Method of and apparatus for drawing plastic film in a tenter frame

Abstract From the Canadian patent

Apparatus and method for producing a novel drawn film by propelling individual carriages along opposed loops from a first speed abutted in stacks in carriage collection sections to a second speed space apart in a drawing section of a tenter frame and to a third speed in stack forming sections where the carriages return to the first speed in the stacks. First primaries positioned adjacent one part of each loop develop electromagnetic waves for engaging synchronous secondaries attached to active carriages to provide controlled spcing of such carriages and, second primaries adjacent another part of the loop develop other electromagnetic waves for engaging hysteresis secondaries attached to …