TIPS WITH TONY: Replace Metal with Plastic to Save Weight, Cost

To decrease weight and potentially cost, you can replace metal with plastic on certain parts through 3D printing and injection molding. At Proto Labs, we use industrial 3D printing process stereolithography (SL) to produce thermoplastic-like parts that have a nickel coating on the surface. This offers the increased strength of aluminum die-cast components, without the weight. With injection molding, the introduction of thermally conductive plastics has broken new ground when looking for heat dissipation of expensive heat sinks.

Stereolithography parts built with SLArmor have a metal coating applied over a thermoplastic-like base.

SLArmor involves a ceramic-filled DSM Somos material, which has a metal coating applied to achieve the look, feel and, most importantly, comparable strength of aluminum without added weight. SL is a cost-effective prototyping method for initial parts that mimic metal before moving to higher volumes of die-casted parts.

The material properties of SLArmor are greatly improved in regards to heat deflection, tensile strength, elongation at break and elasticity. The chart below shows exactly how the material relates to die-cast aluminum in three different thicknesses that can be applied based on geometry of SL parts. Note that the thickness of the nickel plating may vary on each part due to the ability to apply the coatings.

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EYE ON INNOVATION: Vertebrae Implants More Proof of 3D Printing’s Place in Med Tech

3D printing and other rapid manufacturing methods continue to transform the med tech industry, as illustrated recently by an Australian neurosurgeon who, in late 2015, removed cancerous vertebrae in a patient and implanted, in their place, printed vertebrae.

The 3D-printed part that would replace the patient’s cancer-ridden vertebrae. Photo: Dailymail.co.uk and ABC News.

Dr. Ralph Mobbs, a neurosurgeon at the Prince of Wales Hospital in Sydney, called the procedure a “world first.” The surgery was performed on a patient with chordoma, a rare form of cancer that occurs in the bone of the skull and spine. As Wired UK reports, the 60-year-old patient was affected in the two vertebrae responsible for turning the head — meaning that, if the 15-hour surgery had failed, he would have been left paralyzed.

Because of the position and function of these vertebrae, however, they’re extremely hard to replace — they must be an exact fit. Mobbs decided to 3D print the replacements instead, and worked with Anatomics, an Australian medical device manufacturer, to design and build the implants, which were made from titanium. The company also printed exact anatomical models of the patient’s head for Mobbs to practice on before the surgery. Continue reading

Q&A: StarWitness Offers Favorable Testimony of Rapid Manufacturing

Police and other security professionals frequently interview suspects and witnesses, sessions that require officially dated recordings. StarWitness, a supplier of specialty forensic audio-video products used by law enforcement and others, recently called on Proto Labs for prototyping and low-volume production help for a new product, the Field Interviewer.

Photo Courtesy StarWitness

StarWitness is a division of Signalscape, Inc., which is based in the Research Triangle area of North Carolina. Signalscape and its brands supply engineering services and products used by U.S.-based law enforcement, security, intelligence and defense services to combat crime, fight terrorism and provide for homeland security. Mike D’Aurelio, mechanical designer at Signalscape, recently answered a few questions about his company’s work with Proto Labs.

What is the StarWitness Field Interviewer?
The Field Interviewer is a one-touch interview recorder that fits in your pocket. It provides a watermarked video identifier for authentication of recorded interviews, and can be controlled and monitored via secure Wi-Fi from an Android smart phone or tablet. Continue reading

3D Printing Methods for Medtech Prototypes

Being able to quickly produce prototype parts is critical to creating an environment of innovation that can lead to medical device market success. By removing inefficiencies, manufacturers should expect to have prototype parts in a few days, not months. The prototype method must be fast enough to allow multiple iterations in a condensed time frame, and possess the scale to allow for multiple iterations at the same time.

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Rapid manufacturing methods like 3D printing are leveraged to help drastically reduce development time for medical devices.

Additive manufacturing (AM), also called 3D printing, enables quick evaluation of new medical product designs without making compromises due to complex part geometries. Using AM offers easier design changes and at a low cost. When prototyping via 3D printing, designers should not expect a finished part, although it should be noted 3D printing processes can yield finalized products. Stereolithography, for example, has a number of post-secondary finishing processes and direct metal laser sintering produces fully dense end-use metal parts.

There may be limits to color and texture choices, and in certain instances, thermoplastic-like materials will differ from the final production material used in process like molding and machining. If the surface finish, texture, color and coefficient of friction vary from the end material, it is difficult to accurately assess the subtle needs and benefits of these properties.

The main advantage of 3D printing is that it provides accurate form and fit testing. The build process of additive technology can accurately produce the form and size of the desired part, making it very useful for early evaluation of new medical parts. It is best used to identify design flaws, make changes, and then make second-generation machined parts or invest in tooling to create injection-molded parts. This article reviews that various AM printing methods commonly used in prototyping.

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DESIGN TIP: Thermoplastic-like vs. Thermoplastic

Many factors come into play when comparing the material properties of thermoplastics found in injection molding versus “thermoplastic-like” materials used in a 3D printing technology like stereolithlography (SL). At Proto Labs, a thorough selection of thermoplastic-like materials are offered through SL, but what may surprise you is the versatility and range of potential applications for SL parts.

This month’s tip discusses:

  • heat deflection, tensile strength and other important properties of thermoplastic-like materials
  • how SL materials compare to similar injection-molded thermoplastics
  • the benefits and range of suitable applications for each SL material
  • the impact of light and moisture exposure on 3D-printed parts

READ THE FULL DESIGN TIP HERE.