This part of ISO 294 specifies a two-cavity mould (designated the type F ISO mould) for the injection moulding of 80 mm x 90 mm plates with a preferred thickness of 3 mm. Suitable test specimens [ISO 527-2 type 1BA tensile test specimens or type 1 (80 mm x 10 mm) bars] are then machined or die-cut from the plates (see annex A) and used to obtain information on the anisotropy of thermoplastic parts.

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 may influence the orientation of fillers such as fibreglass or the orientation of polymer chains. This may result in anisotropic behaviour. The knowledge of anisotropic behaviour is valuable in designing plastic parts.

For the purposes of this part of ISO 294, 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.