Corrugated cardboard mfr. - with protective plastic coating bonded at same time as layers are bonded by adhesive

摘要

In the mfr. of corrugated cardboard, provided with a protective plastic layer, the plastic film is bonded with the cardboard by thermal sealing at the same time as the corrugated web is secured to the carrier web by fluid adhesive. The layers to be bonded by fluid adhesive are fed in above the layer to be secured by thermal sealing. Pref. plastic material is a bonded polyethylene-paper film, partic. a polyethylene-ethylene copolymerisate/paper with the plastic layer having a low sealing temp. Process allows the plastic film to applied while the corrugated cardboard is mfd. in a single operation, without allowing any adhesive to come near the heated surface of the hot section of the machine.