The glass shells of bulbs (that we use at home) are all made by the ‘forming machines’. These are fully automatic. Generally powered by compressed air, the mechanisms are timed to coordinate the movement of all the parts of the machine. Silica is fed into the furnace once at the beginning and that keeps forming the molten glass that is the necessary ingredient for making any product. Temperatures controller monitors the temperature of each component of the machine. Once ready, the shell falls off gradually on to various conveyor belts of controlled temperature. The rejects of the entire process are put back into the furnace for recycling. One more quality check is done manually and the product is ready to be packaged and shipped.