METPAC: biobased lignin-derived coating for stronger, moisture-resistant paper and liner board packaging

Overview

METPAC is a novel, biobased coating and sizing product derived from lignin, designed to improve the mechanical strength and moisture resistance of paper and liner board used in industrial packaging. Developed by MetGen Oy, a Finnish biotechnology company specializing in industrial enzymes and biomass valorization, METPAC leverages the natural hydrophobicity and mechanical properties of lignin to deliver performance gains without compromising recyclability.

In packaging applications, liner board must withstand stacking loads and humid conditions while remaining cost-effective and sustainable. METPAC addresses these challenges by providing a lignin-based additive that enhances key performance metrics, including Short-span Compression Strength, Box Compression Strength, and Cobb60 water absorption, while contributing only 10 g/m² to the final grammage of the board. The result is stronger, more durable packaging produced from a renewable raw material.

Technical specifications

Key features:

• Lignin-derived, biobased composition providing natural hydrophobicity and mechanical reinforcement
• Spray-applied during liner board production for straightforward integration into existing manufacturing lines
• Contributes only 10 g/m² to final board grammage, minimizing material usage
• Increases board strength by up to 50% (Short-span Compression Test) compared to non-coated liner board
• Improves moisture resistance, achieving Cobb60 values close to industrial requirements of less than 50 g/m²
• Delivers up to 16% improvement in Box Compression Test for finished laminated boxes made from coated liner board
• Fully recyclable within standard paper recycling streams
• Compliant with Regulation (EC) No 1935/2004, German Recommendation XXXVI, and FDA for food-contact applications

Performance validation:

• Laboratory formulation testing has confirmed scalability potential for industrial production
• Pilot trials have reproduced lab-scale results, with laminated boxes demonstrating measurable compression strength improvements

Technology readiness level

METPAC has progressed beyond laboratory validation through successful pilot trials, with demonstrated strength and moisture-resistance gains reproduced at pilot scale and confirmed in finished box compression testing. The product is currently formulated for a shelf life of up to six months under cold storage conditions.

Next steps toward commercial readiness include extending formulation stability to three months at room temperature, characterizing rheology for optimized application, and evaluating additional barrier properties such as water vapor and oxygen transmission. MetGen is actively seeking an industrial partner to support scale-up of METPAC production, advance formulation development, and validate performance in end-user applications to bring the technology to full commercial deployment.