A Communication from the PLACE Div. of TAPPI

Providing practical information to the converting and packaging industries…

EXECUTIVE SUMMARY
New Die Designs And Advancements In Automatic Die Controls For Improved Efficiencies In Film Production

by Jamie Foederer, Extrusion Dies Industries, LLC

Frequent product changes have driven die designers to develop new technologies. This paper focuses on new die designs targeted toward the thin film producer. It will also discuss automatic die lip control and additional die features and coatings that relate to increased extruder up-time and complement the “Lean Manufacturer.”

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.



EXECUTIVE SUMMARY
How Sealant Film Choice Can Affect A Laminated Structure’s Properties

by David G. Timm, Charter Films

APPLICATION: Gauge is significant contributor to laminate performance. It requires additional study since many forces align to push for overall gauge reduction in packaging.
When designing films for use as sealant layers, some functionalities translate well into the properties of a lamination and especially the sealant functionality that a film provides. Some properties such as toughness, stiffness, and “body” are not well understood once the films have been laminated to oriented substrates including primarily polypropylene (OPP) or oriented polyester (PET). Oriented substrates such as OPP and PET demonstrate orders of magnitude increases in stiffness over typical blown polyethylene based films. When combining through lamination a soft, amorphous substrate with a rigid, crystalline substrate, understanding what the properties of the composite lamination will be is therefore difficult will be. Packaging engineers, marketing departments, and brand managers would all like to understand and even predict these interactions better.

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.

For information about the PLACE Division of TAPPI, access the TAPPI web page at tappi.org. To obtain the complete papers whose expanded summaries appear in this section, go to the TAPPI web site at tappi.org., then click on "the PLACE" in the section designated Journals.


Telephone inquiries are welcome at the TAPPI Service Line by calling 800/332-8686 in the United States, 800/446-9431 in Canada, or 770/446-1400 in other countries. Send FAX to 770/446-6947. Address mail to TAPPI, 15 Technology Parkway South, Norcross, GA, 30092.

Submit manuscripts for publication to dbentley@tappi.org. Obtain information about the PLACE Division from tappi.org.


ePLACE Electronic Newsletter
Receive technical information delivered to your computer every other Monday from the PLACE Division. Subscribe on-line at tappi.org by clicking Newsletters under the People heading.


Visit past communications from the PLACE div. of TAPPI in our the PLACE Archives.


Subscribe to PFFC's EClips Newsletter