March 06, 2018 Volume 14 Issue 09

Materials News & Products

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Get 'Digital Manufacturing for Dummies' book gratis

Proto Labs has put together a comprehensive guide to the major 3D-printing, CNC machining, and injection-molding technologies that are frequently used in digital manufacturing. The book helps readers to compare processes, explore material options, and see how digital manufacturing can fit into every stage of the product life cycle.
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Precision ceramic and glass microcomponents

Goodfellow, a favorite materials provider for Designfax readers, also supplies a wide variety of ceramic and glass microcomponents, both standard items and items precision-machined to customer specifications. Examples include: ultra-thin glass microsheet for use as transparent substrates and electrical insulators; precision spheres for use as precision spacers and optical components; micro optics such as prisms, lenses, and windows; injection-molded ceramic microcomponents for surgical equipment and fiber-optic applications; polished sapphire bearings and sub-mm bore nozzles; and single- and multi-bore capillary tubing. Other items are available upon request.
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Smith Metal Products adds Titanium Metal Injection Molding capabilities

Smith Metal Products has added Titanium Metal Injection Molding (TiMIM) capabilities to its MIM portfolio of materials that include stainless steels, alloys, and ceramics. TiMIM involves mixing powdered Titanium metal with a binder material to compose a feedstock capable of being handled by injection molding equipment. Metal injection molding allows complex Titanium parts to be shaped with precision in a single operation and in high volume as compared to traditional Titanium machined metal components.
Learn more.


Entry-level industrial-grade 3D printer

The FabPro 1000 from 3D Systems is a new entry-level system that packs 30 years of industrial 3D-printing know-how into its design to deliver superior quality at up to 3X faster high-throughput print speeds than competing printers. Digital Light Printing (DLP) Stereolithography uses a projector to image each layer within a UV-curable, liquid plastic material. This easy-to-use system, with a build size of 125 x 70 x 120 mm (4.92 x 2.76 x 4.72 in.), has 3D Sprint file preparation and print software included -- all at a price of $4,995.
Learn more about it.


Polyplastics develops metal-resin bonding tech for automotive and electrical/electronics

Polyplastics (Tokyo), a global supplier of engineering thermoplastics, has developed an innovative technology for direct metal-resin bonding, a process that uses metal insert molding. Metal parts and resins are firmly bonded by introducing molten resin through injection molding to metal parts that have already undergone sufficient surface treatment. Metal-resin composites deliver the properties of metals (high rigidity, electrical conductivity) and engineering plastics (low density, electrical insulation). This technology has overcome the many factors that traditionally have had an adverse effect and prevented stable bonding. Polyplastics has a U.S. presence in Farmington Hills, MI.
Click here to learn more.


Surface treatment available for strongest cast aluminum alloy

General Magnaplate Corp. has made an exclusive license agreement with the U.K.'s Poeton Industries for the Apticote A20X surface enhancement process, used for treating the innovative A20X aluminum alloy. A20X is MMPDS certified (as AA205) and is the strongest cast aluminum alloy available today, with strength properties comparable to 7000 series wrought material. A20X cast and additively manufactured parts are in production today for major aerospace customers. The AptiMag-X treatment enhances the surface of A20X parts, improving wear resistance, hardening, and finish. The agreement means that General Magnaplate will become the exclusive supplier of Apticote A20X, which they will brand AptiMag-X in North America. Licensed A20X foundries, additive manufacturing companies, and aerospace customers will be able to have parts treated with AptiMag-X at the company’s facilities in Linden, NJ, and Arlington, TX.
Click here to learn more.


New light and tough structural compounds

RTP Company has developed new light and tough (LT) Compounds, a series of thermoplastic compounds that weigh 5 to 10 percent less than typical filled compounds, but with equivalent mechanical properties and similar shrinkage values. LT Compounds are a fast and easy way to accomplish weight reductions in parts molded with glass fiber reinforcement without compromising performance or requiring modifications to existing tools. They are best used as lightweight alternatives when the goal is to minimize energy consumption or the amount of human effort required to use the part.
Click here to learn more.


How colorants affect plastic characteristics

If you're starting a custom plastic injection molding project, you'll want to select a material with the properties most suitable for the function of your parts. One aspect of polymer characteristics that doesn’t always get the consideration it deserves is the addition of colorant. Believe it or not, there is a whole scientific body of knowledge about the ways in which adding color to plastic can affect the behavioral properties of the plastic. This short article by Denny Scher of ICO Mold takes a high-level look at some of the different, and surprising, ways colorants can have an effect on plastics.
Read the full article.


SABIC adds unique PP Ultra Melt Strength resin to its global foam portfolio for lightweighting

SABIC PP-UMS (Ultra Melt Strength) resin is a completely new generation of melt strength polypropylene. This new resin is unique in the market, with a melt strength of more than 65 cN and outstanding foam-ability. It can be used by all industry segments as a building block to develop new foaming solutions that enable an unprecedented level of lightweighting, from automotive to packaging to the building and construction markets.
Click here to learn more.


Understanding how metal 3D parts are made

Greg Paulsen, Xometry's director of applications engineering, explores key design considerations for Metal 3D Printing. Learn how support structures and build orientations impact the finished part's features and surface finish, so you can know what to expect from your next Direct Metal Laser Sintering (DMLS) project.
Read this insightful blog full of useful examples.


Dow structural adhesive joining solutions enhance lightweight module construction in automotive

Dow Automotive Systems is leveraging its existing structural adhesives portfolio as well as its development expertise to offer BETAFORCE, BETAMATE, and BETASEAL solutions that enhance lightweight module construction. Liftgate/hatchback, decklids, and front-end carrier modules are increasingly designed using a multi-material mix to decrease weight while maintaining design flexibility, styling, and safety performance.
Read the full article.


Epoxy adhesives approved for military use

Master Bond has six epoxy compounds -- EP17HTDA-1, EP21TDCHT, EP33, EP46HT-1AO, Supreme 11AOHT, and Supreme 12AOHT-LO -- that have passed MIL-STD-883J section 3.5.2., the subsection of the U.S. Military Standards set by the U.S. DoD that refers to the thermal stability of a material. This test indicates a consistent product performance for temperatures up to 200 C. MIL-STD-883 section 3.8.5 defines that thermal stability testing should be done by performing a thermogravitmetric analysis (TGA) according to ASTM D3850. TGA is the study of a material’s weight change as a function of temperature and time under a controlled atmosphere. It can be used to determine the thermal stability of a material.
Learn more about military-grade epoxies.


Bosch chooses Ultimaker 3 Extended printers

Robert Bosch GmbH is investing on a global scale in Ultimaker 3 Extended printers. After comparing several desktop 3D printers, the Additive Manufacturing department of Bosch selected Ultimaker as the most reliable, easy-to-use, and professional machine. The printers will now be used in different locations across Germany, Hungary, China, India, the United States, and Mexico for printing prototypes, tooling, jigs, and fixtures -- all in a bid to boost innovation while cutting manufacturing and design costs. Materials include nylon, ABS, CPE, PC, and TPU, along with both a PVA water-soluble support material and a dry breakaway support material.
See what makes Ultimaker dual-extrusion printers a standout.


Make your own bearings with world's first printable bearing material filament for 3D printers

Plastics expert igus has introduced the world's first plastic filament for 3D printers enhanced with tribological, or low-friction, properties. The iglide material, 50 times more resistant to wear and abrasion than conventional 3D-printer materials, is ideally suited for creating custom bearings.
Click here to learn more.


Replace metal parts: KyronMAX outperforms long fiber thermoplastics

Responding to customer demand for a short fiber thermoplastic material that would outperform the mechanical strength of long fiber thermoplastic (LFT) materials, Piper Plastics developed the KyronMAX series of structural thermoplastic compounds, the next generation in injection-moldable metal replacement technology. KyronMAX is based on short fiber technology, so the polymer behaves more like the isotropic nature of metal and eliminates the processing and fiber breakage concerns associated with LFT compounds. The technology enables very complex parts to be molded with unrivaled mechanical performance and consistency -- and often 20 percent lighter and 20 to 50 percent stronger than LFT.
Click here to learn more.


Plastics not always better than metals: New study reveals why polymer coronary artery stents failed

By Anne Trafton, MIT

Many patients with heart disease have a metal stent implanted to keep their coronary artery open and prevent blood clotting that can lead to heart attacks. One drawback to these stents is that long-term use can eventually damage the artery.

Several years ago, in hopes of overcoming that issue, a new type of stent made from biodegradable polymers was introduced. Stent designers hoped that these devices would eventually be absorbed by the blood vessel walls, removing the risk of long-term implantation. At first, these stents appeared to be working well in patients, but after a few years these patients experienced more heart attacks than patients with metal stents, and the polymer stents were taken off the market.

Researchers hope that their work will lead to a new approach to designing and evaluating polymer stents and other types of degradable medical devices. [Image: Pei-Jiang Wang]

 

 

MIT researchers in the Institute for Medical Engineering and Science and the Department of Materials Science and Engineering have now discovered why these stents failed. Their study also reveals why the problems were not uncovered during the development process: The evaluation procedures, which were based on those used for metal stents, were not well-suited to evaluating polymer stents.

"People have been evaluating polymer materials as if they were metals, but metals and polymers don't behave the same way," says Elazer Edelman, the Thomas D. and Virginia W. Cabot Professor of Health Sciences and Technology at MIT. "People were looking at the wrong metrics, they were looking at the wrong timescales, and they didn't have the right tools."

The researchers hope that their work will lead to a new approach to designing and evaluating polymer stents and other types of degradable medical devices.

"When we use polymers to make these devices, we need to start thinking about how the fabrication techniques will affect the microstructure, and how the microstructure will affect the device performance," says lead author Pei-Jiang Wang, a Boston University graduate student who is doing his PhD thesis with Edelman.

Edelman is the senior author of the paper, which appears in the Proceedings of the National Academy of Sciences the week of Feb. 26. Other authors include MIT research scientist Nicola Ferralis, MIT professor of materials science and engineering Jeffrey Grossman, and National University of Ireland Galway professor of engineering Claire Conway.

Microstructural flaws
The degradable stents are made from a polymer called poly-l-lactic acid (pLLA), which is also used in dissolvable sutures. Preclinical testing (studies done in the lab and with animal models) did not reveal any cause for concern. In human patients, the stents appeared stable for the first year, but then problems began to arise. After three years, over 10 percent of patients had experienced a heart attack, including fatal heart attacks, or had to go through another medical intervention. That is double the rate seen in patients with metal stents.

After the stents were taken off the market, the team decided to try to figure out if there were any warning signs that could have been detected earlier. To do this, they used Raman spectroscopy to analyze the microstructure of the stents. This technique, which uses light to measure energy shifts in molecular vibrations, offers detailed information about the chemical composition of a material. Ferralis and Grossman modified and optimized the technique for studying stents.

The researchers found that at the microscopic level, polymer stents have a heterogeneous structure that eventually leads to structural collapse. While the outer layers of the stent have a smooth crystalline structure made of highly aligned polymers, the inner core tends to have a less ordered structure. When the stent is inflated, these regions are disrupted, potentially causing early loss of integrity in parts of the structure.

"Because the nonuniform degradation will cause certain locations to degrade faster, it will promote large deformations, potentially causing flow disruption," Wang says.

When the stents become deformed, they can block blood flow, leading to clotting and potentially heart attacks. The researchers believe that the information they gained in this study could help stent designers come up with alternative approaches to fabricating stents, allowing them to possibly eliminate some of the structural irregularities.

A silent problem
Another reason that these problems weren't detected earlier, according to the researchers, is that many preclinical tests were conducted for only about six months. During this time, the polymer devices were beginning to degrade at the microscopic level, but these flaws couldn't be detected with the tools scientists were using to analyze them. Visible deformations did not appear until much later.

"In this period of time, they don't visibly erode. The problem is silent," Edelman says. "But by the end of three years, there's a huge problem."

The researchers believe that their new method for analyzing the device's microstructure could help scientists better evaluate new stents as well as other types of degradable polymer devices.

"This method provides a tool that allows you to look at a metric that very early on tells you something about what will happen much later," Edelman says. "If you know about potential issues in advance, you can have a better idea of where to look in animal models and clinical models for safety issues."

The research was funded by Boston Scientific Corporation and the National Institutes of Health.

Published March 2018

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