Apparatus for the treatment of sheet materials

1,057,027. Fluidized beds for heating sheet material. DUNLOP RUBBER CO. Ltd. Oct. 10, 1963 [Oct. 24, 1962], No. 40217/62. Heading F4U. [Also in Division D1] A closure 1 for a fluidized bed container 2 for treating lengths of sheet material comprises an open-topped box 3 the base of which has a slot 5; and a pressure chamber 6 air-tightly secured to box 3 and having in the base thereof a slot 12. The chamber 6 is provided with an inlet 11 for compressed air. Each of the slots 5 and 12 is provided with a pair of sealing strips 14 of polytetrafluorethylene co-extensive with the lengths of the slots and held by a clamping plate 15 and bolts 15a and so dimensioned that adjacent edge portions of the strips of each pair contact and distort one another to form a substantial Y-shape in cross-section. The strips associated with inlet slot 12 are directed into the pressure chamber 6 and those associated with the outlet slot 5 are directed outwardly of the pressure chamber. In use, the sheet material 19 is guided via roller 20 through the pressure chamber 6 and into the container 2. Compressed air is supplied to chamber 6 and this compressed air serves to assist in the seal formed by the strips 14 associated with slot 12 and at the same time to hold the strips 14 associated with slot 5 slightly apart, thus permitting the sheet 19 to pass therebetween with minimum drag and permitting the air to leave the chamber and fluidize the bed in container 2. In a modification the inlet slot is provided in the side of the pressure chamber with an associated guide roller within the pressure chamber.