EDI system enhancements make it easier to control edge bead while reducing downtime for width changes and cleaning.
New Design Boost to Plastic Extrusion: Nordson Corp. has streamlined the design of its EPC deckle system for EDI extrusion coating and laminating dies, making it easier to control edge bead and reducing downtime for width changes and cleaning.
The EPC die includes an internal deckle system that reduces resin cost and trim waste by controlling edge-bead formation, plus an external deckle for width adjustment. The new enhanced design introduces the following improvements:
- Easier edge-bead control. For independent adjustment of the internal deckle components, a threaded stud has replaced the rack-and-pinion gear, making it easier to fine-tune the edge bead, reducing the amount of trim required and increasing material savings.
- Easier manual adjustment of deckle width. Nordson has replaced a gear box used for adjusting overall deckle width with a nut on the adjustment rod. This modification reduces the width and weight of the deckle system and improves access.
- A more-robust and user-friendly construction. A durable new deckle rod support guide makes deckle adjustment easier.
- Easier access for cleaning and maintenance. A low-profile external deckle can be removed as a single unit, or it can slide out for installation of a lip scraper without removal of the entire deckle assembly. Similarly, internal deckle components can be taken out by removing six bolts from the end of the deckle system without disengaging the entire unit.
The enhancements were developed in response to requests from convertors seeking to maximize productivity, said Nordson. “Our new-design extrusion coating dies are easier to operate and maintain, while providing the same effective control over edge bead that has been the distinguishing value of the EPC system,” said Patrick Meinen, Global Product Line Manager, EDI Dies.
The internal deckle system in an EPC die provides fine-tuning of the edge profile of a coating, explained Nordson. The molten polymer in a die without an EPC deckle system will exhibit transverse flow, producing an enlarged edge bead from the resulting necking at the die exit. In the EPC system, the internal deckle components for adjusting the edge bead profile are located downstream of the primary manifold — one in the pre-land section, the other in the secondary manifold. By adjusting the positions of these components relative to one another, it is possible to reduce the flow of polymer at the extreme edges of the coating, thereby minimizing edge bead, according to Nordson.
New Design Boost to Plastic Extrusion: Original Article