For the trouble-free and low-maintenance operation of hydraulic and lubrication systems, the cleanliness of hydraulic media is of utmost importance. 70 to 80% of all machine downtime is caused by impurities due to inadequate oil maintenance. Because precision hydraulic and lubrication systems work with gap dimensions in the micrometre range, even the smallest particles can lead to increased energy consumption due to friction, a reduction in the performance capacity or often costly downtime. It is not unusual for this to be caused by an unscheduled oil change or the replacement of sensitive components.
In addition to conventional full-flow filters which usually remove only the particles larger than 3 micrometres, the strategy at Stauff is to rely on a slow but continuous, and therefore very effective filtration of the so-called bypass flow of the system. The OLS offline filters with a built-in motor-pump unit that are used for this purpose can be subsequently integrated into the hydraulic system, and they function independently from the system cycle, even during scheduled machine downtimes. The fine, specially-developed cellulose filter medium removes even the tiniest impurities that are smaller than 1 micrometre.
At a renowned manufacturer of plastic caps and packaging systems, the purity level as per ISO 4406 (1999) improved by several levels within a period of just 6 weeks, thanks to the widespread use of offline filters on the injection moulding machines. In one case, for example, it changed from purity class 22/18/15 (corresponds to more than 2,000,000 particles cumulatively larger than 4 micrometres per 100ml) to purity class 14/11/8 (corresponds to less than 16,000 particles cumulatively larger than 4 micrometres per 100ml).