Abstract: In order to obtain better lap forming and combed sliver quality, that the pressure mechanism and stress have been studied on HC181 Unilip. Through kinematics and mechanical mathematical modeling to mechanism, compiling Matlab program, pressure curve that keeping lap forming better has been computed and drawn, and the corresponded pressure equation has been simulated. After the pressure equation putted into PLC(Programmable Logic Controller), PLC control electronic ratio valve to regulating cylinder pressure, lap pressure then be controlled on-line in the course of lap forming,. Weight unevenness of practical lap produced by above method can decrease to 0.1%.

Key words: Unillap, pressure mechanism, lap, pressure analysis