Rubber seals : Effect of friction and Hardness

From previous article we analyzed the performance of the rubber seals by finite element method. We founded performance of rubber seals depending on the viscoelastic properties of rubber materials . In this article we study the effect of rubber friction and hardness to the performance of rubber seals by finite element method because the assembly load is dependent upon the friction coefficient and hardness. The result are shown in table 1 was based upon a dry assembly condition. If the coefficient of friction is alter the assembly load varies , see table 2

Table 1 Sealing stress at room temperature of rubber seals

	50 IRHC	60IRHC	70IRHC	80IRHC	90IRHC
maximum contact pressure	-1.18	-1.63	-4.24	-4.90	-6.60

The possible change in friction coefficient , i.e. from 0.10 to 0.15 , produce an increase in the assembly load grater than that produce by a 10 degree increase in the hardness of the rubber materials.

Table 2 Assembly load (N) of rubber seals.

Friction Coefficient	50 IRHC	60IRHC	70IRHC	80IRHC	90IRHC
0.010	5.46	6.45
0.050	5.84	6.81
0.100	6.30	8.57	20.26	30.07	45.87
0.125	8.08	9.59
0.150	9.16	10.96