| Polyethylene terephthalate(PET)is becoming more popular in Medical film, film switch, all kinds of labels, and other fields with the advantages of good mechanical strength, high transparency, excellent electrical properties, high heat resistance and low price etc. However, PET film still has many defects in in the realistic application, such as PET film cannot be used as the laser printing film directly due to its high crystallinity, and the slow crystallization rate, large shrinkage rate of molding products, poor shock resistance. So usually we need to increase a corresponding coating on the surface and control the surface resistivity to achieve the ideal laser printing effect. Another example is PET film cannot be used as the inkjet printing film directly due to its neat molecular chain structure, high crystallinity, poor surface affinity and poor adhesion of inks.PET film coating is an important way to PET film modification, but most of previous research and application use solvent-based coating, the production process brings heavy environmental pollution. This paper aiming at the disadvantages of existing laser printing film and inkjet printing film, such as poor adhesion, print resolution is not good enough etc., carrying out research on PET film coating formula optimization and performance around two aspects of PET film laser printing coating optimization and inkjet printing PET film coating optimization. Carrying out research on water-based paint from the angle of environmental coating, coming after this, an evaluation and analysis of the effect of the printing and coating workshop environmental development and emissions reduction of volatile organic compounds(VOCs) by using water-based coating. The main work of this paper and the main results were as follows:1. The study of Environment-friendly PET film laser printing coatingAt present, the adhesion of the PET film laser printing coating is not good enough, as well as its image definition. Aiming at these problems,this article provides an overview of the factors that impact the laser printing effect along with optimization for formula of color laser printing coating on PET film. The results of the research show that :The water-soluble acrylic resin is good at graphic adhesion and temperature resistance. The addition of titanium dioxide helps to improve the temperature resistance of coating as well as the image quality. In addition, adding antistatic agent to reduce the resistivity of thin film can obviously improve the image definition and avoid the graphic tailing phenomenon. The optimal formulation of coating for white laser printing is that:The water-soluble acrylic resin, the amount are72.11%(wt%); The titanium dioxide, the amount are24.04%(wt%); The High polymer antistatic agent,the amount are 3.85%(wt%). The graphic adhesion of the coating prepared by use of the formula reaches 100%.There is no spot during printing and good definition, which meet the requirements of laser printing on PET film.2. The study of PET membrane water-based ink-jet printing coatingThe Experimental results show that PVA-1788 coating ink absorption rate is significantly faster than the PVA-1750 and PVA-235 coating. Polymer polyurethane emulsion PU-303 B is well compatible with pva-1788. With the increase of the amount of emulsion PU-303 B, coating’s transmittance and water resistance are increased, however the adhesion of the coating appears to substantial increase after a slightly reduce, coating’s wear resistance also appear to increase after a reduce. With the increase of the amount of alumina, the wear resistance and adhesion are increased, but the water resistance and transmittance decreased. With the increase of the dosage of cationic polymer fixing agent, the fixation and waterproof performance of the ink absorption coating and image printing resolution increased. In the experimental range, the most suitable PET membrane water-based ink-jet printing coating formula is adhesive based on mass fraction of 10% pva-1788 emulsion and polymer resin emulsion(polyurethane emulsion PU-303B) and the amount are 47.2%(wt%) and 28.3%(wt%); paints with Al2O3, the amount are 22.6%(wt%); poly dimethyl diallyl ammonium chloride composed of cationic polymer fixing agen which amount are 1.9%(wt%). The costing’s adhesion is 95%, coating for printing image appears of neither eclosion nor diffusion, but excellent clarity, can meet the require of general inkjet printing coating, still need to do further study.3. The evaluation and analysis of the VOC pollution emission reduction by using water-based coating at PET film printing productionResults show that compared with the traditional solvent-based coating, waterbased coating of ability can significantly reduce the volatile organic compounds(VOCs) emissions. To replace traditional solvent-based coatings of this new type of environmentally friendly coatings greatly reduces the VOCs emissions in the proce ss of coating preparation and application. Realizing the products’ green upgrade and replacement. |
PDF Full Text Request