METHOD AND APPARATUS FOR MAKING POLYTETRAFLUOROETHYLENE SHEET AND DEVICE FOR PELLETIZING-MIXING Russian patent published in 2002 - IPC

FIELD: processes and equipment for making sheets of polytetrafluoroethylene material by continuously pelletizing and mixing. SUBSTANCE: method for molding sheets of polytetrafluoroethylene comprises steps of compressing powder of polytetrafluoroethylene and lubrication material to sheet between mutually opposite surfaces of pair of belts including horizontal belt and compression belt; distributing material to layer and rolling out it in gap between at least one pair of band type belts; sustaining mutually opposite arrangement of belt surfaces at their motion; providing gap between belts at outlet side more narrow than at inlet side; placing compression belt with inclination between inlet and outlet sides. Opening at inlet side is wide; opening of outlet side is narrow. Horizontal and compression belts are moved lengthwise with the same speed. In description of invention apparatus for molding sheets of polytetrafluoroethylene and device for continuously pelletizing and mixing are offered. Continuous pelletizing and mixing are realized at distributing material by layer in gap between mutually opposite surfaces of pair of belts when material is moved obliquely relative to direction of belt motion. Belts are water repellent ones. There are mechanism for setting different speed values of belts and device for creating crosswise vibration at least of one belt. EFFECT: enhanced efficiency of process for continuously molding sheets. 6 cl, 7 dwg, 1 tbl