METHOD FOR THREE-DIMENSIONAL SHAPING OF MATERIAL

Abstract

A method for the three-dimensional shaping of flat material made from in particular, natural fibers, such as for example, paper or cardboard, using a deep-drawing piston and a die, through which or into which the material is drawn. The diameter of the deep-drawing piston plus the material thickness of the deep-drawn material corresponds at least approximately to the diameter of the die.

Claims

1. Method for three-dimensional shaping of flat material, in particular material composed of natural fibers, such as paper or cardboard, for example, using a deep-drawing piston and a die, through which or into which the material is drawn, wherein the diameter of the deep-drawing piston plus the material thickness of the material to be deep-drawn corresponds at least approximately to the diameter of the die.

2. The method according to claim 1, wherein the material is clamped between the die and what is called a wrinkle holder, thereby allowing the material to slide along in targeted manner during shaping.

3. The method according to claim 2, wherein the wrinkle holder presses against the flat material at a variable pressure, wherein the wrinkle holder can press against the flat material under a spring load and/or the pressure of the wrinkle holder that acts against the flat material can be controlled or regulated.

4. The method according to claim 1, wherein the diameter of the die can be changed.

5. The method according to claim 4, wherein the die is composed of segments that can be moved relative to one another.

6. The method according to claim 1, wherein the die is configured in sleeve shape, wherein a conical embodiment can be provided.

7. The method according to claim 1, wherein the deep-drawing piston is configured to be conical.

8. The method according to claim 1, wherein the deep-drawing piston can be changed with regard to its diameter, wherein segments can be provided, which can be moved relative to one another.

9. The method according to claim 1, wherein the deep-drawing piston can be changed in terms of its shape and/or its dimensions, by means of internal pressure, wherein the pressure can be built up by means of compressed air or a hydraulic medium.

10. The method according to claim 1, wherein a counter-punch to the deep-drawing piston is provided in the axial direction, which punch presses the material against the deep-drawing piston during shaping, wherein the counter-punch can be configured to be variable and regulatable.

11. The method according to claim 1, wherein a calibration device is provided, in which the shaped material is pressed against the piston.

12. The method according to claim 1, wherein the material is moistened, at least on one side, before, during and/or after shaping and/or calibration.

13. The method according to claim 1, wherein the material is heated before, during and/or after shaping and/or before and/or during calibration.

14. The method according to claim 12, wherein the temperature and/or the processing moisture of the material is selected or adjusted as a function of the material used.

15. The method according to claim 1, wherein the material has been provided or is provided with a plastic layer, at least on one side.

16. The method according to claim 1, wherein the finely distributed wrinkles that form during shaping are pressed flat.

17. The method according to claim 1, wherein the open end is folded over to form a sealing edge.

18. The method according to claim 17, wherein the sealing edge is additionally compressed, wherein the compression can take place while supplying heat and/or after previous moistening.

Description

[0040] In the drawing, the invention is illustrated using an exemplary embodiment.

[0041] In this regard, the figures show:

[0042] FIG. 1 a schematic representation of the sequence of the method according to the invention, using a conical die, and

[0043] FIG. 2 a schematic representation of the sequence of the method according to the invention, using a changeable die.

[0044] 1 refers to an apparatus with which paper or cardboard or material 2 that contains fiber can be shaped from a flat state into a cup-shaped or shell-shaped state.

[0045] The apparatus 1 has a piston 3, as well as a die 4 that is configured in conical sleeve shape in this exemplary embodiment, and acts as a counter-part to the piston 3. The material 2 is pressed into the die 4 by the piston 3. In this regard, the material 2 is pressed against the top of the die 4 by a wrinkle holder 5, so that is can slide along only in controlled manner as it enters the die 4.

[0046] The piston 3 is configured to be changeable. Either it is composed of segments, so that the respective diameter of the piston 3 can be changed by displacing the segments relative to one another, or, alternatively, the piston 3 can be changed with regard to size and/or shape by applying compressed air or a hydraulic medium.

[0047] Other embodiments of the piston 3 are conceivable.

[0048] It is essential that the diameter of the piston 3 corresponds at least approximately to the respective diameter of the die 4 minus twice the thickness of the material 2 at every point in time, so that the piston 3, the material 2, and the die 4 lie tightly against one another. At most a small gap should be formed. However, it is also conceivable that the piston 3 presses the material 2 slightly against the inner side of the die 4.

[0049] By means of a combination of these dimensions and the wrinkle holder 5, it is ensured that not only do just small and uniformly distributed wrinkles occur during deep-drawing of the material 2, but rather these are at least also equalized to a great extent. If the piston 3 is slightly smaller with reference to the die 4, it is also conceivable that the object 7 that is produced, the shaped part, is calibrated again after the shaping process, and the finely distributed wrinkles are pressed flat during this process.

[0050] The result is a smooth surface in the walls of the object that is deep-drawn from paper or cardboard.

[0051] An object having walls that run conically is directly formed by means of the conically configured die 4 and a piston 3 that is adapted to it.

[0052] As shown in the second exemplary embodiment, it is also conceivable that a conical piston 23 is provided, and the die 24 adapts its diameter to the respective position of the piston 23.

[0053] For this purpose, the die 24 can be composed of segments that can be moved relative to one another.

[0054] In this regard, the wrinkle holder can press against the flat material 2 under a spring load. However, it is also possible to provide a hydraulic, electromechanical or other pressing means, which is configured so that it can be controlled and/or regulated. A combination of a spring load and controlled or regulated hydraulics/pneumatics/actuators is also conceivable.

[0055] A counter-punch 6, which is disposed in the axial direction of the piston 3, presses against the material 2 from below, so that no material can flow out of the bottom region into the wall region that is to be shaped. However, it is possible that the material 2 is shaped in the bottom region between the piston 3 and the counter-punch 6 itself. In this connection, it is also conceivable that the stamping by means of the piston 3 and the counter-punch 6 takes place before the actual shaping process.

[0056] In this regard, piston 3 and counter-punch 6 can already close under the force of the wrinkle holder, and introduce the stamping. In this regard, a drawing process counter to the actual shaping using drawing is undertaken, and thereby the freedom of movement with regard to the degree of shaping and the configuration of the bottom is expanded.

[0057] It is also conceivable that after shaping, the part 7 that is formed is moved into a calibration device 8 by the piston 3, where the wall region is pressed against the piston 3 and during this process, the small and finely distributed wrinkles that were formed are equalized.

[0058] Furthermore, it is conceivable that the material is trimmed after shaping.

[0059] After calibration, the finished shaped part 7 is ejected by the counter-punch 6 after the piston 3 is moved upward.

[0060] It is also conceivable to pull the object 7 off using lifters or suction devices.

[0061] If the shaping process is carried out overhead, gravity can also ensure that the objects 7 that are produced fall out.

[0062] During this calibration, before or afterward, the upper wall region can be widened or an edge flange can be formed. This edge flange can be transformed either into a flat sealing edge or also into a lip.

[0063] To improve the shaping result, the material 2 can be moistened on one or both sides before shaping or also during this process. Heating is also possible, wherein a radiant heater for the material or a heater for the shaping tools is conceivable.

[0064] Coating, impregnation or other treatment of the material, for example with a plastic, is also possible to improve the tightness of the finished part 7, wherein this coating can be undertaken on the inside or outside or also on both sides.

[0065] Coating or treatment can also influence the deep-drawing process.