Knowledge

Rubber Process Oils (RPOs) are a mixture of different hydrocarbons used as plasticizers in rubber formulations. Plasticizers play a crucial role in dispersing fillers, reducing viscosity, and improving flexibility by inserting themselves between polymer chains.

RPO is classified into four main types based on its composition:

• Aromatic RPO
• Naphthenic RPO
• Paraffinic RPO
• Green RPO (Low PCA)

Aromatic RPO

Aromatic RPO is derived from the extraction process of base oil refining. It primarily consists of ring-structured hydrocarbons with unsaturated tails.

This oil is dark green, sticky, and has excellent solvency properties. It is extensively used in applications where color is not a critical factor, such as:

• Automobile tires
• Tread rubber
• Conveyor belts
• Automotive components
• Floor mats

Naphthenic RPO

Naphthenic RPO is a petroleum-derived oil mainly composed of cycloparaffin hydrocarbons with less than 10% aromatics. It is known for:

• Good oxidation stability
• Light color & low aromatics
• Excellent low-temperature performance
• Good solvency

Unlike aromatic RPO, naphthenic RPO has a lower environmental impact, making it a preferred choice in various applications, including:

• Tyre manufacturing
• Automotive components
• Industrial rubber goods
• LPG tubes
• Hot water bags
• Molded and extruded rubber products

 Naphthenic RPO

Naphthenic Rubber Process Oil (RPO) is a type of petroleum-derived oil used as a processing aid in rubber manufacturing. most of its components are cycloparaffin hydrocarbons and less than 10% of aromatics.

These oils have Good Oxidation Stability, Light Color & Low Aromatics, Excellent Low-Temperature Performance, and Good Solvency.

Unlike aromatic oils, naphthenic RPO has a lighter color and lower environmental impact, making it a preferred choice in applications such as tyre manufacturing, automotive components, and industrial rubber goods. Additionally, its ability to reduce heat build-up and minimize evaporation losses makes it an efficient processing aid in rubber production.

It is extensively used in the manufacturing of LPG tubes, hot water bags, and molded and extruded products.

Paraffinic RPO

Paraffinic Rubber Process Oil (RPO) is a petroleum-derived oil primarily composed of long-chain paraffinic hydrocarbons. It has a high viscosity index, offering better thermal stability and resistance to oxidation compared to other process oils. Its lower solvency makes it less compatible with some rubber types, but it provides excellent lubrication and minimal volatility, ensuring consistent performance over time. Due to its higher flash point, paraffinic RPO is well-suited for applications requiring heat resistance and durability. It is widely used in rubber manufacturing where long-lasting flexibility and aging resistance are essential, such as in automotive parts, seals, industrial rubber, Butyl tubes, EPDM-based rubber-like hose pipes, and profile products. Its lower aromatic content also makes it a more environmentally friendly alternative to traditional aromatic oils.

Green RPO (Low PCA)

Green RPO, also known as Treated Distillate Aromatic Extract (TDAE), is an aromatic rubber process oil with a low polycyclic aromatic hydrocarbon (PAH) content, making it an environmentally friendly alternative to conventional process oils. The PCA content in this type of RPO is less than 3 wt%.

Applications of Green RPO (TDAE)

TDAE is widely used in various industries, from everyday consumer products to industrial applications. It plays a crucial role in manufacturing:

• Rubber products such as rubber bands, toys, and large tires for automotive and aircraft use.
• Tires, white rubber products, construction materials, automotive components, textiles, and medical applications.

Rubber compounds primarily consist of rubber, processing oils, reinforcing fillers, and oil-based softeners. TDAE's unique properties enhance these formulations by improving flexibility, durability, and performance.

Key Benefits of TDAE

TDAE offers excellent compatibility with both natural and synthetic rubbers due to its balanced solvency and viscosity properties. It provides:

• Good wear resistance
• Enhanced flexibility
• Superior thermal stability
• Reduced environmental impact

Regulatory Compliance and Safety

One of the major concerns with conventional aromatic oils is their high Polycyclic Aromatic Compound (PCA) content, which poses health and environmental risks due to its carcinogenic potential. Regulatory bodies, such as the European Union (EU REACH regulations), have imposed strict limits on PAH content in process oils, driving the industry toward TDAE-based Green RPO.

By significantly reducing PCA levels, TDAE ensures compliance with health and environmental regulations while maintaining the performance, durability, and processing efficiency required in rubber manufacturing.