How Additive Manufacturing Can Compete in Full-Scale Factory Production
Isaac Maw posted on July 05, 2019 |
HP recently outlined their plan to make 3D printing competitive with subtractive processes.

By now, most engineers and manufacturers are somewhat familiar with the capabilities of 3D printing. Freedom from traditional design constraints, rapid prototyping capability and revolutionary structures and geometry open up new manufacturing opportunities.

But as long as 3D printing has been around, its applicability in mass production has been an open question at best and deemed impractical at worst. But big, powerful corporations like HP, GE and BASF are betting billions on additive manufacturing (AM). So, how are these investment dollars empowering AM to compete with established mass production processes such as molding, forming, casting and machining?

At the recent ribbon-cutting for a new tech center at HP Barcelona, the printing giant explained its plan for accelerating additive manufacturing adoption in manufacturing. When HP unveiled the Multijet Fusion (MJF) printer in 2016, analysts were surprised that HP, which has a massive consumer printer business, was choosing to target the industrial market instead of the desktop 3D printer market. In Barcelona, HP representatives described in practical, concrete terms the roadmap to making additive—both in polymers and metals—an economically-competitive alternative to injection molding and casting.

Fortunately for those of us who aren’t HP stockholders, the picture they painted applies to the market as a whole. For anyone with an interest in boosting AM onto the factory floor, HP’s plan is highly relevant.

HP’s Plan for Accelerating Industrial Adoption of Additive Manufacturing

asdf
Image courtesy of HP

The first three points seem to focus on competing with established processes such as injection molding. The second three seem to focus on the potential capabilities of additive (the lattice structures, the part consolidation, and so on).

First, AM OEMs need to get printers on shop floors and into the hands of engineers. Only then can the engineers fully explore and realize the technology’s potential.

Data-Driven Insights

According to HP, an MJF printer can generate 4 terabytes of process data per print cycle. This data is gathered by sensors inside the machine, including a thermal camera which monitors the bed temperature at thousands of points across each layer.

Because additive manufacturing is a digital process, there is opportunity for data analysis from design, to prototyping, through the manufacturing process and in QC. While additive manufacturing is new to many mass production operations, this data is valuable for optimization and process improvement. For example, HP has partnered with Siemens to create a digital twin of the additive manufacturing workflow and simulate the workflow. The simulation, powered by real data, allows HP to define bottlenecks and find opportunities for automation.

image courtesy of HP
Image courtesy of HP

Superior Economics

Fancy shapes are fascinating, but the bottom line is the bottom line. Manufacturers will simply not invest in additive unless it is cost-competitive with alternative processes. This is why industries such as aerospace and medical device manufacturing have offered early inroads to additive. Making these parts is very expensive, thanks to a variety of factors such as low volume, costly and difficult-to-machine materials, high quality standards and tight regulations, and complex part designs. But what about other industries?

Image courtesy of HP

Image courtesy of HP

Injection molding is the big dog in plastics manufacturing. Additive has never been able to compare with the productivity of molding once the tooling is made. Casting and machining are also faster and cheaper when parts are designed optimally for those processes. However, part of that advantage is thanks to the decades those processes have been in use by manufacturers, and additive processes of all types have a few tricks up their sleeves. Expensive and time-consuming tooling is not needed. Parts—identical or any number of different SKUs—can be nested together in a build chamber to multiply productivity. Multiple parts can be consolidated into one, saving assembly cost. For example, in one case, six injection molded parts were consolidated into one printed part, reducing cost by 34.3%.

Industrial equipment can’t be economical without strong overall equipment effectiveness (OEE), which is defined as the actual productivity of the equipment divided by its maximum productivity. In machining, “If you’re not making chips, you’re not making money.” In additive, you might say, “if you’re not depositing and fusing layers, you’re not making money.”

This focus on OEE feeds into the next point in HP’s journey.

Manufacturing Predictability

Availability

By decreasing mean time between failures, production equipment is made more available, thereby increasing OEE. For example, HP has identified through production data that the fusion lamp is a significant failure mode for print cycles on the 4200 series MJF machine, and the new 5200 series printer has a redundant backup lamp as a result of that data.

Repeatability

Once key process parameters are dialed in, injection molding and machining are highly repeatable. This reduces the cost of rework and scrap and speeds production and QC. HP has the goal of achieving “injection molding-level repeatability,” which requires data-driven analysis into the sources of variability in prints, such as humidity changes in the build chamber. HP stated that the 5200 printer is capable of a Cpk of 1.3, or 99.93% process yield. Beyond this Cpk, machine learning algorithms can be applied to production data for process control and improvement. According to HP, the state of the art in 3D printing today is close to approaching the quality of precision injection molding.

Applications and Markets Expansion

As mentioned above, low-volume, high cost-per-part markets such as aerospace, prototyping, and medical/dental have been early adopters of additive. However, most additive IEMs seek to enter true mass production markets such as automotive manufacturing.

Metal Printers Must Print Steel

The concept of near-net shape manufacturing helps justify the use of costly, slow metal additive processes for materials such as Inconel and titanium, which are expensive and difficult to machine. However, the fact remains that the vast majority of metal parts manufactured on this planet are made of iron and steel. Additive manufacturing can’t ignore this market.

Image courtesy of HP
Image courtesy of HP

Systems Innovations

Post Processing

If you’ve touched a part printed via any additive process, you likely noticed the characteristic rough or ridged surface finish and recognized the need for post processing, such as machining, sanding or media blasting. This remains a key obstacle for additive as it makes its way onto the factory floor.

Post processing or finishing operations are not unique to additive. Molded or machined parts may require hand or automated deburring or finishing. Investment casting may require machining to establish a datum or finish a hole, mating surface or other feature, but other areas of the surface are typically left unfinished. Additive manufacturing OEMs such as HP’s metal jet are learning from these established workflows and adapting them for printed parts.

Automation

In most manufacturing facilities, the low-hanging fruit for automation are the basic, lever-pulling tasks that workers don’t apply their human problem-solving or flexibility to. Machine tending is a well-established application set for robotic arms, and 3D printer tending is similar. With additive applied at production scale, dozens or even thousands of printers may be working in the same facility, even potentially on the same part order. Manufacturers want their additive manufacturing solutions to work with automation, including material handling and post-processing. Besides physical robots, this includes automated tasks such as print queuing.

Design Thinking

If 3D printers simply replace existing processes for production of the same old parts, very little can be gained by the technology. The true potential of additive is in the freedom from certain manufacturability constraints enabling features such as interior lattice structures and complex curves. Hundreds of unique parts can be printed in a single powder bed.

New Ecosystem Collaboration

In order for the limits of additive manufacturing to be fully explored and pushed, the industry needs engineers and designers using the technology at work, in real applications. This is essentially about network effects: the more users additive manufacturing has, the more value is added for users across the board.

The way HP is approaching this is by collaborating with partners in the 3D printing ecosystem, such as Siemens, BASF and Jabil. These partnerships create opportunities for new use cases and insights into the benefits and shortcomings of industrial additive manufacturing, which helps stimulate improvements to the technology.

As HP continues to develop its additive manufacturing business, other 3D printing manufacturers and end users can learn a lot by observing the strategy it takes.

For another take on how additive manufacturing is being used in real factories today, check out Additive Manufacturing & The Chocolate Factory.






Recommended For You