三、预塑(1Y、2Y、5Y1、7Y0通电)：
3、 Prepreg (1y, 2Y, 5y1, 7y0 electrified)
保压完毕(时间控制)，从料斗加人的熔料随着螺杆的转动被带至料筒前端，进行加热塑化，并建立一定压力。当螺杆头部熔料压力到达能克服注入缸活塞退回的阻力时，螺杆开始后退。后退到预定位置，即螺杆头部熔料达到所需注入量时，螺杆停止转动和后退，准备下一次注入。与此同时，在模腔内的制品冷却成形。
After the pressure maintaining (time control), the molten material added from the hopper is brought to the front end of the barrel with the rotation of the screw, which is heated and plasticized, and a certain pressure is established. When the melt pressure at the screw head can overcome the resistance of piston returning, the screw begins to retreat. When the molten material at the screw head reaches the required injection amount, the screw stops rotating and retreats to prepare for the next injection. At the same time, the product in the die cavity is cooled to form.
一次性餐具设备中的螺杆转动由预塑液压马达通过齿轮机构驱动。泵1和泵2的压力油经电液换向阀15右位、旁通型调速阀13和单向阀12进入马达，马达的转速由旁通型调速阀13控制，溢流阀4为安全阀。当螺杆头部熔料压力迫使注入缸后退时，注入缸右腔油液经单向节流阀14、电液换向阀15右位和背压阀16回油箱，其背压压力由阀16控制。同时，注入缸左腔产生局部真空，油箱中的油液在气压作用下经网11中位进入其内。
The screw rotation in disposable tableware equipment is driven by the pre molding hydraulic motor through the gear mechanism. The pressure oil of pump 1 and pump 2 enters the motor through the right position of Electro-hydraulic Directional Valve 15, bypass speed regulating valve 13 and check valve 12. The speed of motor is controlled by bypass speed regulating valve 13, and relief valve 4 is safety valve. When the melt pressure at the screw head forces the injection cylinder to retreat, the oil in the right cavity of the injection cylinder returns to the oil tank through one-way throttle valve 14, right position of Electro-hydraulic Directional Valve 15 and back pressure valve 16, and the back pressure pressure pressure is controlled by valve 16. At the same time, local vacuum is generated in the left cavity of the injection cylinder, and the oil in the oil tank enters into it through the middle position of net 11 under the action of air pressure.