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OptiCalender Metal Belt

Superior quality & lightweight products

The unique OptiCalender Metal Belt features a long-nip calendering technique that provides boardmakers with a major quality and efficiency boost. The possibilities to increase profit with very high surface quality and decrease raw material cost with the increased bulk are evident.

Extremely long dwell time and the most effective plasticization

The secret behind OptiCalender Metal Belt calender lies in two factors; an extremely long dwell time and the most effective plasticization. OptiCalender Metal belt’s dwell time is 4-15 times longer than with a shoe nip calender and 100 times longer than with a conventional soft nip calender. Effectively plasticized surfaces provide low surface roughness values, good printing quality and a low post-roughening tendency after calendering.

With OptiCalender Metal Belt, the traditional calendering nip has been replaced with a one-meter-long machine-direction calendering zone. The OptiCalender Metal Belt has a smooth, heated metal belt and a thermo roll that calenders both web sides simultaneously in one extended zone.

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Higher bulk => less raw material, increased profit

Metal belt calendering is the ultimate method for bulk saving. It allows significantly higher heat transfer and plasticization, resulting in extremely high bulk and stiffness. Thanks to its one-meter-long processing zone, superb printing quality is achieved while maintaining high strength properties. This enables raw material optimization with savings potential – as much as 10% higher potential than with a Yankee cylinder. Consequently, this generates substantial raw material savings and increases yield.

The numbers behind fast payback are hard to believe. The saving potential with production increase, raw material savings and bulk saving can be counted in millions. An article about Zhuhai S.E.Z. Hongta "How about saving millions?" clarifies these figures almost too hard to believe.

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High end-product quality

In terms of surface properties, the formation scale smoothness is improved, resulting in extremely flat and smooth surfaces and enhanced visual appearance on both sides of the board. For converters, this means excellent printability and consistent ink setting, as well as a decreased tendency towards print mottling.

By using OptiCalender Metal Belt, the board surface quality is outstanding:

  • Excellent macro scale smoothness
  • Even topography after coating
  • Better optical properties
  • Excellent macroscale topography with same or better stiffness.

What more can you hope for? We invite you to carry out your calendering trials at Paper Technology Center. All calendering technologies can be tried out with your own paper or board.

Production increase

Thanks to its simple and compact design, the OptiCalender Metal Belt is especially suitable for rebuilds. The calender provides 40 - 60 % more production by removing existing bottlenecks, such as the Yankee cylinder and wet stacks.

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Easy to operate and maintain

OptiCalender Metal Belt is easy to use. Linear load is the only control parameter that needs adjusting in the calendering process. Two-sidedness can be controlled with temperature. Also the operating window is large. The example in the figure below shows the comparison of coated board calendering (the quality level and bulkiness).

The calender maintenance is also easy because of the opening front. Additionally, the metal belt life time can reach even two years (see article about metal belt lifetime record).

Former ValZone metal belt calender has been included in the OptiCalender family as OptiCalender Metal Belt.

Watch a video about OptiCalender Metal Belt

Watch a video about calendering pilot facilities

Customer success stories and articles

Watch a video about Sappi Maastricht: new 3-layer headbox and metal belt calender for extremely good board quality

Planning a grade conversion?

The world is changing fast; the consumption of newsprint and printing paper is decreasing and the consumption of containerboards or cartonboards are increasing. An old paper machine can be updated with a grade conversion rebuild to produce more profitable products. Turn a new page for your paper machine with the help from Valmet.

How to plan a successful rebuild?

Rebuilding a paper or board machine can improve the competitiveness of your business and your processes. But where do you start? Download our e-book to learn how to develop a winning rebuild concept, how to minimize rebuild related risks, and how to ensure smooth ramp up to full production.

Interested in pilot trials?

We offer the opportunity to experiment and develop paper and board products and processes without having to put your own production on hold. This is very cost-efficient compared to expensive tests in your own production. Follow the activities in the trials on site or remotely through live streaming cameras.

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