MOR Test for Ceramic Products: Methods & Analysis

MOR Test for Ceramic Products: Methods & Analysis

Overview

Similar to the shrinkage test, the MOR (Modulus of Rupture) test is performed for both clays and slip. MOR is crucial in sanitary ware production because high dry MOR indicates strong products from casting to kiln loading, while high fired MOR ensures strong products in the market. Many countries require a minimum of 400 Kg/cc for sanitaryware products.

Test Procedure

To perform the MOR test, a bar is cast using the slip and mould. After demould, the bar is allowed to dry in the atmosphere for 6 hours, then dried in a dryer for 20 hours (or using the production ware dryer). At least 5 samples are used to check dry MOR, and additional samples are fired in the production kiln. The dried and fired bars are tested for their load-breaking point using an MOR machine.

The MOR is then calculated using the formula. The same formula applies for both green and fired MOR, though it varies based on the shape of the bar tested. An average of more than 5 pieces is taken as the final value.

MOR Calculation Formula

For a round-shaped bar, the following formula is used to find MOR:

MOR = (8 X P X L)/(π x D³)

Where:

• P = load applied (kg)

• L = span length (cm)

• D = diameter of the bar (cm)

Importance

This test is essential for ensuring that the sanitaryware has sufficient strength to withstand handling and usage from the production and the end consumer.