An apparatus and process for pulverization of polymeric material having a multi-component screw disposed within an elongated cylindrical housing. The multi-component screw has an independently rotatable extrusion portion and an independently rotatable pulverization portion. A cooling means is provided to maintain the fine powder material produced during the pulverization process at a desired temperature. In one embodiment of this invention, a second multi-component screw having an independently rotatable extrusion portion and an independently rotatable pulverization portion is disposed within the elongated cylindrical housing.
An appliance having a driving mechanism is provided, the appliance (10) comprising two rotatable portions (32, 34) which are rotatable by the driving mechanism (50) about an axis (40). The driving mechanism (50) comprises a gearbox (60) having an input gear (116), two output gears (240, 304) and a locking mechanism (250, 252, 318) movable between a first position and a second position. The arrangement is such that, when the locking mechanism (250, 252, 318) is in the first position and the input gear (116) is driven, both output gears (240, 304) rotate in the same direction and, when the locking mechanism (250, 252, 318) is in the second position and the input gear (116) is driven, the output gears (240, 304) rotate in opposite directions. The arrangement of the axis (40) is horizontal or substantially horizontal. The invention is particularly suitable for use in a front-loading washing machine (10) having a drum (30) comprising two rotatable portions (32, 34). The driving mechanism (50) can be used to selectively cause rotation of the rotatable portions (32, 34) either in the same direction or in opposite directions.
