Operation of twin screw extruder
Seven, twin screw extruder operation
1. The difference from the operation of a single screw extruder
The twin screw extruder operating procedure is generally the same as the single screw extruder, but also
There are differences. To deal with PVGU, for example, the use of reverse rotation meshing type twin screw extrusion
The main points of operation are described below.
(1) temperature setting is generally "saddle" shape distribution, that is, both ends of the high, low,
Die temperature up to 190 t
(2) Power on and shutdown When the new device is turned on, when the set temperature has reached the specified level
Value and insulation for a certain time, add cleaning materials, running at low speed, until the material from the die
After the outflow, add dry mix to run. Before the shutdown, replace the dry mix with the cleaning material
Material, the screw clean up. Can be retained in the mouth of the cleaning material, the next production can be directly heated; also removable mold,
Remove the melt.
1 (3) Quantitative feeding
Unlike single screw extruders
The feed rate should match the extrusion speed.
Line quantitative feeding. Feeding ztitr and f
The charging in the rod groove is judged.
, Twin screw extruder must be real
The main screw can be viewed from the vent hole
For example, tapered twin screw at the vent hole at the groove
Loading 1/2 is appropriate.
(4) Vacuum conditions in the plastic refining process vacuum, you can remove the volatile matter
And moisture, is conducive to improving product quality. The timing of the vacuum can be observed from the exhaust, such as
Fruit material has been partially melted, or reach Wengeng state, you can open the vacuum pump, no Jill, will
The powder pumping vacuum system, or even blocked.
2. CM80 Cone Twin Screw Extruder operating examples
The main process parameters of the machine are as follows.
Number of Screws 2; Screw Type
Tapered (counter-rotating); screw diameter 80 /
143 mm: Effective length of screw
1575 mm, screw speed 0 a 36.4 r / min,
Twin screw extruder at work,
Higher than cylinder temperature. Therefore, CM80
Reduce the screw temperature.
The material produced by the shear heat will cause the screw temperature
The extruder is cooled in a screw core with a circulating oil
CM80 extruder barrel with exhaust port,
And with the vacuum pump connected to the material
Of the gaseous substances discharged to ensure product quality.