🔍 Key Concepts

• Lubricating oil additives (what they are and how they behave in oil) • Difference between absorbent and adsorbent actions • Which filters are designed to remove solid particles only versus those that can remove dissolved or finely dispersed substances

💭 Think About

• Think about which type of filter would actually interact with and remove chemical components dissolved or suspended in the oil, not just dirt or particles. • Consider what happens when oil additives come into contact with materials that have a large surface area and chemical attraction for those additives. • Ask yourself: Which filter types are normally used only for mechanical filtration, and which are used for purifying or polishing the oil by removing more than just solids?

✅ Before You Answer

• Identify which filter type uses physical trapping of particles (screening or straining) versus surface bonding of molecules. • Verify which filter is commonly associated with “polishing” or “reclaiming” lubricating oil by removing oxidation products and additives. • Check which option is designed to retain contaminants by chemical or surface attraction, not just by size exclusion.