Quality Control: Testing Procedures

Walker Ceramics pride ourselves on the quality of our products and after sales service. We provide full technical backup and we are happy to assist clients to develop products to their specific requirements. All of our Products are tested in our laboratory prior to release for sale.

Testing Procedures

We use the following procedures to maintain our high standards:

• Test Room: Batches of clay and glaze are routinely tested thoroughly before distribution.
• Dilatometer: The expansion of the body or glaze is automatically graphed whilst the sample is heated at a set rate. The samples are small bars which have been pre-fired to the recommended firing temperature. This test confirms clay/glaze fit.
• Moisture Content Tester: To rapidly determine the percentage of moisture content of a material.
• Gallenkamp Torsion Viscometer: To test the fluidity and thixotropy of slips. This is a very important test to ensure the slips will pour, cast and drain well.
• Gradient Furnace: This is to test bodies and glazes over a temperature range to a maximum of 1325°C in the one firing. It is automatically controlled for rate of temperature rise and soaking time. The kiln fires 10 separate samples at about 30°C temperature difference between each, thereby we have an accurate firing history of water absorption, shrinkage and colour over a 300°C range to the bodies maximum temperature. The test samples are then compared to our standard results.

Other equipment includes an Automatic Drier, Ford Cup and Walker Fluidity Cylinders, Ball Mills, High Speed Rapido Mills, High Speed Shear Agitators, Sieve Testing Screens and three Test Kilns; one for high speed firing, one Electric Kiln for normal firing and a Gas Reduction Kiln. Standards of all clays, glazes, colours and raw materials are kept for reference. An important part of the daily program of Geoffrey and David Walker is time spent in research and development.