| 摘要 |
Disclosed are an apparatus and method for simultaneously biaxially stretching a film (e.g., a continuous web of film). The apparatus includes upper and lower rails, for guiding a pair of endless links that each has link units for grasping side edges of the film. The endless links have upper and bottom rollers for being guided by (e.g., rolling on) the rails. The upper and bottom rollers are guided respectively by the upper and lower rails in different zones of the apparatus, the endless links being lifted and guided by the upper rail in one zone and being supported and guided by the lower rail in another zone. Since rolling, rather than sliding, friction occurs during movement of the endless links, amount of lubricant needed is decreased and dirt in the system due to large amounts of lubricant used, can be reduced. In response to a change of direction of movement of the endless link, the upper and bottom rails are sheared, so the upper and lower rollers can travel in the direction of movement; as a result, stabilized high-speed travel is possible, and bearing life can be extended.
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