Technical Information

Working Principle of Rubber Roll Husker :

The rubber roller huller is the most efficient hulling machine. As the name suggest two Rubber Rollers of the same diameter are operated at different speeds to remove the husk from the paddy. One roller has a fixed position and the other is adjustable to meet the desired clearance. The adjustable roller rotates slightly slower than the fixed roller. Rubber-roll hullers have an aspirator in the base of the machine to separate the hulls from the brown rice.

General guidelines to get optimium life and performance of Rubber Rollers

  • Paddy should be at 14% moisture content.
  • Before starting the husker, check the alignment of the rubber rolls. Remove any grain present between the roll.
  • Adjust the clearance to nearly 0.5 mm (or) the rolls should be just touching each other.
  • Immediately after starting the machine check the hulling efficiency checked .If the hulling Efficiency is less than 90% decrease the clearance until the hulling efficiency is about 90%-95%.The rolls are not locked in this position.
  • In operation the feed gate above the rollers must be fully opened so that the rollers will wear out uniformly.
  • Check hulling efficiency at regular intervals as the rubber rolls wear.
  • Before stopping the machine, close the feed gate completely and clear the rolls of paddy.
  • The roller's axis must be in perfect line with then of hub and shaft.
  • The roller surfaces must be aligned and must be keep equal distance whilst rotating.
  • While changing the rolls, the bigger roll should always be mounted to the fast moving shaft.
  • Spare rolls must be kept in dark room and if possible should be packed well to protect them from light and sudden changes in temperature.
  • Un evenly worn rolls must be carefully lathed on a lathe machine and the surfaces made uniform and smooth.
  • The huller should be cleaned after every day of operation.
  • The side baffle plates on each side of the rubber rolls should be checked each day to see that there is no leakage of paddy between the plate and the rubber roll surfaces.
  • Whenever rubber rolls are replaced ,it should be ensure that their end faces are in line.
  • The cover plates of the cooling chamber inside the rubber roll housing should be removed once a week and cleaned thoroughly.


  • The huller should not be run with the rolls engaged without feed on the huller.
  • When turned off there should be no grains between the rollers because they would deform the rubber.