Highlights Of CAMX 2015

Thermoplastics as well as 3D printing were hot topics during CAMX 2015.  

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Thermoplastics as well as 3D printing were hot topics during CAMX 2015, the second combined conference and exhibition from the American Composites Manufacturers Association (ACMA) and SAMPE (Society for the Advancement of Material and Process Engineering).

 

One of the showstoppers was the retro Shelby Cobra that was on exhibit by Oak Ridge National Laboratories (ORNL), Oak Ridge, Tenn., which is the stunning product of additive manufacturing, using the Big Area Additive Manufacturing (BAAM) technology developed by Cincinnati Inc. (Harrison, Ohio) in collaboration with ORNL. Design and manufactured in just six weeks, the 635-kg car includes 227 kg of BAAM-printed parts, using a chopped carbon fiber-reinforced ABS provided by Sabic. Cincinnati’s BAAM technology was also a winner of one of the CAMX Awards. BAAM encompasses a number of innovations that enable large-scale 3D printing. The BAAM enables components of arbitrary geometry to be 3D-printed at a scale that is times larger than any other commercial system, using a screw-extrusion technology for deposition, similar to what is used in the injection molding industry. Cincinnati Inc. and ORNL designed an extrusion screw specifically for the BAAM system and mounted it on a high-speed, high-resolution gantry system. BAAM is also the first to deposit with carbon fiber reinforced-plastic pellets and uses a novel Z-table that provides the capability to build large parts. The system also features innovations that improve layer-to-layer adhesion and the ability to easily separate support material from build parts.

 

Receiving the award were Rick Neff, manager market development at Cincinnati Inc., and Lonnie Love, group leader at ORNL. They commented on the Shelby Cobra: “ORNL first mentioned the Cobra on Nov. 10 of last year,” Neff recalled. “By January it was done and you couldn’t tell that it was additive manufactured.” Love and Neff credited a variety of partners, including Techmer, Sabic and Alpha Star.

 

A presentation that stood out was from Axel Boettcher, owner of Boettcher Consult, where he discussed the high potential for carbon fiber in automotive. Automotive OEMs continue to work to reduce the weight of their vehicles due to global legislation setting a mandate to reduce vehicle emissions. As a result, there are high expectations for carbon fiber in automotive as it gives the best mechanical performance/component strength per weight, Boettcher said.

 

He addressed why carbon fiber composites are of interest in automotive and also covered the technical, political, social and economic issues associated with carbon fiber. He also looked into market considerations and production technologies being pursued (RTM, HP-RTM, wet pressing, prepreg, SMC, BMC and organo-sheet methods).

 

So as fuel consumption relates to less emissions, reducing the weight allows the best option for fuel reduction. The forecast for the next five to 10 years is that there will be more of a demand in weight reduction and the biggest potential to achieve this lies at structural components.

 

Boettcher took a closer look at resin choices—thermosets vs. thermoplastics—and their pros and cons. With thermosets, the benefits include chemical resistance and structural integrity. But the limitations of thermoset-based CFRPs include the long process times and and it is difficult to achieve a good surface finish. Whereas thermoplastics allows remolding without impacting physical mechanical properties, provides superior surface finish, “eco-friendly” manufacturing and high impact resistance. A drawback of thermoplastics is high viscosity and high melt temperatures.

 

As far as where composites are leaning more toward, Boettcher said that OEMs can save more weight and have higher performance with thermosets, but in thinner applications like bumpers, they tend to choose thermoplastic.

 

Generally speaking, plenty of barriers for widespread adoption remain as the high cost of carbon fiber is three times that of aluminum. There’s also the high cost investment of production. Another issue is the lack of technology competence and shortage of qualified composites workers.

 

BMW has lead the way of carbon fiber usage in automotive such as in its i Series. And while carbon fiber has been used in exotic race cars and sports cars, Boettcher said the goal should be to find a way to boost volumes to 50,000 cars a year. But to get there, the industry needs to advance automation beyond the early stages.  

 

“Carbon fiber growth will exceed expectations,” Boettcher said. “Regulations are driving innovation primarily and technical performance to a lesser extent.”

 

Other Thermoplastic Highlights

 

CompositesWorld, the sister publication of Plastics Technology, Senior Editor Sara Black reported that thermoplastic specialist Impact Composites, Erlanger, KY, introduced a new molded woven carbon/polyetheretherketone (PEEK) solid billet, intended to be machined to net shape for complex, three-dimensional parts.

 

Sean Reymond, the company’s chief technology officer, says the billet, called VTL (Very Thick Laminate), is a good alternative to replace titanium or aluminum parts, in orthopedic medical applications such as external fixation devices for broken bones or orthopedic tools (VTL is the large block on the table in the photo foreground). VTL can be produced to suit customer needs, in a variety of thicknesses and sizes. “Because it’s a thermoplastic resin, there’s no worry about exotherm during molding,” says Reymond.

 

CW Senior Editor Ginger Gardiner wrote that thermoplastics are also being used to produce 3m by 9m structural composite panels made by Axia Materials (Seoul, South Korea). Using powdered in-house matrix systems, Axia achieves water-like viscosity upon heating which it claims achieves excellent wet-out, including impregnation of the filaments in the fiber, all in a continuous process. The 3m-wide rolls, complete with UV coating on one side, are then laminated onto various core materials, also in a continuous process, to produce composite structural insulation panels (SIPs) which are lightweight, waterproof and UV-resistant for walls, floors and roofs that Axia is developing for military shelters, modular housing and much more. The flat structural panels can be shipped in a container and then quickly assembled using bonding and/or structural connectors on-site.