In-line variable spreading of carbon fibre/thermoplastic pre-preg tapes for application in automatic tape placement

This study investigates a device for in-line continuous spreading of carbon fibre/thermoplastic pre-preg tape for potential application in the Laser-Assisted Automatic Tape Placement (LATP) laminate manufacturing process. The spreading device allows variable tape width to be achieved locally during lay-up. Integration of this device in the LATP process would remove gap and overlap manufacturing defects in variable angle tow (VAT) laminates and complex curvature components. During trials different width tapes were produced using the novel spreading device. Three different width increases were investigated, viz. 15%, 30% and 45%, and were compared with as-received tape. Initial trials indicate that it is possible to achieve a tape width increase of 62%. Preliminary characterisation tests show that the spreading process does not adversely affect the properties of the tapes. Physical properties including cross-sectional area, fibre volume fraction and void content remain similar to as-received tape. Furthermore, differential scanning calorimetry data show that levels of crystallinity increase due to spreading, improving related mechanical properties.