Binders harden ceramic powders as they dry. They enable the use of less plastic material mixes that can still stand up to handling during manufacture.
A glaze or body additive designed to strengthen it during the dry stage or to make it more durable to withstand handling during processing. Binders enable using cleaner but less plastic materials. The mechanism of a binder can be as simple as a glue that hardens and bonds particles together. Other binders, especially inorganics, have more complex mechanisms. Body binders make it possible to form powders that would not otherwise be plastic enough to hold a shape. Likewise, glaze binders make it possible to use slurries with very low clay contents yet still have a hard enough surface to withstand handling.
Binders come at a cost, they slow down drying and often pose issues related to their decompositions during firing (e.g. micro-bubbles in glazes). In some industries, like tile, they are either not used or only selected ones are practical (e.g. sodium silicate).
Orton cones are a good example of the use of a binder. Cones are made from ceramic materials, yet resist re-wetting when immersed in water. Once they do slake the slurry is very sticky and very slow to dewater on a plaster bat. Another common example are prepared commercial hobby and pottery glazes. The binder in them dramatically slows drying so they go on like a paint. It also enables them to adhere to even already-fired glazes or non-porous surfaces. And they dried surface is hard and difficult to remove, even with water.
|Articles||Binders for Ceramic Bodies
An overview of the major types of organic and inorganic binders used in various different ceramic industries.
The green strength of clay bodies is an important property, it makes them resistant to breakage or damage during handling in production.