SCCARE CCS: Surface Treated Sulphur for Improved Dispersion.

Chemical Composition:
Material : Treated Sulphur
Appearance : Yellow Powder
Ash,% : 1.0 Max.
Mesh Size : 200 Min.
Moisture,% : 1.0 Max.

Function:

Sulphur Dispersion has always been problem for rubber industry. This is particularly true for Nitrile Rubber, to some extent Polychloroprene and EPDM Rubber.

SCCARE CCS has been electrically / chemically surface treated to avoid agglomeration. This electric charge allows the particles to disperse well in rubber matrix. It very effectively replaces Magnesium Carbonate Coated Sulphur.

Advantages of Using SCCARE CCS:

1. Avoids blooming during storage of green compound.
2. No formation of aggregates appears in the rubber avoiding local over cure.
Improved dispersion provides higher physical properties, both before and after ageing.
3. In dynamic applications it provides higher service life. E.g. in rice dehusking rollers. Due to local burning and presence of phenolic resin in the product, failure of the product can be earlier and erratic. Proper dispersion of sulphur avoids such failure.
4. In coloured applications, uniform dispersion of sulphur is very important, which is provided by SCCARE CCS. Due to this brown spots are not observed on the surface.

Typical Applications:

Rice Dehusking Rollers, Football Cover, Textile Cots and Aprons, LPG Tubing
Textile blankets and Rolls, Oil Seals and O Rings based on NBR.

Mixing Cycle:

SCCARE CCS treated sulphur should be mixed as usually followed for various rubbers. For Nitrile Rubber, it should be added immediately after rubber is warmed up and forms the band on the mill. For soft compounds, it can be added at the last stage of mixing. Tight nip refining will help further improvement in dispersion of SCCARE CCS.

Compounding Comparison & Guidelines:

Comparison of ageing properties:

Formulation: Nitrile Rubber (Medium): 100, ZnO: 5, Strearic Acid: 1, HAF: 30,
Clay: 10, DOP: 10, CBS: 1.2, TMT: 0.2, Sulphur: 1.5

Rheometric Test Report at 150° C MC SCCARE CCS
a)Scroch Time, Ts2, Mins. 03.94 04.17
b)Cure Time, Tc90, Mins. 20.67 21.39
c)T Min., In LBS. 11.61 11.57
d)T Max., In LBS. 68.84 67.96

Curing Temp °C / Time Min. 150/20 150/20
a)Hardness (Shore A) 62.00 62.00
b)Tensile Strength (kg/cm²) 162.00 171.00
c)Elongation at break (%) 550.00 580.00
d)Modulus: 300% (kg/cm²) 56.00 48.00

Physical Testing After Ageing at 100 °C for 48 hrs.
a)Hardness (Shore A) 68.00 67.00
b)Tensile Strength (kg/cm²) 144.00 162.00
c)Elongation at break (%) 410.00 490.00
d)Modulus: 300% (kg/cm²) 100.00 88.00

Compression Set at 70 °C for 48 hrs, 25% Deflection (%) 34.20 30.10

Observation Remarks: Better physicals are observed with SCCARE CCS over MC Sulphur.