Extrusion Dies Industries LLC is marketing technology that could make double-digit film layers commonplace.
Film with 80 layers, each 50 microns thick, is possible, said EDI, which promoted the microlayer technology recently at NPE 2006 in Chicago. Multilayer films made in typical production lines rarely exceed nine layers.
``We still do not know the practical upper limit,'' said EDI President and Chief Executive Officer Timothy Callahan, referring to the potential number of film layers.
The technology is based on a patented system developed by Dow Chemical Co. of Midland, Mich. EDI licenses the technology from Dow and plans, in turn, to license it to processors.
EDI of Chippewa Falls, Wis., claims the multilayer system can improve barrier properties, encapsulate gels and allow film makers to use high-cost materials more efficiently. EDI predicts wide acceptance in the production of barrier packaging.
``We are establishing relationships with licensees that enable film and coating processors to profit from the production economies and enhanced product performance made possible by the EDI/Dow layer-multiplier system,'' Callahan added. He said in a pre-show interview that EDI is negotiating with eight to 10 potential licensees.
EDI marries Dow's system with EDI's custom-engineered die, feed block and other tooling parts.
In a typical setup, three or more extruders feed melt streams into an EDI-streamlined feed block, producing a multilayer sandwich. The sandwich then feeds into a layer-multiplier device built by EDI based on Dow's design. There, layers are multiplied in stages. Three layers become 12, which then can become 48. The multilayer structure goes to an EDI coextrusion manifold to the target product width.
Other possible benefits include fewer web breaks, particulary in films stretched after extrusion, and new property combinations.
3M Co. has been using technology based on Dow's patents to make sophisticated optical films for electronic screen displays. EDI's license skirts such uses and covers cast film, oriented film, sheet and extrusion coating. EDI has built a 2,000-square-foot development laboratory in Chippewa Falls to help customers adapt the technology to their needs.