The relationship between cold runner and hot runner

　　Cold runner and hot runner are two different runner structures in the plastic injection molding process,which are interrelated,each responsible for specific functions,and jointly contribute to the production of injection molded products.

　　Cold runner refers to a runner system that reduces the injection temperature by circulating cooling water.In the process of plastic injection molding,the molten plastic is injected into the injection mold cavity,and then the heat is taken away from the injection mold through the cooling water flow through the cold channel,causing the plastic to gradually cool and solidify.The cold runner system is usually located in the fixed part of the injection mold and consists of a series of cooling water pipes.The cooling water is introduced into the injection mold cavity through a fixed throat for circulating cooling.The circulating flow of cooling water can effectively control the injection mold temperature and enable rapid solidification of injection molded products,maintaining their shape and dimensional stability.Cold runner is widely used in the production of products that require a large amount of cooling time and have high requirements for product appearance during the injection molding process.

　　A hot runner is a runner structure that uses a heated pipeline system to maintain plastic flow during the injection molding process.Compared to the cold runner,the hot runner is located in the moving part of the injection mold and typically consists of a heating channel,temperature sensor,and hot runner control system.During the injection molding process,the hot runner system heats the plastic to a molten state and maintains its fluidity through the design and control of the hot runner.The main function of the hot runner is to maintain a stable temperature of the plastic during the injection process,enabling it to smoothly fill the injection mold cavity,and improving the production efficiency and quality of injection molded products.The hot runner is suitable for injection molding products that require high precision,as well as injection molding processes with high requirements for plastic temperature control.

　　Cold and hot runners are interrelated and complementary in the plastic injection molding process.The cold runner reduces the injection temperature through the circulation of cooling water,enabling the plastic to quickly solidify and maintain the accuracy of product shape and size;The hot runner maintains the fluidity of the plastic through heating and temperature control,ensuring that the plastic can fully fill the injection cavity during the injection process,improving the quality and production efficiency of the injection molded product.By reasonably designing and controlling the use of cold and hot runners,optimization of injection molding processes and improvement of product quality can be achieved.