Since the invention of clay processing, the sky has been the limit .Countless innovations have been developed by the process of clay firing. Skillfully designed sanitary wares and products have been developed using this process. The process of combining fired clay with glass particles results in the formation of an impervious material which forms the basis of sanitary ware manufacture.
Determining the Best Clay Material for Sanitary Ware Production
The primary consideration which has made ceramic to be the most preferred material for manufacturer of sanitaryware is the ability to resist corrosion and abrasion. This is because the use of sanitary ware involves contact with acidic fluids such as urine and washing detergents. Ceramic products are also easy to clean, cost effective and available in beautiful and classic designs.
They are produced using a variety of raw materials including kaolin clay, ball clay, quartz, feldspar and tale. Clay being the most important raw material, it must be plastic to allow shaping, dries well without developing cracks and must have a wide vitrification range.
Sanitaryware Molding Process
The structure of clay is such that different layers are separated by a thin layer of water molecules which is responsible for the plasticity element of clay. Sheets of clay are able to pass each other easily allowing for the molding process.
The pressure to produce high quality and long lasting sanitary products has led to the shift from the traditional molding process to new techniques. These include the bench or plaster molding, gang casting, capillary casting, and pressure casting.
After the molding process the products are dried. This process removes approximately 5% of the water in the clay layers. At this stage re introduction of moisture reverses the state of the clay and remolding can be done.
Chemical Process of Firing
Firing is done to remove off more water from the molded product. When temperatures of more than 1000 degrees are attained the changes cannot be reversed. Elimination of chemically bound water is achieved. Hydrogen bonds are replaced by the stronger and shorter oxygen bonds in a cross linked structure. The sheet like makeup of the kaolinite is replaced by the Meta kaolinite structure.
Surface Characteristics That Determine the Quality and Handling of Sanitary
The cured clay becomes hard and brittle. It also readily absorbs water but release it on drying without changes to the structure. To make it impervious to water and increase hardness is goes through a process of glazing whereby it is covered with glaze solids using various techniques .It is then fired again at 1200 degrees .At this point partial melting of some components (feldspar to become glass) provides the glue for hardness and more cross linking occurs. This is when complete vitrification occurs.
Surface Maintenance for Longer Life
The use of abrasive material for cleaning of sanitary ware is discouraged as it reduces the lifetime and surface quality. Apart from this hitting sanitary ware products with hard objects may cause breakages and eventual losses.
Safety and Environmental Issues in Sanitary Wares Production
The process of sanitary ware production may pose pollution problems especially the firing process. This however should not be a cause of concern because the process only drives out water. No harmful gases are released.
The invention of the clay processing and used in sanitary ware production have led to development of great and beautiful products for use in homes and institutions.
This process involves heating and modifying kaolin clay which is the raw material, then glazing and vitrification to achieve the finished product.