Introduction to Needle valve type preform injection molds

2025-08-29 09:40:18

Needle valve type preform injection mold is a type of mold used for producing plastic preforms such as PET and PP, and it has the following features:

Structural design: It usually adopts a multi-chamber design, with the number of chambers ranging from 1 chamber to 96 chambers or even more. The core components of the mold, such as the core, cavity and threaded neck ring, are usually made of high-quality mold steel, such as S136 and P20, and undergo vacuum quenching, nitriding and other treatments to enhance hardness and wear resistance and extend the service life of the mold. The hot runner system is a key component. The needle valve type hot runner nozzle can precisely control the flow of the plastic melt, and each nozzle can be independently temperature-controlled.

Working principle: During the injection molding process, the plastic melt is conveyed to each needle valve nozzle through the hot runner system. When the mold is closed, the needle valve opens, and the plastic melt is injected into the cavity. Once the cavity is filled, the needle valve closes to prevent the plastic melt from flowing back. By precisely controlling parameters such as the opening and closing time and temperature of the needle valve, the forming quality of the preform can be ensured.

Product advantages: No need for manual cutting of the rubber joint, saving labor and raw materials. It can effectively control the weight error and eccentricity of the preform, ensuring the concentricity and accuracy of the product. The AA value of the product (i.e., the eccentricity index of the preform) can be at a relatively low level. Advanced hot runner design and cooling system can shorten the injection molding cycle of molds and improve production efficiency.