Efficiency, innovation and sustainability in tissue paper production: technologies compared

Pulp refining is a key stage in paper production. Low-consistency (LC) refining is currently the standard technology in stock preparation. In recent years, however, several Asian paper mills have successfully introduced high-consistency (HC) refining for hardwood pulps—typically eucalyptus—with the goal of reducing imported long fiber usage and lowering costs. This technology, inspired by sack paper production processes, modifies the internal fiber structure while minimizing fiber cutting and fines generation, thus enhancing tissue porosity and softness. Results include: improved hand feel compared to LC refining; good strength properties even with higher eucalyptus content; over 10% savings on furnish costs. The process involves a screw press for dewatering short fiber pulp before HC refining. The compact layout developed by ANDRITZ allows for efficient and flexible refining. The success of the Asian model is now drawing interest from tissue producers in other regions as well.

The implementation of ceramic drilled covers – from existing laths’ design in Uhle box applications, but more in general in suction boxes – enables efficient suction performances (as felt conditioning or wire dewatering activity) while operating at same vacuum levels. These covers, available in a wide range of customized configurations and materials, contribute to substantial energy savings and extend wire/felt lifetime. Enhanced felt/wire support and optimized hole geometries allow for better dwell times, thus entailing more uniform and gentle dewatering, reducing the “stress” of the clothings. Compared to other coated drilled covers, ceramic variants offer greater durability and can be reprofiled multiple times with minimal cost, further extending their service life. Additionally, the technology supports the use of seamed felts and helps maintain felt openness, thereby reducing the need for chemical cleaning. An interesting case study was carried out at one of the most important global customers that produces packaging paper. The installation was carried out on the conditioning pickup felt, where the previous ceramic covering (with slats) was replaced with drilled ones, immediately observing an increase of several percentage points in the felt’s lifespan, an important result confirmed even two years after the installation.

In the papermaking industry, operational variables such as machine speed, basis weight, and felt condition are constantly changing, making a fixed vacuum setting ineffective. Paper machines are often equipped with oversized vacuum systems, with up to 60% of capacity remaining unused. To address the challenges of operational costs and staff availability, Runtech has developed the new RunEco EP650 AMB, equipped with active magnetic bearings, already successfully tested on the EP1000 model. This technology enables frictionless and oil-free operation, reducing maintenance needs and eliminating the risk of oil leakage. Compliant with BAT (Best Available Techniques) as required by the EU Industrial Emissions Directive, the RunEco Vacuum System includes features such as automatic speed control, seal water-free operation, and heat recovery from exhaust air. Installation data show an average energy saving of 45%, with more than 1,100 Turbo Blowers sold worldwide—over 100 of them for tissue machines. This translates into an annual saving of 2.6 TWh and a reduction of 781,000 tons of CO₂ emissions. The presentation highlights, through real-world examples, how a variable capacity vacuum system allows more efficient and flexible operation of the paper machine.

The new Valmet Advantage™ AirCap™ Pro moisture profiling system offers a groundbreaking solution by locally adjusting the temperature of the air supplied by the hood to the paper, intensifying temperature and drying in areas where the paper is wetter than average. Conversely, the system reduces both temperature and drying intensity where the paper is drier than average, resulting in a more uniform moisture profile at the reel. Patented and internationally recognized by Valmet, the Advantage AirCap Pro offers numerous benefits: advanced paper profiling with superior performance (doubling the efficiency of conventional hoods by adjusting both air temperature and speed). The AirCap Pro can achieve higher drying temperatures where needed, surpassing the capabilities of conventional hoods); seamless integration (easily integrates into existing tissue machines, delivering remarkable peak-to-peak performance); energy efficiency (it minimizes electrical energy loss through the profiling dampers and reduces burner gas consumption by lowering the average air temperature used for drying).

In the tissue industry, it is now essential to adopt solutions that not only ensure operational efficiency but are also sustainable and deliver measurable results. In our presentation, we will introduce an innovation in fabric cleaning technology, highlighting the tangible benefits of the M-clean™ system. This solution is based on a combined system of high-pressure water jet extraction and dynamic vacuum, capable of delivering deep and efficient cleaning while significantly reducing resource consumption. Through real-life case studies, we will show how the implementation of the M-clean™ system has reduced water consumption from 9 m³/h to just 0.3 m³/h, resulting in an annual saving of over 74,000 m³ of fresh water. In addition to effectively removing contaminants, the system contributes to improved sheet quality, fewer pinholes in the web, and a reduction of up to 95% in freshwater use. These advantages are further complemented by significant energy savings, quantifiable at over 1,582 kWh per day compared to needle jet or conventional shower systems. Thanks to intelligent monitoring features and a proven ROI, M-clean™ represents a concrete and sustainable evolution capable of creating value in terms of productivity, cost savings, and environmental impact.

Recycling is a key element of Voith Paper’s sustainability strategy, aimed at conserving resources and reducing the carbon footprint. Voith’s goal is to create a closed-loop material cycle for press felts, keeping high-quality materials within the loop and significantly contributing to environmental protection. As an integrated supplier, Voith is committed to incorporating the cradle-to-cradle principle. By applying the Design for Recycling concept, recyclable materials are used throughout the entire product development and manufacturing process. To address the high carbon footprint of virgin nylon derived from crude oil, Voith has begun using chemically recycled polyamide materials obtained from used press felts collected through Voith’s proprietary recycling program and from internal production waste. This marks a major step forward in reducing environmental impact.