Reducing leakage and scrap

A recently patented leakage-free feed roll assembly from Davis-Standard helps minimise the leakage and scrap created during elastomeric extrusion processes.

Known as the ELF (Elastomer Leakage Free) system, the invention was patented earlier this year by Davis-Standard engineers John Radovich and Jeffrey Bryan. The ELF provides feedback of overflow material and can be retrofitted to existing extruders to provide cost savings.

According to Radovich, ‘This development was market driven. Customers did not want the cost of lost product or scrap from feed roll leakage. The maintenance associated with feed roll bearing failures and the clean-up of rubber leakage were also issues. Our patented roll housing and roll end seal design address those problems.’

The new feed roll assembly features a shell, feed roll seal plates and feed roll end plates to curtail leakage. The material is redirected back to the feed section by means of a varying bore diameter of the shell and grooves contained in both the feed roll seal plates and the feed roll end plates. All major components are coated with a solid, dry lubricant coating to reduce friction.

The result is a cleaner and more efficient elastomeric extrusion process that helps processors save on material and maintenance costs.

Radovich and Bryan worked collaboratively to make the new assembly effective, yet practical. They consulted component suppliers and ran prototype tests until they were able to consistently prove mechanics and manufacturability.

There are currently three units in the field and a fourth due to ship in the near future. Feedback from customers has been positive.

For more information about the newly patented feed roll assembly, contact Joe Wnuk, Business Area Manager of Davis-Standard’s Elastomer Group, at