The antistatic epoxy resin coatings using double comb-like quaternary ammonium salt polymers as antistatic agents reach good antistatic property with lower addition amount because polymers can dissolve and nearly linearly arrange in the coatings.

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Wood plastic composites (WPCs) are the industrial products. It is made out of wood waste fibre and waste plastic glued together by heat and pressure. Nowadays WPCs products are preferred over solid wood in many applications due to certain comparative advantages. Sawing is the machining operation frequently used in manufacturing parts of WPCs. The aim of this article is to study the effect of cutting speed on surface roughness in different WPCs sawing. A plan of WPCs sawing experiments was preformed with prefixed cutting parameters. The objective was to establish correlation between rice hull flour/PE composite, rice hull flour/PP, rice hull flour/PVC and cutting speed with the surface roughness after sawing. The results show that the spindle speed had significant effects on the surface qualities of rice hull flour/PE composites, rice hull flour/PVC composites and rice hull flour/PP composites. The advantage of using a high cutting speed in WPCs sawing is evident. With appropriate cutting parameters, one can obtain surfaces with Ra＜6μm and to get surfaces qualities (dimensional precision) in workpiece of different WPCs.

Rock tunnel boring machine is one of the main machineries and equipments for underground engineering, and the failure of tool systems is its main failure form. Rock hob test-bed is the only testing equipment for tool failure and wear. In this paper, the breaking rock by the double disc cutter is simulated and four kinds of rocks are selected to test the influece of rock characteristics and spacing between two disc cutters on the rock breaking by the double disc cutter test-bed. The results show that there is different optimal spacing between two disc cutters for different rock; the optimal spacing is inversely proportional to the hardness of the rocks; the maximum stress appears the boundary between the disc cutter and rock.

To realize accurate prediction of disk cutter performance and determine the crucial parameters in the design process of TBM (Full face tunneling boring machine), a new performance forecasting method of the circular blade cutter is presented, which integrates the parameters of breaking rock such as rock, disc cutter and construction. Furthermore, the second derivation in the process of breaking rock is considered, a new comprehensive performance forecasting model of the circular blade cutter is established based on the Coulomb-Mohr failure criterion. On the basis, the existed performance forecasting models of disc cutter such as Liner Cutting and CSM, and the performance forecasting model of disc cutter presented this paper are analyzed and calculated, according to Colorado linear cutting experiment. The calculation results indicate the prediction accuracy of the performance forecasting model presented in this paper is greatly improved, comparing with the existed models (such as CSM, linear cutting). Finally, the influences of the parameters (rock, disc cutter and construction) are analyzed, which provides for the overall design of TBM cutter and construction with some scientific basis.