Why do quality problems with cylinder lead to vertical lines and oil streaks?

We can see from the following picture that the cylinder of ordinary material has a rough surface under the microscope, while the free cutting alloy steel cylinder has a smooth and clean surface because the alloy is added to make the cutting easier.

The rough surface of the ordinary material cylinder increases the friction between needle and cylinder.During the operation of the machine, the friction heats up and causes the internal temperature of the cylinder to rise.

The high temperature causes the needle lubricating oil to evaporate rapidly, resulting in insufficient lubrication and aggravation of friction, and further vicious circle.

This eventually leads to the cylinder and needle worn down, the knitting needle position is skewed to produce vertical lines, and the rubbing metal powder mixed with needle oil causes the cloth surface to produce oil streaks.

So in the purchase of circular knitting machine, we must understand the material and process of the cylinder.