| 摘要 |
PURPOSE:Specific dents in the form of a saddle or groove are formed on a screen which is made by knitting hollow or dense bars made of thermoplastic synthetic resin to produce a screen for making a laver sheet with reduced contact areas with the laver sheet. CONSTITUTION:Hollow and/or dense bars or sticks of thermoplastic synthetic resin are fastened together to prepare a screen. The resultant screen is pressed with hot pressing piece 3 to form dents 2 of saddle or groove form which is smaller than the diameter of the bars 1. The bars or sticks is made from a polypropylene resin, polyethylene resin, polystyrene resin or another thermoplastic resin into hollow or dense bars or sticks or foamed into these forms. For example, they are 1.5-2.5mm. thick and have round, oval or polygonal cross section as required. |
