Application highlights: long-fibre direct injection moulding combined with organic sheet
As a further innovative process for lightweight construction, Arburg will present long-fibre direct injection moulding. Here, for the first time, glass fibres with a length of up to 50 mm can be added directly to the liquid melt, where they are homogeneously distributed. The fibre length, fibre content and material combination can also be individually adjusted. The new process offers high flexibility and the possibility of developing in-house know-how. Moreover, considerable cost savings can be achieved because the base materials, plastic and fibreglass rovings, are cheaper than finished long glass fibre granulates.
The process will be demonstrated on an energy-optimised hydraulic Allrounder 820 S with servo-hydraulic drive, operating with a mould from Georg Kaufmann Formenbau AG. Through the overmoulding of continuous-fibre reinforced thermoplastic inserts (organic sheets), high-strength, resilient composite parts are created, which weigh less than 300 grams at a length exceeding 500 mm. Organic sheets combine two or more materials in a targeted manner, whereby their properties mutually enhance one another. The continuous fibres - generally glass, carbon and aramide in woven and non-woven forms - determine the mechanical properties such as strength and rigidity. The matrix material is responsible for the force transfer between the fibres in the composite and protect the reinforcing structure from buckling and environmental influences.
In this application, a six-axis robot picks up the organic sheets from a magazine. These are gently heated and transferred to the LIPA (Lightweight Integrated Process Application) mould at the forming temperature. Here, forming of the insert and injection moulding of the functional and reinforcement elements such as edging, end eyes and ribbed structures take place simultaneously in a cycle time of around 40 seconds. The produced component provides a good illustration of how lightweight parts can be produced with a high level of functional integration and short cycle times by combining organic sheets and long-fibre direct injection moulding.
Arburg to show trend-setting innovation at K 2013