Chlorine two part wood bleach oxalic acid and peroxide.
Chlorine bleach wood pulp.
Pulp and paper industry currently uses chlorine dioxide bleaching also known as elemental chlorine free or ecf.
For over four decades we have helped the industry navigate the changing landscape of bleaching technologies.
According to an industry group the use of chlorine dioxide in these processes has reduced the dioxin generation to under detectable levels.
In the production of paper residual lignin from wood pulp is chemically liberated by using chlorine bleaching forming chlorinated lignin derivates such as chlorolignols.
There are four types of bleach that woodworkers commonly use.
As a core component of best available technique bat for production of pulp paper and board ecf bleaching will likely continue to dominate.
It has been found that bleaching can result in the formation of dioxin in the pulp when chlorine reacts with organic constituents of wood.
Recently paper makers have begun using chlorine dioxide to bleach paper.
Bleaching wood subtract color to add life.
Biobleaching is an important alternative to reduce the use of chlorine.
Ecf is a pollution prevention technology recognized and accepted globally by such organizations as the united nations environment.
Ecf bleaching is the worldwide bleaching standard despite tcf being 100 chlorine free.
Elemental chlorine free ecf is a technique that uses chlorine dioxide for the bleaching of wood pulp.
For example the use of elemental chlorine in the bleaching of wood pulp produces organochlorines and persistent organic pollutants including dioxins.
Read on to find out what each one does and how to use them safely.
Chlorine dioxide serves as a bleaching agent for wood pulp and it is used because chlorine dioxide minimizes the amount of organochlorine compound that are produced in the process.
It is used at moderately acidic ph 3 5 to 6.
Traditionally the paper industry used chlorine gas to bleach pulp.
Chlorine is commonly used as a bleach.
These are toxic carcinogenic and recalcitrant to degradation.
The use of chlorine dioxide minimizes the amount of organochlorine compounds produced.
About 95 of all bleached kraft pulp is made using chlorine dioxide in ecf bleaching sequences.
Chlorine dioxide ecf technology currently is the most important bleaching method worldwide.
Elemental chlorine free ecf.
Although preliminary surveys have detected dioxin in pulp mill wastes the scope of the problem is not yet known.
It does not use elemental chlorine gas during the bleaching process and prevents the formation of dioxins and dioxin like compounds carcinogens.
Two part bleach changes the actual color of wood and the other three remove stains.