This International Standard specifies two methods for the determination of the cure characteristics of fibre- reinforced thermosetting moulding compounds and prepregs.

The characteristics measured are

• the heat generated by the exothermic reaction;
• the thermal expansion of the compound accompanying the rise in temperature:
• the shrinkage due to the curing reaction.

The methods specified are applicable to all compounds comprising thermosetting matrices reinforced with fibres. The major field of application is compounds based on unsaturated polyester resins.

Method I describes a test method to determine the reactivity of a thermosetting compound by a simple procedure. This method examines only the reactive behaviour of the matrix and its state of stabilization (one factor affecting the shelf life of the moulding compound).

Method II describes a test method which needs more sophisticated equipment, takes more time but provides additional detailed information about the physical behaviour of the compound under simulated practical moulding conditions. It produces a plate which can be used for further testing to determine properties of the moulded article.