Metso Insights Blog Mining and metals blog Maintenance of rubber and Poly-Met mill linings
Mar 23, 2017

Service Tip - Maintenance and storage of rubber and Poly-Met mill linings

Services Marketing
Services Marketing
Under normal circumstances, once installed, a Skega® mill lining should require no maintenance other than periodic inspection and wear readings over its wear life, up to the time of replacement.
Two service engineers checling the mill liners.

Our rubber mill linings are individually designed, based on the operating conditions of each specific application. In some cases, however, it may be economically practical to extend the wear life of a lining by repositioning strategic lifter bars and plates to achieve uniform wear over the entire life-cycle.

To avoid unexpected production disturbances, we recommend that the lining be inspected (and wear measurements be taken) at regular intervals in order to estimate the time when the liners may need to be repositioned or replaced.

Inspection schedule

We recommend that the condition of a rubber mill lining be inspected at approximately the intervals mentioned in the inspection schedule below (preferably in connection with planned stops).

We suggest that an inspection schedule be established immediately upon installation of a rubber mill lining.

Image of mill liner.

Inspection schedule:

  • 1st at 25% of estimated wear life*
  • 2nd at 50% of estimated wear life
  • 3rd at 75% of estimated wear life

*often only needed with the first installation

To maximize lining economy, it is essential that routine inspections and measurements are carried out to determine the optimum replacement intervals for the lifter bars, as this is calculated by balancing the wear rate of the lifters against that of the plates.

Metso can supply tools that have been purposely designed to take wear measurements in a convenient, efficient manner. Data derived from these measurements is entered into a computer algorithm, which generates an estimate of the remaining wear life.

Storage and safety

If rubber or Poly-Met mill linings are stored for periods longer than 2 months, they should be stored indoors, or at least under a protective cover. In the case of outdoor storage, the parts must be protected against excessive heat and direct sunlight.

Rubber lining parts.

The components should also be stored in such a way that deformation is avoided. Do not store rubber lining parts close to large electrical motors, which generate ozone in large quantities.

Welding, gas cutting, grinding and any other work generating sparks or heat in the mill lining’s vicinity must be avoided. In the event that these types of work have to be carried out, the customer must accept full responsibility.


We are proud of our 60+ years of experience in optimizing grinding mill liners and implementing best practices. Metso Outotec offers the market’s widest range of products to choose from.