AIR RING FOR COOLING BUBBLE IN INFLATION TYPE FILM FORMING DEVICE

摘要

PURPOSE:To form excellently transparent film which is appropriately adjustable in inner diameter regardless of change of film diameter and inflation ratio by installing a device capable of changing an inner diameter in an upper air ring of the air rings equipped at two stages, upper and lower. CONSTITUTION:A ring device A comprises a stop mechanism made of blades 12 which are equipped between a ringed holder 10 of an upper air ring 4 and a ringed rotary plate 11 with the same inner diameter as the holder 10 and move to or from the center by the turning operation of the rotary plate 11. In the stop mechanism, a suitable number of arch blades 12 are combined and arranged in the circumferential direction and in piles between the ringed holder 10 and the rotary plate 11. One end of the arch blade is pivoted rotatively about a spindle 13 on the holder 10 and a spindle 14 pivoted to the other end thereof is fitted slidably and loosely to the guide grooves 16 on the rotary plate 11. Therefore, when the rotary plate 11 is revolved in any direction the spindles 14 slide in the guide grooves and the blades 12 turn above the spindles to change the inner diameter D.