Study And Development Of A New Type Nozzle With Heat Pipe In Hot Runner System

Abstract: The technology of the heat-pipe-type nozzle in hot runner system is another original technology of industrial development in injection molding and die, which makes up the shortcomings existed in common hot runner techniques for the application of heat pipe in hot runner system. In order to verify the feasibility of this new technique, the comparison of heat transfer capacity between heat-pipe-type nozzle and common nozzle was studied in theory firstly, and then a heat-pipe-type nozzle was designed to do the successively heat transfer experiment and injection molding experiment.As the results show, the heat-pipe-type nozzle has preferable isothermal performance and more excellent heat transfer capacity in contrast to the common nozzle. The interior temperature difference of common nozzle in axial direction is surging between 8℃～18℃ whereas that of heat-pipe-type nozzle is within 1℃ under same heating conditions. The heat transfer capacity of heat-pipe-type nozzle is 9.3 times of that of common nozzle while the energy loss is half that of common nozzle when one end of the heat-pipe-type nozzle is heated and the whole common nozzle is heated. In experimentation of polyformaldehyde (POM) injection molding, the heat-pipe-type nozzle is running well and the article appearance looks good.