Question

In a paper mill bleaching powder is not added while preparing paper pulp the paper obtained was yellowish brown in colour what is the reason for this ???

Answer 1

Because bleaching powder makes the paper white in colour. here bleaching powder is not added so it makes yellowish brown .

Answer 2

In a paper mill, if bleaching powder is not added in the process of paper making, then the paper will look yellowish brown in color because of the presence of traces of residual lignin.

Pulp is the primary raw material  required in the paper manufacturing process, which is a fibrous material obtained by separating the cellulose fibers from wood. It has brown colored appearance due to the presence of residual lignin.

After the Kraft bleaching process, this brown colored paper is turned white, by removing the lignin content.