Heat-insulating corrugated cardboards and method for making them

摘要

A corrugated cardboard includes a corrugated core sheet comprising a plastic sheeting having thereon a skin layer having a specific cell diameter and a plastic film laminated on at least one side of the corrugated sheet. This corrugated cardboard is improved in terms of heat insulation and so can be used for packing such materials as petals and perishables, while protecting them against heat and keeping them fresh. More preferably, shielders may be provided in the corrugated core sheet grooves. A specific method for making such cardboard products is also provided.