Process for producing a tight connection between a multilayer plastic material and a filter medium

摘要

End plates of the filter unit comprise a multi-layer plastic material(13,18), one meltable layer of which has a different heat absorption to a supporting layer(12,19). Using infra-red radiation the layer(13,18) with better heat absorption is melted to form a sealed connection with the filter material(16) while the other layers remain solid. An independent claim is included for a filter unit(10) comprising a multi-layer end disc and a hollow filter material whose end faces are sealed by multi-layer plastic discs with layers containing different pigments.