Butt-Weld Thermal Splicer for Polyester Motion-Picture Films

The editing, assembly, and convenient use of motion-picture film requires that film splices be easily made, and be invisible in the projected image. In those applications when polyester film base is preferred for its balance of physical properties, splicing of such film base has not yet become convenient. Thermal weld splices can be produced on polyester, however, and the simplicity of one procedure has now been demonstrated with a prototype tabletop unit for the thermal butt-weld splicing of 35mm polyester motion-picture film. — The welding process employs radiant heating to achieve fusion. The film is initially positioned and trimmed to lengths that provide about 0.035 in of additional length in the splice area, compressed into a butt-weld after two seconds of heating. The excess length is forced out of the film plane into a bead, which is then skived away. The necessary orientation and crystallinity of the polyester base are maintained over most of the splice area by controlled, rapid heating and cooling. A group of tests has been developed to evaluate both the weld and its adjacent areas, and has been correlated with practical use. Design data are presented.

Print ISSN

0361-4573

Published

1971-02

Content type

Original Research

DOI

10.5594/J13530