Glass grain tests

Glass durability tests There are two types of durability tests for glassware, viz. grain or powder tests and whole articles tests. 

Whole article tests Grain tests are open to the criticism that they do not necessarily reflect the behaviour of the finished product in service, hence various tests on complete glass articles have been developed. These are normally carried out under accelerated conditions, and on completion various relevant factors are determined, such as loss in weight, alkali or other constituents extracted, the weight of soluble and insoluble materials in the extract and an assessment of surface condition. The advent of the electron microscope as a standard tool has made the latter study much more objective. 

Glass fibres present a particular problem. The water resistance of the base glass can of course the measured by a grain test, but this is unlikely to be representative of the performance of the final product. Generally, purely empirical methods are used to test the glass fibres in situ in a composite... 

Minch s method is designed for determination of the abrasive power of powders and polishing micropowders, grain-size 160-3 (am. The test outfit miniaturized when compared to Bohme s disc, shows an average of three times lower wear of the glass plate for the same abrasive action time and the same grain size (A. Szymanski, 1972). 

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