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利用Polyflow计算机软件,在相同温度的条件下,通过最大剪切速率、最大剪切应力、最大混合指数和累计停留时间这4个指标,研究螺杆螺棱截面形状为梯形时其梯形底角角度和凹槽半径两个变量对聚乙烯在单螺杆反应挤出机中流场的影响。结果表明,当螺杆螺棱截面梯形底角角度为60°时,螺杆提供的最大剪切速率、最大剪切应力、最大混合指数均较底角为30°和45°的高,粒子累积停留时间则居中;在底角为60°的梯形螺棱上开半径为1.5 mm的半圆凹槽时,该结构所提供的最大剪切速率、最大剪切应力和最大混合指数均较不开槽(凹槽半径0 mm)和凹槽半径为2 mm的高,粒子累积停留时间相对最短。当螺杆螺棱截面梯形底角角度为60°且凹槽半径为1.5 mm时,可使物料获得的剪切效果最好且使其在流道中的停留时间最短,从而为大规模生产加工节约了时间。
Using Polyflow computer software, under the condition of the same temperature, through the four indexes of the maximum shear rate, the maximum shear stress, the maximum mixing index and the accumulated residence time, the angle of trapezoidal bottom angle Influence of Two Variation of Groove Radius on Flow Field of Polyethylene in Single Screw Reactive Extruder. The results show that the maximum shear rate, the maximum shear stress and the maximum mixing index provided by the screw when the angle of trapezoidal bottom angle is 60 ° are higher than those of the bottom angle of 30 ° and 45 °. The cumulative residence time The median shear rate, the maximum shear stress and the maximum mixed index provided by this structure are all less grooved (in the case of a semicircular groove with a radius of 1.5 mm) on a trapezoidal rib with a base angle of 60 ° Groove radius 0 mm) and groove radius 2 mm height, the cumulative residence time of particles is relatively shortest. When the screw trapezoidal cross-section trapezoidal bottom angle of 60 ° and the groove radius of 1.5 mm, can make the material to obtain the best shear effect and to minimize the residence time in the flow channel, thus saving large-scale production time.