At present, our plant has test tools like roll of sticky Direct Thermal Label
, paper thermal-humidity test chamber, steel rulers (the smallest scale value is 0.5mm), refrigerator, paper detector, reflection density instrument, ordinary magnifying glass and non-adhesive testing equipment. Aim at present screen printing machine, there are some test methods of the adhesive sticker.
(1) Bonding test. Using manual testing and experience-based judgment method, that is opening the adhesive paper and pressing it with a thumb or index finger for many times to test its cohesion, bigger cohesion is with better viscosity.
(2) Test of the lowest labeling temperature and using temperature range. If samples can keep cling for 3 hours below 20℃ or 70℃, that means it works. Different adhesive sticker material has different lowest labeling temperature, the supplier of adhesive sticker material always provide a technical parameter with the lowest labeling temperature.
(3)Test about heat resistance, water resistance, and light resistance. Use paper thermal-humidity test chamber to test above-mentioned performance of adhesive sticker, testing heat resistance in the state of 70℃ in paper thermal-humidity test chamber, using water immersion method to test water resistance (practice shows that adhesive sticker material with synthetic paper has good water resistance), its light resistance can be tested by bath lamp, if it can keep cling for 3 hours so that it meets the standard.
(4) Printing density test. Using reflection density instrument to test field density value that matches up relative control strip, image density contrast, and dot increment value.
(5) Size. Using steel rulers to test the size of adhesive label and dimension error.
(6) Adhesive sticker material should be provided quality certification of the adhesive sticker by the supplier.
(7) Some performance is not convenient to be tested, they can be tried with a small batch, it is better to test the performance of adhesive sticker.