| 摘要 |
A method of manufacturing a helmet containing a hollow layer and a helmet manufactured by the same are provided to increase the impact-absorbing force through the second step-absorption operation of the impact energy by the inner and outer layers. A method of manufacturing a helmet comprises the steps(100,102) of filling a raw material in the cavity made by a set of molds to mold the helmet and of operating the injection molding; a step(106) of injecting gas in the cavity when the injection molding step is around 80~90% done; and a step of integrally molding the inner and outer layers of the helmet and forming the hollow layer between the inner and outer layers. The filled volume of the raw material is weighted to prevent the residual volume of the raw material from being left in the mold after the injection molding completion(108) at the injection molding step. The temperature of the mold is around 50~85 degree. The thickness of the inner and outer layers of the helmet manufactured by the injection mold is practically constant through the whole helmet. |
