Rigid PVC/Flexible PVC Co-Extrusion with Live Hinge and Flex Cap

This example of New Jersey Precision Technologies, Inc’s custom plastic extrusion tooling is for a horizontal 2.5″ Davis-Standard plastic extruder with a 1″ Davis-Standard satellite extruder feeding downward from above the main body at a 90° angle.

Our engineering department used four-axis wire EDM programming software to create the extrusion profile and we machined the parts using our state-of-the-art Mitsubishi wire EDM machines in conjunction with CNC milling.

The main body of the extrusion is rigid PVC, while the co-extrusion is flexible PVC fed through a port in the transition plate, which has polished milled tracks designed to flow smoothly into the rear of the die face.

The co-extrusion has two feed areas: one of the feed areas forms a live hinge and the other area is a surface cap to coat the rigid PVC with a layer of flexible PVC as a grip function. We also added user-friendly flow-limiting screws to the die, allowing the operator to control the flow independently of the two co-extrusion feed areas’ throttle valves.

The tooling is made from 420 stainless steel and the interface between the components is located by dowel pins.

We also made two six-inch long vacuum calibrators for the downstream portion of the extrusion process. Each vacuum calibrator has .015″ wide vacuum slots and we machined the extrusion contour to a 16 RMS finish, enabling our customer to achieve fine plastic extrusion smoothness and very high extrusion rates.

We help our customers achieve the fastest flow rates possible by optimizing our tooling to eliminate eddies and turbulence and maintain balanced laminar flow. The feed head is partitioned and balanced to help distribute plastic in correct proportion to all areas. Streamlining the extrusion pathway can improve feed rates by up to 25 percent or more.

This tooling was built in 3 to 4 days after the receipt of the order.

http://www.njpt.com

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