Directionally reinforced moulding compound

For moulding compounds the difference between the values for SMC and DMC is due to the presence of longer fibres in the former case. Overall the SMC values compare favourably with those of mat polyester. The materials with continuous fibre reinforcement have much higher impact properties provided a reasonable proportion of the fibres is in the direction in which the main bending stresses are generated in the impact test. 

To maximise the mechanical properties of short fibre-reinforced thermoplastic composites, it is necessary to achieve effective stress transfer between fibre and polymer matrix and appropriate fibre alignment in the finished component relative to the direction of applied stress. The former requirement is governed primarily by the method of compounding, whilst fibre orientation is very dependent on moulding conditions [76]. 

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