It is found that viscosity, oxidation resistance, compatibility with digitalized needle selecting machine, compatibility with fiber under different temperature and other features of lubricating oils have great impacts on choosing lubricating oils for circular knitting machine.
Circular knitting machine has complex working conditions. So it needs lubrication oils having different rolling frictions. 4-ball machine test in laboratory does not always conform to the requirements on site. Relatively, SRX test can adjoin to simulate site more scientifically. SRX pays more attention friction coefficient under different periods and loads.
Besides, mobility and corrosion resistance of lubricating oils also should be taken into consideration.
Different types of yarns may contain different solvents, such as paraffin and spindle oils which have different influences on oil needles elimination. Knitting oil forms oil needles on the surface of knitted fabrics. Most of needles can be identified after being dyed. So, washing of lubricating oils cannot be ignored.
In general, washing is classified into 5 levels in laboratory. However, manufacturers are still lack of unified quantized data to precise definition. And new gray fabrics using cotton yarn, terylene or cotton Dacron as raw materials have new requirements for washing of lubrication oils.
Compatibility of elastic fibers
Compatibility of elastic fibers attracts less attention in market. It has two aspects. One, knitted fabrics have been stored for a long time before being dyed, which causing oil spots be oxidized on grey fabrics. The other aspect is that oil spots cause elastic fibers losing elasticity or uneven breakage partially under high temperature. Then, the fabrics after being set only can be observed under light conditions.