NORDSON EDI TO SHOW MOST SOPHISTICATED EPC™ EXTRUSION COATING DIE TO DATE, REDUCING DOWNTIME AND CONTROLLING EDGE BEAD
CHIPPEWA FALLS, WI, March 15, 2013: Guided by feedback from converters worldwide, Nordson EDI has completely re-engineered its widely used EPC™ edge bead-reducing extrusion coating die, yielding a more robust system that is even easier to operate and cuts back substantially on downtime for width changes and cleaning, the company announced today. Nordson Extrusion Dies Industries (Shanghai), will feature the enhanced system at Chinaplas 2013 (Hall 2, Booth 1A31).
The EPC system at Chinaplas (shown in the accompanying photo) will be the most advanced yet available, incorporating: 1) an Autoflex® VI automatic gauge profile control; 2) an Ultraflow® V feedblock for multilayer coatings; 3) a new-design deckle system for rapid width adjustment and simplified removal for die cleaning; and 4) a device for quick removal of die buildup. Within the Ultraflow V feedblock are adjustable “combining planes,” located where the melt streams join the central flow channel, that operate in two modes—either automatically adjusting layer material flows or permitting fine tuning through manual adjustment.
“Nordson EDI’s next-generation EPC die eliminates the need to disassemble the deckle system for cleanouts of carbonized polymer buildup inside the lip, replacing a job that used to take an hour or an hour and a half with a simple procedure that takes just five minutes,” said Sam G. Iuliano, chief technologist. “And because it is now possible to remove the entire deckle assembly as a self-contained unit, it takes half the time to completely open the die for ‘split-and-clean’ maintenance.”
Deckles are mounted at either end of a die and used for varying the width of the coating. As in the past, the next-generation EPC die includes an external deckle as a secondary seal to prevent leakage and an internal deckle system that sets coat width and seals polymer at the die exit. Internal deckle parts provide independently adjustable components that seal off portions of the internal flow channel and can be positioned to minimize edge bead. Similarly, a manual or automated system for adjusting a flexible lip of the die makes it possible to maintain coat weight uniformity.
The next-generation EPC die provides these enhancements in performance:
● Rapid and accurate changes in width. A more robust support structure and drive mechanism for the deckle ensures a more stable and repeatable width-adjustment system. The deckle system is easier and faster to operate, with less adjusting movement required to make changes in width. The system provides coat width adjustments that can be manual or motorized.
● Easily inserted scraper to remove buildup. A patent-pending system enables operators to quickly retract the deckle components and insert a simple brass scraper that cleans away
carbonized polymer that causes die lines in areas impossible to reach by conventional shims. In the past it was impossible to remove such buildup upstream of the lips without disassembling and removing the deckle components.
● Fast removal of deckle system for ‘split and clean.’ It is now possible to open the die without completely disassembling the deckles at either end. Instead, the deckle assembly can be readily removed intact. Cleaning and maintenance of the die can take place while it is still online, or the die can be taken off-line. Nordson EDI supplies special die carts for off-line maintenance.
How the EPC™ Die Minimizes Edge Bead Formation
Internal deckle systems used for fine-tuning the edge profile of a coating are effective because of the tendency of molten polymer to exhibit transverse flow if lateral barriers to flow are removed at the die exit. In the EPC die, the internal deckle components for adjusting the edge bead profile are located downstream of the primary manifold—one in the preland section, the second 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.
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