Abstract A method and apparatus for manufacturing a biaxially oriented cylindrical film body, which comprises providing a guide bar projecting above a mandrel to be inserted into a cylindrical film body, conducting said film body from the upper nip rollers positioned at the top of said guide bar down said guide bar to said mandrel and further to the lower nip rollers located below said mandrel with said guide bar and mandrel suspended by a plurality of pairs of rollers, whereby there is biaxially stretched said cylindrical film body by introducing compressed gas thereinto, while forming a thin layer of gas between the outer surface of said mandrel and the inner wall surface of said cylindrical film body.
A method according to claim 1 which comprises stretching said cylindrical film body by introducing compressed gas present in the stretched portion of said cylindrical film body into the nonstretched portion thereof through mutually communicating passages running through said mandrel and guide bar.
Claim 2
Independent Claim
103 words
An apparatus for manufacturing a biaxially oriented cylindrical film body which comprises a mandrel to be inserted into a cylindrical film body, a guide bar projecting above said mandrel, shock-preventing rollers pressed to said guide bar so as to prevent the shaking of said mandrel, a pair of rollers rotatably embedded in the peripheral surface of said guide bar, support rollers adjacent to said rotatably embedded rollers upon which are suspended said mandrel and guide bar, upper nip rollers positioned at the top of said guide bar, lower nip rollers disposed below said mandrel and means for introducing compressed gas through said mandrel.
Claim 3
Dependent Claim
22 words
An apparatus according to claim 3 where the last mentioned means comprises mutually communicating passages running through said mandrel and guide bar.