TM03 Moisture Content

Straight moisture content may be carried out on it’s own although more usually it is assessed as part of the ceramic properties testing.

For the clay additives industry, an indication of the solids content is sometimes required which may be determined by using the moisture content test method.

A quick moisture content result can be measured accurately using a moisture balance under laboratory conditions or on production plants a slightly less accurate “speedy moisture tester”.

Most customers prefer the weighing and drying technique where results can be expressed as either dry basis or wet basis.

Results are calculated using one of the following formulas:

M.C._DB                        =            Wet Mass - Dry Mass             *            100

                                                            Dry Mass

                        M.C._W.B.             =            Wet Mass - Dry Mass    *            100

                                                                                Wet Mass

Critical Moisture Content

For quick efficient drying under production conditions it is useful to know the moisture content at which the clay stops shrinking. Once this moisture content is reached, it is possible to increase the drying temperature and preheat the product ready for firing.

A graph is plotted,  % contraction against moisture content. The point at which the sample stops shrinking is the critical moisture content.