Screen printing of heated glass panes - using stencils with layers running across meshes for boundaries without sawteeth

摘要

Electrically heated panes of glass for road and rail vehicles are produced by narrow resistance strips with a compsn. contg. metallic silver which are applied by screen printing and fired. The screen printing stencil which is used has layers which run across the fabric meshes to form a smooth strip boundary. After firing, a preliminary copper plating produces resistance 15% above the final value. The resistances are now measured and the panes are divided into resistance groups. The final plating stage is applied under the same conditions for all panes in a group in automatic plant. This results in a smaller scatter band for the resistances and requires less labour and equipment. The amount of scrap is reduced and the stencils have a longer life. The whole operation can be automated more readily.