Glass workability during the forming process was discussed from the aspects of rheology, heat transfer & microstructure. Rheological behaviour & heat transfer characteristic of glass determine workability, but accidentally caused changes of structure during melting etc, can affect workability. Apparent liquidus temperature & crystal structure of bad workability glass were studied & compared with good workability glass. It is found that the apparent liquidus temperature study is an effective method for determining good & bad workability glasses. Results from the mechanical strengths study of good workability glass shows evidence of microvoids of the order of 400Å existing in the glass structure, but there is no such evidence in the bad workability glass; it is believed that a large flaw size, or stress concentration around the inclusions existed in the bad workability glass.
