When paddy comes into the mill, it contains foreign materials such as straw, weed seeds, soil, and other inert materials. If these are not removed before hulling, the efficiency of the huller and milling recovery will be reduced. The capacity of the paddy pre-cleaner is normally 1.5 times the milling capacity.
Brown rice is produced by removing the husk from rough paddy rice. The husk is removed by friction as the paddy grains pass between two abrasive surfaces that move at different speeds. After dehusking, the husk is removed by suction and transported to a storage dump outside the mill. Husk accounts for 20% of the paddy weight and an efficient husker should remove 90% of the husk in a single pass.
The rice is then polished to improve its texture and appearance, often by passing it through machines that buff the grains. The final product is white rice, which is smoother and has a longer shelf life but loses some nutrients compared to brown rice.
After polishing, white rice is separated into head rice, large and small broken rice, and “brewers” by an oscillating screen sifter. Head rice is normally classified as kernels that are 75−80% or more of a whole kernel. To attain a higher degree of precision for grading and separation a length or indent grader is used.
Rice packaging involves several key steps to ensure quality and safety. After milling, the rice is cleaned and inspected for impurities. It is then weighed and measured into specific quantities, typically ranging from small consumer-sized bags to large bulk sacks. The rice is then sealed in packaging materials, often made from plastic or paper, which are designed to protect it from moisture, pests, and contamination. Labels with essential information, such as the brand, weight, and nutritional details, are added. Finally, the packaged rice is boxed, palletized, and prepared for distribution and sale.
