High Filling Granulation System
The high filling operation is to fill a high proportion of inorganic powder into the matrix resin to make the filler uniformly dispersed. During the processing, the matrix resin must not be excessively broken by shearing and maintain good physical properties; and the equipment must maintain high output , Reduce wear and loss, maintain reasonable economy. The key technologies are as follows:
1. The formula system is designed reasonably and properly lubricated. The base resin has reasonable melting index and ratio, uniform powder particle size, and suitable surface treatment. The typical formula is PE/PP+85%CaCO3+ lubricant to produce calcium powder filled masterbatch. Generally, coupling agent is added to increase the binding of calcium powder and resin.
2. Each formula can be independently metered into the extruder through a weightlessness scale, or it can be pre-mixed through a blender and then added to the extruder
Based on the multi-feeding method of weightlessness scale, the main feed port is filled with resin, additives and part of calcium powder, and the other or two side feeds are added with remaining calcium powder. All materials are mixed by the extruder. The equipment has a high degree of automation, and requires high extruder exhaust, mixing capacity and wear resistance.
The pre-mixing method based on the high-speed mixer is to add all the formula materials to a high-speed mixer to pre-mix to a certain time or a certain temperature, and then add the pre-mixed materials to the twin-screw extruder for further mixing. In the premixing process, the lubricant has a strong infiltration effect on the powder, and a large amount of water vapor is naturally discharged after premixing to a high temperature, so the difficulty of feeding the material to the extruder is reduced and the output is greatly improved. It is also possible to configure a cold mixer after the high-temperature mixer to cool high-temperature materials to avoid resin degradation and performance degradation during long-term storage of high-temperature materials
The pre-mixing method based on the internal mixer is to add all the ingredients into the internal mixer for pre-mixing for a certain period of time, and then force the pre-mixed materials into the twin-screw extruder for further mixing. Compared with a high mixer, the internal mixer is deeply pre-mixed until the resin has been plasticized, which greatly reduces the requirements for the extruder's mixing capacity and greatly improves the output. Because the internal mixer is fully pre-mixed, it does little damage to the material, and can be used in high dispersibility and high physical property requirements, such as film filling masterbatch, stone paper filling masterbatch, etc.
3. The maximum screw speed is 900rpm, the maximum torque level is 11N.m/cm3, the inner and outer warp ratio Do/Di of the screw is 1.66, and the large length-to-diameter ratio is 56, which can significantly increase product output while ensuring the mixing capacity