Study on Preparation and Performance of Saturated Polyester Coating

Abstract

The aluminum can be coated finishing varnish film to protect the printing pattern after the printing process. The coating can be affected by external forces of jar flanging and necking, such as friction, impact force and bending force, etc. In order to improve the quality of finishing varnish film on metal cans, the effects of different coating process parameters on coating were studied. Polyester light oil material for aluminum cans was prepared by uniform stirring method, and the mass fraction of material composition were saturated by polyester coating, amino resin, heavy aromatics solvent naphtha, low aromatics solvent naphtha, isophorone and other solvents, the rest are various auxiliaries and de-ionized water. The influences of coating process parameter such as viscosity of coatings,curing time and baking temperature on film quality were discussed, while the distance between material and coating, the ratio of mandrel to roller, the viscosity of coating were adjusted, the coating surface was prepared by roller coating method and cured by baking. Scanning electron microscopy (SEM ，TESCAN VEGA Ⅱ , 20 kV) was used to characterize the surface structure and morphology. Intelligent gloss meter (GZ-1) was employed to analyze the surface of the final products. The surface of aluminum pot is dense; and glossiness is good with surface quality improved obviously. The optimal coating process parameter was obtained. Film with superior adhesive force, hardness, thermal resistance could be available. Finishing varnish coating process parameters were set as follows when the hardness, glossiness, and water resistance of the film are best with the viscosity,curing time and curing temperature being 85 secs, 7 min, and 170°C, respectively.