Valve rubber is commonly used in various applications due to its excellent elasticity and flexibility. However, with the rapid development of new materials in recent years, polyurethane materials have increasingly become a better alternative for many rubber applications. In this article, we will discuss why vulcanized rubber should be replaced by a CPU (cast polyurethane) material, and compare the advantages and disadvantages of traditional plastic rubber and polyurethane materials through data and tables.
The superiority of CPU over traditional plastic rubber lies in its excellent mechanical properties. The CPU material has high tensile strength, tear strength, and wear resistance, which enables the material to be used in harsh environments without being easily damaged. The following table shows the comparison of mechanical properties between cured rubber and CPU material:
| Material | Tensile Strength (MPa) | Tear Strength (kN/m) | Hardness (Shore A) |
| Cured Rubber | 20-40 | 15-40 | 30-90 |
| CPU Material (70A hardness) | 55-70 | 40-80 | 75-95 |
As shown in the table, the CPU material features significantly higher tensile strength, tear strength, and hardness compared to cured rubber.
Besides, CPU materials possess better resistance to chemicals, UV light, and ozone, which extends its lifespan even in corrosive and outdoor applications. The following table shows the comparison of chemical resistance, UV resistance, and ozone resistance between cured rubber and CPU material:
| Material | Chemical Resistance | UV Resistance | Ozone Resistance |
| Cured Rubber | Poor | Poor | Poor |
| CPU Material (70A hardness) | Excellent | Good | Excellent |
From the table, we could find the CPU material performs significantly better than traditional vulcanized rubber in all aspects.
In conclusion, although traditional valve rubber has been widely used in various applications, the polyurethane material is increasingly becoming a better alternative due to its excellent mechanical properties, chemical resistance, UV resistance, and ozone resistance. In the future, more applications will adopt the advanced CPU material for better performance and a longer lifespan.
