After Shaping, the articles shaped are dried for a particular time schedule in closed chamber driers using the waste heat from the kilns. After drying, the wares are fired. Firing forms one of the most important steps in the manufacture of ceramics. Sanitary wares are generally fired in a 10-16 hour firing cycle in a continuous kiln to a temperature of 1210-1220C range. Almost 80% of the wares coming from first fire will be of good quality and of the remaining 20%, 5% will be rejects and these cannot be repaired and has to be considered as losses. The remaining 15% of the wares will be defective that can be repaired and re-fired. The defects like clay cracks or glaze defects like dry spots, too thick glaze or too thin glaze can be repaired and re-fired in a time temperature schedule of 10 to 24 hours in re-fire kilns. Of the re-fired wares about 10% will be loss and 5% of the wares can be repaired and re-fired again. The 85% of the wares will be of good quality.
