Corrugated cardboard from waste paper - by coating with calcium stearate before corrugation to reduce friction and cracking

摘要

Corrugated cardboard is formed by passing a plane sheet of cardboard over pref. a heated roll and then pref. between crimp wheels to corrugate, a friction reducing calcium stearate solution being applied, either to crimp wheels or the cardboard sheet to reduce friction during crimping and so prevent cracks forming the cardboard sheet. Pref. after crimping, which is carried out at 160-185 degrees C, and adhesive is applied to one face of the corrugated cardboard sheet and a pre-heated backing cardboard sheet is applied to the corrugated cardboard sheet. Corrugated cardboard can be produced at high speeds (e.g. 250 m/min. throughput) from low quality cardboard sheet formed from waste paper without risk of the cardboard cracking.