Annealing assessment

Our annealing assessment assesses the quality of the annealing process for glass containers, domestic glassware and other glass products, in order to ensure the quality of the end product.

Annealing assessments are carried out o determine the levels of residual stress present within the glass after annealing has been carried out. A general inspection is carried out using polarised light and the residual stress is calculated in accordance with American standard ASTM C148. In addition to the areas specified in ASTM C148, any areas of high residual stress such as at the rim or foot of stemware is also recorded and reported.

Residual stress assessment can also be carried out to ASTM F2179-02, which applies to candle glasses.

• ASTM C148-00 - Standard Test Methods for Polariscopic Examination of Glass Containers
• ASTM F2179-02 - Standard Specification for Annealed Soda-Lime-Silicate Glass Containers That Are Produced for Use as Candle Containers