TAPPI T 235 CM-09 provides a standardized procedure for measuring the alkali solubility of bleached and delignified pulps using sodium hydroxide solutions at 10%, 18%, or 21.5% concentration. The method covers required apparatus, reagents, sampling, specimen preparation, extraction, filtration, dichromate oxidation, titration, calculations, reporting, precision, and related standards.
This technical document supports evaluation of cellulose degradation and hemicellulose loss or retention during pulping and bleaching processes. It also includes safety cautions for hazardous chemicals, reporting guidance for alkali solubility results, and historical and precision information for laboratory testing.
Application Scope: Intended for pulp, paper, cellulose, and laboratory quality-control professionals testing bleached or delignified pulp; it is not applicable to unbleached pulp.
