A Liming Process with Sodium Silicate Compound as a Swelling Agent

Low modulus sodium silicate was prepared with a polysilicon byproduct-silicon tetrachloride, and used as a swelling agent. Calcium chloride, hydrazine and protease were selected as auxiliaries for the swelling agent. Dosage of the auxiliaries was optimized through the weight increase, thickness increase, proteoglycan removing and skin histology in swelling. Based on the auxiliary optimization, a sodium silicate compound with 67% sodium silicate, 17% hydrazine and 3% protease (SSC swelling agent) was prepared as a swelling agent and its swelling ability was investigated with SEM and proteoglycan removing analysis. Also, the environmental impact of the swelling process was evaluated by total solid of the effluent. The results showed that a comparable opening up of fiber bundles was obtained with 6% SSC swelling agent (based on the unhaired weight) and proteoglycan removal in the skin was improved. Compared with a traditional liming process, there was a less total solid in the effluents. The results could provide a new valuable reference for cleaner swelling process.