Selection of Clay Body Formula

The selection or creation of formulas (mix) clay body is the first step clay testing needs to be done. For testing materials should be provided some kind of clay taken from several locations, the advantage is some kind of mix (soil formula) clay can be made. From the test results will be obtained some of the best formulas to be used as the main ingredient production.

It is important to note that not all clay has physical and chemical properties of perfect. Clay material mixing system for testing can be done with the mixing system of lines (line blend) with two kinds of natural clay and mixing triangular system (triaxial blend) which uses three different kinds of clay source.

Line Mixing System
For example, clay has a good plasticity so easy to set up, but the dry shrinkage and shrinkage burn too big so much to cause problems, otherwise B plasticity clay is very low but dry shrinkage and shrinkage of small fuel so it is not easily formed.

So, to get a clay material that meets the requirements of both types of clay are combined through a mixing system line (line blend) to make some formula and after going through some sort of testing will be obtained mixture of several formulas that are eligible for the manufacture of ceramic objects.

Mixing System Triangle
Mixing with the triangular system (triaxial blend) as the table below using three types of clay A, B, and C.

A clay

 

Figure 7.2. Mixing clay triangle system.

From the table above, there are fifteen mix, but of the formula (mixture) that there are only three formula that uses all three clay materials.
Three of the mixture is

If the mixture is continued there will be a lot of formulas that can be obtained for material testing. By using both methods students can make mix formula in addition to the secondary clay with secondary clay, a mixture can also be made between secondary clay with clay secondary to primary clay or other minerals, such as clay = A, B = feldspar and C = quartz.

In addition to the two sisitem mixing, clay formula can also be developed with a mixed system bleak table below which uses five kinds of different materials.

Clay testing process can be done with some kind of clay such as:
a. Secondary clays are clay single (single clay), which is an Earthenware or stoneware clay.
b. A mixture of two or more secondary clay which Earthenware or stoneware clay.
c. Secondary clay mixture with clay minerals processed from the primary
d. Mix some of the primary clay minerals treated