THE ADDITION OF AEROBIC WATER TREATMENT SUPPORTS PAPER PRODUCTION QUALITY AND RESOURCE EFFICIENCY

At Räpina paper factory, we have taken the next step in developing our production process by adding an aerobic treatment stage to our existing anaerobic water treatment system. This is an important addition that helps improve process water quality and supports stable board production.

Our production is primarily based on collected wastepaper, meaning that the composition of the raw material can vary over time. This directly affects the composition of the water circulating in the production process. We use a closed loop water system, where process water is reused continuously and supplemented with fresh water when needed. For this reason, maintaining process water quality is a key factor in ensuring overall production stability.

The previously used anaerobic treatment allows for efficient breakdown of organic matter and the production of biogas. The addition of an aerobic stage takes the treatment process further by improving water quality before it is returned to the process.

More precise control of process water in paper production

Aerobic treatment helps reduce residual compounds in the water that are not fully removed by the anaerobic process alone. This results in cleaner process water, which has a direct impact on production.

Improved water quality supports a more stable production process and contributes to more consistent board quality. Although water treatment is not directly visible in the final product, it significantly affects how fibres behave during production and, ultimately, the quality of the end result.

This is particularly important as most of the board produced is used internally for edge protector manufacturing. The quality of process water directly influences board properties and, consequently, the strength, stability and performance of the final product.

A step forward in resource efficiency

More effective water treatment supports the operation of the closed loop water system, allowing water to be reused more consistently within the process. This helps reduce the need for fresh water in paper production and improves overall resource efficiency. As a result, environmental impact is reduced and the long term sustainability of production is improved.

One goal, multiple solutions

The addition of aerobic water treatment is part of a broader development approach focused on improving process understanding and control. Both fibre analysis and water treatment development contribute to the same goal: better control, greater stability and more consistent quality.

Alongside water treatment improvements, we are also advancing the monitoring of the production process, including the introduction of a new paper machine scanner, which we will cover in more detail in our next update.

FIBRE ANALYSIS IN RECYCLED PAPER PRODUCTION: VARIABLE RAW MATERIAL, CONSISTENT QUALITY

In paper production, the final result is largely determined by the properties of the fibres used. At Räpina paper factory, we primarily use collected wastepaper as our raw material, which means that the characteristics of the input material can vary over time. For this reason, continuous monitoring of fibre properties is essential to ensure consistent board quality and a stable production process.

Traditionally, process control has relied on indicators that describe how quickly water is removed from the pulp. These provide a good overview of the current process condition, but they are composite indicators that reflect the combined effect of several fibre properties. They do not allow us to distinguish whether a change is caused by fibre length, width or fine content. For this reason, we focus on fibre geometry, particularly fibre length and width.

Fibre analysis helps control variable raw material

Using recycled paper as a raw material means that input quality is never fully uniform. Fibre composition, origin and previous use directly influence fibre properties and, consequently, the production process.

Real-time fibre analysis makes it possible to detect these variations early and adjust the process accordingly. Instead of reacting only after issues appear in the final product, necessary corrections can be made during the process itself.

Our first encounter with real-time fibre analysis technology took place in autumn 2025, when the ABB demo bus visited Räpina paper factory. This provided an opportunity to see how the analyser works and the value it can bring to process monitoring and control. Based on this experience, we decided to test the analyser in our own production environment in order to make decisions based on real operational data.

An important part of the implementation was configuring the analyser according to our specific process conditions. Before commissioning, pulp samples were taken from our production, and key fibre parameters were determined. These results were then used to calibrate the system and define reference values, ensuring that the measurements accurately reflect our raw material and operating conditions.

Fibre length and width are the key quality indicators

Although the analyser can measure a wide range of parameters, in our daily work we focus on those that provide the most direct input for process control.

For us, the most important parameters are average fibre length and average fibre width. These determine how fibres bond with each other, influence the strength of the board, and affect how the material behaves in the production process. In addition, we monitor average fibre shape, which provides further insight into fibre deformation and refining level.

This approach allows us to identify the root causes of changes before they affect final product quality. A general process indicator may show that something has changed, but fibre geometry reveals what exactly has changed.

Fibre analysis ensures consistent and reliable end products

Fibre analysis is not only important for process control; it also has a direct impact on the customer. For us, fibre analysis is not just a production tool, but a way to ensure consistent and reliable product quality. Since we use recycled paper as raw material, variation in input is inevitable. Fibre analysis allows us to control the impact of this variability and ensure that our products behave consistently and predictably.

This is especially important for our main product, edge protectors, where material strength, stiffness and durability must be reliable throughout the supply chain. As most of our produced board is used internally for edge protector manufacturing, monitoring fibre properties enables us to control the entire value chain from raw material to final product.

A data-driven approach helps us move from reactive to proactive process control and supports the continuous development of our paper production.

The analyser was commissioned at the end of last week and provides an opportunity to detect changes at an earlier stage. We look forward to seeing the added value it will bring to our understanding of the production process and to quality management in the longer term.

NEW TRADE FAIR VISITS

In the coming months, the paper mill will be visiting several trade fairs taking place in Germany. We are open to meetings!

• 4–6 February – Fruit Logistica (Berlin)
  An international trade fair focused on the fruit and vegetable sector and related supply chains. We will be attending as visitors.

• 24–26 March – LogiMAT (Stuttgart)
  A trade fair focused on warehousing and intralogistics solutions. We will be attending as visitors.

• 7–13 May – Interpack (Düsseldorf)
  A trade fair for packaging and processing technologies. We will be present with our own exhibition booth and a larger team.

To arrange a meeting, please contact Sales Manager Maarek Sikamägi:

| +372 515 0793

NEW CATALOGUE

We are proud to present our brand-new product catalogue for edge protectors, unveiled at the Fachpack packaging trade fair in Germany, taking place on September 23–25, 2025.

This catalogue showcases our product portfolio with striking 3D lifelike visuals that provide a far clearer and more realistic impression of our profiles than traditional 2D graphics. The new layout highlights a broader range of applications and offers inspiring packaging solutions beyond the obvious. The new catalogue is a bound booklet, making it easier to browse, handle and keep.

"Best Range of Packaging Profiles" reflects not only the variety we offer but also our commitment to sustainable production: powered by 100% green energy from a combination of solar and hydropower. We are confident that our edge protectors are among the lowest-footprint solutions on the market.

RAPPIN edge protectors are designed to shield goods from damage during storage and transport, helping to prevent unnecessary costs caused by cargo being harmed. Produced at Räpina paper factory, they are made to order in the exact width, length and thickness our customers need.

With our flexibility in cuts, softening, tapes, coatings and printed cover papers, you can create packaging solutions tailored to your products and your brand. Our in-house printing facility enables shorter lead times and faster production. We deliver across Europe and the Americas, always with reliable due date shipments.

Ask for your copy of the new catalogue at Fachpack. We will be there next week from Tuesday to Thursday!

NEW SHEET CUTTER BOOSTS PRODUCTION SPEED & QUALITY

A cutting-edge upgrade made in late 2024 enhanced speed, precision, and efficiency, elevating production to a new level.

In December 2024, a custom-built sheet cutter, designed to meet the paper factory's needs and manufactured in Turkey, was installed in the post-production unit. This upgrade enhances efficiency, boosting both production speed and final product precision. The previous sheet cutter could no longer fully meet production needs.

Enhanced Capabilities and Workflow

The new sheet cutter processes material up to three times faster. Its maximum speed reaches 300 metres per minute, depending on the material's thickness—thinner materials take longer to cut. For example, cutting 1.5 tonnes of 80-gram paper once took an entire workday; now, it takes just two hours.

The machine has introduced several key improvements. The maximum sheet size has increased from 1.1 x 1.2 metres to 1.6 x 2.0 metres. Sheet length adjustments, previously done manually, now require only a button press, saving time. Accuracy has also significantly improved, reducing deviation from ±10 mm to just ±0.25 mm. Additionally, the machine allows for sheets to be trimmed or split in half, enabling the production of either one wide sheet or two narrower ones in a single run.

Technological Advancements

The cutter features built-in edge trimming, eliminating the need for separate guillotining. Cut-off scraps are automatically transported through tubes to a waste container, keeping the workspace cleaner and improving efficiency. The machine also smooths sheets, reducing curling—an essential advantage for industries using robotic handling, where flat sheets improve grip and operational reliability.

Automation and Increased Productivity

An automatic braking system removes the need for manual adjustments. The machine tracks material by both sheet count and weight, simplifying waste management and defective sheet replacement.

The impact on production efficiency is significant. One of the most notable examples is a 12.5-tonne order that previously took 2.5 workdays and produced 25 pallets of cut sheets now takes just 6.5 hours.

The introduction of this sheet cutter marks a major step forward, improving efficiency, speed, and quality—helping the factory stay competitive and adaptable in the industry.

THE HISTORIC PAPER MILL BUILDING WILL BE FULLY RESTORED

The part of the building built of red bricks, on the edge of Pargi Street, where the paper mill started working in 1734, has undergone several reconstructions over the years.

The building to be restored is a nationally protected cultural monument in Estonia and one of the most unique examples of industrial architecture in Europe. Due to the uniqueness of the paper mill, it was necessary to coordinate the planned works with the Heritage Protection Board.

Part of the former paper mill building will be covered with a hand-rolled roof. The walls and window openings of the building were restored according to the old plans. In the 1730s, the local brick factory, which was once located above today's Ironman Park, produced bricks for the construction of the paper mill. In order to restore the old building, a large amount of whole stones were needed, matching the dimensions of the stones produced in the brick factory. For example, the stones used during the repairs also come from the old railway station in Lepassaare, Võrumaa, Estonia.

The hydroelectric plant, which is located in the old part of the paper mill and produces hydropower for the paper factory, was restored in 2023. This summer, a new river border was installed and the site in front of the hydroelectric plant was concreted.

The restoration works of the paper mill will be completed in November at the latest.

NEW MACHINE IN PAPER PRODUCTION UNIT

Räpina paper mill is innovating the next time-consuming production process by adding a starch boiling machine to its fleet.

The new starch cooking machine designed in Finland starts working using technology developed in Tartu, Estonia. 

In order to make starch mass, it is needed to add starch powder, water and hot steam into the machine. The necessary quantities are calculated by the device, dosed accordingly and next, the appropiate mass is boiled. The starch cooking machine is able to boil 1,2-4t of starch mixture per hour, which is directed straight into paper machine's pressure box.

Compared to the starch mixture used today, it is denser and aids to make the cardboard produced stronger and stiffer. The renewed quality of cardboard makes it possible to produce edge protectors, which are even more resistant, including to moisture.

The installation of the starch cooking machine started in the middle of August. In mid-September, the first tests can be run and the old starch boiling process can be replaced with the new one. As a result, the time and resource demanding manual production process used today, is automated.

Through innovation, the starch adding process in the paper production system is modernised.

FAIRS OF AUTUMN 2024

The team of Räpina paper factory participates in three great packaging-related trade fairs in Europe, Scandinavia and America during the autumn period of 2024.

The first fair will take place already on the 24-26th September in Nuremburg, Germany. FACHPACK is Europe's leading packaging fair, which focuses on the development of its technology and processes, shaping the sector's trends for the coming years. We are waiting for our cooperation partners at booth 657 located in hall no 3. 

In October, we can be found at the Swedish fair, Scanpack from 22-25 October, in Gothenburg. Scanpack turns attention to the sustainable future of packaging industry, combining it with new digital technologies and smart solutions of biomaterials, being the most versatile packaging fair in Northern Europe. Our team is located at stand C00:06.

In November, we will participate as visitors in Pack Expo International, held in USA. The fair will be held November 3-6 in Chicago, Illinois. This year's largest trade fair in North America offers innovative packaging and processing solutions for any industry.