1)The JKB(SJD) series vacuum extruder's main part is welded with extra fine steel. 2)The double grade both are drove by one motor which have features of contact structure, high pressure extrusion, high vacuum, sturdy and durability and easy maintenance but lower energy consumption. 3)They are the perfect equipments for medium size brickfield and small size brickfield because of only with small investment. 4) They are applicable for all kinds of solid bricks, bearing porous bricks and high-rate hollow bricks with the materials of coal gangue, shale, high-volume fly-ash, urban construction waste, gangue waste, inferior soil.