Additive 'A'

Alternate Names: Additive A, Additive

Notes

The manufacturer claims: "Lignin products have lubricating, binding and anti-scumming properties in ceramics. They provide benefits to stiff mud and soft mud face bricks, engineering bricks, refractories, sewer tiles, roof tiles, ramming and gunning mixes, terracotta ware, whiteware and throwing bodies."

Stated benefits:
Improved clay workability
Reduced need for die lubrication
Increased extrusion rate
Increased life of wearing parts
Increased green strength
Reduced free water
Faster drying rates
Reduced energy consumption
Flexibility to use less plastic clays

The material is not typically available to potters or hobbyists. Ones who have used it have reported remarkable improvements in dry strength, even in percentages less that 0.05%. However it makes clay bodies much more subject to microbial attack (and the odor that comes with it). And where available it is expensive in small quantities.

Related Information

Calcium lignosulfonate used as a glue to hold ball clay bags on a pallet

Some companies (e.g. Old Hickory Clay) use this as an alternative to shrink-wrapping every pallet of bagged materials (for environmental reasons for example). This wood derivative material is very sticky and behaves like a glue. However it redissolves quickly when whetted. Dark hard particles of this glue can be a concern in batching operations where they fall into the mix. However in a pugmill the particles dissolve during movement through the barrel and are not visible in the extruded product.

Links

Oxide	Analysis	Formula

URLs	http://lignin.org Organization of Lignin producers
URLs	https://www.jeffzamek.com/clay-body-additives Details about the use of Additive A lignosulphate by potters - By Jeff Zamek
Articles	Binders for Ceramic Bodies An overview of the major types of organic and inorganic binders used in various different ceramic industries.
Typecodes	Additives for Ceramic Bodies Materials that are added to bodies to impart physical working properties and usually burn away during firing. Binders enable bodies with very low or zero clay content to have plasticity and dry hardness, they can give powders flow properties during pressing and impart rheological properties to clay slurries. Among potters however, it is common for bodies to have zero additives.

By Tony Hansen
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