Hydraulic Oil filtration
Hydraulic oil are one of the typical lubricant categories where filtration of the oil can significantly extend the oil drain interval, but most importantly the lifespan of the machine even 5x (source: Hyprofiltration - see table page 4). Filtration normally provides minimum 2 to 3 times longer oil change interval. Dirty oil cause unscheduled downtime, increased wear of the machine and lost production. Oil monitoring and filtration can lower your production cost per unit significantly. Filtration is done during regular machine operation.
See Oil Filtration for info regaring statistics for unscheduled downtime by Rexroth
Arburg is informing that in 70 to 90 % of cases, damage to hydraulic components is attributable to impurities in the hydraulic system. ARBURG oil management
Arburg requires minimum cleanliness level of 18/15/12 (ISO 4406- number of particles larger then 14/6/4 microns - ISO Oil Cleanliness codes). Conventional oil from the barrel does not conform to the required purity class and results in contamination of the hydraulic system, thus it needs to be filtrated when filling the machine.
Information regarding the lifespan extension of parts see here page 4 of the document