The Difference between Round Barrel and Square Barrel on Extruders

Regarding the main machine of the extruder, sometimes we see that the barrel made by the manufacturer is round, and sometimes the barrel is square. Then, what is the difference between a round barrel and a square barrel?

1. The square barrel has high machining accuracy
2. There is an alloy sleeve inside the square barrel
3. The material of the square barrel is better
4. Production cost of square barrel is higher
5. The heating rod of the square barrel is heated more evenly and the temperature is more accurate than the heating piece of the round barrel.

Principle: The square barrel is internally heated. The heating rod is inside the square barrel is close to the temperature control probe, so the heating is more uniform; While the round barrel is an external heating plate. The temperature gradually rises from the outermost to the inner, so the temperature is uneven.