What Is CV (Constant Viscosity) Rubber? What Does the "60" in CV60 Mean?

What Problem Does It Solve

Natural rubber can harden during storage, leading to increased Mooney viscosity and changes in mastication and mixing conditions. The CV process controls storage hardening to keep Mooney viscosity within a specified window, ensuring more consistent processing batch after batch.

Specific allowable ranges are governed by the contract, technical data sheet, and certificate of analysis.

Common Misconceptions

CV60 is not "premium 3L": 3L emphasizes cleanliness, color, and standardized quality, whereas the core attribute of CV60 is constant viscosity. Their application logics differ, so they are not interchangeable based on price or name alone.

The abbreviation "CV" is also used in cure systems to mean Conventional Vulcanization, which is entirely unrelated to CV rubber. Take care to distinguish the two when reading English technical literature.

Value Assessment

For customers with existing pre-mastication steps, the value of CV60 should be evaluated on total processing economics: whether it reduces mastication time, energy consumption, and equipment utilization, and whether it lowers dump-temperature variation, rework, and scrap. Without process data, raw-material price differentials alone cannot demonstrate the true value of CV60.