**2.1 Indirect methods of rapid tooling**

To achieve various lead times, expenses, and process capabilities, there occurred several pattern-based methods in manufacturing a mold. To compose a pattern, the precision of RP processes gets considered with each part structure and the precision of the RP process preferred:

**91**

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

*2.1.1 Investment cast tooling*

*Methods of rapid tooling.*

**Table 1.**

*2.1.2 3D Keltool*

and packed.

inserts in a die base [6].

high melting point metals being used.

Investment casting has been used for thousands of years as a manufacturing method and is particularly suited to finely detailed metal parts being formed and

Founded in 1947, Vaupell uses SLA patterns for casting to quickly deliver 3D-printed patterns for casting to customers in aerospace industry. Here, AM (SLA) is used to manufacture a sacrificial model. Using this sacrificial model, investment casting is carried out as it would traditionally be the model with a ceramic coating, scorching the model, filling the remaining ceramic shell with molten metal, and removing the ceramic case after the metal has been solidified and cooled [6].

As a first step in the 3D Keltool process, cavity mold inserts and a core get designed in CAD to get followed by manufacture of the core and cavity patterns with stereolithography or some other processes. Once these core and cavity patterns meet the requirements of the surface, silicone rubber cast gets applied on them to form molds in which a mixture of a metal powder and binder get poured

The instruments used in this process illustrate very qualified surface finish and definition. In general, lead time results in shorter time period than the conventional tooling. The main limitation is the size restriction. The size of a mold insert could be 100 × 150 × 215 mm (4 × 5.9 × 8.5 inches) at most. If the x and/or y dimension gets smaller, the z-direction has the possibility to extend to 145 mm (5.75 inches). To manufacture larger items, some tool makers have two or more cheek-to-cheek


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

*Design and Manufacturing*

**Figure 1.**

**2. Additive methods to produce tools (rapid tooling)**

*Data transfer between the computer-aided design (CAD) and the RP system [1].*

the real inserts of the core and cavity mold.

**2.1 Indirect methods of rapid tooling**

of the RP process preferred:

• Vacuum casting.

• Kirksite tooling.

• Electroforming.

• RIM.

• Spin casting.

• Plaster molds.

• Sprayed steel.

• Cast resin tooling.

• RTV silicone rubber molds.

• Rapid solidification process.

• Wax injection molding.

There are two main categories. One category includes indirect methods using AM techniques for prototyping master designs to manufacture a mold, while the other category is a direct strategy, where the rapid prototyping machine constructs

Due to its market potential, many businesses prefer AM techniques for tool produce and growth. Each method comes with a number of strengths that are contracted by limitations. Yet these advances cause a flurry of requests from businesses in the Americas, Europe, Asia, and other advanced markets due to their potential effect. Meanwhile, in both of these methods, numerous facilities are working hard to determine whether the time is correct to phase further information can be seen in **Table 1**.

To achieve various lead times, expenses, and process capabilities, there occurred several pattern-based methods in manufacturing a mold. To compose a pattern, the precision of RP processes gets considered with each part structure and the precision

**90**

**Table 1.** *Methods of rapid tooling.*

#### *2.1.1 Investment cast tooling*

Investment casting has been used for thousands of years as a manufacturing method and is particularly suited to finely detailed metal parts being formed and high melting point metals being used.

Founded in 1947, Vaupell uses SLA patterns for casting to quickly deliver 3D-printed patterns for casting to customers in aerospace industry. Here, AM (SLA) is used to manufacture a sacrificial model. Using this sacrificial model, investment casting is carried out as it would traditionally be the model with a ceramic coating, scorching the model, filling the remaining ceramic shell with molten metal, and removing the ceramic case after the metal has been solidified and cooled [6].

#### *2.1.2 3D Keltool*

As a first step in the 3D Keltool process, cavity mold inserts and a core get designed in CAD to get followed by manufacture of the core and cavity patterns with stereolithography or some other processes. Once these core and cavity patterns meet the requirements of the surface, silicone rubber cast gets applied on them to form molds in which a mixture of a metal powder and binder get poured and packed.

The instruments used in this process illustrate very qualified surface finish and definition. In general, lead time results in shorter time period than the conventional tooling. The main limitation is the size restriction. The size of a mold insert could be 100 × 150 × 215 mm (4 × 5.9 × 8.5 inches) at most. If the x and/or y dimension gets smaller, the z-direction has the possibility to extend to 145 mm (5.75 inches). To manufacture larger items, some tool makers have two or more cheek-to-cheek inserts in a die base [6].
