Investigating the microwave based heat pressing of commingled yarns made from nanomodified polypropylene and glass fibresThursday (29.09.2016) 11:15 - 11:30 Part of:
Both the automotive industry as well as the aerospace industry aim to achieve the lowest possible weight at maximized mechanical properties. The use of lightweight structures mainly results in a reduction of operating costs of the finished products [WKK14]. In order to achieve these efficient lightweight structures while staying profitable, fibre reinforced thermoplastic composites (FRTCs) are being developed. For instance, FRTCs can be produced from hybrid yarns consisting of commingled thermoplastic and reinforcement fibres. The hybrid yarns are processed to fabrics through various textile processes subsequent to commingling. In a final step the fabrics are heated and consolidated by the use of heat pressing to form fibre reinforced components. Considering the production process, the heating and cooling times of the organic sheets are the cycle-time determining factors. Shorter cycle times lead to higher outputs, thus reducing the costs per part. To achieve a reduction of heating times, microwave active hybrid yarns containing nanomodified polypropylene filaments are produced and examined at the Institute for Textile Technology Aachen (ITA). The “Micropress” project is based on researches dealing with nanomodification and commingling of hybrid yarns [KSG12, Kra12]. The microwave technology exhibits further advantages like high energy efficiency and volumetric heating [Pfe07]. By implementing microwave technology into an existing heat pressing process, FRTCs are being manufactured from unidirectional polypropylene and glass fibre woven fabrics. The investigation of this modified manufacturing process includes the commingling of glass and nanomodified polypropylene fibres, the characterisation of the yarns’ properties and the manufacturing of applicable textile fabrics. Furthermore, the heating behaviour of various specimens by microwave irradiation is observed with laboratory microwave equipment. In the final step, the manufacturing of FRTCs by the newly developed production method is realised and the obtained samples are optically and mechanically characterised.