JPS5940087B2 - Method and device for laminating thermoplastic resin film - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides, firstly, a method for laminating a thermoplastic resin film onto a thermoplastic resin sheet in a molten state without wrinkles; and secondly, a method for laminating a thermoplastic resin film in a wrinkle-free state. This invention relates to a device for laminating a thermoplastic resin sheet immediately after extrusion.

In the conventional method, the thermoplastic resin film was simply fed out from a roll and laminated directly onto the extruded thermoplastic resin sheet. Therefore, the weaker the film, the lower the heat resistance, and the thinner the film, the more difficult it is to laminate the film. The problem was that wrinkles easily appeared on the laminate product, and the wrinkles remained on the laminate product.

Possible causes of film wrinkles include:
This is due to the characteristics of the film itself and mechanical factors (variations in tension depending on the location of the film during lamination). The present invention was achieved as a result of the following extensive studies, with the main purpose of eliminating wrinkles caused by mechanical factors in particular.
That is, although there are various causes of film wrinkles, shrinkage in the width direction of the film has a particularly large effect.

Conventional methods for tensioning the film in the width direction include installing tension rolls, but this is only effective until slightly before lamination. Therefore, it can be presumed that the lamination will be improved by tensioning the film in the width direction, and the present invention is designed to maintain the width of the film at the time of laminating the thermoplastic resin film on the thermoplastic resin sheet immediately after extrusion or a little after that. By applying directional tension, it became possible to obtain a laminate sheet with no wrinkles at all. The tension in the width direction of the thermoplastic resin film is resolved by mechanical means. Endless belts are disposed on both sides of the extruder and extend to the rotation axis of the cooling roll or in front of it and pass through the gap between the cooling rolls. An apparatus is used in which belts hold both sides of the thermoplastic resin film for lamination.

The present invention will be explained below with reference to the drawings.

The endless belts 2 placed on both sides of the extruder 1 are
It extends slightly forward of the rotation axis of the cooling rolls 3, 3', 3'' and is positioned so as to pass through the gap between the cooling rolls 3, 3'.

A pin 4 is implanted on the surface of the endless belt 2. The thermoplastic resin film 5 for lamination in a wound state is pulled out and passed through a tension roll 6 to reach a guide roll 7, where both sides are held by the pins 4 of the endless belt 2 and pulled in the width direction. Thereafter, the thermoplastic resin film 5 is stacked on the extruded thermoplastic resin sheet 8 near the gap between the cooling rolls 3 and 3', and is pressed and heat-sealed to the thermoplastic resin sheet 8 in the gap. It is held by the pin 4 and kept in tension until immediately afterward. The fused sheets are then passed through cooling rolls 3/, 3
It passes through the gap 7' and becomes a laminate sheet 9. What is required here is that the thermoplastic resin film 5 is
3/, 3/I, and both side pins 4
must be maintained.

In order to prevent the thermoplastic resin film 5 from shrinking due to surrounding heat before lamination, a heat insulating plate 10 may be interposed between the extruder 1 and the thermoplastic resin sheet 8 immediately after extrusion. The endless belt 2 is driven by the sliding roll 11, and its speed is controlled by the cooling rolls 3, 37, 3/3.
In order to obtain a good laminate sheet, it is necessary to make the rotation speed approximately equal to the rotation speed of /. Further, the tension roll 6 is used to remove wrinkles from the thermoplastic resin film 5 until it is held on the pin 4. The endless belt 2 has some flexibility, and is connected to the extruder 1 and the cooling rolls 3, 3',
3' and 7 is narrow, the position can be changed.

In particular, when the thermoplastic resin sheet 8 is drawn down, it is effective to change the position of the endless belt so that it is introduced from the direction B in FIG. 1, and the workability is good.

Example 5 An ABS resin sheet was extruded using a 0φ extruder, and a 50 μm acrylic resin film was laminated onto the extruded sheet using the above-mentioned device. A good laminated sheet with no film wrinkles was obtained.

Reference Example 1: When an acrylic resin film similar to that described above was directly laminated onto an extruded sheet similar to that of the above example through a guide roll, horizontal wrinkles appeared on the sides of the sheet and vertical wrinkles appeared in the center, resulting in a laminated sheet that was defective in appearance. All I could get was that.

The present invention has the following features which solve the drawbacks of the prior art.

When laminating a thermoplastic resin film onto a thermoplastic resin sheet immediately after extrusion, the film can be laminated under tension in the width direction, so a good laminated sheet without wrinkles can be obtained regardless of the material properties of the film. .

This is particularly effective because the pins of the endless belt operate until the time of lamination or immediately thereafter.

[Brief explanation of the drawing]

FIG. 1 is a side view showing one embodiment of the present invention, and FIG. 2 is a side view showing one embodiment of the present invention.
FIG. 2 is an explanatory diagram of the main parts of the figure as viewed from direction A. FIG. 1 is an extruder, 2 is an endless belt, 3, 31, 3'' is a cooling roll, 4 is a pin, 5 is a thermoplastic resin film, 6
is a tension roll, 7 is a guide roll, 3 is a thermoplastic resin sheet, and 9 is a laminate sheet.

Claims (1)

[Claims] 1. When a thermoplastic resin film is layered on a thermoplastic resin sheet in a molten state immediately after extrusion and guided to a cooling roll for lamination, tension in the width direction is applied to the thermoplastic resin film to reduce the tension at least. A method for laminating a thermoplastic resin film, characterized in that the lamination is continued until the time it is introduced into a cooling roll or immediately thereafter. 2. Endless belts are arranged on both sides of the extruder that extend to the rotation axis of the cooling roll or in front of it and pass through the gap between the cooling rolls, and on the endless belts, both sides of the thermoplastic resin film are placed over the thermoplastic resin sheet immediately after extrusion. A laminating device for thermoplastic resin film that holds parts.