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AssigneeLindauer Dornier Gesellschaft mbH
InventorAndreas Rutz
Estimating the term…
A thermoplastic film stretching apparatus includes a first and a second separate transport chain system including the respective guide tracks and tentering clamps. The tentering clamps are guided without the conventional chain plate connections. The first chain transport system performs the tentering clamp transport from the inlet of the system to the setting zone of the system, where the tentering clamps are released by the first transport chain system and taken over by the second transport chain system. The transport of the tentering clamps by the second system through the setting zone, the cooling zone, and along the way to the outlet zone of the film stretcher, takes place with a smaller transport speed than that of the first transport system. The speed difference between the first and second transport chains is the measure for the film shrinkage to be imposed onto the thermoplastic film.
An apparatus for the simultaneous biaxial stretching and axial shrinking of a thermoplastic film web, comprising a plurality of tentering clamps (17) for gripping longitudinal edges of said film web, two separate transport systems (TS1, TS2) including separate first and second endless tentering chains (18, 38) for moving said tentering clamps through said apparatus, said transport systems comprising a first transport system including a first section (1) and a second section (2) each having a first portion and a second portion, said first portions extending in parallel to each other, said second portions diverging from each other at an angle to a transport direction (10) of said film web (7) and a second transport system also including a first section (3) and a second section (4) extending in parallel to each other, said first transport system comprising endless rails forming first guide tracks for said first tentering chains, said second transport system comprising separate endless rails forming second guide tracks for said second tentering chains, and transition tracks (16A, 16B, 16C, 16D) interconnecting only portions of said first and second guide tracks for transferring said tentering clamps from said first transport system to said second transport system and vice versa while circulating said first and second tentering chains independently of each other respectively in said first and second transport systems (TS1, TS2).
Dependencies are inferred from the claim text.