Screen printing error control on the evaporator line

Challenge: In the process of AL belt printing with screen printing technology, deficient or partial coating, smear and similar errors may appear. These errors are further intensified in the process of hot rolling and harmfully affect the functioning of the evaporator in terms of inadequate formation of flow channels. Belt speed is 10 m/min, width ~500 mm, minimum error is 0.3 × 0.3 mm, spatial constraints and adverse ambient conditions occur, belt guidance shows swinging.

Solution: A dedicated linear imaging module in correlation with moving forward is used for painting the surface of a reference impression as a template. Nonlinear deformation of production print, caused by inaccurate guidance or swinging of the medium, is firstly corrected through multi- resolution analysis. Nonlinear distortions are then compared with the template. The comparison results in clearly expressed errors.