Calender Rolls

Extended Life for Traditional Calender Rolls

Capital Expansion with Ongoing Payback

Situation:

Abrasives eat away at calender rolls causing roughness, uneven pressure, and wear on the overall surface. Scratches occur from slippage and doctor blade usage. Calipering diminishes and uniformity of thickness deteriorates. And when paper width changes, deckel edge wear results in inferior product and costly waste.

This pair of Calender Rolls regains a “like-new” look after carbide coating and finishing.

Traditional Solution:

The rolls are pulled from operation and sent out for regrinding. Time is lost, productivity is reduced, and the ultimate result is only a temporary solution: each time the rolls are ground, the original depth of the hardened material is reduced, ultimately requiring the purchase of new rolls.

The Hayden Solution:

Whether for new rolls or those that have retained up to 50 percent of their original chilled iron, Hayden has the solution that can maximize roll life by two or three times, or even more!

Using a coating of extra-hard tungsten carbide, a Vickers Hardness of 1100-1200 is obtained, significantly reducing or retarding wear on the roll surface. The rolls are then ground and superfinished, assuring maximum performance and consistent PLI, even for changeable, controlled-contour rolls. When Hayden grinds the rolls, we grind the applied coating only, and not the chilled iron.

Case Study:

A paper manufacturer pulled their rolls and sent them out for regrinding on an average of once a month. Rolls lost their chilled iron rapidly, and maintenance costs and paper scrapping rates were high. Additionally, production was greatly affected because of the length of time it took to change the rolls each month; then came the Hayden Solution.

We initially took in a roll and coated and superfinished it. Upon reinstallation, the results were outstanding: the roll performed with maximum effectiveness for six months!

Pleased with the results, the firm then had us recoat and superfinish their “spare pair.” It has now been more than a year since the spare pair have been up and running … and they’re still going strong!

Preliminary inspection of calender roll after super-finishing maximizes quality control and helps assure the most effective results possible.

The Hayden Benefits:

  • Extended roll running time
  • Fewer shutdowns – reduced downtime
  • Longer production runs – increased productivity
  • Consistent throughput with maximized quality
  • Less scrappage
  • Lower maintenance
  • Labor savings – rolls are not changed as frequently
  • Longer overall life of rolls – no continual grinding of the chilled iron
  • Allows for potential increase in calender speed
  • Reduces energy requirements for calendering – less horsepower is needed because rolls run more efficiently without need for excessive nip pressure
  • Enables expansion through production of additional paper grades or product lines through quality improvements