Numerical Simulation Research On The Effect Of Screw With Bionic Non-smooth Structure On The Ceramic Paste Extrusion Process

Vacuum pug mill is the key mechanical equipment in ceramic industrial production and it is used to produce the plastic mud segment. But due to the characteristic of screw extrusion, the ceramic paste will appear some defects in vacuum pug mill working process unavoidably, such as non-uniform flow velocity, layering, spiral shape veins, frictional heating and material oriented etc. These defects will influences the quality of the shaping base body seriously, and them finally influences on the quality of ceramic product.For maximum eliminate these pug defects in extrusion forming process, this paper raise a viewpoint of bionics and take advantage of the body surface resistance reduction characteristic to design the continuous screw with bionic non-smooth surface structure by imitate soil animals. After the screw surface become non-smooth, the friction among screw and ceramic paste will be reduced, the power transmission and movement form of ceramic paste on barrel will be optimized, and then achieved the aim of decrease these pug defects.Based on the model of TL-125B vacuum pug mill, with comprehensive application of rheology, finite volume method, calculate fluid dynamic etc, calculate the flow field of ceramic paste in continuous screw part by numerical simulation method. The results show that bionic non-smooth screws relative to original screw, their Cf declined by an average of 17%, their S2 declined by an average of 4%, their max(d?/dr) declined by an average of 18%. It illustrates the bionic non-smooth screw has the function of resistance reduction, the relative slip among layers of ceramic paste is minished and the quality of plastic mud segment is improved.Finally, based on orthogonal experimental design method, analyze the factors of form, size and population density of non-smooth surface structure how to influences the effect of vacuum pug mill. Then, elect the optimal scheme of bionic non-smooth screw on two types and provide the reference for bionic optimal design of vacuum pug mill.