Characteristics of cold and hot runners

　　Cold runner and hot runner are two commonly used runner systems in plastic injection molding processes.They have different characteristics and application scenarios.Below,I will provide a detailed explanation of the characteristics of the cold channel and the hot channel.

　　Cold runner characteristics:

　　1.Cheap and simple:The cold runner system is relatively simple and does not require additional heating equipment.It only relies on air or water cooling to control the solidification of plastic.Therefore,cold flow props have lower costs.

　　2.Suitable for general plastics:Cold runner is suitable for most common plastic materials,such as polypropylene,polyethylene,etc.For plastic materials with lower heat resistance,a cold runner is a common choice.

　　3.Suitable for small products:As the cold runner does not require heating equipment,it is usually more suitable for small products or smaller injection molded parts.

　　4.Easy to produce defects:Cold runner may produce some defects,such as warping,short shot,etc.Due to the lack of thermal control,plastic may contract unevenly or at inconsistent speeds during the cooling process,resulting in a decrease in product quality.

　　Hot runner characteristics:

　　1.Excellent thermal control:The hot runner system can accurately control the temperature of plastic in the runner through heating elements,maintaining the fluidity of plastic and the dimensional stability of injection molded parts.The hot runner has excellent thermal control ability.

　　2.Suitable for high heat resistant plastics:The hot runner is suitable for high heat resistant plastic materials,such as PC,PA,PBT,and other plastics with high melting points.For these materials,the flow and cooling process can be better controlled through a hot runner.

　　3.Suitable for large products:Hot runners are often used for large products or large-sized injection molded parts.By controlling the heating and cooling of the hot runner system,internal stress and defects in large products can be avoided.

　　4.Accurate control and multi channel:The hot runner system can achieve accurate temperature control,making plastic flow uniform.It can also design a multi channel runner system,allowing multiple injection points to be injected simultaneously,improving production efficiency.

　　5.High cost:The hot runner system is relatively complex and requires additional equipment such as heating elements and temperature control equipment,therefore the cost of the hot runner system is relatively high.

　　In summary,cold and hot runners have different characteristics and adaptability scenarios.Cold runners are suitable for general plastics and small products,while hot runners are suitable for high heat resistant plastics and large products,and have good thermal control capabilities.The selection of a suitable runner system depends on a comprehensive consideration of multiple factors such as plastic material,product size,and quality requirements.