This document specifies a mould (designated the type F ISO mould) for the injection moulding of plates with a preferred size of 80 mm × 120 mm, and a preferred thickness of 2 mm for single-point and multi-point data acquisition. Suitable test specimens according to ISO 20753 type A22 or B3 are then machined or stamped from the plates and used to obtain information on the anisotropy. For the design of plastic parts, this will provide upper and lower bounds for the tensile properties.

Investigation of the anisotropy of materials is a special procedure intended to provide guidance in the design of mouldings for end-use applications and is not intended as a quality control tool.

In the injection moulding of thermoplastic materials, the flow of molten polymer can influence the orientation of fillers such as fibreglass or the orientation of polymer chains, resulting in anisotropic behaviour.

For the purposes of this document, the flow direction is defined as the direction from the gate to the far end of the mould cavity and the cross direction as the direction perpendicular to the flow direction.

The type F mould is not intended to replace the type D mould used to determine the moulding shrinkage of thermoplastics.