Product Center
HulunbuirFirst IS90-80
Phone: 0750-6680778
Product Description
Pain point you may have faced
You have seen it before: a freshly mixed compound looks perfect, but after a few days in storage, a white or yellowish powder appears on the surface – sulfur bloom. The bloom not only ruins the appearance of the final product but also reduces tackiness, interferes with adhesion to fabrics or steel cords, and can even cause uneven cure. Switching to different accelerators or adjusting the mix cycle hasn't solved the problem.
Why IS90‑80 is different
First® IS90‑80 is a high‑thermal‑stability insoluble sulfur specifically designed for natural and synthetic rubbers. Unlike ordinary sulfur, it remains in a polymeric, insoluble form during mixing and storage, which dramatically prevents sulfur migration to the surface. This means no more unsightly bloom, even for compounds that sit on the shelf for weeks.
What you gain
Bloom‑free surfaces – your tires, hoses, belts, and footwear look clean and professional.
Better adhesion – the rubber compound stays tacky, improving bonding to reinforcing materials (steel cord, fabric, etc.).
Less accelerator‑induced blooming – works well with thiazole and other accelerators without triggering sulfur migration.
Consistent cure – the full amount of sulfur remains available inside the compound, not on the surface.
Real‑world result
A tire manufacturer in Southeast Asia struggled with sulfur blooming on their steel‑cord belt skim compound. After switching to First® IS90‑80 at the same dosage (2.5 phr), the bloom disappeared completely. Adhesion values measured after two weeks of storage increased by 35%, and customer complaints about ugly white spots on the sidewall dropped to zero.
Typical specifications
Appearance: light yellow granules
Active ingredient: insoluble sulfur (approx. 90%) + polymeric binder
Thermal stability: excellent (resists conversion to soluble sulfur during processing)
Recommended dosage: 1–5 phr depending on the recipe (replace ordinary sulfur 1:1)
Packaging: 25 kg carton with inner PE liner
Storage: 12 months in unopened packaging, cool and dry (below 40°C)
Try IS90‑80 at no cost
We know that each compound behaves differently. We are happy to send you a free sample. Test it on your most bloom‑prone recipe – no pressure, just your own evaluation.
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