Rubber Process Oil (RPO) is a petroleum-derived hydrocarbon oil used as a key processing aid throughout the rubber manufacturing industry. Refined from crude oil, RPO is composed of a blend of paraffinic, naphthenic, and aromatic hydrocarbon compounds — and it's the ratio of these three fractions that defines an oil's character, performance, and best-fit application.
How It Works?
Functionally, RPO works its way between the polymer chains of raw and compounded rubber, improving processability while simultaneously helping manufacturers reduce production costs. It is a foundational ingredient across a huge range of everyday rubber products — tires, hoses, footwear, conveyor belts, seals, and carbon black masterbatches, among others.
RPO Grades
Because rubber compounds and end-use requirements vary so widely, no single oil type fits every application — which is why RPO is produced and supplied in distinct grades tailored to different rubber types and performance needs.
| Specification | Test Method | RPO245 | RPO250 | RPO290 | Furfural Extract (DAE) |
|---|---|---|---|---|---|
| Density @ 15°C, kg/m³ | ASTM D-1298 | 980-1040 | 990-1020 | 980-1015 | 980-1040 |
| Flash Point (COC), °C | ASTM D-92 | 200 | 245 | 230 | Min. 180 |
| Kinematic Viscosity @ 100°C (cSt) | ASTM D-445 | 6-12 | 50-80 | 19-28 | 7-65 |
| VGC | ASTM D-2501 | Max. 0.96 | 0.96 | 0.96 | 0.96 |
| Aniline Point, °C | ASTM D-1287 | Max. 26 | Max. 32 | Max. 32 | - |
Core Applications
The core applications of RPO include the following:
- Adjusts solvency and compatibility across a versatile range, allowing precise tuning of how the oil interacts with different rubber polymers.
- Reduces the viscosity of rubber compounds, making them easier to handle and shape during manufacturing.
- Improves processing efficiency, streamlining mixing, extrusion, and molding operations while lowering energy and time costs.
