Compared with ordinary single-screw extruders and parallel twin-screw extruders, the counter-rotating conical twin-screw extruder (hereinafter referred to as "cone twin") has its unique characteristics of large feeding area, large compression ratio, and conical twin extruder. The barrel screw is more efficient in shearing and mixing materials in the longitudinal and transverse directions, and has a better plasticizing ability. Therefore, it is particularly suitable for producing plastic profiled products with high-calcium-filled PVC powder as raw material.
The conical twin-barrel screw is an important part of the injection molding machine and the core of the injection molding machine. It can be said that the correct use and maintenance of the conical twin-barrel screw plays a decisive role in the production efficiency and service life of the injection molding machine. To effectively extend the service life of the conical twin-cylinder screw, correct cleaning and use are the key.
In the industry, the cleaning and maintenance of conical twin-cylinder screws mainly include the following two points:
1. Use barrel cleaner
If the product is replaced frequently with raw materials or the plasticization temperature range of the residual material in the barrel is quite different from that of the refill, in order to save raw materials and improve work efficiency, it is more economical to use a barrel cleaner. The special cleaning agent is a kind of substance similar to rubber material. It does not melt in the barrel at high temperature. It is softened in the screw groove of the conical twin barrel screw. It can be moved forward in the screw groove of the conical twin barrel screw. The residual material is taken away, so that the inside of the barrel can be cleaned.
2. Use the refueling ejection method
The plasticizing temperature range of the raw material to be replaced is higher than the plasticizing temperature range of the residual material in the barrel. The barrel and nozzle can be heated to the extremely low plasticizing temperature of the newly replaced raw material, and then the new material is added and continuous air injection , Until there is no residual material in the barrel.
In addition, the correct use of the conical twin barrel screw method can extend its life. When the injection molding machine is started, the injection molding machine must be fully preheated at this time. When the barrel reaches the preset temperature, keep the temperature under Φ60mm for another 15 minutes. After the above 30 minutes, start the motor start cone twin barrel screw related actions; the material and the cone twin barrel screw must match, especially corrosive materials and hard materials, such as PVC and fuel resistance, and glass fiber increased materials Use professional screws, never use ordinary screws; and please pay attention to the following points:
1. If the corrosive materials for ordinary machines must be cleaned and replaced with stable materials such as HDPE, HIPS, etc. in time after use;
2. If glass fiber material is accidentally used in an ordinary machine, be sure to use high material temperature, low screw speed, and low back pressure.