| 摘要 |
PROBLEM TO BE SOLVED: To provide a tenter unit for maintaining a line speed at a set line sped even when a chain is elongated in a transverse orienting step using a tenter system for transverse orienting, and a method for manufacturing a film of stable quality (particularly heat shrink characteristics in a longitudinal direction) with stable steps by using the unit. SOLUTION: In the method for manufacturing a biaxially oriented film comprising the step of transverse orienting by the tenter unit 2 to control a line speed by a rotating speed of sprockets 23 for driving a chain 21, it corrects to cancel a speed difference of the line speed generated due to elongation of the chain 21 of the unit 2. As the unit 2 usable for the method, a line speed setter 26, an elongation measuring unit 27 for the chain, and a speed correcting unit 26 for correcting to cancel the speed difference due to the elongation of the chain based on an elongation amount measured by the unit 27 are provided. |
