Process for bonding contaminated substrates
The introduction of vibration energy such as ultrasound into an uncured adhesive matrix during and/or after the joining of substrates leads to the effective dissolution and/or dispersion of adhesion-reducing contamination of the substrate surfaces into the adhesive matrix. In many cases, this can reduce the cost of expensive cleaning processes or quality control measures.
1. A process for bonding a first substrate surface to a second substrate surface wherein an adhesive is used to bond said first substrate surface and said second substrate surface and wherein at least one adhesion-reducing contaminate is present on at least one of said first substrate surface and said second substrate surface prior to bonding, said process comprising introducing vibration energy into the adhesive to remove at least a portion of said adhesion-reducing contaminate from at least one of said first substrate surface and said second substrate surface by dissolving or dispersing or both dissolving and dispersing said portion of said adhesion-reducing contaminate in said adhesive.
2. A process as claimed in claim 1 , comprising the steps:
a) applying said adhesive to said first substrate surface, wherein said at least one adhesion-reducing contaminate is present on said first substrate surface to form an adhesive-coated first substrate surface;
b) applying said second substrate surface to the adhesive-coated first substrate surface;
c) introducing vibration energy into the adhesive; and
d) curing the adhesive.
3. A process as claimed in claim 1 , wherein the adhesive is applied to one of said first substrate surface or second substrate surface while vibration energy is introduced.
4. A process as claimed in claim 1 , wherein the vibration energy is ultrasound energy.
5. A process as claimed in claim 1 , wherein the vibration energy is introduced by fitting a sound head (sonotrode) to at least one of said first substrate surface or said second substrate surface.
6. A process as claimed in claim 5 , wherein the sound head is directly coupled with an adhesive applicator.
7. A process as claimed in claim 5 , wherein the adhesive, first substrate surface and second substrate surface form a bonded joint and the sound head or a combination of said sound head and an adhesive applicator is guided by a machine along the bonded joint.
8. A process as claimed in claim 7 , wherein said machine is a program-controlled robot.
9. A process as claimed in claim 1 , wherein during the introduction of the vibration energy, the adhesive has a temperature above ambient temperature.
10. A process as claimed in claim 1 , wherein during the introduction of the vibration energy, the adhesive has a temperature in the range from 25° C. to 90° C.
11. A process as claimed in claim 1 , wherein during the introduction of the vibration energy, the adhesive has a temperature in the range from 35° C. to 70° C.
12. A process as claimed in claim 2 , wherein during the application of the adhesive, the adhesive has a temperature above ambient temperature.
13. A process as claimed in claim 2 , wherein during the application of the adhesive, the adhesive has a temperature in the range from 25° C. to 90° C.
14. A process as claimed in claim 2 , wherein during the application of the adhesive, the adhesive has a temperature in the range from 35° C. to 70° C.
15. A process as claimed in claim 1 , wherein the adhesive is a two-component adhesive which cures at room temperature or with the aid of heat.
16. A process as claimed in claim 1 , wherein the adhesive is a one-component adhesive.