1. Products produced by hollow blow molding machines require uniform wall thickness.
2. Usually, hollow containers below 0.2L can be without a billet wall thickness control device. In other cases, the billet wall thickness control device should be considered, especially hollow formed products with complex sections.
3. At present, the wall thickness is usually controlled by changing the gap between the die lip at the head sleeve and the die core. According to the different shape of the head cover and the mold core, the adjustment method of the lip gap is also different.
4. The up and down movement of the mold core is generally driven by hydraulic cylinders.
5. When the middle air blow molding machine processes plastic hollow containers with relatively simple shapes, it can be realized by switching hydraulic system.
6. The electro-hydraulic reversing valve only accepts the power or power off signal, so that the hydraulic cylinder up or down, the distance of the hydraulic cylinder moving (that is, the opening change of the die) is adjusted by the upper and lower limit nut, the speed of the hydraulic cylinder moving is set by the throttling action of the flow valve, and the electrical signal of the electro-hydraulic reversing valve is controlled by the time relay.
7. This control method is simple and inexpensive, but the wall thickness change law is simple, there are only two wall thickness changes, and it can only be used for extrusion and blowing hollow containers with simple shapes.
