Development of Production Process for Improved Plastic Moulded Single Row Cono Weeder (Manual) by Injection Moulding for Wetland Paddy

The rotors/cones of the commercial cono weeders in the country are made of MS which has lots of functional limitations in wet field. These are very difficult to fabricate, and not easy to maintain. In view of this, a process was developed for production of the cones of the cono weeder, by using polypropylene copolymer. The cost of production of plastic moulded cones for cono weeder was Rs. 280/cone, which is almost on par to that of MS sheet cone (Rs. 260/cone). The production output per person per day has increased from four to fifty by plastic moulding process. Plastic moulded cono weeder recorded higher field capacity (by 28.30 per cent), weeding Index (by 7.04 per cent) and performance index (by 49.61 per cent) over commercial model of cono weeder, with lower pushing force (by 13.39 per cent) and recorded lower plant damage (by 3.27 per cent). The ergonomic study revealed that heart beat/min, VO₂/min, ODR score, body part discomfort score, OCR as VO₂ max, per cent cono weeder with plastic moulded cono weeder was found better over commercial metallic model of cono weeder by 20.43 per cent, 12.41 per cent, 11.29 per cent, 33.14 per cent and 8.63 per cent, respectively.