Abstract:Using crop straw as material to produce degradable plant fiber film is an ideal utilization of crop straw, which could effectively solve the white pollution caused by plastic film. Efficient, clean and energysaving fiber preparation is an important prerequisite for the production of plant fiber film. At present, there are still some shortcomings in the process of straw fiber manufacturing. Firstly, the yield of straw fiber is too low and the obtained straw fiber could only be used after screening, which increased the procedure of fiber production. Secondly, large energy consumption consumed during producing lead to the increase of production cost. To improve the yield of straw fibers and reduce energy consumption, D200 straw fiber making machine was used as carrier, and the main factors influencing fiber yield and energy consumption of the machine were determined, based on the principle of nonpollution, low energy consumption, and high quality production of straw fibers. Three factors and five levels quadratic orthogonal rotation center combination test method was carried out by using rice straw as material, and spindle speed, processing temperature and cavity gap of D200 machine were chosen as test factors. Fiber yield and energy consumption were used as test indexes. Considering the structure and working parameters of D200 type straw fiber manufacturer, also combining with the previous theoretical research and pretest, the range of spindle speed was selected as 85~135r/min, processing temperature was 88~120℃ and cavity gap was 3.5~8.5mm. The regression analysis of the test data was carried out, and the regression model between performance index and test factors was established under the condition of reliability α=005. At the same time, the influence of factors on the energy consumption and fiber yield performance index was also analyzed. The results of quadratic equation coefficients of fiber yield and fiber lengthwidth ratio were used to judge the influence degree of the test factors on the performance index. Results indicated that the influence of spindle speed, processing temperature and cavity clearance on the energy consumption was very significant (P<0.01). The effect of interaction between spindle speed and cavity clearance on the energy consumption of the machine was extremely significant (P<0.01), and the effect of interaction between processing temperature and cavity clearance was significant (P<0.05). The order of influence of each factor on the energy consumption was as follows: cavity clearance, processing temperature and spindle speed. All factors had a significant effect (P<0.01) on the yield of rice straw fiber. The effect of interaction between processing temperature and spindle speed was significant (P<0.05), and the effect of interaction between processing temperature and cavity clearance was extremely significant (P<0.01). The order of influence of each factor on fiber yield was cavity clearance, spindle speed and processing temperature. Based on the principle of clean and highquality rice straw fiber production, and taking high yield and low energy consumption as requirements, it was concluded that when processing temperature was 106.6℃, spindle speed was 97.1r/min and the cavity clearance was 5.65mm, the fiber yield was 86.60%, and power consumption of the machine was 39.04kW/h. Straw fiber with high yield and low energy consumption was prepared, which could provide better raw materials for degradable plant fiber film. According to the optimum technological results, processing temperature, spindle speed and cavity clearance were chosen as 107℃, 97r/min and 5.7mm respectively to measure the power and fiber yield of the machine. Ten parallel validations were carried out. Results showed that the final power consumption of the machine was 39.67kW/h and the fiber yield was 87.58%, which confirmed that the optimized results were correct and credible. The research results can provide reference for the clean production of rice straw fiber.
