Saturating kraft paper suitable for lignin-based resin

A paper that allows the use of wood-based resins in the manufacture of laminates

Phenol, traditionally used in the manufacture of laminates, is an oil-based raw material. By replacing fossil-based phenolic resins in laminates with renewable lignin-based resins, the carbon footprint of the product is significantly reduced. MM Kotkamills has developed a saturating kraft paper suitable for lignin-based resins. This will help the laminate industry to move away from oil dependency to bio-based raw materials, without compromising the product properties of the laminates.

How it works in practice

Absorbex® saturating kraft paper is made from pulp, whose raw material is the by-product of sawing logs into boards and planks – sawdust. The product has been produced on the MM Kotkamills’ paper machine for 50 years. The new paper innovation, a saturating kraft paper suitable for lignin-based resins, has been developed in response to customer demand for more environmentally friendly laminates for the construction and furniture industry. Saturating kraft paper is used in the production of high pressure laminates. The paper is impregnated with resin and several layers of impregnated paper are pressed together into a sheet under high pressure, making the laminate hard and durable. Lignin has a larger molecular size than phenol, which has a negative effect on the absorption of lignin resin into the paper. The new special paper allows effective and adequate absorption of lignin resin.

The new paper, optimised for lignin resins, can be used with the same equipment as the paper grades designed for phenolic resins and therefore does not require new machinery investments. High-pressure laminates produced from the laminating paper will remain in their intended use for up to decades while sequestering carbon throughout their life cycle. The recycling of laminates after their long service life is achieved by the industrial combustion of the laminate sheets into energy. The longevity of the product promotes responsible consumption. Made from saturating kraft paper containing sawdust pulp and lignin-based resins, laminate is an eco-innovation for various applications in the construction industry, using both sawdust and pulp by-products, and is also ideal for public buildings due to its durability, strength and easy cleanability. An ecological building material is the choice of the conscious consumer.

Economic opportunities and broader social significance

For decades, the traditional impregnating resins used to impregnate saturating kraft paper have been based on phenol, an oil-based fossil substance with a limited global supply. To solve this problem, companies in the laminate production chain have developed resins based on renewable raw materials, such as wood lignin, to replace oil-based resins. However, the larger molecular size of lignin-based resins compared to phenolic resins has also placed new demands on the laminating papers into which the resin is absorbed in the manufacture of laminates.

As a result of product development, laminate manufacturers now have a saturating kraft paper optimised for lignin resins developed by MM Kotkamills, which works perfectly with the same machinery as papers designed for phenolic resins. The transition away from oil dependency to bio-based raw materials such as lignin-based resins is no longer dependent on the carrier material of the laminates, i.e. the paper. The shift from fossil to bio-based and renewable raw materials is realistic, with a significant positive impact on the climate. The market for phenol has fluctuated recently, both as a result of the pandemic and the war in Ukraine, creating a strong demand for alternative raw materials. MM Kotkamills is contributing to this need.

Further information

MM Group is a leading global producer of paperboard and paperboard packaging, including sawn timber, packaging papers, speciality saturating kraft papers and uncoated fine papers for various end products. MM promotes sustainability through innovative, recyclable packaging and paper products.

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