To ensure some metal-to-metal contact and a firm grip in the cold rolling mill, the viscosity of the cold rolling oil should be as low as possible. However, low viscosity oils generally have low flash points and undesired VOC emissions. This is not the case with the new generation of HDM cold rolling oils with increased safety.

Most cold rolling mills require low viscosity pure cold rolling oil for optimum metal surface quality. Cold rolling oil is needed to lubricate the roll bite and cool the metal strip.

Why Cold Rolling Mills Need Low Viscosity Cold Rolling Oil

The cooling efficiency of cold rolling oil increases with the decrease of viscosity. At higher speeds, low viscosity cold rolling oils are required to prevent hydrodynamic film formation. Higher viscosities may form hydrodynamic films at high rolling speeds. Lubrication of the hydrodynamic areas means there is no metal-to-metal contact, thus reducing friction and grip. In order to process metal strips with roll nip and reduce surface roughness, metal-to-metal contact is required.

This means that the viscosity of the cold rolling oil should be as low as possible within the design range. For cold rolling mills that also use cold rolling oil to lubricate bearings, a certain minimum viscosity is required (eg kinematic viscosity at 40 C is 7.6 mm2/s).

Safety Issues with Low Viscosity Oils

Obviously, low viscosity oils also have low flash points. The new development was made because some cold rolling mill temperatures can approach the flash point of standard cold rolling oils. These increased flashpoint investigations can often be aligned with reductions in VOC emissions. Smaller (organic) molecules play an important role in flash point and VOCs. Furthermore, this is not only to reduce VOC emissions in the environment, but also to improve the air quality of the people who work closely in the factory.

HDM cold rolling oil has higher safety

Over six years ago, HDM launched a range of products with lower VOC emissions and higher flash points to comply with stricter local emissions and safety regulations. Recently, HDM research departments in Italy and the Netherlands jointly developed a next-generation cold-rolled oil with higher safety.

This new range of high purity synthetic base stocks is the latest in technology, featuring high flash points and advanced safety characteristics. It contains additives specially developed for the manufacture of metal strips to ensure a high quality surface finish.