Method for stress-free positioning of a planar transfer segment or several planar transfer segments on an elastic pressing device for bubble- and distortion-free, contour-accurate lamination of a workpiece

Abstract

Method for the stress-free positioning of a planar transfer segment or several planar transfer segments on an elastic pressing device for bubble- and distortion-free, contour-accurate lamination of a planar, gas-tight substrate of less than or equal to 3 mm layer thickness onto the surface of a gas-tight workpiece, without the use of supporting gas and without a clamping frame for the transfer segment, in which a) by using gravity, the lamination from a horizontal or nearly horizontal position of an elastic pressing medium, on which the transmission segment(s) rest, onto a workpiece arranged above it, is carried out, b) either the elastic pressing device with the supporting transmission segment is moved from bottom to top against the workpiece by means of a pressure difference on both sides of the elastic pressing device or additionally by means of a stamping pad supporting from below, or the workpiece is moved onto the transmission segment from above, or the transmission segment and workpiece are moved towards each other simultaneously, c) Tilting movements of the workpiece and / or any stamp pad support distortion-free contact, d) a tensioning frame for the transmission segment or segments is eliminated, which increases transmission precision and freedom from delay, and e) Additionally, the need to use a support gas is eliminated.

Description

State of the art: Contour-accurate lamination of a three-dimensional workpiece using a double-chamber vacuum process:

[0001] In the contour-accurate lamination of a three-dimensional workpiece using a double-chamber process, a flat substrate is either clamped in a clamping frame or applied to an elastic pressing element clamped in a frame using an adhesive, thus indirectly clamping it into a frame. A clamping frame always influences the stress distribution within the flat substrate and can lead to distortions. This can be countered by using a removable, fixed, or movable oval clamping frame (variable in dimensions x, y, z) for positioning the flat substrate to be applied. Such a procedure is known, for example, from DE 10 2022 000 188 A1, but involves additional equipment. The prior art documents EP 1 000 731 A1, DE 198 12 402 A1, JP S62 - 80 025A and JP S61 - 242 825 A should also be mentioned. IMD (In-mould Decoration) / Deep drawing process for polymers

[0002] In a thermoforming process, polymer films are clamped into a clamping frame, heated, and, if necessary, forced into a curved shape using supporting air, into which the workpiece is inserted from below. The supporting air works against the effect of gravity on the film.

[0003] The present invention solves numerous current problems, simplifies the process, can contribute to material savings and thus represents a further development of the state of the art. DESCRIPTION

[0004] The present invention is suitable for the stress-free placement of planar substrates up to 3 mm thick for the contour-accurate lamination of three-dimensional workpieces using machines in an automated or semi-automated process sequence.

[0005] The initial placement of the flat substrate(s) is carried out manually or mechanically. Due to the horizontal or near-horizontal position of the flat substrate on an elastic pressing device, fixation in a clamping frame is unnecessary, as the adhesive contact between the flat substrate and the elastic pressing device, supported by gravity, is entirely sufficient to ensure a stable position. The flat substrate can nevertheless be bonded to the elastic pressing device, either fully or partially, using an adhesive. The preferred application is to position the flat substrate without adhesive between the flat substrate and the elastic pressing device.

[0006] Unlike a conventional deep-drawing process, the flat substrate can be positioned and laminated onto the workpiece entirely without the use of a clamping frame. The complete elimination of clamping the flat substrate results in significant material savings compared to the full-surface clamping required in, for example, the classic deep-drawing process. In particular, the complete elimination of any clamping of the flat substrate significantly reduces material stresses during the lamination process, while simultaneously ensuring high positional accuracy.

[0007] The elimination of a clamping frame for the flat substrate allows the simultaneous use of several flat substrates that are not or only partially connected to laminate one or more workpieces in a single operation.

[0008] Due to the horizontal or near-horizontal position of the flat substrate, tilting and / or rolling movements of the workpiece are possible during the lamination process in the main process, without requiring clamping of the flat substrate. Similarly, to a lesser extent, tilting and / or rolling movements of any stamping pad located below the pressing device are also possible, as is a combination of movements of the workpiece and any stamping pad, without the need to clamp the flat substrate.

[0009] In the method claimed according to the invention, tilting movements of the workpiece and / or any stamp pad support the distortion-free contact.

Claims

[1] Method for stress-free positioning of a planar transfer segment or several planar transfer segments on an elastic pressing device for bubble- and distortion-free, contour-accurate lamination of a planar, gas-tight substrate of less than or equal to 3 mm layer thickness onto the surface of a gas-tight workpiece, without the use of supporting gas and without a clamping frame for the transfer segment, wherein a) by using gravity, the lamination from a horizontal or nearly horizontal position of an elastic pressing medium, on which the transmission segment(s) rest, onto a workpiece arranged above it, is carried out, b) either the elastic pressing device with the supporting transmission segment is moved from bottom to top against the workpiece by means of a pressure difference on both sides of the elastic pressing device or additionally by means of a stamping pad supporting from below, or the workpiece is moved onto the transmission segment from above, or the transmission segment and workpiece are moved towards each other simultaneously, c) Tilting movements of the workpiece and / or any stamp pad support distortion-free contact, d) a tensioning frame for the transmission segment or segments is eliminated, which increases transmission precision and freedom from delay, and e) Additionally, the need to use a support gas is eliminated. [2] The method of claim 1, wherein adhesive contact of the transmission segment with the membrane surface results in a process-stable positioning of the transmission segment or segments, wherein optionally the membrane is moved towards the workpiece with or without the aid of a plunger, or the workpiece is moved towards the transmission segment, or the workpiece and membrane are moved towards each other with the transmission segment or segments with or without a plunger. The workpiece and / or plunger can be moved parallel or at variable angles. [3] Method according to claim 1, wherein instead of a single transmission segment several transmission segments that are not or only partially connected are laminated onto one or more workpieces in a single operation. [4] Method according to claim 1, wherein one or more transmission segments have a 3D contour. [5] Method according to claim 1, wherein a gas-tight support film is either completely omitted or replaced by a non-gas-tight support or positioning material, for example a mesh structure. [6] Method according to claim 1, wherein the transmission segment or transmission segments are fixed in their position by means of adhesive, partially by means of adhesive or entirely without adhesive, only by gravity-assisted adhesive contact with the elastic pressing agent.

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