Papermart
HEADLINE Industry Watch

Roll Modernization – A Path towards the Better Runnability of Paper Machine

Mr. Rajiv Kumar Agarwal, CEO, Amar Elastomers Pvt. Ltd.

Roll modernization can improve roll performance to the next higher level by reducing maintenance expenditures and failures of rolls. It has to be understood that regular service and inspection of press rolls and suction rolls always reduce the unexpected roll failures thus providing the paper machine with the least mechanical downtime. The various parameters to be thoroughly checked during the roll change include:

  • Inspection of rubber surface and the required geometry of roll surface and improving the same by proper grinding of the roll.
  • Inspection of journal bearing size tolerances to attain better bearing fitment and thus improving better dynamic stability of the roll.
  • Regular crack inspections of roll journals and shell minimize risks of unexpected failures.

A suction press, pickup, or couch roll is one of the most critical high-value rolls and the failures of such rolls should be checked periodically for optimum runnability of the paper machine. Amar Elastomers has designed a much superior Suction Roll Shell alloy for higher nip loaded rolls and faster speed machine rolls called AMAR NICHRO-SUC ANS-40, which satisfies our PREN≥40 theory (≈Cr% + 3.3Mo% + 16N%).

The most neglected elements like nitrogen and copper had added the strength in our shell steel composition in the ultimate binding of the molecular granular structure and had resulted in the higher tensile strength of the produce. The fine selection of hardness and Young’s modulus keeps the deflection of the material within the required limits.

Interestingly, AMAR NICHRO-SUC shell is drilled by a gun drilling process on high-speed CNC programmed multi-spindle drilling SPM. That’s not to say the sophisticated SPM delivers a wide range of drilling patterns, satisfying the paper machine and mills requirements as far as the nip loads and drainage are concerned.

Amar Elastomers also provides comprehensive services through its network of technicians by closely following the customers and rendering them the latest know-how and technology on suction roll advancements. Regular inspections and scheduled maintenance of manufactured and delivered complete suction rolls with internal vacuum units happen to be a key feature of the company’s intensive drive for suction rolls. Talking of scheduled maintenance would mean emphasizing more on periodic inspections, grinding, and sealing strip changing of the rolls to improve the performance of the rolls.

A suction roll modernization and improvisation can improve roll performance to new heights and the parameters to be designed are:

  • Selection of corrected suitable bearings
  • Designing the required airflow efficiency
  • Selection of sealing strips and holders
  • Designing the showering system inside for lubrication and flushing
  • Designing the open area as per the application requirement

At Amar Elastomers, we are dedicated and committed to the total engineering development in the rubber roll industry for paper-making machines. We have made it our mission to create technically viable solutions in the rubber-covered rolls sector and sustainable paper industry. This gives us a key role in the transformation of the rubber roll industry and working on different parameters such as selection of metallurgy of the shell to be used, the end plugs to be used along the machining accuracies and tolerances to be maintained.

Amar Elastomers has a state-of-the-art steel melting shop with a vacuum oxygen de-carbonizer to refine the melt to attain the highest level of undesired alloying elements. This gives us a flawless material and a better quality of the centrifugally casted shell, free from all surface and internal defects with good machining property. To be more precise, Amar Elastomers has been a one-stop destination for engineered rubber roll coverings and complete roll shells. We had, from the very beginning, continuously fought with all the odds of the industry for better sustainability of new and advanced roll coverings.

Amar Elastomers is an integrated rubber covered roll manufacturing unit, engaged from shell manufacturing in its steel melting shop followed by shell machining and assembly in huge mechanical machine shops. This is followed by rubber coverings, grinding, and drilling on CNC multi-spindle drilling machines.