JPH06182869A - Manufacture of plastic sheet with uneven pattern - Google Patents

Abstract

PURPOSE:To provide a method for manufacturing a plastic sheet having an uneven pattern which is scarcely collapsed even at the time of vacuum molding to accurately and clearly form the pattern on a surface. CONSTITUTION:A heated thermoplastic sheet 10 is wound on an outer peripheral surface of a pattern forming roll 14 having an uneven pattern on a surface to continuously supply it between the roll 14 and a press roll 16. A method for manufacturing the sheet having the uneven pattern on the surface has the steps of forming the uneven pattern on a surface of the sheet by pressing with the rolls 14, 16, and peeling the sheet 11 formed with the pattern from the surface of the roll 14, and comprises the steps of cooling a rear surface of the sheet 1 wound on the surface of the roll 14 and formed with the pattern with cooling medium, and then peeling the sheet 11 from the surface of the roll 14.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a plastic sheet having an uneven pattern on its surface. The uneven pattern is also called a squeeze pattern or a satin pattern.

[0002]

2. Description of the Related Art Conventionally, the following method has been known as a continuous method for producing a plastic sheet having the above-mentioned concavo-convex pattern which is used as a skin material for various products. That is, as shown in FIG. 2, the thermoplastic resin sheet 30 whose surface is softened by heating to a predetermined temperature is wound around the outer peripheral surface of a pattern forming roll 32 having an uneven pattern on the surface to form the pattern. A thermoplastic sheet 30 continuously supplied between the roll 32 and the pressing roll 34 and pressed between the rolls 32 and 34 to contact the surface of the pattern forming roll 32.
This is a method of forming an uneven pattern on the surface and then peeling off the plastic sheet 31 on which the pattern is formed from the surface of the pattern forming roll 32 to continuously obtain a plastic sheet having an uneven pattern on the surface.

However, in the above method, the plastic sheet 31 after the pattern formation, which is wound around the outer peripheral surface of the pattern forming roll 32 after being pressed by both rolls 32 and 34, is still in a high temperature and easily deformed. . Therefore, when the plastic sheet 31 is peeled off from the outer peripheral surface of the pattern forming roll 32, the unevenness portion of the surface of the plastic sheet 31 is expanded by the tension applied for peeling off, and the height difference of the unevenness pattern is reduced, and the unevenness pattern is reduced. There is a problem that the pattern cannot be accurately reproduced and a pattern tends to be unclear. In particular, as shown in FIG. 3, the concave portion 36 on the front surface is extended, and a concave portion 38 is likely to be formed on the rear surface portion corresponding to the concave portion 36 as shown by a chain line. Therefore, when the plastic sheet 31 on which the pattern is formed is to be formed into a predetermined shape by vacuum forming, the concave portion 3 on the back surface is formed during the vacuum forming.
There is also a problem that the plastic sheet 31 stretches at 8, and the uneven pattern on the surface further collapses and becomes unclear.

[0004]

In view of the above points, the present invention is directed to the production of a plastic sheet having an uneven pattern which can be accurately and clearly formed on the surface and which is not easily collapsed during vacuum forming. It provides a method.

[0005]

SUMMARY OF THE INVENTION The present invention is directed to heated heat.
The plastic plastic sheet has an uneven pattern on the surface
The pattern forming roll is wrapped around the outer peripheral surface to simulate
Continuous feeding between the forming roll and the pressing roll,
Of the thermoplastic tape that presses between the
After forming an uneven pattern on the surface of the plastic sheet,
Pull the formed plastic sheet from the surface of the pattern forming roll.
Peeled-off plastic sheet with an uneven pattern
In the manufacturing method of 1., the pattern shape after pressing by both rolls
A plastic sheet after forming a pattern wrapped around the surface of the roll
After cooling the backside of the board with a cooling medium,
Peel the plastic sheet off the pattern roll surface
A plastic sheet having an uneven pattern characterized by
Related to the manufacturing method of.

[0006]

After the pattern formation by the both rolls, the pattern-formed plastic sheet wound around the surface of the roll is still in a high temperature state and is easily deformed. However, since it is cooled from the back side by the cooling medium in the wound state, the temperature decreases and it becomes difficult to deform, and it does not stretch even when peeled off from the surface of the pattern forming roll thereafter, and accurate and clear unevenness A pattern is obtained.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the accompanying drawings. FIG. 1 is a schematic view showing a pattern formation in an embodiment of the present invention.

In this embodiment, the thermoplastic sheet 10 is heated to a predetermined temperature by a heating device 12 and then pressed against the pattern forming roll 14 so as to be wound around the surface of the pattern forming roll 14 having an uneven pattern. Roll 1
It is continuously supplied between 6 and is pressed between both rolls 14 and 16 to transfer the uneven pattern on the surface of the pattern forming roll 14 to the surface of the plastic sheet 10. The plastic sheet 11 on which the pattern has been formed is cooled by spraying water on the back surface of the plastic sheet 11 by the spray device 18, and then peeled off from the surface of the pattern forming roll 14 and taken by a take-up device (not shown).

The thermoplastic sheet 10 is
It may be directly supplied from an extruder or a calender device, or may be once wound on a winding roll and then rewound and supplied. The material of the thermoplastic sheet 10 is a thermoplastic material used for ordinary thermoforming. For example,
Polyvinyl chloride, polypropylene, polyethylene, AB
S resin or the like is used. Thermoplastic sheet 1
The heating temperature of 0 is a temperature at which the surface becomes a softened state and varies depending on the material, but in the case of vinyl chloride resin, it is 1
A temperature of 80 to 200 ° C is suitable. As the heating device 12, an electric heater or the like is used. In addition, 17 and 19 are guide rolls.

The pattern forming roll 14 is composed of a rubber roll or a metal roll having an uneven pattern on its surface. The pattern forming roll 14 is connected to a drive motor so as to be rotatable in the direction of the arrow and via the thermoplastic sheet 10. The surface of the pressure roll 16 can be pressed or separated from the surface of the pressure roll 16. The pattern forming roll 14 is
The thermoplastic resin sheet 10 is heated to a predetermined temperature in order to form a good uneven pattern on the surface and to prevent the plastic sheet 11 after the pattern formation from sticking to the surface of the roll 14. The heating temperature is almost the softening temperature of the thermoplastic sheet 10, and when the thermoplastic sheet 10 is vinyl chloride, it is 200 to 240 ° C.
Is preferred. The pattern forming roll 14 is heated by the roll 14
It may be carried out by circulating a heating medium such as oil in a pipe (not shown) provided inside, or by applying hot air to the surface of the roll 14.

The pressing roll 16 is for pressing the thermoplastic sheet 10 against the surface of the pattern forming roll 14 to form an uneven pattern corresponding to the uneven pattern of the surface of the pattern forming roll 14 on the surface of the thermoplastic sheet 10. It is made of rubber and can be rotated in the direction of the arrow by a drive motor. Further, in order to form a good uneven pattern on the thermoplastic sheet 10, it is preferable to regulate the elongation of the back surface of the plastic sheet 10 when forming the uneven pattern. Therefore, the lower portion of the pressure roll 16 that is in contact with the back surface of the plastic sheet 10 is soaked in water in the water tank 20 so that the temperature becomes 0 to 60 ° C. Reference numeral 22 in the drawing denotes a draining brush for removing water in the water tank 20 attached to the surface of the pressing roll 16.

The spray device 18 includes a pattern forming roll 14
It is for cooling the back surface of the plastic sheet 11 by spraying water on the back surface of the plastic sheet 11 after the pattern formation in the state of being wrapped around. At that time, the plastic sheet 11 is heated to about 50 to 60 ° C.
It is preferred to spray water at ~ 35 ° C. The water to be sprayed is preferably atomized. The mist-like water evaporates by the heat of the plastic sheet 11 immediately after spraying and removes heat of vaporization from the plastic sheet 11, so that the plastic sheet 11 can be cooled efficiently. In addition, this cooling is preferably performed at a position before and including the point X at which the plastic sheet 11 after pattern formation is peeled from the pattern formation roll 14. As a preferable example,
The spray range a is about 40 cm. The cooling of the back surface of the plastic sheet 11 is not limited to water,
A cooling medium such as cold air may be blown onto the back surface of the plastic sheet 11.

The plastic sheet 11 thus obtained after pattern formation has no recess on the back surface corresponding to the recess on the front surface. Further, the plastic sheet 11 is thereafter vacuum-formed into a predetermined shape as appropriate according to the application.

[0014]

As shown and described above, according to the manufacturing method of the present invention, the back surface of the plastic sheet on which the concavo-convex pattern is formed is cooled to make it difficult to stretch, and then the plastic sheet is peeled off from the surface of the pattern forming roll. Therefore, even if a tensile force is applied at that time, the uneven pattern portion does not extend, and a clear uneven pattern can be obtained. In addition, since the plastic sheet after pattern formation is wound around the pattern forming roll and cooled to fix the shape, the uneven pattern on the surface of the pattern forming roll can be accurately reproduced on the surface of the plastic sheet.

[Brief description of drawings]

FIG. 1 is a schematic view showing formation of a concavo-convex pattern in an embodiment of the present invention.

FIG. 2 is a schematic view showing a conventional concavo-convex pattern formation.

FIG. 3 is a cross-sectional view of a plastic sheet after pattern formation.

[Explanation of symbols]

 10 Thermoplastic Plastic Sheet 11 Plastic Sheet After Pattern Formation 14 Pattern Forming Roll 16 Pressing Roll 18 Sprayer

Claims (1)

[Claims] 1. A heated thermoplastic sheet is continuously supplied between the pattern forming roll and the pressing roll so as to be wound around the outer peripheral surface of the pattern forming roll having an uneven pattern on the surface, and between the both rolls. After forming a concavo-convex pattern on the surface of the thermoplastic sheet which is in contact with the surface of the pattern forming roll by pressing, the plastic sheet after the pattern formation is peeled off from the surface of the pattern forming roll,
In the method for producing a plastic sheet having an uneven pattern, after pressing by both rolls, the back surface of the plastic sheet after pattern formation wrapped around the surface of the pattern formation roll is cooled by a cooling medium, and then the plastic sheet after pattern formation is subjected to pattern formation. A method for producing a plastic sheet having an uneven pattern, which comprises peeling from a roll surface.