ADHESION


Print can be removed by scratching the surface. Print fails adhesion tape, rub or wrinkle tests.

 

Causes:

- Wrong ink used for substrate;

- Ink over-thinned;

- Wrong or weak solvent mixture used;

- Insufficient heat or drying applied;

- Insufficient or over treatment of substrate surface;

- Surface contamination of film by additives;

- pH too low.

 

Solutions:

- Ensure the correct ink is being used for the substrate;

- Use correct viscosity and ensure ink film weight by using reducing medium;

- Ensure correct solvent mixture to give good ink film forming and wetting of substrate;

- Increase heat and air volume. Some inks need to be fused to the substrate coating;

- Check the treatment level of substrate. If low, very high or variable, contact supplier,

- Try wiping and washing an area and printing. A primer wash coat may assist.

- Ensure pH is correct.