- December 31, 2005, David J. Bentley, Jr., Contributing Editor
Providing practical information to the converting and packaging industries…
New Die Designs And Advancements In Automatic Die Controls For Improved Efficiencies In Film Production
by Jamie Foederer, Extrusion Dies Industries, LLC
Most extrusion tooling for cast film production lines has been traditionally designed for long runs with high output rates. The time required to change from “Product A” to “Product B” has historically been a lower priority design criterion because of relatively infrequent product changes. This traditional design is not well suited for many film markets today that are driving producers to shorter, more frequent, and highly specialized runs. These market forces have created a need for extrusion dies that can quickly achieve acceptable product tolerances after a product change. Some more modern die designs have produced dies that maintain good thickness control and are mechanically stable for a broad range of rates and materials, but they achieve this at the expense of flow streamlining. A novel die design is now available to provide remarkably stable thickness control while simultaneously promoting rapid purging and low inventory time.
The increasing demand for tooling that can accommodate frequent product changes has driven die designers to develop new technologies. Flow channel designs have come full-circle. The classic coat-hanger channel that provides optimal flow path characteristics as a result of its diminishing volume design can now be incorporated into a novel sculpted exterior die body shape. This combination of a streamlined and accurate flow channel housed within a die shape that resists clam-shelling provides the user with the ability to change output rates and materials and return to saleable product tolerances quickly.
How Sealant Film Choice Can Affect A Laminated Structure’s Properties
by David G. Timm, Charter Films
From a macro point of view, the study in this paper creates some doubt regarding how important sealant film strength is when designing a laminated structure. Many properties studied showed little and in some cases no impact of film strength on the strength of a resultant lamination. To be fair, some methods chosen for this study are “fast response” film tests. They are quick failure tests such as dart impact and tear strength. These tests impart stresses very quickly. This favors the stiff PET and PET/foil materials. Nevertheless a message appears. A better understanding of film selection on package performance is necessary. In many tests performed, the effect of gauge was a more significant contributor to laminate performance. This makes pragmatic sense since the film has more mass and can better assist the oriented components. This gauge effect also requires additional study since it is particularly critical when many forces align to push for overall gauge reduction in packaging. In many cases, this translates to gauge reduction in a sealant film.
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