附着力（adhesion）.doc

附着力（adhesion） The metal printing is a non absorbent material of low carbon tinplate, commonly known as tin. Tinplate printing principle and offset are similar, but in the process it has special side, for example: 1. tin iron after printing ink retention on the surface, to be through some form of heat to dry curing; The 2. tin tin layer surface brightness, with spectral analysis is black. In color printing, must be on the tin surface coated with a layer of white paint. Of course, sometimes according to the special artistic effect of product pattern, can be partly coated with white paint or directly using the surface appearance of tinplate tin itself; After 3. tinplate printing products. To enter into the next process of machining to produce containers into various shapes or other packaging. In the machining process, the ink coating tinplate surface must be resistant to mechanical shock, anti extension. Special products such as canned containers, the ink coating also have physical properties of high pressure cooking. This requires between coating and printing ink tin surfaces must have excellent adhesion. Oftinned surface coating ink adhesion is good or bad, has been a professional staff to study and practice in the long-term problem. It is related to the surface properties of the oftinned itself, many factors in the process of printing ink, coating type, baking temperature and the thickness of the ink coating etc.. Now how to enhance the adhesion between the coating and printing ink tin problem, talk about personal superficial view. First, the surface properties of tin and ink coating adhesion Tin is a steel plate as the base material, plating on pure tin, low carbon steel thin plate so bright. Tinplate with different tin plating, divided into hot dip plating tin and tin plate two. Oftinned structure is composed of steel substrate, Sn Fe alloy layer, tin layer, oxide film and oil film. As shown in the figure: From the oftinned structure, its surface is coated with a