Why Repulpability Is Essential for Paper&Board Recycling?

In this blog post we summarize the importance of recyclability in packaging materials and outline the concept of repulpability testing: what it means in practice, why it is important, how it is tested, and the interpretation of the results.

Recyclability of packaging materials, particularly paper and board, refers to the ability of these materials to be processed in a recovered paper treatment plant according to established engineering guidelines. This ensures that the resulting secondary fibre furnish allows for the undisturbed and cost-effective manufacture of new, recycled fibre-based paper and board of acceptable quality.  

Repulpability describes how effectively a material breaks down into pulp under specific conditions; essentially, it is the act of disintegration into fibres.  

The Growing Challenge of Packaging Waste

The volume of packaging waste is increasing rapidly, driven by factors such as urbanization, the growth of e-commerce, consumer behavior, and the prevalence of fossil-based materials. In 2022, the European Union generated 83.4 million tonnes of packaging waste¹, amounting to 186.5 kg per inhabitant, a 22% increase between 2016 and 2022². Controlling and limiting packaging and waste is a priority. Rising living standards and consumer preferences are driving trends in the opposite direction.  

Recycling and reuse offer options to reduce the environmental impact of packaging and packaging waste. However, limitations in recyclability, collection infrastructure, and material usage pose challenges. These challenges also lead to significant differences in the recycling rates of various materials. Globally, over 60% of paper and board materials are recycled, with the figure reaching 83.2% in the EU³.

In comparison, the recycling rate of plastic-based packaging materials is lower. OECD estimates plastic recycling rates between 14-18%, while the United Nations places the global recycling rate for plastics below 10%. The EU has set targets to increase recyclability rates, for example, for municipal waste and paper-based packaging, the target is 85% by 2025 and 90% by 2030. This necessitates a strong emphasis on material selection and recyclability.  

The Rise of Fibre-Based Packaging

Fibre-based packaging materials offer a significantly more sustainable and recyclable alternative, making the shift away from fossil-based materials transformative. Historically, the adoption of fibre-based materials has been limited by the availability, properties and performance of these materials. Fossil-based materials have provided critical properties such as durability, barrier properties, processability, and availability, often with a low-cost structure. There have been fewer alternatives in fibre-based materials, particularly for barriers and coatings.  

In the last five years, technologies and investments in new materials have evolved rapidly. Fibre-based and biomass-based materials are increasingly bridging the gaps in critical properties, availability, and cost structure. Replacing fossil-based barriers with easily recyclable bio-based alternatives presents a significant opportunity to reduce the overall amount of plastic packaging and increase the recyclability rate of packaging waste.

The paper and paperboard value chain exemplifies circularity, demonstrating very high recycling rates. Furthermore, technical innovations are leading to new products made from paper and cardboard, as well as other cellulose fibre-based and biomass products, which are increasingly replacing traditional packaging materials. To maintain and further enhance the sustainability and circularity of the paper and board value chain, and to support EU Member States and other European countries in meeting ambitious recycling targets, it is essential to ensure that paper and board-based materials, along with other cellulose fibre-based and biomass products (e.g., molded fibre products and barrier coatings), are recyclable by the paper industry⁴.

The Importance of Recycling

The transition to circular practices offers significant environmental and economic benefits. Fibre-based packaging demonstrates how sustainable materials can align with circular economy objectives without compromising convenience or quality⁵. Effective recycling of packaging materials requires partnership and collaboration among industries, policymakers, and waste management sectors. Political support, including European standardization of waste collection and recycling systems, is crucial to ensuring that packaging contributes to circularity objectives.

While industrial innovation drives change, policy must help define a common direction for a coherent and simplified approach to recycling and packaging across the EU, which is necessary to achieve greater environmental and economic benefits. A prime example of cross-functional collaboration is the work of the 4evergreen Alliance. This underscores the importance of European standardization of waste collection and recycling systems, upgrading recycling facilities to close the loop on fibre-based packaging, and supporting packaging design that adheres to recyclability standards to ensure that products placed on the market contribute to circularity objectives⁶.

The 4evergreen Alliance promotes the recyclability of fibre-based materials by establishing standards for recyclability evaluation protocols, design guidelines, and material collection and sorting. For instance, the newly updated Recyclability Evaluation Protocol is the result of extensive collaboration and input from over 100 stakeholders across the fibre-based packaging value chain. It supports the industry’s journey toward circularity by providing businesses with a comprehensive, science-backed tool to assess and enhance the recyclability of their packaging. The Recyclability Evaluation Protocol, provided by CEPI and included in the 4evergreen toolbox, offers clear, data-driven guidance to help companies improve packaging design, meet regulatory expectations, and strengthen their sustainability strategies. This industry-wide harmonized and standardized approach provides practical solutions for advancing a truly circular economy⁷.

Repulpability: Definition and Testing

Repulpability, while it may sound unfamiliar, is directly related to the recyclability of fibre-based materials. Simply put, repulpability is the ability of paper and cardboard materials to be broken down into a watery mixture of individual fibres (pulp), enabling them to be used again to make new paper products. The recyclability of materials or products made predominantly from paper and board is determined through laboratory procedures that simulate the most relevant industrial phases of a conventional paper and board recycling mill.  

CEPI Test Method 27.02 provides a harmonized European laboratory procedure for assessing the repulpability testing of paper and board materials. The method simulates the initial stages of a standard paper recycling mill to predict how well a material will disintegrate into fibres and the amount of non-fibrous residue it will leave behind.  

The repulpability testing process generally involves these key steps⁸:

• Sample Preparation: A representative sample of the paper or board material, including any coatings, inks, or adhesives, is cut into smaller pieces of a defined size. A specific amount of this sample (typically around 50-100 grams dry weight) is used for the test.  
• Disintegration (Pulping): The prepared sample is immersed in a defined volume of water at a controlled temperature (usually around 50°C) and a specific consistency (fibre-to-water ratio). This mixture is agitated in a standardized laboratory pulper for a set period (commonly 20 minutes, but this can be adjusted based on the material and the presence of wet-strength agents). The pulper’s action mimics the mechanical forces in an industrial pulper, breaking down the paper structure.  
• Coarse Screening: After pulping, the resulting slurry is passed through a coarse screen with defined slot widths (e.g., 0.5 mm). This step separates larger, undispersed contaminants (coarse reject) from the pulp suspension containing the liberated fibres (accept). The coarse reject is collected, dried, and weighed to quantify the amount of material that did not break down into fibres.  
• Fine Screening: A portion of the accept from the coarse screening is further processed through a fine screen, typically a Somerville screen with finer slots (e.g., 0.15 mm). This step identifies smaller, undispersed contaminants (fine reject) that passed through the coarse screen. The fine reject is also collected, dried, and weighed.  
• Filtrate Analysis: The water (filtrate) from the pulping and screening stages can be analyzed to assess the presence of dissolved and colloidal substances that might cause issues in the recycling process. This analysis, while optional, is recommended and can involve measuring the evaporation residue and, optionally, the Chemical Oxygen Demand (COD).  
• Handsheet Formation and Visual Assessment: A handsheet is prepared from the accept (the fibrous pulp that passed through the screens). This allows for a visual assessment of the quality of the recycled fibres, including any visible impurities, specks, or undispersed particles. The presence and stickiness of macrostickies (larger sticky contaminants) can also be assessed on the handsheet.  
• Evaluation and Scoring: The results from each stage—the amount of coarse and fine reject, the characteristics of the filtrate, and the visual quality of the handsheet—are evaluated against predefined criteria. CEPI Test Method 27.02 often leads to a scorecard assessment, providing a numerical score that indicates the overall repulpability of the tested material. Higher scores generally indicate better repulpability and fewer issues expected during industrial recycling.  

Understanding Repulpability Test Results: What Do the Results Tell Us?

The repulpability testing method evaluates recyclability performance (yield, coarse and fine reject, dissolved and colloidal substances) as well as the quality of recycled paper (visual impurities and sheet adhesion). Several output values from the lab tests are considered when calculating the Technical Recyclability Score. The Total Screening Reject (TSR) value is a measurement representing the sum of coarse and fine reject. The Total Screening Yield (TSY) is the total amount of packaging minus TSR, expressed as a percentage. The DCS value measures dissolved and colloidal substances, representing the mass of substances in the filtrate obtained following filtration of pulp and disintegration related to the packaging mass. Other key measures include Visual Impurities (VI), Sheet Adhesion (SA), and Disintegration Time (DT).  

Output values are translated into a final Technical Recyclability Score, which ranges from -100 to +100. The Recyclability Evaluation Protocol provides two main conclusions: whether a material is technically recyclable in a recycling mill using a conventional process or not. However, it also supports the eco-design process by providing a more granular description through the total score and the breakdown of this total into its individual parameters. Various parameters have different impacts on the Technical Recyclability Score. This classification is the result of an extensive consensus-building process using real test data and represents the best available expert knowledge from 4evergreen’s members. Understanding the significance of each score component is crucial for efficient eco-design processes and optimizing circular fibre-based packaging.  

The highest score (100-90) indicates that the packaging results in a high screening yield in a recycling mill using a conventional process. There are no visual quality or adhesion issues, and the material poses negligible problems in the recycling mill process, thus it is considered “best in class”. Lower scores between 89-70 suggest higher amounts of rejects that affect the recycling mill process, as well as visual and adhesion issues. Scores between 69-50 indicate that packaging should be further optimized for recycling. Scores between 49-0 indicate that packaging creates a significant amount of rejects, which can lead to technical problems in the screening step of the recycling process, while a score below 0 indicates that the packaging material should not be recycled and used in the conventional mill process.  

Why Repulpability Is Essential for Paper&Board Recycling?

In a world grappling with increasing waste volumes and the urgent need for resource conservation, the adoption of repulpable materials offers a powerful pathway towards a more sustainable future. The inherent ability of these materials to be efficiently reintegrated into the paper recycling loop unlocks a range of environmental and economic advantages.  

Firstly, repulpable packaging significantly enhances circularity. By ensuring that paper and board can be effectively broken down and reused as valuable cellulose fibres, we move closer to a closed-loop system. This reduces our reliance on virgin resources such as forests, water, and energy, fostering a more sustainable utilization of the Earth’s finite natural capital.

Furthermore, the widespread use of repulpable materials plays a crucial role in reducing landfill waste. When packaging can be readily recycled, less of it ends up in landfills, alleviating pressure on these already burdened sites and mitigating the associated environmental problems like leachate and greenhouse gas emissions.  

The recycling of repulpable materials also leads to significant resource efficiency. Compared to the energy-intensive process of producing paper from virgin pulp, recycling requires less water and energy, contributing to a lower overall environmental footprint. This conservation of resources is vital for long-term sustainability.  

Repulpability is linked to the recyclability of packaging materials. That is a major contributor to the PPWR (Packaging and Packaging Waste Regulation) and to EPR (Extended Producer Responsibiliity), which determine the cost of packaging in the near future. Low amount of recycled content in packaging leads to high ecomodulation fees, determined in the EPR. This is an important factor determining the materials used in the packaging.

Beyond these direct environmental benefits, easily repulpable materials contribute to improved recycling stream quality. By minimizing non-fibrous contaminants that can hinder the recycling process, we obtain cleaner and more valuable recovered fibres. This, in turn, benefits the entire recycling industry by making the process more efficient and resulting in recycled paper of higher quality.  

Finally, embracing repulpable materials allows businesses to meet increasingly stringent sustainability goals and cater to the growing consumer demand for eco-friendly packaging. Choosing repulpable options demonstrates a commitment to environmental responsibility, enhancing brand reputation and resonating with environmentally conscious consumers. While not always a direct short-term cost saving, the long-term benefits of a more efficient recycling system and a positive brand image can translate to economic advantages.  

In essence, the shift towards repulpable materials is not just an environmentally sound choice; it’s a strategic move towards a more resource-efficient, circular economy that benefits both the planet and businesses.  

Ecohelix WOODMER^® Seal: A Bio-Based, Fully Repulpable Heat Seal Coating Solution

Written by Jari Oinonen

For more information and samples, please contact:
Daniel Jonsson – daniel@ecohelix.se or
Jari Oinonen – jari@ecohelix.se

Sources:

1. Eurostat: https://ec.europa.eu/eurostat/statistics-explained/index.php?title=Packaging_waste_statistics ↩︎
2. EPA Ireland ↩︎
3. The Parliament: Circular Solutions: Realising the potential of sustainable packaging, Feb 2025 ↩︎
4. CEPI Paper&Board -Recyclability Laboratory Test Method, February 2025 ↩︎
5. 4evergreen was featured in the Parliament Magazine – 4evergreen ↩︎
6. The Parliament: Circular Solutions: Realising the potential of sustainable packaging, Feb 2025 ↩︎
7. A Major Leap for Circularity: The Finalized Recyclability Evaluation Protocol – 4evergreen ↩︎
8. CEPI: Harmonised European laboratory test method to generate parameters enabling the assessment of the recyclability of paper and board products in recycling mills with conventional process, version 3, February 2025 ↩︎