Injection pressure loss in hot runner systems cannot be ignored. Many hot runner mold users have a misconception that the cold runner has a much smaller injection pressure loss than the hot runner. The reason is that the plastic solution located in the hot runner is always hot throughout the injection molding process. In fact, many times the situation is just the opposite. Due to the design of the hot runner structure in the hot runner mold, the flow distance of the solution in the hot runner system is greatly increased. Therefore, the injection pressure loss in the hot runner system is also often large. In practical applications, there are many cases in which injection molding is difficult due to excessive injection pressure loss in the hot runner system. Therefore, for processing plastics with poor fluidity (such as PC, POM, etc.), the flow distance of the solution in the hot runner system is large, or the weight of the workpiece is large, CAE software should be used for flow channel analysis and calculation. The CAE software that focuses on the flow path analysis calculation has MoldCAE and the like.