The main products of the pulp industry are bleached softwood and hardwood kraft pulps. In addition, the pulp mills produce renewable energy and a number of by-products.
The primary end-uses for the market pulp are manufacturing of packaging board, graphic papers, tissue and specialty products.
Pulp mills are a good example of bio-economy. The raw material is renewable wood that the mills source from responsible sources, sustainably managed forests and plantations.
The cellulose fibers are separated from wood in a chemical pulping process where sodium sulfide (Na2S) containing caustic soda (NaOH) as a cooking liquor makes the lignin holding the fibers together in the wood dissolve. This process is called the sulphate or kraft process and the product hence softwood kraft or hardwood kraft, also softwood and hardwood sulphate pulps.
After the cooking process, the pulps can be bleached. Today, the most common bleaching method is elemental chlorine free (ECF) bleaching. Also totally chlorine free (TCF) bleaching is prevalent.
EPIS collects statistics from bleached softwood and hardwood market pulps.
A modern pulp mill is a net producer of renewable bio-energy, where the newest mills have an energy self-sufficiency as high as 240%.
Examples of other bio-products or by-products that the pulp industry is producing are
- Crude tall oil
- Biogas from sludge
A number of new bio-products are being developed from pulp, lignin as well as bark and wood residues. Bio-composites (bio-plastics) and new textile-fibers are examples of new products made from pulp.