Study On The Printing Quality Control Based On IMD Technology

The past few years,IMD(in mold decoration) technology has developed from the two-dimensional technology of double structure to three-dimensional forming technology of mutiple structure,and the problem which ink is easy to separate from film is a key issue.Polycarbonate and Polyester are the most used in all kinds of IMD films.However,their surface energy is a little low,so they have little affinity to ink and the printability is not good.At present,the common used method to modify the film surface in domestic is corona discharge treatment,but this method has many limitations.Therefore,it is very important for using a more effective way to improve the printability of IMD films and trying a new measuring method which has higher accuracy to evaluate its modifing degree on the printability of films.This paper applied the low temperature plasma technology to IMD process,tried to use O2 plasma to increase the surface polarity,surface energy,surface roughness and the adhesion strength of ink,therefore improved the printability of IMD films.Moreover,used a Nano-Indenter to evaluate quantitively the adhesion strength of ink deposited on IMD films.Firstly, this paper did a specific theory analysis on the printability of films from the three influence factors of contact anger,surface tension and surface roughness.Secondly,used the low temperature plasma technology to modify the surface of PC and PET films;After this treatment,used an atomic force microscope to examine the surface topographic image of untreated and treated films.Then used a liquid drop morphology analyser to measure the contact angle of water and ethylene glycol on the untreated and treated films,combined the measure value of contact angle and geometric average equation to calculate the surface tension of untreated and treated films.At last,for evaluating the modifing degree of film printability and comparing the printability of PC and PET which have different structure,used a Nano-Indenter to measure the adhesion strength of ink deposited on the untreated and treated films,meanwhile,analyzed the impoving degree of LTP on the IMD films.