What are the printing conditions of PET ink?
When printing PET film, it is necessary to pay attention to some special printing conditions to ensure the printing effect and firmness. Here are some of the key printing conditions:
Drying conditions: PET inks need to be printed under specific drying conditions. In general, you can choose to dry it naturally for 24 hours or bake it at 70°C.
Clean the surface: Before printing, dust and oil stains must be removed from the surface of the PET film. It can be cleaned with absolute ethanol or trowel water.
Diluent selection: Choose the right diluent according to the actual environmental conditions. In cold days (≤ 15°C) you can choose a quick drying agent, and in hot days (≥ 30 °C) you can choose a slow drying agent.
Add transparent paste or general slow drying paste: When the font is diffused, hairy and blurry when printing small lines, patterns and words, you can add transparent paste or general slow drying paste appropriately.
Choose the right screen: choose the right screen according to the actual situation, generally 77-150T screen.
As a plastic material with low to medium surface energy, PET film needs to be pre-treated before printing to improve surface energy or wetting ability. Otherwise, the firmness of the ink and ribbon will be affected and will easily fall off.
Basic methods of surface pretreatment:
Use a special detergent to clean the surface of the PET film.
A special coating agent is used to form a wetting layer on the surface of the PET film.
Plasma treatment is used to change the chemical properties of the surface of PET film.
PET inks can be purchased in different sizes and packages, and the common ones are 1kg, 5kg, and 20kg. When storing, you need to avoid strong light exposure and avoid contact with strong acids and alkalis. Under the condition of 5°C-25°C, PET ink can be stored for two years.
Printing conditions for PET inks include drying conditions, surface cleaning, thinner selection, addition of transparent pastes or all-purpose slow drying pastes, selection of suitable stencils, and surface preparation. The rational use of these conditions can ensure the quality and firmness of PET film printing.