Extrusion: Adjustable Feedblock Allows Fine-Tuning of Layer Thickness—December 2010

A new-generation feedblock for flat-die coextrusion simplifies fine-tuning of layer thicknesses, reducing downtime.

A new-generation feedblock for flat-die coextrusion simplifi es fine-tuning of layer thicknesses, reducing downtime. Developed by Extrusion Dies Industries, LLC (EDI), Chippewa Falls, Wis., the new Ultraflow V feedblock has adjustable “combining planes” where the melt streams join the central flow channel. The combining planes can operate in two modes, each with different advantages:

  • Eliminating feedblock adjustment by the operator. By leaving the adjustable plane in free-floating mode, operators can let the position be determined directly by the equilibrium pressure developed by flow from the extruders. A change in flow from one of the extruders causes a readjustment of the combining plane at the point where materials merge.
  • Optimizing layer-to-layer interfaces. For polymers whose interaction at the point of confluence can possibly disrupt or compromise the multilayer structure, the adjustable plane can be moved manually to fine-tune polymer flow. Shafts extending from outside the feedblock into the centers of the adjustable planes provide ease of operation. Simple settings change the adjustable planes from free-floating mode to varying levels of responsiveness to melt-fl ow pressure. Once adjusted, an adjustable plane remains in a fixed position.


Ultraflow V feedblocks can be designed for any number of extruders or layers. The accompanying photo shows a feedblock designed for three layers with three extruders. Inside it are two combining planes for the outer-layer melt streams, while the stream for the core layer enters the feedblock via the central channel.
(715) 726-1201 • extrusiondies.com


Extrusion Dies, Inc.
911 Kurth Rd. Chippewa Falls, WI 54729-1443
Phone (715) 726-1201 Fax (715) 726-2205