Dispensed Polyester Film

Our Dispensed Polyester Film has diamond-shaped resin dots on a PET film base. The base is PET film. The resin dots are epoxy. They are arranged in a diamond grid. What is the use of Dispensed Polyester Film? In dry-type transformers, there is a need to bond copper foil to the insulation layer. Ordinary DDP uses paper as the base. Paper absorbs moisture. PET film does not absorb moisture. Also, PET film has much higher mechanical strength than paper. So our Dispensed Polyester Film is suitable for applications that need high strength. A foil-wound dry-type transformer factory came to us. Their copper foil was very thin. Only 0.2 mm. If they used DDP, the paper's rough surface might scratch the foil. PET film has a smooth surface. It will not scratch the copper foil. We recommended our Dispensed Polyester Film. The resin dot height was 50 microns. After heating, the dots melted and bonded the foil to the insulation layer. They tested 100 samples. None were scratched. Now they have switched to our Dispensed Polyester Film.

It is harder to put resin dots on PET film than on paper. The PET surface is slippery. The resin dots tend to move. We adjusted the resin formula. We increased the thixotropy. The dots do not flow after they are placed. The shape stays good. The peel strength of our Dispensed Polyester Film after curing at 180°C reaches 4 N/cm. The resin dot height is 50 ± 10 microns. The dot density is 60 dots per square centimeter. The base film itself has a breakdown voltage of 8 kV. After dotting, it drops a little but still stays above 6 kV. We supply our Dispensed Polyester Film in rolls. Widths from 100 mm to 1600 mm. MOQ is 500 kg. Free samples are available.