Films and polymer objects are chemically inert and have non-porous surfaces with low surface tension, which results in a low adherence of substrates, printing inks, adhesives and coatings.
Thanks to Corona Treatment it is possible to resolve these issues.
Pretreated films, i.e. those which have undergone treatment during their manufacture, have a higher surface tension value that is crucial to good quality printing, coating or laminating. Untreated films do not readily accept printing, coating or laminating.
Each type of film has an inherent surface tension that can be increased through corona treatment at the time of its manufacture. The quality of this treatment, however, decreases with time. Therefore, over time, film that is printed and coated immediately after its production and its corona treatment can lose sufficient surface tension to become non-printable and non-coverable.
Since it is almost impossible to ensure that any film is converted within the time limit, it is often necessary to retreat the film again in line immediately before printing.
* ability of a liquid to lie completely on a flat, horizontal surface of a solid. It has complete wettability when the contact angle approaches 0° and the liquid is completely relaxed; alternatively it has poor wettability when the contact angle approaches 180° and the liquid is divided into droplets.