Fourcault process the pit must be "heated back" and then the process can continue anew. Glass chemistry has a huge impact on the process since it controls the melting, forming and annealing temperatures, liquidus temperature (point where various chemicals that make up the glass start to crystallize out of the glass) and rates of change of characteristics of the glass itself. Occasionally the ribbon will break or crack, leading to failure of the drawing process. Such breaks, known as "checks" can be alleviated by using proper operating parameters. Sometimes an expedient measure, using a portable source of heat, can be used to
Fourcault process By changing the chemistry it is possible to affect the surface characteristics of the glass, improving its quality and durability. Glass rollers hold the ribbon throughout various parts of the process, supporting its weight and continuing the drawing process. The process continues as the ribbon is drawn upwards into a chimney like structure, where it is quenched or rapidly cooled. When the ribbon reaches the end of the process it is scored, or cut, and then removed for further processing in discrete sheets of flat glass. The "bulb edges" are recycled as cullet (flawed glass which is remelted) or were