国产人妖视频一区在线观看_亚洲国产精品丝袜国产自在线_va亚洲va日韩不卡在线观看_日本欧美一区二区三区在线_国产精品视频公开费视频_2020久久国产最新免费观看_亚洲精品自在在线观看_亚洲va久久久久综合_99视频在线免费观看

Honeycomb paperboard

Honeycomb paperboard is according to the nature of the principle of makinghoneycomb structure, which is the corrugated paper with adhesive meansconnected into a plurality of hollow three-dimensional hexagonal, formingan integral stress parts-paper core, and the double-sided adhesive paperand a new kind of sandwich structure of environmental protection and energysaving materials.