Tinplate's Offset Printing Technology Discussion III

4, polishing process
After the tin plate is printed, it is necessary to apply bright oil to protect the ink film on the screen and increase the gloss of the printed material so as to make the products more beautiful and beautiful. Polishing oil should be colorless and transparent, and it should not be discolored after being baked and stored for a long time. Adhesion should be good, and the leveling property should be good. After the film is formed, it can withstand can bending and mechanical impact. New process methods can now also coat matte or wrinkle oils.

Third, tinplate printing common faults and exclusion
method
1. Packaging and Decoration The promulgation standard for tinplate prints is ZBA82001-86, in which the technical requirements in the content are as follows:

1) Appearance index
a. There are no obvious dirt or wrinkles on the front and back of the printed matter.
b. There are no obvious scratches on the main parts of the printed matter, and minor scratches on the minor part do not exceed three.

Note: * The main part refers to the pattern, text, mark, etc. of the subject reflected on the print screen.
* Slight scratching means that the traces of the printed matter that are not exposed to iron are not more than 0.3mm x 20mm.

c. The text lines are clear, complete, and not deformed.
d. The outlets are clear, complete and structured.
e. The ink is uniform and the hue is accurate.

2) Physical and chemical indicators
a. Impact strength After the impact test, the ink layer is not cracked.
b. The adhesion is stretched, the interface is leveled, and the inside and outside crimping test ink does not fall off.
c. gloss gloss value not less than 60%.
d. The whiteness value of printed whiteness printing process is not less than 50%, and the whiteness value of printed whitening process is not less than 60%.
e. ink surface hardness pencil hardness 2H.
f. Resistant to Cooking After ink cooking, the ink layer does not lose light, does not fade, and does not bleed.
Note: The cooking resistance index is only used for the production of tinplate prints that require high temperature sterilization food cans.

2, tinplate printing common faults and exclusion methods (Table 1)