large ironing board cover_ironing board cover material

This is one of the frequent reasons for oil seal failure, and this is majorly because of the volatility of any of the elastomer’s constituents. These causative constituents may be part of the elastomer formulation, or gases that got entrapped in the elastomer during the molding process. The deceiving fact about this failure is that sometimes the oil seal won’t show any visual sign of out-gassing, however, sometimes when the out-gassing is extreme, they shrink.

There is a British Standard laid down for the control of synthetic rubbers. BS 3574 (1989) helps to determine shelf life – for instance, Nitrile (NBR) and Polyacrylic (ACM) are Group ‘B’ rubbers and have a 7-year life, whilst Silicone (VMQ) and Fluoroelastomers (Viton®) are Group ‘C’ rubbers and have a 10-year shelf life. PTFE and Leather do not come into this category but like the others should be kept in the original packing for as long as possible away from direct light, dust, and humidity. Ozone, which can also be produced by battery-driven forklift trucks has a very bad effect on synthetic rubbers. Finally, protect the sealing lip – DO NOT hang the seals on nails, wire etc.

Minor lip The minor lip prevents the entry of dust and contaminants from outside.
Lubricant can be retained in the space between the main lip and the minor lip.