Cooling lubricants are being used in ever increasing quantities in machining production. They ensure effective cooling of the tools and at the same time increase the surface quality of the workpieces. Cooling lubricants are now indispensable for the manufacturing process: according to the Federal Office of Economics and Export Control, around 70,000 tons of water-miscible and non-water-miscible cooling lubricants were consumed in the metalworking industry in 2016.

As useful as cooling lubricants are, it is important to handle them with care. Caution is particularly important on machines with high cutting speeds and open-pored grinding wheels: Here, for example, water-mixed cutting fluids produce increased aerosol and vapor concentrations in the air. These atomized cutting fluids often contain carcinogenic nitrosamines or germs that promote infections. They can also cause skin diseases or inflammation (e.g. in the case of micro-injuries). Last but not least, cooling lubricants contaminate production areas and endanger the safety of personnel by creating slippery surfaces. Contamination of the workplace with cooling lubricants should therefore be kept to a minimum.

The DVS Group, to which Pittler T&S belongs, has therefore been equipping its machining centers with fully sealed safety windows from Hema since 2010. These consist of a polycarbonate and a safety glass pane and are designed to offer significantly more protection than the simple polycarbonate (PC) panes used in many machine tools. The latter are constantly exposed to wetting with cooling lubricants and therefore quickly become brittle. As a result, the panes lose their ability to deform and only provide the operator with limited protection against flying chips and workpiece parts. The tightness of the discs also decreases significantly due to wear, meaning that coolant vapors can quickly escape to the outside.

PC machine safety windows from Hema, on the other hand, not only have an abrasion-resistant coating, but are also combined with a safety glass pane on the working area side. Thanks to encapsulation and sealing, this safety glass composite is permanently protected against external influences. The effectiveness of the protection has been confirmed in tests: For example, the penetration resistance of the 12 mm thick PC panes used at Pittler is a remarkable 1,125 Nm in an impact test in accordance with DIN EN 12415 with a 100 g projectile.

However, the all-round seal not only ensures stability, it also prevents coolant from penetrating the polycarbonate pane and attacking it. The PC pane therefore retains its protective properties for a significantly longer period of time than simple, unprotected PC panes.