Functional film sizing and coating color application

OptiSizer Film

OptiSizer Film and its functional and innovative design provides excellent runnability. The design of OptiSizer Film has evolved for simple and reliable solutions resulting in easy operation and installation and fast initial start-up, which also makes it the perfect choice for rebuild projects. Multiple production and speed world records set on a number of production lines serve as the best evidence of OptiSizer Film’s capabilities.

High quality sizing

Steep start-up curve

Easy maintenance and operation

High process know-how and many references

A thin film of size or coating color is applied to the surface of an applicator roll. Simultaneous application on both sides of the sheet also saves space, which provides a competitive advantage in the case of high-capacity investments. The film is transferred to both sides of the paper sheet in a nip formed between two transfer rolls.

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High quality sizing and raw material savings

Valmet's advanced film application method uses a unique, patented perforated sealing blade to minimize feed and return flow and for low circulating volumes. It eliminates harmful flow disturbances and air entrainment even at high speeds, and the flexible sealing blade tolerates well wrap breaks and is easy to change. This leads directly to high quality sizing.

Film sizing offers raw material savings potential due to increased z-strength and stiffness. It applies a starch layer that also binds the surface and fills pores, improving the holdout of coating color. The film application method means that the starch applied contains less water compared to pond sizing, helping to minimize the swelling of fiber flocks in the middle ply.

Film sizing also flattens the surface topography before coating. This, combined with better coating holdout, enables reduced of coat weight and lessens the need for calendering.

High-quality components are keys to excellent CD profiles. The composite structure of the application beam means that:

Coefficient of heat expansion is low
There is no need for water circulation
There is no need for maintenance
And, the temperature variations of the color or size have no effect on beam straightness

Wide application area.png

Wide application area

Steep start-up curve

Steep start-up curve is a must for each project from a smaller improvement toa complete line installation. Full workshop pretesting is one of the key elements to make sure that everything is in order when the start-up takes place. Valmets sizers are fully equipped and easy to operate. You will have a professional Valmet team to support you all the way.

Easy maintenance and operation

Valmet's sizers are easy to operate. The nip loads are precise and sizer application beam is easy to adjust. The controls are very versatile to fulfill all the requirements set for sizing.

Process know-how & references

As for all Valmet's projects, you will have an experienced project personnel from Valmet to support your investment project. You will also get sizing process optimization support from Valmet.

Valmet's deep knowledge about projects and paper machine processes come from the numerous deliveries and references.

Read our latest customer success stories about Valmet OptiSizer Film deliveries

Practical collaboration and efficient production for high quality

Apr 22, 2025

Shandong Bohui Paper’s huge new flagship papermaking line PM 8 produces premium-quality product with new levels of efficiency. Valmet delivered the entire papermaking line, including all automation and flow control solutions.

Successful market expansion through grade conversion rebuild – Cascades Containerboard Packaging – Bear Island

Dec 10, 2024

Article: Cascades selected Valmet as their partner for a strategic market expansion project in southeastern U.S. An old newsprint machine was acquired and converted to produce lightweight, high-quality, 100% recycled linerboard and corrugating medium for the North American market.

Liansheng Pulp and Paper: big success with PM 1 carton board and PM 3 high-grade fine paper lines

Feb 27, 2024

Living up to expectations, Liansheng’s PM 1 carton board and PM 3 high-grade fine paper production lines have been recognized as a success not only by Liansheng, but also by their customers.

Elevating containerboard manufacturing in India

Dec 13, 2023

Sri Andal is aiming at producing high-quality containerboard with tangible efficiency improvements and Valmet offers a suitable solution for achieving these targets.

Mondi Ružomberok PM 19 – A complete delivery from OCC to board

Jun 7, 2023

Want to know the secret behind Mondi Ružomberok PM19's successful paper production? Check out this fascinating reference story that takes you behind the scenes of their new containerboard machine.

A 15-year collaboration has made Valmet an all-round developer for Liansheng Paper

Aug 12, 2021

During the past 15 years, Liansheng Paper has been deepening its cooperation with Valmet through several equipment deliveries to its sites in Changtai, Longhai and Zhangpu.

Valmet continues to invest in its pilot facilities

Feb 11, 2020

Valmet’s Paper Technology Center in Järvenpää, Finland, provides the best available paper finishing piloting trials. To be even better and to correspond more accurately to the mill environment, the sizing section at the pilot facility has been updated with new spray beams, rolls, hard roll covers and web heating system.

The intelligent giant - Bohui Zibo BM6

Dec 12, 2019

A giant was born when Bohui started their new BM 6 – the widest and largest of its kind in Asia. From the initial start-up to the conversion to printing paper production, machine optimization has been supported from Valmet’s Performance Center.

Interested in pilot trials?

Get in touch with our pilot trial experts to discuss how you could benefit from our pilot trial services.

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Planning a grade conversion?

The world is changing fast; the consumption of papers is decreasing and boards increasing. Update your paper machine with Valmet to produce more profitable products.

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How do you plan a successful rebuild?

Rebuilding a paper or board machine can improve the competitiveness of your business and your processes. Download our e-book to learn more.

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Learn more about the services and automation solutions for sizing

Sizer roll covers

The film sizing and film coating process have a direct impact on paper and board quality, both on paper strength as well as on paper appearance. Moreover, as on-line processes they are critical for the paper machine line efficiency. This puts high demands on the sizer roll covers.

Roll maintenance

Valmet’s modular maintenance service solutions consists of roll maintenance, roll reconditioning, and roll upgrade services. These solutions help board and papermakers achieve maximum performance with transparent and consistently high-quality maintenance services.

Tail threading

A reliable tail threading process decreases tail threading times, minimizes waste and improves safety. This means an investment in your process is an investment that pays for itself. Whether you need improvements in paper or board machines, we have an advanced tail threading solution that clearly enhances your production efficiency. Our comprehensive range of tail threading services, from preventive maintenance to tail threading study secures optimal operation of your equipment and reduces threa...

Doctor blades for board and paper making

Valmet offers a comprehensive range of doctor blades for all types of process needs in board and paper making. The continuous testing of blade materials and development of blades ensures the reliability and high quality of our doctor blades.

Sizer consumables

Sizer consumables play an important role in film sizing and coating. When you choose products that are optimized for your machine and process, you chieve outstanding paper quality, maximized production capacity and a stable process. Our consumables have excellent wear resistance – meaning less downtime and fewer consumables used, and, thus more production and lower costs. 