The effect of pressure and temperature on microthermoforming thermoplastic films integrated in the injection moulding process
Abstract Injection moulding is a widespread large-scale production technology for the manufacturing of thermoplastic parts, with small wall thicknesses limiting the feasible flow length. Introducing microthermoforming into the injection moulding process with dynamic mould temperature control enables the production of film-based, plane microstructured parts with further three-dimensional functional structures (e.g. for handling or for fitting in devices/assembly groups). Investigations show that considerable forming is possible with pressures up to 140 bar and forming temperatures far below the glass transition temperature of 50-μm-thick polycarbonate films in cycle times of <3 min. Generally speaking, the novel technology is expected to allow for multifunctional, thin-walled microstructured parts at large scales with short cycle times.