JP2000318032A - Supply method for molten resin sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stably separate a molten resin sheet, which is supplied to a mold, from a supply device in a supply method for the molten resin sheet. SOLUTION: The molten resin layers 31m, 32m, 33m extruded from the extrusion orifices 21a, 23a, 25a of die heads 21, 23, 25 are passed through the nip between a pair of rotary rollers 27a, 27b to be drawn out as a molten resin sheet 30m to be supplied to a mold. After the supply of the molten resin sheet to the mold is completed, the rotational speed of the rollers is made faster than the extrusion speed of the molten resin layers from the die heads to separate the molten resin sheet supplied to the mold. At the time of separation of the molten resin sheet, it is pref. that the extrusion of the molten resin layers from the die heads is stopped and the rotational speed of the rollers is increased. A plurality of die heads are provided and the molten resin layers extruded from the extrusion orifices of them are passed through the nip between rolles to be superposed and bonded mutually to be formed into a molten resin sheet.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for supplying a molten resin sheet extruded from an extrusion opening of a die head to a molding die as a molten resin sheet, and more particularly to a method for supplying the molten resin sheet onto the molding die after the supply is completed. And a method for supplying a molten resin sheet having a function of separating the molten resin sheet.

[0002]

2. Description of the Related Art As a method for supplying a molten resin sheet of this type, for example, there is a method as shown in FIG. This uses three die heads 21, 23, 25 provided with supply pipes 22, 24, 26 of molten resin material, respectively, and a supply device composed of a pair of rollers 27 a, 27 b. 25 extrusion ports 21a, 23a, 25
a, three molten resin layers 31m, 32m,
33m are overlapped and passed between rollers 27a and 27b, and one molten resin sheet 30m which is superimposed and joined to each other.
The entirety of the supply device is horizontally moved to supply the molten resin sheet 30 m onto the molding surface 11 of the molding die 10. In this example, three molten resin layers 3
1m, 32m, 33m are overlapped and molten resin sheet 3
0 m, and the central molten resin layer 31 m is a foamed synthetic resin layer kneaded with a foaming agent. However, the molten resin sheet may be a two-layered sheet having no foamed synthetic resin layer, or may be a single molten resin layer. It may be composed of layers.

[0003] The molten resin sheet 30m supplied onto the molding surface 11 needs to be separated from the supply device after the supply is completed. This separation is performed, for example, as shown in FIG.
A pair of cutter blades 1a, 1b provided below 7a, 27b
Is usually cut by approaching as shown by the arrow.

[0004]

In the prior art described above, the cutter blades 1a, 1b are used for separating the molten resin sheet 30m.
However, the resin of the cut molten resin sheet 30m adheres to the cutter blades 1a and 1b little by little at every cut and hardens and deposits. There is a problem that 30 m cannot be cut well. After the separation, the molten resin sheet 30m and the molten resin layers 31m, 3 are provided between the die heads 21, 23, 25 on the supply device side and the cutter blades 1a, 1b.
Since 2 m and 33 m remain, and the temperature is lowered until the next supply is started, the molten resin material cannot be used for the next molding. An object of the present invention is to solve each of these problems.

[0005]

According to a method of supplying a molten resin sheet according to the present invention, a molten resin layer extruded from an extrusion port of at least one die head is rotated at a rotation speed corresponding to the extrusion speed of the die head. In a method for supplying a molten resin sheet, the molten resin sheet is drawn out as a molten resin sheet and supplied onto a molding die through a pair of rollers. The rotation speed of the roller is set to be higher than the extrusion speed of the molten resin layer to separate the molten resin sheet supplied to the molding die. After the supply of the molten resin sheet, since the rotation speed of the roller is higher than the extrusion speed of the molten resin layer from the die head, the molten resin layer extruded from the extrusion port of the die head is thin between the extrusion port and the roller. The molten resin sheet supplied to the mold side is separated from the die head and the roller side.

A plurality of die heads according to the invention described in the preceding paragraph are provided, and the respective molten resin layers extruded from the respective extrusion ports are overlapped and passed between rollers, drawn out as a polymerized molten resin sheet, and supplied onto a molding die. Is preferred.

[0007] The separation of the molten resin sheet according to the second aspect of the invention is performed by:
It is preferable that after the supply of the molten resin sheet to the molding die, the extrusion of the molten resin layer from the die head is stopped without stopping the rotation of the roller. With this configuration, the molten resin layer is not extruded from the die head until the start of the next supply.

[0008] The separation of the molten resin sheet according to the first and second aspects of the invention is performed after the supply of the molten resin sheet to the molding die is completed.
It is preferable to stop the extrusion of the molten resin layer from the die head and increase the rotation speed of the roller. In this way, the separation of the molten resin sheet is performed promptly.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A method for supplying a molten resin sheet according to the present invention will be described with reference to the embodiments shown in FIGS. As shown in the drawings, the molten resin sheet supply device used in this embodiment includes first to third die heads 2.
It comprises a pair of rollers 1, 23, 25, and a pair of rollers 27 a, 27 b for supplying a molten resin sheet 30 m onto the vacuum forming die 10.

As shown in FIG. 3, a molding surface 11 having a shape corresponding to the surface of the skin of the laminate to be molded is formed on the upper side of the vacuum molding die 10, and the outer periphery thereof extends outwardly therefrom. A substantially planar peripheral portion 11a is formed. Between the cavity 12 formed in the mold 10 and the molding surface 11, a number of intake holes 13 are provided almost all over the surface, and an intake port 14 opened in the cavity 12 is provided with a vacuum pump and a vacuum tank. And a vacuum source 15 comprising an on-off valve. A grain pattern (fine uneven pattern) is formed on the molding surface 11.

First to third die heads 21, 23, 25
Move independently of each other but are integrally joined and move in a substantially horizontal direction above the molding die 10.
Each of 1, 2 and 25 has three independent extruders (not shown) for supplying the molten resin materials to be the foamed layer, the base material and the skin via the first to third supply pipes 22, 24 and 26. Are linked. The resin material to be a flexible foam layer is melted in a first extruder, a foaming agent (for example, azodicarbonamide having a foaming temperature of 130 ° C.) is kneaded, and a slit-like material is formed below the first die head 21 located at the center. From the extrusion port 21a,
It is extruded as a sheet-like foamed molten resin layer 31 m having a foaming temperature or lower (for example, 110 ° C.). The resin material serving as a rigid base material is melted by the second extruder, and from the slit-shaped extrusion port 23 a below the second die head 23 located on one side of the first die head 21, from the foaming temperature to 50 to 10
It is extruded as a sheet-like base resin molten resin layer 32m at a high temperature of 0 ° C (for example, 230 ° C). The resin material that becomes a soft skin is melted by a third extruder, and the first die head 2 is melted.
1 through a slit-shaped extrusion port 25a below the third die head 25 located on the other side of the third die head 25, at a temperature of 50 to 100 ° C.
High temperature (for example, 200 ° C.) sheet-like skin melt resin layer 3
Extruded as 3m. Each molten resin layer 31m, 32
m and 33 m are, for example, olefin-based copolymers, each having a thickness of, for example, 0.7 mm, 3.0 mm, and 0.5 mm.
It is.

The extrusion ports 21a, 23a, 25a of the die heads 21, 23, 25 are parallel to each other and orthogonal to the direction of movement, and are supported by parallel support shafts 28a, 28b to be rotated by a pair of rollers. 27a and 27b are provided below and parallel to the extrusion ports 21a, 23a and 25a. As described above, the synthetic resin materials to be the foamed layer, the base material, and the skin are melted by the respective extruders, and the extrusion ports 21a, 23a, and 2 of the die heads 21, 23, and 25 are melted.
Each of the molten resin layers 31m, 32m, and 33m is extruded from 5a. As shown in FIG. 1 and FIG.
The molten resin layers 31m, 32m, and 33m are rotated in the direction indicated by the symbol w in conjunction with the extrusion speeds of the molten resin layers 31m, 32m, and 33m. And is integrally joined to each other to form a molten resin laminated sheet (hereinafter simply referred to as a molten resin sheet) 30 m.

The foamed molten resin layer 31m is provided on the first die head 2
In the state extruded from No. 1, the foaming temperature is lower than the foaming temperature, so that the foaming remains as it is. However, after passing between the rollers 27 a and 27 b, the foam is heated and foamed by the molten resin layers 32 m and 33 m joined on both sides. You. Each molten resin layer 32m, 33
Since m is bonded to the entire surface on both sides of the foamed molten resin layer 31m, the heating is performed quickly and uniformly, the foaming is also performed quickly and evenly, and the molten resin sheet 30m after passing through the rollers 27a and 27b is thickened. Increases uniformly, and the roller 2
7a, 27b hangs down and is sent out.

While feeding the molten resin sheet 30m from the rollers 27a and 27b in this way, as shown in FIG.
Is moved from one side to the other side (from left to right in FIG. 3) on the molding die 10 along the X direction orthogonal to the axial direction of the molten resin sheet 3 in which foaming is substantially completed.
0 m is supplied so as to cover almost the entire molding surface 11 of the mold 10 with the skin molten resin layer 33 m serving as the skin 33 facing downward. When the supply is completed, the supplied molten resin sheet 30m is separated, and the molten resin sheet supply device is retracted to the side from above the mold 10 (see FIG. 2).

The separation of the molten resin sheet 30m is performed by separating each molten resin layer 31m from each die head 21, 23, 25.
At the same time as stopping the extrusion of 32m and 33m,
7a, 27b are increased (for example, 12
(Increase from 100 revolutions / minute to 100-120 revolutions / minute). Thereby, each molten resin layer 3 between the rollers 27a, 27b and each die head 21, 23, 25
As shown in FIG. 2, 1 m, 32 m, and 33 m are rapidly stretched and cut to be thin, and therefore, the molten resin sheet 30 m which is superimposed and supplied onto the mold 10 is provided.
Is also separated from the molten resin sheet supply device and the roller 27
a, 27b fall away. As described above, the separation of the molten resin sheet 30m is performed without using a cutter blade whose sharpness is reduced due to the adhesion of the molten resin, and thus can be stably performed for a long time. In addition, each die head 2
1, 2, 25 are heated to a predetermined temperature by a heater (not shown).
The synthetic resin material in a molten state remaining in 1, 23, 25 is maintained at a predetermined temperature and is not cooled.

In this embodiment, each molten resin layer 3
The distance between the rollers 27a and 27b is reduced as the thickness of the molten resin sheet 30m becomes thinner. By doing so, the shape of the separation portion becomes clear, but without doing so, there is no trouble in separation.

Since the molten resin sheet 30m supplied onto the vacuum forming die 10 is in a semi-molten state and is rich in plasticity, it is deformed by its own weight into a shape substantially along the forming surface 11,
A peripheral portion of the skin molten resin layer 33m is substantially closely attached to a peripheral portion 11a of the molding surface 11. Next, as shown in FIG. 2, a negative pressure from a vacuum source 15 is applied to the cavity 12 of the mold 10 through the suction port 14, and the molten resin sheet 30 m is sucked through the many suction holes 13. As described above, the molten resin sheet 30m is a skin molten resin layer 33 serving as the skin 33.
m is closely adhered to the peripheral portion 11a of the molding surface 11, so that the molten resin sheet 30m is completely adhered to the entire surface of the molding surface 11 by this suction and is shaped, and the skin molten resin layer 33m The grain pattern formed on the molding surface 11 is transferred to the surface of.

The molten resin sheet 30m formed in close contact with the molding surface 11 is cooled by heat transfer to the molding die 10. After being sufficiently cooled and cured, the vacuum source 15
When the supply of negative pressure from is stopped and the molded product is released from the mold, one cycle of molding of the laminate in which the base material is integrally covered with the foam layer and the skin is completed. If necessary, unnecessary portions around the laminate may be cut and removed. After taking out the molded product, the supply of the molten synthetic resin material to each die head 21, 23, 25 from each extruder, which has been once stopped, is resumed, and each molten resin layer 31m is fed from the extrusion ports 21a, 23a, 25a. , 32m, 33m and roller 2
The molten resin sheet 30m polymerized and joined through the space between 7a and 27b is drawn out, and a molded product is formed in the same manner as described above. At this time, the molten resin sheet 30m drawn from the rollers 27a and 27b
Since it has just been extruded from 3, 25, it can be used without wasting everything.

In the above-described embodiment, three die heads 21, 23, 25 are used, and each of the extrusion ports 21 is used.
The three molten resin layers 31m, 32m, and 33m extruded from a, 23a, and 25a are passed between rollers 27a and 27b to be drawn out as a joined molten resin sheet 30m. By doing so, the roller 27 for joining the three molten resin layers 31m, 32m, and 33m is formed.
Since a and 27b can be used for cutting each of the molten resin layers 31m, 32m and 33m, the equipment can be simplified.

In the above-described embodiment, when the extrusion of the molten resin layer 31m from the die heads 21, 23, and 25 is stopped, the rotation speed of the simultaneous rollers 27a and 27b is increased. The separation of the molten resin sheet 30m supplied to the mold is performed promptly, and the molding cycle time can be shortened.

In the above-described embodiment, the molten resin sheet 30m is composed of the foamed molten resin layer 31m and the base molten resin layer 3m.
Although 3 sheets consisting of 2 m and the skin molten resin layer 33 m were used, the foamed molten resin layer may be omitted and a two sheet consisting of the base molten resin layer and the skin molten resin layer may be used, or the molten resin sheet 30 m may be used. It may be formed by only one molten resin layer.

In the above-described embodiment, an example in which the molten resin sheet 30m is supplied to the vacuum forming die has been described. However, the present invention uses the molten resin sheet 30m drawn from the rollers 27a and 27b using a pair of matched dies. It may be carried out by supplying it onto the lower mold of the stamping mold.

[0023]

According to the present invention, since the rotational speed of the roller is made larger than the extrusion speed of the molten resin layer from the die head and the molten resin layer is thinned and cut, the sharpness is caused by the adhesion of the resin. Unlike the case of using a decreasing cutter blade, the separation of the molten resin sheet supplied onto the mold can be stably performed for a long time. Also, since the molten resin layer is thinned and cut between the extrusion port and the roller, the amount of the molten resin layer remaining on the supply device after the separation of the molten resin sheet supplied on the forming die is reduced, and therefore, the wasteful consumption is caused. The amount of synthetic resin material to be used can be reduced.

In the above invention, a plurality of die heads are provided, and the respective molten resin layers extruded from the respective extrusion ports are overlapped and passed between rollers, drawn out as a polymerized molten resin sheet, and put on a molding die. According to the supply device, a pair of rollers used for drawing out the molten resin sheet and cutting each molten resin layer can also be used for joining each molten resin layer. As a result, manufacturing costs can be reduced.

According to the second aspect of the invention, the separation of the molten resin sheet is performed by stopping the extrusion of the molten resin layer from the die head. Since the layers are not extruded, the consumption of the synthetic resin material is further reduced.

According to the first and second aspects of the invention, the extrusion of the molten resin layer from the die head is stopped, and the rotation speed of the roller is increased to separate the molten resin sheet. Since the separation of the molten resin sheet supplied onto the mold is performed quickly, the molding cycle time can be shortened.

[Brief description of the drawings]

FIG. 1 is a partially enlarged sectional view showing a molten resin sheet supply state in one embodiment of a molten resin sheet supply method according to the present invention.

FIG. 2 is a partially enlarged sectional view showing a state in which a molten resin layer in the embodiment shown in FIG. 1 is cut.

FIG. 3 is an overall cross-sectional view showing a molten resin sheet supply state in the embodiment shown in FIG.

FIG. 4 is a partially enlarged cross-sectional view showing an example of a method for supplying a molten resin sheet according to a conventional technique.

[Explanation of symbols]

10: mold (vacuum mold), 21, 22, 23 ... die head, 21a, 23a, 25a ... extrusion port, 27a,
27b: roller, 30m: molten resin sheet, 31m, 3
2m, 33m: molten resin layer.

Continued on the front page F-term (reference) 4F201 AG03 AP07 AR08 AR09 BA06 BC01 BC12 BC17 BC21 BD07 BN31 BQ09 BQ12 4F207 AG01 AG03 AP07 AR08 AR09 KA01 KA17 KB26 KM05 KM16 KW23 4F208 AG01 AG03 AP07 AR08 AR09 MA01 MB01 MB22 MC01 MG04 MG22 MJ10

Claims (4)

[Claims] 1. A molten resin layer extruded from an extrusion opening of at least one die head is passed through a pair of rollers rotating at a rotation speed corresponding to an extrusion speed of the die head, and is drawn out as a molten resin sheet. In the method for supplying a molten resin sheet to be supplied onto a molding die, after the supply of the molten resin sheet to the molding die is completed, the roller is compared with an extrusion speed of the molten resin layer from the die head. A method for supplying a molten resin sheet, wherein the rotation speed is increased and the molten resin sheet supplied to the molding die is separated. 2. A plurality of die heads, and each molten resin layer extruded from each extrusion port is overlapped and passed between the rollers, drawn out as a polymerized molten resin sheet, and placed on the mold. The method for supplying a molten resin sheet according to claim 1, wherein the supply is performed. 3. The separation of the molten resin sheet is performed by stopping the extrusion of the molten resin layer from the die head without stopping the rotation of the roller after the supply of the molten resin sheet to the mold is completed. Claim 1 performed by
Or the supply method of the molten resin sheet of Claim 2. 4. The method of separating the molten resin sheet, comprising: stopping the extrusion of the molten resin layer from the die head and increasing the rotation speed of the roller after the supply of the molten resin sheet to the mold is completed. The method for supplying a molten resin sheet according to claim 1 or 2, wherein the method is performed.