av中文精品在线_少妇爱做高清免费视频_亚洲A无码天堂在线观看_双腿国产亚洲精品无码不卡_大地影院的节目表_www.午夜日韩欧美在线观看_无码任你操久久AV_情五月少妇色欲网_狠狠躁夜夜躁人人爽天天古典_国产私拍精品视频福利推出

The base paper for paper cups is called "cup board", and is made on special multi-ply paper machines. It has a barrier coating for waterproofing. The paper needs high stiffness and strong wet sizing. The cup board grade has a special design for the cup manufacturing processes. The mouth roll forming process requires good elongation properties of the board and the plastic coating. A well formed mouth roll provides stiffness and handling properties in the cup. The basis weights of the cup boards are 170–350 g/m2.

To meet hygiene requirements, paper cups are generally manufactured from virgin (non-recycled) materials.[citation needed]The one exception to this is when the paper cup features an extra insulating layer for heat retention, which never comes into contact with the beverage, such as a corrugated layer wrapped around a single-wall cup.