Views: 57 Author: Site Editor Publish Time: 2022-09-15 Origin: Site
The tray twin screw extruder consists of several parts, such as transmission device, feeding device, cylinder and screw. The function of the individual components is similar to that of a single screw extruder.
What are the classifications of twin screw extruders?
What are the differences between twin screw extruder and single screw extruder in the way of material conveying?
What is the daily maintenance of the twin screw extruder?
From the point of view of the principle of motion, the same-combing and counter-combing and non-combing types differ in twin screw extruders.
1. Simultaneous interlocking twin screw extruder
There are two types of extruders of this type, low speed and high speed extruders, the former mainly used for profile extrusion and the latter for special polymer processing operations.
(1) Narrow-meshed extruder. Low speed extruders have a tight-combed screw geometry where the gear profile of one screw closely matches the gear profile of the other screw, a conjugated screw profile.
(2) Self-cleaning extruder. Mitrothering high-speed extruders have closely coordinated flight profiles. Such a screw can be executed with a relatively small screw gap, so that the screw has a closed self-cleaning effect. This twin screw extruder is referred to as compact self-cleaning concurrent twin screw extruder.
2. Combating twin screw extruder
The gap between the two worm gears of the closely combed counter-rotating twin-screw extruder is very small (much smaller than with the co-rotating twin-screw extruder), so that positive conveying characteristics can be achieved.
3. Non-interlocking twin screw extruder
The axis distance between the two screws of the non-combing twin screw extruder is greater than the sum of the radii of the two screws.
Type of material delivery
In a single screw extruder, there is a friction resistance in the solid conveying area and a viscous resistance in the melt conveying area. The friction properties of the solid and the viscosity of the melt determine the conveying behavior. If some materials have poor friction properties and the feeding problem is not solved, it will be difficult to insert the materials into the single screw extruder. In twin screw extruders, in particular interlocking twin screw extruders, the transmission of materials to a certain degree is forward displacement transmission, and the degree of forward displacement depends on the gear of one screw and the ratio between the other screw. The screw geometry of the tightly combed counter-rotating extruder results in a high degree of forced displacement conveying characteristics.
1.After the twin screw extruder has been used for 500 hours, iron chips or other impurities from gear grinding are in the gearbox. Therefore, the transmission should be cleaned and the transmission lubricating oil changed.
2.After a certain period of operation, a comprehensive inspection of the twin screw extruder should be carried out to check the firm fit of all screws.
3.If the twin screw extruder suddenly loses power during production, stop main drive and heater. When power is restored, each section of the cylinder must be reheated to the specified temperature and held for a certain time before the extruder can be started.
4.When the twin screw extruder finds the control fill of the instrument and pointer, it should check whether the contact between the thermocouple and other sidelines is good.
Nanjing Haisi is a professional manufacturer of granular extruders for dyeing/dyeing, masterbatch filling, plastic modification and compounding and plastic recycling. Innovative machines are built according to the concept of durability, high efficiency and economical power consumption. And we also have extensive experience in research and development, engineering and customer service. And for some materials we deliver turnkey projects.
