This Part describes a method for determining the stability of a hot melt adhesive during processing at elevated temperatures. The method does not apply to adhesives in the final bonded state. It is particularly applicable to hot melt adhesives used in processes or equipment where a reservoir of adhesive is kept molten at or near the application temperature.
The test can be used in two ways:
(a) to examine test portions at intervals to determine the trend in the properties under investigation;
(b) to establish whether or not the adhesive meets the specified or agreed requirements, for example that its viscosity stays below a given value when the adhesive is held for a given period at a given temperature.
The method of test is suitable for temperatures up to 300 ℃ and a maximum ageing period of three days.