kraftprocessen
The kraft process, also known as the sulfate process, is the most common method for pulping wood to produce paper. It is a chemical pulping process that separates lignin from cellulose fibers. In this process, wood chips are cooked in a strong alkaline solution, primarily sodium hydroxide and sodium sulfide, in a large pressure vessel called a digester. This mixture is known as white liquor. The heat and chemicals break down the lignin, which acts as a binder holding the wood fibers together.
After cooking, the resulting slurry is a mixture of cellulose fibers and spent pulping chemicals, called black
The cellulose fibers, now separated and cleaned, are bleached to achieve the desired brightness for papermaking.