High performance tesa adhesive tapes are finding success in the resin infusion moulding process used to manufacture wind turbine blades

The resin infusion mould process enables the manufacture of high quality composite parts in a wide range of fibre and resin combinations. Central to the structural integrity and performance of finished parts made this way is saturation of the glass fibres with the resin to eliminate voids and provide a pinhole-free surface finish. The resin infusion moulding process (RIM) delivers on all these fronts and is used to produce parts for marine, aerospace, transportation and infrastructure applications.

RIM relies on vacuum-assisted resin transfer provided through spirals located in the moulds. These are temporarily fixed and removed after processing with tesa 51960 fabric reinforced double sided PP film with a differential (different adhesive coat weight either side of the carrier) acrylic adhesive. The side with the highest adhesive coat weight bonds to the spiral preventing lift-off during moulding while enabling residue-free removal after processing.

Similarly, resin infusion profiles which speed up preparation process before RIM starts are securely positioned and fixed into the resin distribution net using tesa 4970, a double sided PVC tape with acrylic adhesive and tesa 4914, a double sided non-woven tape, again with differential adhesive. In the production of wind turbine blades the acrylic adhesive is essential as a natural rubber based adhesive system would contaminate the blade structure and affect its life cycle performance properties.

Essential anti-stick surfaces inside RIM moulds are created with tesa 4810, a single sided PTFE laminated glass cloth tape with a silicon adhesive. The use of this tape eliminates the time-consuming process of using liquid mould releasing agents and avoids the potentially damaging transfer of liquid release agent to the surface of the turbine blades and other finished components.

Also assisting the RIM process during infusion are ‘flash tapes’ which are used for temporary masking inside or around the mould. The excellent performance of both tesa 61122 and 61123 on the low energy surface of moulds makes them ideal for this task. The different thicknesses of these tapes are used to meet varying tensile strength requirements.