Polytronic™ Coated 5 mil Heat Stabilized Polyester.
PolyTronic 5 mil clear is a non-pressure sensitive polyester used for spacers/layers in membrane switches, usually under the graphic overlay. Pressure sensitive transfer adhesive may be applied to it before cutting. It is heat treated so that it doesn’t expand or contract under extreme heat. If it expanded it would cause the circuitry to break.
Polytronic comes in both print treated and non-print treated rolls formulated for the Gerber Edge®. The treated version should be used if you intend to print on it. Both materials are formulated for Gerber cutters. The “print treated” version may also be used to print circuitry using InkTronic conductive foil.
The bottom layers (3 on the left) in the picture below are made from Polytronic. The graphic overlay was printed on Armalex Velvet Gloss. Click here to see it in action.