Troubleshooting I Adhesion Problems with UV Coatings

The challenges of coatings' adhesion

If the surface tension of a substrate is too low, adhesion problems can occur. Also, separating and lubrication agents on the substrate’s surface as well as the appearance of fission products during the drying process of printing inks can result in adhesion problems. The adhesion must be tested very carefully using a high ink coverage, special colours, neutral odour or fresh inks.

Solving for adhesion problems with UV coatings

S​​tep by Step

1. Control your surface tension

The surface tension of a printed and/or coated area should not be below 32 nN/m. A well-known testing method refers to the drop shape analysis. With this method, the surfaces of substrates and coatings can be characterized. Also, it is possible to check these surfaces regarding their printability or ability for varnishing. Contact our Technical Services. In the case of plastic surfaces, a Corona pre-treatment may increase surface tension. Important: the complete curing of UV coatings.

2. Check the adhesion of your UV coating before processing

However, please consider: Tape resistance cannot be guaranteed in each case.

3. More recommendations:

Prefer, if possible, an uncolourful structure and check the application of metallic inks. For suitable inks please talk to your ink manufacturer. Depending on your application, check the use of a primer as an adhesive agent.

Your checklist

Influence factor: Printing
Measure: Check surface tension

Influence factor: Coating
Measure: Check the adhesion of your UV coating

Still have open questions? Contact us and we will support you with the application.

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