When customers search "TDI prepolymer cast polyurethane", "MDI cast elastomer", "CPU moisture sensitivity", or "longer pot life polyurethane casting", they're usually trying to solve one thing: choosing a CPU system that matches both factory processing conditions and end-use performance.
CPU is made from prepolymer + curative
In cast polyurethane elastomers, a prepolymer reacts with a chain extender/curative to form a solid elastomer. This is the foundation of CPU technology, and the type of isocyanate used in the prepolymer strongly influences reactivity, moisture sensitivity, mixing, and final properties.
TDI-based CPU: fast, forgiving, widely used
Many processors like TDI-based prepolymers for their practical processing behavior. Industry references note that, compared with MDI influence, TDI systems can be less sensitive to moisture and easier to mix-helping stability in everyday production. These characteristics often translate to smoother operations when the workshop environment is not perfectly controlled.
Common search phrases you may recognize:
TDI cast polyurethane elastomer
TDI prepolymer CPU
fast curing polyurethane
high rebound cast urethane
MDI-based CPU: toughness, stability, and premium performance
On the other hand, MDI-based polyurethane is often associated with excellent overall durability, and many sources emphasize stronger toughness/strength, chemical resistance, and long-term stability as key advantages in many applications. Additionally, MDI can provide slower cure / longer open time in some cases-useful when you need more working time for mixing and pouring large molds.
However, MDI systems may require tighter process control: some references highlight higher moisture sensitivity and the need for efficient mixing in MDI-influenced systems.
Practical casting keywords: pot life, degassing, curing temperature
Production success in CPU casting is not only chemistry-it's also processing discipline:
Pot life: the workable time before viscosity rises and gelling starts
Vacuum degassing: to reduce bubbles and voids in thick parts
Curing: cold cure vs hot cure (many systems use elevated temperature curing for optimized network structure)
These terms appear frequently in technical guides for cast polyurethane processing.
How to choose: match your plant conditions + part demands
A reliable decision usually considers:
Part geometry (thick section? complex mold? large pour volume?)
Available equipment (vacuum degassing? moisture control? precision metering?)
Performance priorities (abrasion resistance, tear strength, rebound, compression set, chemical/oil resistance)
If you tell us your target hardness (e.g., Shore A 80–95 or Shore D), operating temperature, and wear environment, we can recommend the most suitable CPU prepolymer + curative route for stable mass production.
Contact (WhatsApp & Email)
WhatsApp: +86 18853364460
Email: greilyn@beiqiao.net