Development of Modified Power Operated Lac Scraper

Abstract

Lac is the hardened resin secreted by the tiny lac insect (Kerria lacca Kerr). It is the only resin of animal origin. Lac insect S thrive only on certain trees called lac hosts. Butea monospenna (Fa/as), Zizyphus mauritiana (Ber) and Schleichera oleosa (Kusum) are the major lac hosts used for lac cultivation in India. India is the largest producer of lac. Indian lac is considered to be the best in quality. Apart from India, Thailand, Myanmar, Indonesia, Vietnam and China also produce lac. In India about 3 million farmers mostly tribal are involved in the lac cultivation spread over states of Jharkhand, West Bengal, Madhya Pradesh, Chhattishgarn, Maharastra, Andhra Pradesh, Gujarat and Orissa. Lac cultivation involves five major operations i.e., pruning, inoculation, used up broodlac (phunki) removal, harvesting and lac scraping. Mostly lac cultivation operations are carried out manually with the aid of locally manufactured traditional tools. Manual lac scraping is very slow and a tedious process. In one of the method farmers sit on the ground in a group and scrap lac with the traditional tools like small scraping knife (dauli) and sickle. In other method, farmers remove lac encrustation by beating lac sticks with bamboo stick. One person scrapes, 10-15kg of lac in a day. As scraping is done on the ground, unwanted foreign materials like sand, soil, wooden twigs etc. find their way into scraped lac, fetching less price to farmers and creating problems during lac processing in industry. In order to increase the output and reduce the drudgery of lac farmers a simple power operated lac scraper was designed and developed modifying the earlier developed machine. In the earlier machine V-belt and V-pulley type speed reduction mechanism in two steps was used, which made machine voluminous. To make the machine compact, a gearbox instead of V-belt and V-pulley was used to reduce the 1450 rpm speed at motor shaft to 30-40 rpm at scraping roller shaft. Machine consisted of scraping rollers, separating screen, feed hopper, drive mechanism and machine frame. The machine scrapes lac under action of shear and compressive forces. One person operates the machine and scrapes 10.6 kg lac stick in an hour with scraping efficiency of 92 per cent. The machine gets power from 0.5 H.P. single phase AC motor. The capacity of the developed machine is more than the capacity of earlier developed Hand Operated and Pedal Operated Lac Scraper and at par as compared with Power Operated Lac Scraper. It is suitable for villages having electricity.