Biaxially oriented polyester film is used to release films the mandrel and the resin in GRP/FRP manufactured products. It is mainly used in GRP/FRP application like pipe, tank, chemical vessels, and roof sheet. It is also used in CFW and HFW continuous filament winding / helical filament winding.

Firstly a release film e.g. Polyester film, is wound on the mandrel, followed by a surfing mat, both of them supported by proper winders, glass roving together with chopped glass, sand aggregate, polyester resub are applied simultaneously on the proper mandrel positions according to design specification. At the end, a layer applied next to the steel tape provides the required chemical resistance (inner layer), while the material supplied over the inner layer represents the mechanical resistance outer layer. The laminate building up thus can easily be made in compliance with the appropriate design by controlling the amount of various material applied.

The polyester film is important for this application so this film should be free from pinholes and the surface defects which can affect the glossy, smooth finish of the manufactured products. The film winding should be uniformly tight.

The clear transparent film is ideal for its use as a release liner and as a separator in GRP/FRP products, apart from the toughness, flexibility and clarity for smooth and glossy finish. The film is supplied in roll form and as per the width required for CFW machines. Polyester film is release film for GRP/FRP demold. It is used in filament pipes, compression mould etc. system which keep the mould from the polyester resin to come in contact thus give more life to the mandrel mould, which is a heart of these industry.

Polyester film is also laminated with high quality glass fiber sleeves / tapes with one or two layer used as high quality electrical grade glass fiber tapes by using appropriate adhesive to produce laminate of class.