Polyurethane casting is a process that uses liquid reactive molding (RIM) or conventional casting methods to inject polyurethane raw materials into a mold, where a chemical reaction occurs, forming a solid product. Its core lies in the addition reaction between polyols and isocyanates. By controlling the ratio, temperature, and time, materials with different properties can be prepared.
Polyurethane materials possess excellent elasticity, wear resistance, oil resistance, and corrosion resistance, making them widely used in industrial rollers, seals, cushioning pads, and screens. Compared to injection molding or extrusion, casting offers advantages such as lower equipment investment, suitability for small to medium batch production, and the ability to manufacture complex structural parts.
In actual production, casting processes are typically divided into manual casting and mechanical casting. Manual casting is flexible but less stable, while mechanical casting achieves precise control through metering pumps and mixing heads, making it suitable for large-scale production.
Furthermore, the moisture content of the raw materials must be strictly controlled during casting, as moisture reacts with isocyanates to produce bubbles, affecting product quality. Therefore, drying treatment and environmental control are key to the success of the process.
