AT517695B1 - Method for producing flattened supply rolls of a pre-compressed sealing strip - Google Patents

Abstract

A method is described for producing flattened supply rolls (1) of a pre-compressed sealing strip, wherein an open-pored foam web is wound onto a hollow core under compression onto a parent roll and held in place by a sheathing, before the sheathed mother roll is divided into individual supply rolls (1) and these supply rolls (1) are flattened per se. In order to create simple production conditions, it is proposed that the supply rolls (1) are each inserted into a gas-tight envelope (4) consisting of two cover films (5, 6) which are connected at the edges with the exception of an insertion opening (7) and are clamped in a vacuum chamber (2 ) and that the insertion opening (7) of the shell (4) after an evacuation of the vacuum chamber (2) is gas-tight, before the supply rolls (1) by a ventilation of the vacuum chamber (2) are flattened.

Description

Description: The invention relates to a method for producing flattened supply rolls of a precompressed gasket strip, wherein an open-pored foam web is wound under compression onto a hollow core to a parent roll and held by a sheath before the sheathed mother roll is divided into individual supply rolls and these supply rolls are flattened for each.

For producing precompressed sealing tapes of an open-cell plastic, a corresponding foam web is first wound onto a hollow core under sufficient tension for precompression and the compression of the formed coil is held by a jacket. The mother roll produced in this way is then separated into individual supply rolls according to the required bandwidth. Since the severing of the parent roll, the cutting tool penetrates into the parting line while an axial displacement of the separated turns takes place, the separated from the parent roll supply rolls are not flat, but have a bowl-like curvature, due to the effective by the precompression of the sealing tapes radial forces in Connection with the mutual axial displacement of the tape turns is reinforced over time. Therefore, the separated from the parent roll supply rolls are flattened before their packaging with the aim to counteract a mutual axial displacement of the tape turns and thus to prevent a curvature of the supply roll leading edge-side widening of the sealing strip. However, this flattening of the separated from the parent roll supply rolls represents an additional, the production cost increasing processing step.

The invention is therefore an object of the invention to provide a method that allows the production of packaged, flattened supply rolls with a relatively low workload.

Starting from a method of the type described, the invention solves the problem set by the fact that the supply rolls are each used in a gas-tight envelope of two with the exception of an insertion at the edge interconnected, tensile cover films and placed in a vacuum chamber and that the insertion the envelope is gas-tightly sealed after evacuation of the vacuum chamber before the supply rolls are flattened by venting the vacuum chamber.

As a result of these measures, the cover sheets apply to the supply roll when venting the vacuum chamber, which is flattened in a surprising manner, without the need for additional external forces. This effect is probably related to the fact that due to the tensile strength of the cover sheets, the cover sheet on the concave side of the supply roll can hardly be drawn against the core ring of the supply roll, while the cover sheet on the opposite convex supply side because of their opposite the cover sheet on the concave side larger area is retracted within the outer periphery of the supply roll by the outer air pressure in the core ring and thereby exerts a force on the tape roll, which leads to a flattening of the supply roll. The supply roll is not only flattened, but held in this flattened position due to the vacuum packaging within the gas-tight envelope of the two cover sheets, so that after opening the shell a supply roll from a pre-compressed sealing tape with flush tape turns is available.

In the drawing, the subject invention is shown, for example. FIG. 1 shows a vacuum chamber for carrying out the method according to the invention with a supply roll of a pre-compressed flattening roll. FIG

Sealing tapes after a welding of the insertion opening of the shell in a schematic longitudinal section and Figs. 2 and 3, the supply roll immediately after the ventilation of the vacuum chamber and after the flat printing by a contraction of the shell in a

Axial section on a larger scale.

1, a vacuum chamber 2 is provided for flattening a supply roll 1, which comprises a welding device 3 for gas-tight sealing of a shell 4 for the supply roll 1. This shell 4 is composed of two tensile cover films 5, 6, which are connected in a gastight manner along their peripheral edges with the exception of an insertion opening 7 for the supply roll 1. The supply roll 1 is separated from a master roll formed from a porous open-cell foam sheet wound around a hollow core under compression, the compressed roll of the foam sheet being held in place by a sheath. The open-cell foam sheet may optionally be impregnated prior to winding. In the separation of the supply roll 1 of the mother roll according to the width of the sealing strip to be produced results in a mutual axial displacement of the individual turns of the compressed sealing strip with the effect that the turns of the supply roll 1 does not extend in the plane of the core ring 8, but from this plane be displaced, which leads to a tipping of the supply roll 1, as shown exaggerated in Figs. 1 and 2.

In order to flatten the bowled supply rolls 1, the supply rolls 1 are each placed in a shell 4, which is sealed gas-tight inside the vacuum chamber 2 after its evacuation via the welding device 3, before the vacuum chamber 2 is vented again. For evacuation and ventilation of the vacuum chamber 2, a corresponding connection 9 for a vacuum pump is indicated.

As can be seen in FIGS. 2 and 3, the cover sheets 5 and 6 apply as shown in FIG. 2 in the ventilation of the vacuum chamber 2 to the supply roll 1, as far as the dimensions of the cover layers 5 and 6 of the shell. 4 allow. The tensile strength of the cover sheets 5 and 6 requires that the cover sheet 5 on the concave side of the supply roll 1 opposes an insertion into the cavity of the core ring 8, so that the external air pressure pulling the cover sheet 6 on the convex side of the supply roll 1 in the cavity of Core ring 8 conditioned because this cover sheet 6 in comparison to the cover sheet 5 with respect to the supply roll 1 has a radial excess length. The vacuum within the gas-tightly sealed shell 4 caused in cooperation with the external air pressure compression of the shell 4 in the region of the cavity of the core ring 8 with the effect that forces are exerted on the supply roll 1 through the cover sheet 6 on the convex side, the lead a flattening of the supply roll 1, as shown in Fig. 3 is drawn. The supply roll 1 is thus not only flattened within the evacuated shell 4, but also held in the flattened state, so that the shell 4 is an advantageous packaging for the supply roll 1.

Claims (2)

claim Anspruch [en] A method of manufacturing flattened supply rolls (1) of a precompressed gasket tape, wherein an open-pored foam web is wound under compression onto a hollow core to a parent roll and retained by a sheath before the sheathed mother roll divides into individual supply rolls (1) and these supply rolls (1) each flattened for themselves, characterized in that the supply rolls (1) each in a gas-tight envelope (4) of two with the exception of an insertion (7) peripherally interconnected, tensile cover films (5, 6) used and in a Vacuum chamber (2) are brought and that the insertion opening (7) of the shell (4) after evacuation of the vacuum chamber (2) is gas-tight, before the supply rolls (1) by a ventilation of the vacuum chamber (2) are flattened. For this 2 sheets of drawings