JPH0415463Y2 - - Google Patents

Description

[Detailed explanation of the idea] [Industrial application field]

The present invention relates to an embossing mold for a foam having an uneven pattern, and in particular, the embossing roll is made of breathable ceramics.

[Conventional technology]

Conventionally, as a method for forming an uneven pattern on the surface of a synthetic resin foam, there is generally an embossing method (for example, Japanese Patent Publication No. 13330/1982).
As shown in FIG. 3, a tubular synthetic resin foam 1 is placed between a pair of drum-shaped embossing rolls 2, 2
It is pressed between the layers and continuously pulled out to form an uneven pattern. In addition, a method of embossing the foam while suctioning it using a porous embossing roll was disclosed in Japanese Patent Application Laid-Open No. 1986-
The one disclosed in Japanese Patent No. 065525 has been proposed, but the suction holes are rough and the number is limited.

[Problem that the idea aims to solve]

Among the conventional molding tools mentioned above, since embossing involves stamping, the thickness of the synthetic resin tubular foam is reduced to form the pattern, which increases the amount of resin required, making it difficult to use conventional embossing molding. However, this method was not suitable for clearly forming a fine uneven pattern on the surface. In particular, the embossed shape was not sufficiently transferred in the direction A perpendicular to the pressing direction shown by diagonal lines in FIG.

[Means to solve the problem]

In view of the above-mentioned drawbacks, the embossing mold of the present invention consists of a pair of drum-shaped rolls made of a sintered, air-permeable ceramic having a large number of air-permeable micropores and having an uneven pattern formed on the outer surface for forming. A substantially circular gap is formed between the pair of rolls, and a suction passage with an H-shaped cross section is provided around the center axis of the rolls to allow the softened synthetic resin tubular foam to pass through. It is characterized in that an uneven pattern can be formed while partially increasing the thickness of the surface of the synthetic resin tubular foam by suctioning from the inside. In the present invention, the roll that has a large number of air permeable micropores and has an uneven pattern formed on its outer surface for molding is made of an air permeable fired ceramic body, and the desired uneven pattern is formed on the entire surface of the roll from the mold. It is provided by molding or cutting. The synthetic resin tubular foam used in this invention is
It is a foam made of polyethylene, polyvinyl chloride, polyurethane, etc., and at least its surface can be softened by heating it to near its softening point. In the present invention, a softened tubular synthetic resin foam is passed over a roll and suction is applied from the inside of the roll to partially increase the thickness of the surface of the tubular synthetic resin foam while creating an uneven pattern. It is something that forms.

[Effect]

The embossing mold of the present invention consists of a pair of rolls made of a sintered body of air-permeable ceramics having a large number of air-permeable micropores and an uneven pattern formed on the outer surface for molding, and between the pair of rolls. By using a material in which approximately circular voids are formed in the material, the adhesion with the tubular foam is improved, and a fine uneven pattern can be formed freely. According to the embossing mold of the present invention, the softened tubular foam made of synthetic resin is passed over the roll and suction is applied from the inside of the roll, so that the tubular foam is closely attracted to the roll surface and softened. Since a clear uneven pattern is formed while partially increasing the thickness of the surface of the synthetic resin tubular foam, there is no need to reduce the thickness of the synthetic resin tubular foam before suction.

【Example】

Hereinafter, an example of the present invention will be explained in detail using the drawings. FIG. 1 is a sectional view showing an embodiment of an embossing mold for forming a fine uneven pattern on a tubular synthetic resin foam. In the figure, the reference numeral 9 is a tubular foam made of polyethylene, polyvinyl chloride, polyurethane, etc. This foam 3 is heated in advance to near its softening point using a heater or heating box, and then rotated in this state to provide air permeability. It is passed between rolls 10 and 10'. The rolls 10, 10' have a fan-shaped suction guide plate 7 attached to a metal core 6 for efficient vacuuming, and the entire outer periphery is made of a ceramic sintered body 8 or the like having a large number of air permeable micropores. A corresponding uneven pattern is formed on the drum-shaped portion of the outer peripheral surface. A vacuum pump (not shown) is connected to the shaft 6 of the rolls 10, 10'.
Suction can be performed between the suction guide plates 7, 7 from the inside of 0'. This structure includes rolls 10,
2, which is a longitudinal cross-sectional view of 10'.
Therefore, a gap having a circular cross section is formed between the rolls 10 and 10', and the ceramic sintered body 8 is in contact with the entire circumferential surface of the tubular foam 9, which is formed by the suction guide plates 7 and 7. A suction channel with an H-shaped cross section now surrounds the tubular foam 9, so that a substantially uniform suction is achieved. When the softened tubular foam 9 passes between the rolls 10 and 10' having a large number of air permeable micropores in this manner, the suction force of the vacuum pump causes the roll 1 to
The tubular foam 9 is brought into close contact with the outer periphery of the rolls 10, 10' by suction from the inside of the rolls 10, 10', and an uneven pattern is applied to the surface of the softened tubular foam 9 while partially increasing its thickness. Example 1 A polyethylene foam pipe with an outer diameter of 30 mm and a wall thickness of 10 mm was heated to 120°C in a heating box.
While passing between a pair of drum-shaped rolls 10 and 10' having a large number of air permeable micropores shown in FIG. 2, suction was applied from inside the rolls with a suction force of 500 mmAq.
The obtained pipe had an uneven pattern uniformly formed on the entire circumferential surface, and no decrease in thickness was observed.

[Effect of the idea]

As explained above, the embossing mold of the present invention passes a softened tubular foam made of synthetic resin between the rolls of breathable ceramics, which have a large number of breathable micropores on the entire surface, while sucking from the inside. The resin tubular foam is not pressed like an embossing roll and its thickness is not reduced. Further, the roll exhibits uniform suction, and it is possible to clearly form a desired uneven pattern on the surface of a pipe-shaped synthetic resin foam without crushing the tubular cross section. Furthermore, since the embossing mold of the present invention partially increases the thickness of the surface of the synthetic resin tubular foam, it is not necessary to use an extra amount of resin to form the uneven pattern. There's nothing left to do.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal cross-sectional view for explaining one embodiment of the embossing mold of the present invention, Fig. 2 is a longitudinal cross-sectional view of the roll shown in Fig. 1, and Fig. 3 is a front view for explaining the conventional embossing mold. It is a diagram. 10,10'...Breathable roll, 6...Mandrel,
7... Suction guide plate, 8... Ceramic sintered body, 9... Pipe-shaped foam, 11... Micropore.

Claims (1)

[Scope of utility model registration request] It consists of a pair of drum-shaped rolls made of sintered air-permeable ceramics with numerous air-permeable micropores and an uneven pattern formed on the outer surface for molding, and a roughly circular gap is formed between the pair of rolls. is formed, and a suction passage with an H-shaped cross section is provided around the center axis of the roll, and suction is applied from the inside of the roll while passing the softened tubular foam made of synthetic resin. 1. An embossing mold for a foam having an uneven pattern, which is capable of forming an uneven pattern while partially increasing the thickness of a body surface portion.