Kraft process, a paper maker’s craft
- December 18, 2023
- Posted by: OptimizeIAS Team
- Category: DPN Topics
No Comments
Kraft process, a paper maker’s craft
Subject :Science and Tech
Section: MSC
- It is a technique that accepts wood chips as input to produce cellulose fibres, which are then used to make paper and other materials used in everyday objects.
- Paper is most commonly produced by the kraft process today.
- Process:
- The process is chemical in nature. The chips are treated with water, sodium hydroxide, and sodium sulphide – the last two forming a highly alkaline mixture called white liquor – at a relatively high temperature.
- This breaks the bonds between lignin (an organic polymer and important constituent of cell walls), hemicellulose (cellulose-like fibres that are shorter), and cellulose.
- The steps are followed by those to obtain the wood pulp, wash off and recover the reaction chemicals, bleaching, and processing.
- Advantage:
- Kraft-process paper has higher sulphidity (a measure of strength) than that produced by other processes.
- Drawbacks:
- The process is not environmentally friendly. It requires a large volume of water; the process of removing lignin from the wood chips also discharges the lignin through water along with dissolved carbon, alcohol ions, and heavy metals.
Source: The Hindu