JP2005035188A - Tire molding drum - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tire molding drum which improves the adhesion of an air permeation preventing layer to the surface of the molding drum, while sharply reducing air gatherings, and thereby suppresses occurrence of a blister fault. <P>SOLUTION: The molding drum 1 is provided in a round shape by a plurality of expansible-contractible drum flanges 2 made of a metal. The drum flanges 2 may also be formed of a resin material. On the surface of the molding drum 1 constituted of the drum flanges 2, an extensible-contractible flexible sheet-like material 3 is stuck at a position of disposition of the air permeation preventing layer W (an inner liner in this embodiment) formed beforehand like a film out of a thermoplastic elastomer composition. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a tire molding drum, and more specifically, when a film-like thermoplastic elastomer composition is used for an air permeation prevention layer (inner liner layer) of a tire, the air accumulation is greatly reduced to reduce blister (bubbles). This relates to a tire molding drum that can suppress the occurrence of failure.

  Conventionally, in tire molding, an inner liner (air permeation preventive layer) made of a film-like thermoplastic elastomer composition is pasted on a plurality of expandable / contractible drum flanges, and a reinforcing layer is formed on the inner liners near both ends of the drum flange. A method of attaching a carcass material thereon is further performed (for example, see Patent Document 1 and Patent Document 2).

However, since the thickness of the thermoplastic elastomer composition film constituting the inner liner is very thin, about 130 μm to 200 μm even when combined with the adhesive, the inner liner is placed on a general metal tire molding drum. When affixed first and then a rubber member such as carcass material, the air remaining in the slight gap from the surface of the tire molding drum and the uneven part is still air even when a stitcher roll such as a sponge roll is applied after the member is attached. There is a problem that it is difficult to remove, and there is a problem that this air reservoir causes a blister (bubble) failure.
Japanese Patent Laid-Open No. 10-35232 (second to third page, FIG. 1) Japanese Patent Laid-Open No. 11-199713 (pages 2 to 5)

  This invention pays attention to such conventional problems, and by adhering a flexible sheet-like material that can be expanded and contracted to the member application position on the surface of the forming drum, the adhesion of the air permeation preventive layer to the surface of the forming drum is improved, It is an object of the present invention to provide a tire molding drum that can significantly reduce air accumulation and suppress the occurrence of blister failure.

  In order to achieve the above object, the present invention provides a tire molding drum for molding a tire by using a film-like thermoplastic elastomer composition as at least an air permeation preventive layer of a tire constituent material. The gist is that a flexible sheet-like material that can be expanded and contracted is provided at the position of the layer.

  Here, the flexible sheet material is composed of a material having a hardness of 30 to 85 and a thickness of 0.5 mm to 5.0 mm, and the flexible sheet material may be an elastomer, urethane, or foam. One of the selected materials is used.

  As described above, by providing the flexible sheet-like material that can be expanded and contracted at the position where the air permeation preventive layer is provided on the surface of the forming drum, the adhesion of the air permeation preventive layer to the surface of the forming drum is improved and the air pool is retained. Can be greatly reduced to suppress the occurrence of blister failure.

  The present invention improves the adhesion of the air permeation preventive layer to the surface of the molding drum by providing the flexible sheet-like material that can expand and contract at the position where the air permeation preventive layer is provided on the surface of the molding drum as described above. At the same time, there is an effect that the occurrence of blister failure can be suppressed by greatly reducing the air accumulation.

  In addition, after inserting a film-shaped air permeation prevention layer formed in a cylindrical shape in advance into the molding drum, when winding the tire constituent member, by rotating the molding drum while applying a stitcher roll such as a sponge roll, Further, the air permeation preventive layer and the tire constituent member can be adhered and bonded together.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

  1 is a perspective view of a molding drum embodying the present invention, FIG. 2 is a partially enlarged sectional view taken along the line AA of FIG. 1, and the molding drum 1 has a plurality of (in this embodiment, 10). It is divided into circular shapes by a metal drum flange 2 (which is divided but not limited to the number of divisions). Note that the drum flange 2 can be made of a resin material.

  On the surface of the molding drum 1 composed of the plurality of drum flanges 2, the air permeation preventive layer W (in this embodiment, the inner liner) previously formed into a film shape with a thermoplastic elastomer composition is stretched and contracted. A possible flexible sheet material 3 is applied.

  The flexible sheet-like material 3 has an A hardness of 30 to 85, preferably an A hardness of 40 to 70, and a thickness of 0.5 mm to 5.0 mm, preferably a thickness of 0.7 mm to 2.0 mm. Thus, one of materials selected from elastomers, urethanes and foams is used.

  The hardness was measured with a type A durometer hardness meter specified in JIS K6253.

  When the A hardness is 30 or less and the thickness exceeds 5.0 mm, the molding drum is excessively deformed, and there is a problem that when the stitcher roll 4 is hung, an excessive wrinkle or folding is generated. As described above, it was found that no effect was obtained when the thickness was 0.5 mm or less.

  Moreover, the flexible sheet-like material 3 may be pasted on the surface of the existing molding drum 1 later, or the flexible sheet-like material 3 is pasted on the molding drum 1 manufactured by making the diameter smaller by the flexible sheet-like material 3 and the diameter is set. It may be the same as the existing forming drum 1.

  Thus, the cylindrical air permeation preventive layer W formed in the form of a film with the thermoplastic elastomer composition on the surface of the forming drum 1 in advance with the flexible sheet-like material 3 as described above attached thereto. Is inserted, and after the sheet-shaped tire constituent material (not shown) is wound, or simultaneously with the winding, the molding drum 1 is rotated while the stitcher roll 4 such as a sponge roll is applied from the outside of the molding drum 1. Due to the elastic deformation of the flexible sheet-like material 3, the air permeation preventive layer W and the tire constituent member can be brought into close contact with each other, and the air staying between them can be efficiently discharged to greatly reduce the air pool. Thus, the occurrence of blister failure can be suppressed.

It is a perspective view of the forming drum which implemented this invention. FIG. 2 is a partially enlarged cross-sectional view taken along line AA in FIG. 1.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Molding drum 2 Drum flange 3 Flexible sheet-like material 4 Stitcher roll W Air permeation prevention layer

Claims (3)

In a tire molding drum for molding a tire using a film-like thermoplastic elastomer composition on at least an air permeation prevention layer of a tire constituent material,
A tire molding drum, characterized in that a flexible sheet-like material capable of expanding and contracting is provided at a position where an air permeation preventive layer is provided on the surface of the molding drum. The tire molding drum according to claim 1, wherein the flexible sheet-like material is made of a material having an A hardness of 30 to 85 and a thickness of 0.5 mm to 5.0 mm. The tire forming drum according to claim 1 or 2, wherein the flexible sheet-like material uses one of materials selected from an elastomer, urethane, and foam.

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