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US 6,916,440 B2Granted
Processes and apparatus for making transversely drawn films with substantially uniaxial character
Assignee3M Innovative Properties Company
InventorsJeffery N. Jackson, William Ward Merrill, Andrew T. Ruff, Desiree L. Thompson, Dennis L. Krueger
Life of this patent
Estimating the term…
Abstract
A process for stretching films is described. The process preferably stretches films in a uniaxial fashion. Preferably, optical films are stretched including multilayer optical films. Other aspects of the invention include a roll of stretched film and an apparatus for stretching films.
Claims15
A method of processing a film, the method comprising:
- conveying a film within a stretcher along a machine direction while holding opposing edge portions of the film;
- stretching the film within a stretching region of the stretcher by moving the opposing edge portions along diverging paths to form a stretched region of the film;
- releasing the opposing edge portions of the stretched region of the film;
- and
- grasping the stretched region of the film at opposing take-away regions positioned inside each of the opposing edge portions prior to releasing the opposing edge portions to take the stretched film away from stretching region.
2 more elements
A method of processing a film, the method comprising:
- conveying a film within a stretcher along a machine direction while holding opposing edge portions of the film;
- stretching the film within a stretching region of the stretcher by moving the opposing edge portions along diverging paths to form a stretched film;
- slitting the stretched film between the opposing edge regions and opposing takeaway regions to form selvages that continue along the diverging paths while a remainder of the stretched film is conveyed in the machine direction;
- and
- releasing the opposing edge portions of the stretched film.
2 more elements
Dependencies are inferred from the claim text.