The material of the food packaging box and the role of the ink, of course, the first choice is to be environmentally friendly, in fact, it can meet the requirements of the corresponding quality. The printing sheets currently used in mold injection are mainly PET and PC materials, and PMMA. (1)
The printing sheets currently used in sheet mold injection are mainly PET, PC materials and PMMA.
Among them, PET materials are used most. There are many kinds of PET materials on the market, both produced by regular large factories and from other sources.
If the initial printing material does not carry out some necessary tests, it will lead to no adhesion between the film material and the ink, resulting in a series of processes in vain.
It is suggested that customers who use different batch numbers of materials for injection molding should first carry out some tests on the materials: for example, the adhesion test of ink, to test whether the ink is attached to this material.
The temperature resistance test of the material is to test whether the material can withstand the temperature in the injection mold during the later injection molding.
In fact, the best way to test the adhesion of ink is to test it directly with UV ink. At present, the general UV ink in the industry must be printed on materials that are easy to attach before it can have adhesion, if UV ink has adhesion on this material, solvent-based ink will certainly have no problem printing on the material. (2)
At present, the injection molding inks in the ink market are mostly Japanese and German, and some domestic manufacturers are producing them, but they are rare in practical application and have few successful cases.
In the process of using ink, the following problems should be paid attention to: a.
The ink has no adhesion on the film material. Confirm with the ink manufacturer the scope of use of the ink, whether it needs to add curing agent, whether it needs special diluent;
Confirm the type of film with the film manufacturer and whether it has undergone some easy adhesion treatment; B. The ink will solidify and not fall into the net during printing.
After the general ink is added with curing agent, the use time of the ink will be limited. After adding two curing agents, the use time of some inks will be shorter, so it needs to be confirmed to the manufacturer before printing;
If it is a one-component ink, just add a diluent. C. When the ink is injection molded, there is a phenomenon of 'rushing flowers.
Cause Analysis: The ink is not resistant to high temperature or the ink is directly exposed to high temperature injection resin.