Assessing the properties of lac mixed with salt during storage

Abstract

Lac is a natural resin secreted by tiny insects called Kerria lacca (Kerr.). Mixing of salt (sodium chloride) in fresh scraped lac is commonly practiced in some places such as Gujarat, West Bengal etc. to avoid lump formation during storage and transportation. Fresh kusmi scraped lac was mixed with salt and a control sample were kept separately in jute sack for three years at ambient condition. The scraped lac samples were washed with 0.1% washing soda (sodium carbonate) and converted to seedlacs at regular interval of six months. Physico-chemical and coating properties of seedlac were studied. Yield of the seedlac obtained from salted sample was less (~ 8%) in comparison to that obtained from control sample. Flow, hot alcohol insoluble and color index were found better in seedlac obtained from salted sample, while life under heat and rate of filtration were better in seedlac obtained from control sample. Coating properties such as gloss, scratch hardness, impact resistance and flexibility was found inferior in seedlac obtained from salted sample to that of seedlac obtained from control sample.