Metal 3D printing requires new thought process
24 July 2018
As product development speeds up, the design rules are changing. Nowhere is this more apparent when looking at the industrial 3D printing process of direct metal laser sintering (DMLS). Direct metal laser sintering is an additive manufacturing technology with significant potential in the medical device space.
But it requires a new way of thinking even at the early design phases. In many ways it represents the transition designers must face when looking at new technologies to make medical device design and manufacturing faster and more innovative.
There are several benefits of DMLS explains Tommy Lynch, metals project manager at Protolabs Inc., primarily that designers can prototype designs in unusual shapes at both time and cost savings. “DMLS is different from other 3D printing because you are using real metal. Many of these materials have been used for industrial applications for decades.”
Lynch says designers like the process because they can experiment with organic shapes that can’t be readily machined. For example, one intriguing opportunity is the ability to build implantable body parts that are custom fit to the recipient.
“These implants would normally need to be delicately built on a five-axis machine at a high expense,” he says. “Technology exists to scan a person’s actual bone structure, and print a direct DMLS replacement.”
Another opportunity is surgical tools with organic shapes. These devices may be designed for metal injection moulding or casting, both of which have relatively high tooling costs and lead times that can span weeks.
“We can print a prototype surgical hand tool at the exact weight and strength of the final product. In many cases, it can be in a surgeons hands within three to five days,” he says. “Traditional metal injection moulding is still valuable, and will have a lower piece price at higher quantities, but it is still six to 12 weeks versus a couple of days.”
The attributes of time, cost savings, and design freedom are key to being able to experiment, design quickly, and see what works. For both of these types of products says Lynch, “engineers are enabled to shorten their design cycle to a matter of days, not weeks.”
But DMLS does require a shift in design thinking. “You have to think about it differently at the design phase,” says Lynch. One of the biggest adjustments is how to adapt to the introduction of internal stresses during the build process.
“You are taking a room temperature metal powder, applying heat for an instant melt, followed by rapid cooling,” he explains. The rapid change causes stress at each layer of during the build process. “The part tries to curl upwards as it is building.”
You can find out more at www.protolabs.co.uk.http://www.engineersjournal.ie/2018/07/24/metal-3d-printing-requires-new-thought-process/http://www.engineersjournal.ie/wp-content/uploads/2018/08/dmls.pnghttp://www.engineersjournal.ie/wp-content/uploads/2018/08/dmls-300x300.pngSponsored3D Printing