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Effect of wall slip on melt filling flow behaviors in micro injection molding are investigated based on analysis of wall slip mechanism for polymer melt flowing at filling stage. By means of comparisons, slip coefficients in different microchannels are confirmed. With finite element method, the relationship between slip velocity and inlet flow rate or length-diameter ratio is analyzed. The results indicate that the wall slip happen for polymeric melt in microchannels, and slip coefficients are related with the size characteristics of microchannels. Moreover, wall slip velocity has the size effect and increase with the decrease of the section size of microchannels, which cause melt velocity distribution to smooth. At the same time, slip velocity is proportional to length-diameter ratio of microchannel, namely when wall shear stress is uniform, the slip velocity rises with increasing length-diameter ratio of microchannel.

Micro-structure injection molding machine is mainly used for processing the plastic products in micron-size or with micro-structures. This paper focuses on the design and control of the clamping mechanism of micro-structure injection molding machine. Firstly, the deformation of the clamping mechanism was analyzed. The simulation results shows that the clamping force is 5.0051×105N, and it’s bigger than the design value 500kN. Secondly, the kinetic characteristic of the clamping was simulated by ADAMS software. The curves of the displacement, velocity, clamping force of moving platen were analyzed. Thirdly, the control model of clamping mechanism was established. And the LQR controller was designed and simulated by Matlab. The rise time is 0.010s, the settling time is 0.026s and the steady-state is 0.307m.