatable belt provided so that the resin extruded into a sheet from the nozzle can be transferred to a predetermined thickness. 4. An extruder for kneading and melting an olefin-based resin mixed with a foaming agent and an auxiliary agent and extruding a sheet-shaped unfoamed sheet portion is provided, and the foamed sheet is heated by heating the unfoamed sheet portion. A foaming furnace to be formed, a heating roll for further heating and melting one side of the foamed sheet is provided, and pressed against the back surface of a separately formed skin, to form a laminated sheet integrally formed, wherein a tip portion of the extruder A dice having a radial branch is provided therein, a mixing portion having a parallel flow passage connected to the branch flow is provided, a mixing means for a foaming agent is provided in the mixing portion, and a laminating flow connected to the parallel flow passage is provided. Provide each discharge section with a built-in path,
The lamination flow path is provided with a lamination nozzle which is discharged at a position deviated from each other and laminated to form a multi-layer sheet, thereby forming an unfoamed multilayer sheet, and irradiating the transferred unfoamed multilayer sheet with an electron beam. A laminate sheet provided with a device and further provided with a foaming chamber for heating. 5. The mixing means includes a mixing port for mixing a predetermined amount of the foaming agent into each of the parallel flow paths, a plurality of foaming agent hoppers reaching the mixing port, and The laminate sheet according to claim 4, wherein a mixer is inserted in a rear portion of the flow path of the mouth.