What Can Additive Manufacturing Do for Tooling?

The global tooling industry is the largest horizontal industry, sustaining every major vertical industrial manufacturing sector. Since manufacturing and tooling are highly interdependent, none of them would ever be as productive without its support. Countless products are assembled using jigs and fixtures or are produced by molding (injection, blow, and silicone) or casting (investment, sand, and spin). No matter the application, manufacturing tools increase efficiency and profit while maintaining quality.

CNC machining is the most common technique applied in the manufacture of tools. Although it delivers highly reliable results, it may be expensive and time-consuming. As did many others, the tooling industry actors also started looking for more efficient options. Additive layer manufacturing (ALM) for tooling is an increasingly attractive method, especially because molds, patterns, jigs, and features are generally produced in low volumes and feature complex shapes.

Today, the process and variety of printable materials (plastics, rubber, composites, metals, wax, and sand) have already convinced many industries such as automotive, aerospace, and healthcare and medical, amongst others, to integrate ALM in their supply chain, including for tooling manufacture.

Which tooling applications can benefit from ALM?

Several processes involved in tooling can take advantage of ALM’s benefits:

• Molding (blow, LSR, RTV, EPS, injection, paper pulp molds, soluble cores for hollow composite parts, fiberglass lay-up molds, etc…)
• Casting (investment, sand, spin, etc…)
• Forming (thermoforming, metal hydroforming, etc…)
• Machining, assembling and inspection (jigs, fixtures, modular fixtures, etc…)
• Robotics end-effectors (grippers)

Fabricating tooling with ALM offers a number of potential advantages:

1) Lead time for tooling is shortened

ALM for tooling compresses the whole product development cycle and acts as a driver for innovation. Companies sometimes choose to delay or forgo product design updates because of the need to invest in new tooling. By reducing lead time of tooling production and enabling for quick updates of an existing tool design, ALM enables companies to afford for more frequent tooling replacement and improvement. It allows tooling design cycles to keep pace with product design cycles.

Moreover, “in-house” ALM for tooling is fast and allows high flexibility/adaptability. Strategically, it secures the supply-chain against the risk of extended deadlines and downtimes, in the case where improperly fabricated tools are received from suppliers.

2) Costs are reduced if benefits are cautiously considered

If today costs are generally higher in metal ALM than in conventional metal manufacturing, cost reductions can for sure be achieved more easily for plastic. Then, the main material consideration is whether plastic will satisfy the required needs or not.

Metal ALM for tooling could be financially advantageous for small series of end products (fixed costs are poorly amortized), or in the case of really specific geometries (optimized for ALM). Even more when expensive material is used and traditional tooling fabrication induces a high rate of material wastes.

Moreover, the possibility to manufacture within hours a precise tool as soon as it is required positively affects workflows and profits. It can be of a great benefit when production downtime and/or tooling inventory are costly.

Finally, designs are often modified after the production has begun. ALM’s flexibility enables engineers to try numerous iterations simultaneously that may reduce upfront costs caused by tooling design modifications but it is highly case-specific so that cautiousness is required.

3) Improving tooling design offers more functional final products

Generally, ALM’s specific metallurgy and refined microstructure gives rise to fully dense printed parts with mechanical and physical properties as good as or better than those of comparable wrought or cast materials (depending on post heat treatment and test direction). ALM offers to engineers unlimited options to improve tool designs. When they are composed of several sub-components, ALM’s ability to consolidate design minimizes the number of assembly operations and associated tolerance challenges.

Moreover, its ability to incorporate complex features eventually supports a faster production of highly functional end parts with fewer defects. For instance, the overall quality of injection molded parts is influenced by the heat transfer between the injected material and the cooling fluid that flows through the tooling fixture. If manufactured with traditional techniques, the channels conducting the cooling material are usually straight, resulting in a slower and uneven cooling of the molded part.

ALM enables free-form channel geometry to ensure a conformal cooling, more optimal and homogeneous, which eventually leads to higher-quality parts and lower scrap rates. Additionally, a faster heat removal significantly reduces the cycle time for injection molding, since cooling time can account for up to 70% of the overall cycle.

4) Optimizing tooling improves ergonomics and bottom line performance

ALM lowers the threshold for justifying a new tool (which allows addressing unmet needs within the fabrication process) and for putting more optimized jigs and fixtures into service. Traditionally, due to the expense and effort required to redesign and manufacture them, tooling designs and equipment (that were still sufficient to “do the job”) were used as long as they could be. With ALM, revisions are no longer reserved for those that don’t work as specified.

With little time and initiative required, ALM makes it more affordable to optimize tools that exhibit a marginal performance. Ergonomics can be included in the design to improve technician comfort, process cycle time and ease of tool access and storage. While doing so may only drive out just a few seconds from an assembly operation, small things adding up, optimal design can freed significant amount of labor time and also reduce costs of scrap parts.

5) Customizing tooling helps to customize the final products

Shorter lead times, the ability to produce complex geometries, and eventually lower costs, enable the fabrication of numerous individual tools that support the production of custom parts. ALM for tooling encourages customization, which is particularly useful in–but not limited to–the medical device and healthcare industries. It provides surgeons with 3D printed personalized instruments such as surgical guides or tools, enabling them to improve patient outcomes and reduce surgical time.

Conclusion:

Beside ALM for prototyping and manufacturing, ALM for tooling can be a valuable method and a great investment for companies when the nature of tooling needs is fairly assessed. Suitable opportunities are low-volume production cases in which the ability to create complex geometries can improve tooling performance. For dimensional accuracy, companies should consider ALM for tools requiring tolerances above 0.1 mm and involving high losses of expensive materials throughout the traditional fabrication.

As the technique continues to mature and ALM for tooling expands to more applications, it will further impact supply chain and final products by pushing innovation forward and boosting traditional manufacturing methods. In order to speed up ALM’s adoption and take advantage of its full potential, challenges that are common to general applications of ALM must be overcome. They include the need for quality and speed improvements, and a more diversified portfolio of materials, along with the ability to produce bigger tools and a workforce skilled in design for ALM.

Discuss these insights in the ALM Tooling forum thread at 3DPB.com.

Writer Bio

Alban Leandri is a technical content writer with background and work experience in mechanical engineering. Passionate about design, materials and new manufacturing technologies, he is a member of Spartacus3D, and keen on sharing his extended knowledge about metal additive manufacturing, offering a particular standpoint. Follow us on Google +.