The characteristics, advantages and shortcomings of the parallel corotating twin screw extruder and the conical counter-rotating twin screw extruder, two important equipments for the compounding and processing of wood plastics composites,were emphatically discussed and compared.

This paper finds out the mixing ways and producing technique by the property of ramie/cotton mixed yarn,which help to solve some problem——worse fiber regularity,wrapping easily,and drafting difficulty,etc.

Based on the chemical parameters of component coal, the method predicting combustion behavior of blended coal has been established, which is proved to be correct by the test burning of blend in a small-scale boiler.