Manufacture of Origami Pattern Crash Box Using Traditional Investment Casting Method

The origami pattern crash box has the advantage of producing a predictable mode collapse because it has a pre folded pattern. Investment casting method can be used in the manufacture process of an origami pattern crash box because it can make a complicated product and does not require a lot of machined processes. This study used traditional investment casting with several stages, the first stage was making the wax mold, the second stage was coating the wax mold with calcium bentonite and mixture of soil, husk ash and water. The third stage was heating, the fourth stage was pouring and the fifth stage was finishing. In this research, two metal casting products with origami pattern crash box model were made with the thicknesses of 2 mm and 3 mm. It can be concluded that the result of the 2 mm origami pattern crash box casting cannot be shaped like the design because the liquid metal is unable to enter the mold cavity since it is too narrow. The result of the 3 mm origami pattern crash box casting can be shaped like the design. The casting results have a lot of defects, one of the causes is that the slag has not been thoroughly cleaned before casting. The surface is not smooth evenly since the first coating material is too thin, resulting in direct contact of the liquid metal to the second material layer, which is rough. Future research requires a smooth refractory material to coat the wax mold and further research using investment casting method with high precision that has been developed in the industry.