"Discharge door : A drop door beneath the mixing chamber facilitates rapid unloading of the mixed batches to minimize the cycle time. The leak proof door is self - aligning to the underside of the mixing chamber ensuring perfect sealing. The internal face of the discharge door can be easily replaced on being worn out due to mixing action. "
http://www.amcl.in/mixtronbbseriesmixers.html

"A machine for the incorporation of compounding ingredients into rubber or similar materials. Two rotors revolve in an enclosed chamber which is provided with a hopper for feeding the materials and a sliding or drop-door for discharge of the batch."
http://www.btb.termiumplus.gc.ca/tpv2alpha/alpha-eng.html?la...