Introduction to PU Injection Molding Machine Production Systems – Other Systems

1. Mold Temperature Control System

In the operation of a polyurethane injection molding machine, mold temperature control is a crucial aspect that directly affects product quality and the production cycle. Every polyurethane injection molding machine must maintain specific mold temperatures at different process stages, depending on the product type and manufacturing method.

When producing heat-molded foam products with a polyurethane injection molding machine, air is typically used as the heat transfer medium. After pouring, hot air is applied to the mold during the curing phase, and preheating is conducted before pouring to ensure temperature stability. For high-resilience foam or self-skinning foam, where precise temperature control is critical, a polyurethane injection molding machine is often equipped with an independent thermostatic water system. This system circulates water at a set temperature through built-in pipes within the mold, enabling heating or cooling as needed. This process helps maintain the mold temperature within the optimal range, ensuring consistent product quality and stable operation of the polyurethane injection molding machine. Depending on mold type, the thermostatic system may be stationary or move with rotary or oval-track molds, typically servicing 2–4 mold stations per unit.

2. Control System

A well-designed control system is fundamental to the performance of any polyurethane injection molding machine. Its primary function is to regulate and monitor parameters such as temperature, pressure, flow rate, mixing ratio, and injection timing throughout the process. Earlier systems relied heavily on manual operator input, but modern polyurethane injection molding machines now use advanced control technologies.

Today’s polyurethane injection molding machines are managed by programmable logic controllers (PLCs) and computer systems. These technologies work together to automate the production process and ensure accurate process control. In addition to production control, the computer system in a polyurethane injection molding machine also handles quality monitoring, trend analysis, and database management. This comprehensive approach ensures that each polyurethane injection molding machine delivers high product quality, real-time data tracking, and excellent reliability in manufacturing.

3. Ventilation System

The polyurethane injection molding machine also incorporates a ventilation system to maintain a safe working environment. During pouring, demolding, and mold release agent spraying, trace amounts of harmful gases may be released. Therefore, localized mechanical ventilation units are installed at key workstations, especially those involving mold release agents. Some polyurethane injection molding machines also feature water curtain absorption systems to further enhance operator safety and ensure environmental protection.