Gravure printing technology of food packaging bag
1. Selection of specific ink model
It is produced according to the ink model specified by the food packaging process. For example, some inks of different colors are not suitable for BOPA / / PE printing.
2. When the old ink is reused, more than 50% of the new ink should be added, and the deteriorated ink should not be used.
3. If necessary, a certain proportion of curing agent can be added to the white ink
The purpose of adding a certain proportion of curing agent in white ink has two purposes: one is to improve the heat resistance of ink; the other is to offset the consumption of curing agent by resin groups in ink, so as to avoid incomplete curing of adhesive layer in summer.
Add method: first dilute with solvent, then slowly add ink while stirring, until the mixture is uniform.
Wrong method: directly add curing agent into the ink, or add to the ink tray, which will mix unevenly, but can not play the effect of adding curing agent.
In addition, we should pay attention to the timeliness: adding timeliness is generally 12 hours, overnight ink curing agent has failed, or should add a certain amount of curing agent.
4. Moisture proof management of nylon film for food packaging bag
If nylon absorbs moisture, it is easy to appear lotus leaf edge, swing edge, stripe, difficult coloring and inaccurate color registration.
It is better to control the temperature and humidity of the production workshop. When the humidity of the production workshop exceeds 80%, the nylon film is easy to absorb moisture and swell, which will cause a series of printing product quality problems.
Specific attention should be paid to the following aspects: ① do not open the package too early before use. ② Try to use it at one time, and wrap the remaining film with good barrier material. ③ When printing, the first color group is not on the plate roller and pre dried. ④ Ensure the reasonable temperature (25 ℃ ± 2 ℃) and humidity (≤ 80% RH) in the production workshop. ⑤ The printed nylon film should be packed with moisture-proof film. www.dgbpk.com/
Dongguan Beite packaging materials Co., Ltd
Dongguan special bag, plastic bag, plastic bag, plastic bag