Kraft - What does Kraft mean?
This term refers both to a method of producing paper pulp and the paper that is made using this process.
The Kraft process uses a mixture known as "white liquor" to produce paper pulp; this mixture is made of sodium hydroxide and sodium sulphide, which break down the bonds between the cellulose fibres in wood and the lignin (a natural glue that holds wood fibres together). Wood chips are treated with steam and then impregnated with white liquor and a small amount of black liquor (made from the waste produced by the pulping process). The chips are then cooked in a large digester, where the combination of heat and chemicals breaks down the lignin. The usable pulp is then separated from the unwanted elements (black liquor) and sent on for further processing (such as bleaching).
The Kraft process is popular because it can process wood from almost every species of tree, the process breaks down lignin without causing great damage to the cellulose fibres, the unwanted elements are easy to separate and recover (before being reused in the pulping process or becoming a useful byproduct, such as tall oil and crude turpentine), and it produces a much stronger, higher quality pulp than other processes (the name "Kraft" is a German word for strength).
Kraft paper has long fibres, which give it greater elasticity, durability, strength, and tear resistance; this material is therefore a popular choice when making packaging, paper bags and sacks, wrapping paper, envelopes, and, of course, labels. Kraft pulp can be bleached or unbleached; the term is most commonly used to refer to unbleached pulp, which is brown in colour.
We have a range of Kraft labels, which have a ribbed finish to create a subtle touch of pattern and texture.Go Back to Glossary