ALTERNATIVE JOINING METHOD

Abstract

The disclosure relates to an alternative joining method and to the use of the shaped part produced by means of the alternative joining method in drive technology and connection technology.

Claims

1-14. (canceled)

15. A method for joining moulded parts, at least one first moulded part being a thermoplastic and at least one second moulded part being a thermoset or a ceramic, and the second moulded part comprising a structured surface, said method comprising the following steps: a) providing the first and the second moulded part in an alternating sequence in a stack, and b) applying a surface pressure and making a sonotrode create ultrasonic vibrations or making the sonotrode create ultrasonic vibrations and applying a surface pressure.

16. The method according to claim 15, wherein the thermoset is selected from the group consisting of phenol formaldehyde resins, thermosetting polyurethanes, epoxides, thermosetting polyesters, vinyl esters and any mixtures of two or more of said thermosets.

17. The method according to claim 15, wherein the ceramic is selected from the group of silicon carbides or carbons.

18. The method according to claim 15, wherein the structured surface of the second moulded part has a roughness of Ra: 1-100 μm, Rk: 4-150 μm, Rpk: 1-50 μm and Rz: 20-300 μm.

19. The method according to claim 15, wherein the first moulded part has a thickness of <25 mm.

20. The method according to claim 15, wherein the second moulded part has a thickness of from 0.1-2.5 mm.

21. The method according to claim 15, wherein the surface pressure in step b) is applied by the sonotrode or an abutment.

22. The method according to claim 15, wherein the surface pressure is in the range of 6-60 bar.

23. The method according to claim 15, wherein the ultrasonic vibrations in step c) last for 0.05-3 s.

24. The method according to claim 15, wherein the second moulded part is a fibre-reinforced thermoset or a fibre-reinforced ceramic.

25. The method according to claim 24, wherein the fibre volume ratio is 35-55%.

26. The method according to claim 24, wherein the fibre reinforcement is selected from the group of carbon fibres, glass fibres, aramid fibres, highly crosslinked polymer fibres, cellulose fibres, basalt fibres or mixtures thereof.

27. A use of a moulded part produced as per a method according to claim 15 as a friction element in drive technology and joining technology.

28. The Use of a moulded part according to claim 27, wherein the operating temperature is between −20 and 140° C.

Description

[0033] In the following, the present invention will be described purely by way of example on the basis of advantageous embodiments and with reference to the attached drawings. The invention is not restricted by the drawings, in which:

[0034] FIG. 1 shows different macroscopic structures of the surface in cross section;

[0035] FIG. 2 shows the setup of the alternative joining method in cross section;

[0036] FIG. 3 shows a detail of the setup of the alternative joining method in cross section;

[0037] FIG. 4 shows the process of joining the moulded parts (1, 2) in cross section; and

[0038] FIG. 5 is a schematic view of the roughness of a structured surface.

[0039] FIG. 1 shows different possible macroscopic structures in cross section, such as semi-ellipses, semicircles, acute triangles or equilateral triangles. Within the context of the invention, combinations of these macroscopic structures are also possible.

[0040] FIG. 2 shows the moulded parts (1, 2) inserted into the holder (4) and the sonotrode (3) arranged thereabove in cross section.

[0041] FIG. 3 shows a detail of the moulded parts (1, 2) inserted into the holder (4) and the sonotrode (3) arranged thereabove in cross section. The moulded part (2) comprises a structured surface (5).

[0042] FIG. 4 is a cross section showing that, by means of the sonotrode (3) that is made to create ultrasonic vibrations, the softened first moulded part (1) is pressed into the structured surface of the second moulded part (2) by the surface force applied.

[0043] Once the ultrasonic treatment has finished, the softened moulded part (1) immediately solidifies so that the joined component can be removed immediately.

[0044] FIG. 5 is a schematic view of the roughness of a structured surface, as can be measured by means of a profilometer. The roughness can be stochastically distributed over the surface.

[0045] In the following, the present invention will be explained on the basis of an embodiment, the embodiment in no way restricting the invention.

EMBODIMENT

[0046] A first moulded part having the dimensions (internal diameter: 20 mm, external diameter: 27 mm, thickness: 2.2 mm) and a second moulded part having the dimensions (internal diameter: 21 mm, external diameter: 26 mm, thickness: 0.4 mm) are provided in a stack beneath the sonotrode, the second moulded part being arranged beneath the first moulded part. The first moulded part consists of polyamide 6.6. The second moulded part consists of carbon fibre-reinforced phenolic resin. The sonotrode is moved towards the stacked moulded parts at a defined surface pressure of 40 bar and is then made to create ultrasonic vibrations having a frequency of 30 kHz for 0.2 s. The sonotrode is then moved away from the moulded parts and the joined moulded parts can be removed.

[0047] Both the frictional properties and adhesive properties are identical to those of a glued product, but it was possible to improve the process time by 30 decades.

LIST OF REFERENCE NUMERALS

[0048] 1 first moulded part [0049] 2 second moulded part [0050] 3 sonotrode [0051] 4 holder [0052] 5 structured surface of the second moulded part