JPS6020172B2 - Peripheral cutting device for thermoplastic thin film products - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an apparatus for cutting the peripheral edge of a product made by drawing a thermoplastic thin film for so-called trimming.

Conventionally, this type of apparatus is one in which a thermoplastic thin film a is drawn with a male mold b and a female mold c to produce a product d, as shown in the first diagram. A type is known in which a cutter e is provided and the circumferential twill is cut by the cutter e, but in this case, the cutter e is provided slightly protruding from one of the facing surfaces and the other is provided as shown in the figure. A general method is provided with a relief recess f opposite to this.In such a method, when the thin film a is preheated and softened in preparation for deep drawing,
At the point where the cutter e acts, the thin film a tends to be pushed by the cutter e and tend to curl into the recess f and escape, and this has the disadvantage that it is difficult to obtain a good cut.

The object of the present invention is to obtain an apparatus that does not have the above disadvantages, and a heat cutter is provided on one of the opposing surfaces of the peripheral edges of a male mold and a female mold for drawing a thermoplastic thin film. In the peripheral edge cutting device for thermoplastic thin film products, the heat cutter is provided so as to be slightly deviated inward from the mold surface on which it is provided, and a heat-resistant cutter is provided on the mold surface opposite to the outside of the heat cutter, protruding slightly from the mold surface. It is characterized by having a catch made of an oil-resistant elastic body.

The drawing shows a case in which a thermoplastic thin film is drawn to obtain the surface layer of an automobile instrument panel as a product. In this case, the thin film 1 is made of relatively thin leather such as polyvinyl chloride. It is composed of a composite sheet made by laminating a sheet 2 and a relatively thick foam sheet 3 of polypropylene foam or other foam one above the other.

The composite sheet, i.e. the membrane 1, is attached to both outer clamps 4, 4.
After being clamped and guided between the lower male mold 5 and the upper female mold 6, it is then drawn by the closing operation of both molds 5 and 6 to obtain the product 7. Both types 5,5
A heat cutter 8 is prepared in advance on one of the facing surfaces of the mold 5, for example, the upper surface of the lower male mold 5, and when the molds 5 and 6 are closed, the cutter 8 cuts the surrounding green part. I made it so that it would happen. In this case, the thin film 1 is preheated to a temperature close to its softening point in preparation for deep drawing. In the drawing, numeral 9 indicates an ejector that operates when the product 7 is taken out. Although the above is not significantly different from the conventional one, according to the present invention, a seat 10 made of fluororubber or other heat- and oil-resistant elastic material is provided on the other of the opposing surfaces of both molds 5 and 6.

To explain this in detail, in the illustrated example, the heat cutter 8 is provided on the upper surface of the lower male mold 5, and the seat 10 is provided on the lower surface of the upper female mold 6. In this case, the cutter 6 is provided on the upper surface of the upper female mold 6. Generally, the cutting edge is located within the groove 11 formed in advance and is slightly offset downward from the upper surface, and the seat 9 is provided so as to protrude slightly downward from the lower surface.

To explain its operation, when the thermoplastic thin film 1 is placed between the two molds 5 and 6 and then the two molds 5 and 6 are closed, the thin film 1
is thus drawn to obtain the product 7. At this time, the upper seat 10 first hits the upper surface of the thin film 1 and presses it downward in the peripheral green part, as shown in the third figure.
Next, as shown in the fourth figure, the pressing part is applied with a heat cutter 8 from its lower surface to cut it.

In this way, according to the present invention, the heat cutter provided on either one of the facing surfaces of the central edges of the male mold and the female mold is provided slightly inwardly from the mold surface on which it is provided, and The mold surface facing the heat cutter is provided with a catch made of a suitable material that is heat-resistant and oil-resistant and slightly protrudes from the mold surface. During molding, the tip first contacts the surface of the thin film and presses it against the other mold surface to regulate the position of the thin film, and then the thin film is cut with a heat cutter that is press-fitted to the seat. Despite the complicated three-dimensional shaping of a thin film, it has the effect of being able to cut it accurately and reliably.

[Brief explanation of drawings]

Fig. 1 is a cut front view of the conventional example, and Fig. 2 is a cutaway view of the device of the present invention.
The cutaway front view of the example, and FIGS. 3 and 4 are enlarged views for explaining the operation of the body part. 1... Thermoplastic thin film, 5... Male type, 6... Female type, 7...
...Product, 8...Heat cutter, 10...
...Ukeza. Figure 1 Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] 1. In a peripheral edge cutting device for thermoplastic thin film products, in which a heat cutter is provided on either side of opposing surfaces of the peripheral edges of a male mold and a female mold for drawing a thermoplastic thin film, the heat cutter is placed a little further from the mold surface on which the heat cutter is provided. Peripheral cutting of a thermoplastic thin film product, characterized in that a seat made of a heat-resistant and oil-resistant elastic material is provided on the mold surface facing the heat cutter and slightly protrudes from the mold surface and is provided offset inward. Device.