Ecosky-3103 is typically used at 20-60 phr (parts per hundred rubber) as an extender oil and plasticiser in tyre and technical rubber compounds. You can start at the same phr as the TDAE/MES oil it replaces, then fine-tune by verifying mix viscosity, filler (carbon black/silica) dispersion and cure time. R&D validation is recommended for each formulation.
Dosage ranges (phr)
The role of a process oil is to soften the rubber, wet the filler and improve mix processability. Ecosky-3103 fills this role much like petroleum-based oils. As a starting point, these ranges can be used by application type:
- Tread compounds: about 20-40 phr; tuned to the hardness and grip balance.
- Sidewall and inner liner compounds: about 30-50 phr; flexibility and low-temperature behaviour prioritised.
- EPDM seals/profiles and technical rubber: about 40-60 phr; the upper range in soft, high-filler-loaded compounds.
- Conveyor belts and industrial goods: within 20-60 phr depending on the application.
Carbon black and silica dispersion
One of a process oil's most critical functions is wetting the filler so it disperses homogeneously through the mix. Ecosky-3103 shows good wetting behaviour in carbon-black-loaded compounds and preserves mix homogeneity. In silica compounds, working alongside a silane coupling system, it is important that the oil does not interfere with the silica-silane reaction; the oil is therefore usually added at the appropriate mixing stage and the dosage tuned to target Mooney viscosity and dispersion quality.
- At high filler loading, a higher phr softens the mix and improves processability.
- Excess oil eases dispersion but can lower hardness and modulus; balance it against target mechanical values.
- In silica systems, control the oil addition sequence so silanisation efficiency is not affected.
Viscosity and processability effect
Ecosky-3103's viscosity is 200-500 mm²/s at 40°C and 20-40 mm²/s at 100°C (ASTM D445); density at 15°C is 955-995 kg/m³. This profile lowers mix Mooney viscosity and eases calendering and extrusion. The low pour point and typical glass transition temperature (Tg) of about -65°C support cold-weather flexibility. Because its viscosity range is similar to petroleum-based oil, the switch requires no major change in process parameters.
Cure and final-mix notes
A process oil is not a curing agent, but its dosage and type indirectly affect cure kinetics and final crosslink density. When switching to Ecosky-3103 the sulphur/accelerator system is usually kept; still, it is recommended to verify optimum cure time (t90) and reversion behaviour on a rheometer. For a gradual switch you can start by blending with TDAE/MES and move step by step to a full replacement.
Safe handling and storage
What is the typical dosage for Ecosky-3103?
The typical use range is 20-60 phr. Tread compounds usually use the lower end (20-40 phr), while soft/high-filler technical rubber and EPDM profiles use the higher end (40-60 phr). The exact value should be set by R&D based on formulation targets.
Can I use my existing TDAE dosage as-is?
As a starting point, yes; you can begin at the same phr as TDAE because the viscosity profiles are similar. Then fine-tune the dosage by verifying Mooney viscosity, filler dispersion and cure time.
What should I watch for in silica compounds?
The addition sequence matters so the oil does not interfere with the silica-silane reaction; the oil is usually added after the silanisation stage. Dosage should be set against target Mooney viscosity and dispersion quality.
Does Ecosky-3103 change cure time?
A process oil is not a curing agent, but its dosage can indirectly affect crosslink density. The sulphur/accelerator system is usually kept; verifying t90 and reversion on a rheometer is recommended.
How should I make the transition?
You can switch fully at once or blend with TDAE/MES for a gradual transition. In both cases, R&D testing is recommended to confirm the final compound's mechanical and cure properties.
