Promote Stability of Vinyl Sticker Through Surface Finishing
In custom sticker printing market, although adhesive paper constitute a high proportion, plastic film labels (adhesive vinyl sticker) has a positive growth in recent years. The most frequently used vinyl sticker are PP and PE, whose usage is twice as much as the latter. While other vinyl material, including the concerned of PET have only a 10% market share.
A good printing process is very important for vinyl sticker material. But usually used PE&PP can not be much satisfactory for labeling. To make sure without any problems during labeling and having good ink retention after labeling, the sticker’s surface needs to be pretreated, Corona or Coating.
Prerequisite of Film Sticker Printing
Film Sticker material is as a information carrier, not only ensure that the ink is well wetted on its surface, but also solidify the ink layer.
The Importance of Ink Wetting
The wettability of ink on thin film material can be greatly influenced by ink surface tension and plastic film surface. If the ink surface tension is the same as that of the film surface, that means wetting; If the ink surface tension is greater than film, the ink will shrink on the film surface and not be wetted. If the film surface tension is higher than ink’s, then ink’s can be spread on the film surface to achieve wetting.
Thus obtained a criterion is very important for film printing, the ink surface tension at least as large as a thin film surface, otherwise ink can't be wetted at all or fully wetted on film surface, which will not be able to accomplish the transfer of ink to the film, or lead to lack of printing image.
The Importance of Ink Fixation
Ink fixation effect on the substrates plays an important role for the perfection of label quality. Not only should we consider to print in a short period of time after adhesion effect, but also to consider after long enough ink adhesion.
If an appropriate substrates surface roughness and porous are helpful for ink mechanical fixation, then forming a polar functional groups in the surface of plastic chemical and physical adhesion of printing ink adhesion is necessary. Since the functional groups are mostly polar, it helps to improve the surface energy of the materials. Therefore it is very important that the functional group is fully integrated with the polymer network. Even they have certain polarity, but the ink can't be stick to the film surface with good adhesion.
