Blow moulding of long glass fibre composites

Precompounded discrete fibres have long been used as reinforcement in injection moulding particularly with polypropylene and nylon matrixes. Usually the lengths of the fibres in the finished article have been in the range 0.2-1.00 mm and for convenience arc labelled short glass fibres. The last 15 years has seen the development of precompounded long glass fibres, having lengths in the finished article of typically an order of magnitude longer than for short glass fibres. The present paper describes experiments on the blow moulding of long glass fibre reinforced virgin and recycled polymers. The long glass fibre compounds have been made using in house technology, for which the matrix interface conditions are known and can be varied. Bottles of 2 L capacity with integral handles were blown as the primary testpieces for evaluating blowability of these new materials and for investigating the reinforcing structures obtained in the bottle walls. Mechanical properties were evaluated at room temperature before and after recycling and at elevated temperatures up to 100°C, which are particularly relevant to the blow moulding applications envisaged.