Foamed Lignin

Lignin is a residual by-product of the cellulose industry; these days, used almost only forenergy.High-value insulation products offoamedlignin are being developed (Lund, 2003; Wimmer et al, 2001; Stocklund, 1962). Conventional baking powder can be used to expand the product at between 60 and 90 °C. Energy use for production is approximately 10% ofthat needed for mineral wool products. It needs no fungicides, has no emissions, and can be composted or burned after use.

Cellulose building paper is usually manufactured from recycled paper and unbleached sulphite cellulose. It can also contain up to 20% wood pulp. Boards are manufactured by laminating the sheets of paper together to a thickness of 2 to 3 mm, most often with polyvinyl acetate adhesive (PVAC), about 3% by weight. Waterproofing and water-repelling substances are added to all of these products, e.g. bitumen, latex and paraffin wax. Cellulose building paper is also combined in laminates with, for example, polyethylene and aluminium and can be supplied with a matrix of polyester as reinforcement.

Durability is good. Pure cellulose paper and laminated weather-proofing boards (with natural latex) can, most probably, be recycled into new cellulose products, e.g, loose fill thermal insulation. Wastes from other products are best suited for energy recovery or use as a low quality cellulose fill in asphalt, etc.

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