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
Planing (shaping) are more easily sharpened and fabricated. Internal shapes can be made by using a special extension tool. Although the most common material to be planed or shaped is wood, there are planers and shaping machines capable of processing anything from metal pieces to plastic objects. [1] Todd, Robert H and Allen, Dell K. (1994) "Manufacturing Processes Reference Guide". New York, NY: Industrial Press Inc. pg. 124-125. Planing (shaping) Planing is a manufacturing process of material removal in which the workpiece reciprocates against a stationary cutting tool producing a plane or sculpted surface. Planing is analogous to shaping. The main difference