A local valve making plant has a rubber crushing machine, similar in concept to an old fashioned mangle. The
rubber masticating mill is used to process raw rubber into sheet. The rubber sheet is then moulded into various
shapes to line valves.
The rollers of the machine rotate at about 30 rpm and their phosphor bronze bearings needed to be lubricated
daily. The traditionally used phosphor bronze bushes for this machine were imported from the United States at a
This is a heavy duty application with a 40 kg (88lbs) batch of rubber being put through the machine at a time.
The forces generated in the rubber mill are sufficient to cause the surrounding work area to vibrate. The machine
operates 9 hours a day, five days a week and is water cooled.
The phosphor bronze bushes were replaced with Vesconite XL (extra large) bushes. The Vesconite XL range, being
locally produced and on the shelf in one of the world's widest size ranges, are considerably cheaper than
imported bronze bushes. They only need to be greased twice a week.
The advantages of changing to Vesconite include:
- Lower cost
- Less maintenance
- Immediate availability