Methylcellulose
Notes
Cellulose ethers have been around for many years and are used in countless products. They can function as highly efficient thickeners, film formers, binders, water retention agents, suspension aids, hardeners, lubricants, protective colloids and emulsifiers.
In glazes, they are used to provide many of the above qualities. They burn away so do not have an impact on the chemistry of glazes, only the physical working properties. They are soluble in cold water, but since the particles are so fine, they must be well dispersed in hot water or in a powder mix first. Different types vary in the temperature at which they become water soluble and problems with dispersion usually relate to incomplete wet-out of the individual particles when outer gelatinous membranes on agglomerations of particles shield the remainder from hydration. It is almost a must to have a good variable speed mixer to produce a good solution of these materials. In addition, the materials have a shelf life (e.g. three or four years).
Methylcellulose is also used in alumina and cordierite refractories to give them extrudability and dry strength (amazing since these powders have zero plasticity).
Related Information
Links
| Oxide | Analysis | Formula | Tolerance |
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| 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. |
| Typecodes |
Generic Material
Generic materials are those with no brand name. Normally they are theoretical, the chemistry portrays what a specimen would be if it had no contamination. Generic materials are helpful in educational situations where students need to study material theory (later they graduate to dealing with real world materials). They are also helpful where the chemistry of an actual material is not known. Often the accuracy of calculations is sufficient using generic materials. |
| Typecodes |
Additives for Ceramic Glazes
Materials that are added to glazes to impart physical working properties and usually burn away during firing. In industry all glazes, inks and engobes have additives, they are considered essential to control of cohesion, adhesion, suspension, dry hardness, surface leveling, rheology, speed-of-drying, etc. Among potters, it is common for glazes to have zero additives. |
| Articles |
Binders for Ceramic Bodies
An overview of the major types of organic and inorganic binders used in various different ceramic industries. |
| URLs |
http://en.wikipedia.org/wiki/Methylcellulose
Methylcellulose at Wikipedia |
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Methocel
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Mecellose
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Polyvinyl Alcohol
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CMC Gum
CMC gum is indispensable for many types of ceramic glazes. It is a glue and is mainly used to slow drying and improve adhesion and dry hardness. |