A compound, whose formula is Na2SO4, that was for a time believed to be the substance responsible for the production of high quality wood pulp in papermaking. Sodium sulfate was originally added to the older soda process, and a much stronger pulp resulted. (It has since been found, however, that the responsible chemical was actually sodium sulfide.) The pulping process has since been somewhat erroneously known as the sulfate process, although its alternate name, the kraft process (after the German and Swedish word for "strength"), is perhaps more accurate. (See also Chemical Pulping.)
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