Surface energy injection moulding

The solubility parameter of the polymer is calculated from bond energies. The sensitivity to ESC is affected by the polymer molecular weight and by molecular orientation at the surface of injection mouldings. 

However, a plate that deforms to this degree is not in danger of brittle fracture at low impact energy. Hence, the value of the test is to screen injection mouldings for brittle failure, at forces well below fmax, due to orientation, weld lines or a weak surface structure. 

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