Bonding objects together

Patent metadata

Field	Value
Publication number	US-9415543-B2
Application number	US-201314649399-A
Country	US
Kind code	B2
Filing date	Dec 2, 2013
Priority date	Dec 5, 2012
Publication date	Aug 16, 2016
Grant date	Aug 16, 2016

Abstract

A second object, which includes a thermoplastic material, is bonded to a first object, which includes a first object material having an at least partially cross-linked polymer not miscible with the thermoplastic material. The method includes the steps of pressing the second object against the first object and coupling energy into the second object until the thermoplastic material is at least partially liquefied and the first object material in a vicinity of an interface to the thermoplastic material is above its glass transition temperature, and until the thermoplastic material is caused to penetrate into at least one of cracks, pores and deformations of the first object material, and letting the thermoplastic material re-solidify.

First claim

What is claimed is:

1. A method of bonding a second object to a first object, the method comprising the steps of
providing the first object comprising a first object material comprising an at least partially cross-linked polymer or pre-polymer;
providing the second object comprising a thermoplastic material;
pressing the second object against the first object and coupling energy into the second object until the thermoplastic material is at least partially liquefied, and until the thermoplastic material is caused to penetrate into at least one of cracks, pores and deformations of the first object material, while the first object material is above its glass transition temperature at least in a vicinity of said cracks, pores or deformations into which thermoplastic material penetrates; and
letting the thermoplastic material re-solidify.

2. The method according to claim 1 , wherein the first object material is porous.

3. The method according to claim 1 , wherein the first object material further comprises a non-polymeric filler.

4. The method according to claim 1 , wherein the first object consist of the first object material.

5. The method according to claim 1 , wherein the first object comprises portions of the first object material and further comprises portions of further material, wherein the portions of the further material are weldable to the thermoplastic polymer or are capable of being interpenetrated by the thermoplastic polymer in a manner that after re-solidification of the thermoplastic polymer a positive fit connection results.

6. The method according to claim 1 , wherein for a glass transition temperature T G,1 and a temperature T f1,2 above which the thermoplastic material is flowable, the relation T f1,2 >T G,1 holds.

7. The method according to claim 1 , wherein the first object material and the thermoplastic material are chosen so that firstly either the first object material is not meltable or the first object material is meltable but not miscible with the thermoplastic material and so that secondly they do not undergo any chemical bonding when brought in contact with each other at room temperature or a temperature T f1,2 above which the thermoplastic material is flowable.

8. The method according to claim 1 , wherein the energy coupled into the second object is mechanical vibration energy.

9. The method according to claim 8 , wherein in the steps of pressing and coupling energy into the second object, the second element is compressed between a sonotrode and the first object.

10. The method according to claim 8 , wherein the first object material during the step of coupling energy into the second element absorbs energy due to internal friction.

11. The method according to claim 1 , wherein the first object material is chosen so that after the steps of pressing and coupling energy into the second element, the first object material remains under internal stress.

12. The method according to claim 1 , wherein the second object comprises a bonding surface that is, prior to the steps of pressing and coupling energy into the second element, brought into contact with a corresponding surface portion of the first object, and wherein the bonding surface comprises at least one protruding feature.

13. The method according to claim 12 , wherein the at least one protruding feature comprises at least one tip or ridge.

14. The method according to claim 13 , wherein the at least one protruding feature prior in the step of pressing is caused to be driven through the corresponding surface portion of the first object.

15. The method according to claim 1 , wherein during the step of pressing at least one portion of the second object is caused to penetrate into the first object material in a manner that the first object material is locally ruptured.

16. The method according to claim 15 , wherein a surface portion of the second object is pointed and concave.

17. The method according to claim 15 , wherein the second object or a protruding feature thereof comprises a broadened portion and, proximally of the broadened feature, a neck portion with a radial extension that is smaller than a corresponding radial extension of the broadened portion at least in one direction.

18. The method according to claim 1 , wherein after the step of coupling energy into the second object, the step of pressing is continued during an after-pressure period.

19. The method according to claim 1 , wherein the second object comprises a body of a non-liquefiable material and a portion of the thermoplastic material.

20. The method according to claim 19 , wherein the body constitutes a core that is at least partially coated by the thermoplastic material.

21. The method according to claim 19 , wherein the body comprises a bore open to the proximal side and at least one opening to the bonding surface, the second object further comprising at least one element of the thermoplastic material, wherein the element is inserted in the bonding surface and the energy during the step of coupling energy into the second object, is coupled at least partially into the thermoplastic element.

22. The method according to claim 1 , wherein during the step of coupling energy into the second object, the first object is caused to be further cross-linked at least locally.

23. The method according to claim 1 , wherein the first object material maintains a shape memory during the step of coupling energy into the second object.

24. The method according to claim 1 , wherein the step of pressing sets in prior to the step of coupling energy into the second object.

25. The method according to claim 1 , wherein the step of pressing sets in simultaneously with the step of coupling energy into the second object.

26. The method according to claim 1 , wherein the step of pressing comprises the sub steps of initially pressing with a first pressing force and subsequently pressing with a second, higher pressing force.

27. The method according to claim 1 , comprising the further steps of providing a third object and of fastening the third object to the first object by the second object.

28. The method according to claim 27 , wherein the third object is fastened by a positive-fit connection.

29. The method according to claim 27 , wherein in the steps of pressing and coupling energy into the second object, thermoplastic material of the second object is liquefied at an interface between the second and third objects.

30. The method according to claim 29 , wherein the thermoplastic material of the second object that is liquefied at an interface between the second and third objects is caused to interpenetrate structures of the third object to yield a positive-fit connection.

31. The method according to claim 29 , wherein the third object comprises a thermoplastic region that is welded to thermoplastic material of the second object.

32. The method according to claim 1 , wherein the first object comprises an indentation and the second object has a shape adapted to the indentation.

Assignees

• Woodwelding Ag

Inventors

• Lehmann Mario
• Mayer Jörg

Classifications

• B29C66/91943

  higher than said glass transition temperature · CPC title

• B29C66/73117

  Tg, i.e. glass transition temperature · CPC title

• B29C66/7394

  characterised by the material of at least one of the parts being a thermoset · CPC title

• B29C66/9516

  by controlling their vibration amplitude · CPC title

• B29C66/1142

  Single butt to butt joints · CPC title