100 percent safety concerning the production of PET bottles

The ZD-high-pressure compressors by Atlas Copco are the first worldwide to allow a complete oil-free inflation of PET preforms. For the bottle makers and fillers this reduces the risk of contaminating the products with oil and unclean compressed air to zero. The testing method for certification according to ISO 8573 was implemented by TÜV Rheinland on the basis of the strictest regulations currently existing and by simulating lifelike industrial operating conditions. The tests have been dealing with all possible kinds of contamination with oil, regarding liquids, aerosols and vapours. Result: Oil was not traceable under any circumstances. So Atlas Copco is the only manufacturer with a Class 0 certification for its whole oil-free compressed compressor fleet.

Contamination with oil is the snake in the grass for all bottling plants and sterile environments. Many users don’t trust the quality of their compressed air and therefore implement additional process steps after the stretch blow-moulding in order to maintain the required sterility. By establishing ZD-high-pressure compressors this effort could easily be avoided. The ZD compressor doesn’t just compress oil, it also requires an all-time low amount of energy due to its four-level architecture with standard ZR screw compressor and downstream booster. In addition the ZD is equipped with an integrated adsorption drier of the MD-production run and is also available with rotation speed control (VSD, variable speed drive). “Implementing such a machine is especially useful with frequently varying bottle sizes”, says Reimund Scherff, business line manager Oil-free Air, Atlas Copco, “because then the system needs highly variable amounts of compressed air“. By accordingly modulating its rotation speed the VSD compressor was able to react faster. That was how energy savings from up to 35 percent could be achieved. In reusing the compressed air from the blow-moulding line these values could be increased further still.