*2.1.3 Spray metal tooling*

Metal spray molds had been used effectively in low-pressure procedures including RIM, vacuum forming, and rotational molding. Currently, the improvements in spray metals and spraying methods give rise to its use in injection molding.

The order of steps is like the one applied to manufacture epoxy molds, with the exception that the pattern is sprayed first with metal and then supported by epoxy resin filled with metal. The process of spraying with, for example, an electrical compressed air gun gets applied until the required shell thickness is met (0.5 mm + − mm is reported). In this technique, the material consisting of pattern must have increased strength and durability to withstand the thermal impact inherent: in this regard, the use of ABS FDM masters, polycarbonate SLS masters, and machinable wax gave positive results some of the indirect methods which uses AM, and their advantages and disadvantages are shown in **Table 2**. In addition to them,


#### **Table 2.**

*Advantages and disadvantages of indirect methods, which use AM.*

**93**

*Utilization of Additive Manufacturing to Produce Tools DOI: http://dx.doi.org/10.5772/intechopen.89804*

spray metal tooling depicted in **Figure 2** [6].

**2.2 Direct methods of rapid tooling**

injection molding by up to 40% [6].

going on in order to increase its applicability [6].

SLS process can be seen in **Figure 3** [6].

*2.2.3 Copper polyamide tooling*

*2.2.1 Direct AIM*

*2.2.2 SLS RapidSteel*

a reflective coating could be protective. Also, SLA models were tried process of the

All the past AM techniques mentioned include indirect production of a master model producing the tool. The time required to manufacture and complete its pattern is one of the major issues with the manufacturing tool. Moreover, such replication methods can still cause increase in inaccuracies. As a result, although the most of direct tooling techniques have constraints, corporations ask directly produced tooling. Applying additive "layer manufacturing" methods, further properties may get included in the item, which cannot be acquired with conventional tooling techniques. Conformal heating (or cooling) channels provide the system with the ability to heat or cool the exact points needed, and it is the most critical property of it. It is shown that conformal channels could result with the reduction in cycle times of

Rather than making a master stereolithography pattern around which a material is cast, it also is possible to build the cavity directly on the stereolithography machine. This method has been described as Direct AIM by 3D Systems (Valencia, CA). (AIM stands for ACES Injection Molding. ACES stands for "accurate clear epoxy solid," which is a stereolithography construction style.) Even though they are not as strong or difficult as standard tools, various thermoplastics can get injected into those cavities so that elements to get used could get manufactured. Even though only less abrasive and lower melting polymers can get molded, studies are

Just as a cavity can be produced directly by stereolithography, the laser sintering method can also be used to construct tool cavities directly. Digital core and cavity geometry models are developed and sent to a Sinterstation manufacturing device in RapidSteel powder with DTM's RapidSteel (also known as RapidTool, earlier similar methods are known as Indirect Metal Selective Laser Sintering). This material comprises of mild stainless-steel particles that are covered with a thin layer of a material for a polymer binder. The Sinterstation generates green components that fire in a furnace afterwards. The furnace removes the polymer binder and by capillary action infiltrates bronze into the inserts of the mold. This method generates a completely thick tool consisting of approximately 60% steel and 40% bronze. Then the inserts are completed, drilled for ejector pins, and fitted to the base of the mold. The technique generates a durable mold that can be used as well as die-casting apps for injection mold tooling. Hundreds of aluminum, zinc, and magnesium components were casted using RapidSteel molds. The technique enables complicated geometries, and molds from RapidSteel can resist injection molding circumstances. RapidSteel, however, needs finishing and polishing that can take time scheme of the

The DTM (Austin, Texas) copper polyamide tooling method is consisted of selective laser sintering of a matrix of copper and polyamide powder to manufacture

**Figure 2.** *Spray metal tooling [7].*

a reflective coating could be protective. Also, SLA models were tried process of the spray metal tooling depicted in **Figure 2** [6].
