Method for Permanently Obturating Holes, Especially in Metal Sheets of Plastic Part of an Automobile

Abstract

The invention relates to a method for permanently obturating holes, especially in metal sheets or plastic parts of automobile bodies. The inventive method is characterized by using a punched article which is at least partially provided on one side with an adhesive material and includes an especially textile support whose surface is greater than the surface of the hole to be obturated and which is especially provided with a non-expanded expandable body in the center of the adhesive side. The punched article is fixed on the hole together with the support in such a manner that the hole is completely covered by the punched article and the expandable body comes to rest inside the hole. The punched article and the expandable body are heated to such an extent that the expandable body expands, heat is supplied until the expanded expandable body completely fills and/or covers the hole, and the expanded expandable body cools off and cures.

Description

Below, with reference to two figures, the method for permanently obturating holes, especially in metal sheets or plastic parts of automobile bodies, will be illustrated in greater detail, without any intention that this should in any way have a restrictive effect.

FIG. 1 shows the state before the hole to be obturated is encapsulated by exposure to heat, and

FIG. 2 shows the state after the hole has been obturated by foaming expansion of the diecut.

In the body 1, as a result of the construction system, there is a hole 2 requiring obturation.

For this purpose a partly, single-sidedly self-adhesively treated diecut having a textile backing 4 whose area is greater than the area of the hole 2 to be obturated is fixed to the hole 2 in such a way that the hole 2 is completely covered by the diecut.

Located centrally on the diecut, and on the adhesively treated side, is the non-foamingly expanded EVA foam body 5. This EVA foam body 5 is arranged centrally within the hole 2.

On the diecut the adhesive 3 is applied over the full area—even the region beneath the EVA foam body 5 is coated.

As a result of the heating of the EVA foam body 5 to preferably 160° C., the foam body 5 foams expandingly, leading to a considerable three-dimensional expansion thereof. The foaming expansion of the EVA foam body 5 by supply of heat takes place during the conventional coating operation on after the body shell, in particular during the drying coating or after cathodic electrodeposition. In the course of this operation the EVA foam body 5 expands foamingly, so that the hole 2 is completely filled, and therefore covered, by the foamingly expanded EVA foam body 6. After cooling, the foamingly expanded EVA foam body 6 hardens and thereby closes the hole 2 in an airtight, watertight and also noise-suppressing manner.

FIG. 2 shows the state after heat has been caused to act on the diecut.

Claims

1. A method for permanently obturating holes, especially in metal sheets or plastic parts of automobile bodies, by fixing an at least partly single-sidedly self-adhesively treated diecut having a backing, in particular a textile backing, whose area is greater than the area of the hole to be obturated and which is provided, in particular centrally, on the adhesively treated side with a non-foamingly expanded foam body, said fixing being carried out on the hole in such a way that the hole is completely covered by the diecut and the foam body is located within the hole,heating the diecut with the foam body in such a way that the foam body foamingly expands,the supply of heat being continued until the foamingly expanded foam body completely fills and/or covers the hole,cooling and hardening the foamingly expanded foam body.

2. The method of claim 1, wherein the diecut is provided with adhesive over its full area beneath the foam body.

3. The method of claim 1, wherein the unfoamed foam body is composed of polyurethane or, EVA foam and/or has a thickness of 1.5 to 4 mm.

4. The method of claim 1, wherein the diecut has an adhesive coating of natural rubber and/or a PVC coating or acrylic coating on the side opposite from the adhesive.

5. The method of claim 1, wherein backing material used for the diecut comprises woven cotton fabric having a weft count of 70 to 80 and/or a warp count of 70 to 80.

6. The method of claim 1, wherein the foaming expansion of the diecut by supply of heat takes place during the during the drying of the body shell after coating or after cathodic electrodeposition.