3D printing for tooling applications
All manufacturing methods require tooling in some capacity. The process of tool-making can be tedious due to high tolerance requirements, complex geometries, and materials that are difficult to machine. In-house metal 3D printing enables tool-makers to meet these challenges with greater efficiency
Tooling is a general term for components used in various manufacturing processes—including injection molding, extrusion, stamping, casting, cutting, and assembly. A single tooling mechanism may consist of several complex parts, and the production of tooling can be a complicated process that is both time-consuming and expensive.
It’s common for tooling—such as mold cavity inserts, extrusion dies, end-effectors, stamps, and cutting inserts—to be produced in low volume and require complex geometries and materials whose hardness makes them difficult to work with. This can have a significant impact on cost and lead time. In the automotive industry, for example, the production of tooling components can mean hundreds of millions of dollars and add years to the product development timeline. Additionally, third-party tool-makers are limited by strict deadlines, requiring that their processes be efficient with little to no room for error.
For tool-makers, leveraging the benefits of metal 3D printing allows them to offer more advanced services that result in higher-quality parts. Bringing this technology in-house makes it possible to win more bids with a more competitive timeline and reduced cost-per-part as a result of the on-demand production of tooling components.
EXAMPLE #1: INJECTION MOLDS WITH CONFORMAL COOLING
One example of this would be injection mold makers who design and build complex molds in which plastic or metal material will be injected at high heat and with great force to form a part. The challenges for making a complex mold—and all of its components—are amplified by the limitations of traditional manufacturing methods which can make it difficult to achieve necessary quality and detail based on the specifications for the intended application.
In applications like injection molding and thermoforming, the process of cooling the newly molded part is critical to quality assurance and can account for about 95% of the cycle time. The ability to cool parts quickly and uniformly are key considerations. Due to the limitations of traditional manufacturing methods, cooling channels are often limited to straight lines. The introduction of 3D printing enables conformal channels that follow the shape of the part and allow for uniform cooling. This reduces or eliminates hot spots and increases coolant flow turbulence—resulting in better part quality, an overall reduction in cost-per-part, and as much as a 40% increase in throughput.
Why 3D print?
Key advantages of using additive manufacturing (AM) to produce tooling include cost, design flexibility, and fabrication time. Cost and fabrication time do not necessarily increase with part complexity, so producing complex tools—for example, molds with conformal cooling channels—is of no concern. Processes like Bound Metal Deposition™ allow for the printing of geometries that are otherwise impossible using traditional manufacturing methods. With this design freedom comes the ability to consolidate many parts into one.
The Studio System is significantly faster and more affordable than traditional manufacturing methods, allowing for multiple design iterations to ensure optimal part performance. Another benefit is the ability to replace physical inventory with a digital inventory, producing parts on-demand as they are needed. This eliminates the cost and hassle associated with producing and storing extra parts that may or may not be used. While other metal AM methods—such as laser-based systems—offer some of the benefits of 3D printing, they are often impractical due to high operating costs.
Beyond the design flexibility and ease with which 3D printing solutions can achieve complex internal structures, the implications this has on part cost are significant. This is demonstrated in the an evaluation of the fabrication process of an extrusion die, shown below.
Studio System-fabricated extrusion die
Printed in 17-4 PH stainless steel, the part was fabricated with the Studio System™ to achieve complex extrusion profiles—specifically, a hexagonal shape through which material will be injected.
Fabricating the extrusion die with the Studio System reduces cost-per-part by about 92% compared to Direct Metal Laser Sintering (DMLS) and by about 87% compared to CNC machining.
STUDIO SYSTEM : $134
CNC : $1013
DMLS : $1708
Metal vs Plastic
While there have been advances in plastics, the vast majority of tooling will perform better if made out of metal. Generally, tooling is used in environments with high heat and they are often exposed to abrasive chemicals and media. Plastic parts will distort and warp in these environments and, after repeated use, they will begin to wear. The lifetime of metal tooling is much greater than that of plastic. Additionally, it is much stronger and stiffer than plastic, so for tooling applications in which a significant force will be applied, metal tools are required to prevent deflection and preserve repeatability.
The Studio System is capable of printing some of the most difficult to manufacture materials that are desirable for tooling—H13 tool steel, Inconel 625, 17-4 PH stainless steel—and can produce tools quickly and affordably.