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A comprehensive collection of news and information about composites.

Posted by: Jeff Sloan

23. April 2014

The Life Module of the BMW i3 all-electric is comprised of resin transfer molded carbon fiber composite structures that are assembled via robotics at the company's manufacturing and assembly plant in Leipzig, Germany.

The composites industry is full of innovators and creative thinkers, people who move the industry forward incrementally toward greater efficiencies, lower costs and higher quality. But the big material and process leaps the composites community has seen throughout its history have required more than individual expertise. The Chevrolet Corvette or The Boeing Co.’s 787 Dreamliner, for example, is the product of a massive, collective corporate commitment, backed by a capital investment as big, bold and precedent-setting as the envisioned product — a commitment that, to some composites pessimists, appears reckless, hasty, ill-timed and doomed.

Corporate trailblazers are rare, and rarely attempt such leaps without a good command of the materials, processes and technologies required to achieve success. Even so, the risk of doom is real, and redoubles with the size of the enterprise. Missed deadlines and technical setbacks are all the more embarrassing for being so public — and inevitably exploited by naysayers. But at the end of what is, at best, a colossal controlled experiment is the honor and recognition as the first to reach a bold and audacious goal.

Onto this less-traveled corporate road the BMW Group steered when, in 2009, it elected to manufacture an all-electric, four-door passenger car using carbon fiber composites. Originally denoted the MegaCity Vehicle, the commuter car now known as the i3 is designed primarily for urban driving and can travel about 100 miles/160 km on a single charge.

As is widely known by now, the i3 features two primary structures, the aluminum Drive Module – which incorporates the powertrain, chassis, battery, and structural and crash functions – and the Life Module (passenger cell), made from carbon fiber composites. The latter is capped by a composite roof made with recycled carbon fiber, and features a spare but comfortable interior that also incorporates recycled materials and other composites made with natural fiber reinforcements. 

We were invited in March to visit the i3 manufacturing and assembly plant in Leipzig, Germany and was offered a chance to see, firsthand, the materials and technologies employed in the creation of this unique vehicle. You will find, in the June issue of Composites Technology magazine, a full report on the facility, materials and processes.

In the meantime, some highlights and impressions from the tour:

  • BMW, as might be expected, exerts strict control over the quality of carbon fiber produced and woven for the i3, starting at the SGL Automotive Carbon Fibers plant in Moses Lake, Wash., USA.
  • Process control of the resin transfer molding (RTM) process used to make the carbon fiber structures for the Life Module is carefully managed. BMW uses, in Leipzig, seven Schuler presses for RTM, with two KraussMaffei RTM injection units on each press.
  • BMW clearly is looking for opportunities to speed up its RTM process, reduce carbon fiber scrap rates and minimize resin usage. Thermoplastics are on the radar.
  • The roof of the i3 makes creative use of carbon fiber scrap with the applicaiton of a stitched, nonwoven carbon fiber fabric made by SGL Group. 
  • Assembly of the Life Module — fully automated by 173 fully articulating ABB robots — is impressive. Only adhesive bonding is used, with no mechanical fasteners.
  • BMW, when we visited, was making 70 i3 vehicles per day, which BMW says is on par with expectations — and expected to grow. With the i8 sports car (also with a carbon fiber Life Module) about to start production, the company's RTM throughput will be well tested.
  • Driving the i3 is fun (see below image). It's smooth, peppy, quiet and responsive.

CompositesWorld conferences director Scott Stephenson (left) with editor Jeff Sloan (right) in front of the BMW i3 they drove while visiting the BMW Group manufacturing and assembly plant in Leipzig, Germany.

Posted by: Sara Black

22. April 2014

Altaeros' BAT (Buoyant Airborne Turbine) prototype will be tested soon in Alaska

 

Remote settlements or communities far from the power grid pay dearly for electricity. In Alaska, for example, the cost of energy from diesel generators reportedly can reach $1 per kilowatt-hour (compared to $0.10/kW-hr or less for coal-, natural gas- or wind-sourced energy in the lower 48 states of the U.S.). Altaeros Energies (Boston, Mass.) aims to change the situation. The new wind energy startup, a spin-off from the Massachusetts Institute of Technology (MIT), has developed the Buoyant Airborne Turbine (BAT), a lighter-than-air wind turbine that can harvest more consistent winds at higher altitudes because its height is not limited by the need for a tower. To demonstrate that capability, a $1.3 million (USD), 18-month project, partially financed by the Alaska Energy Authority’s Emerging Energy Technology Fund, is set to break a world record at a site south of Fairbanks for the highest wind turbine ever deployed, at 1,000 ft/308m.

           Adapted from aerostats (blimps) that have long lifted heavy communications and weather equipment skyward, the BAT consists of a helium-filled inflatable shell, surrounding a turbine. High-strength tethers do double-duty, holding the BAT steady and transporting electricity to microgrid power on the ground. Altaeros cofounder and CEO Ben Glass says the Alaskan BAT prototype uses a small Skystream turbine, supplied by XZERES Wind Corp. (Wilsonville, Ore.), with carbon fiber composite blades made by the University of Maine’s Advanced Structures and Composites Center (ASCC, Orono, Maine). Altaeros replaced the turbine’s aluminum nacelle with a sandwich construction of three-ply carbon fiber skins over an aramid honeycomb core, says Glass, to save additional weight. The prototype nacelle was made in-house.

           “BAT is a low-cost power solution … that can power more than a dozen homes,” explains Glass. “The BAT can be transported and set up without the need for large cranes, towers or underground foundations that have hampered past wind projects.” Altaeros estimates the expenditures for remote power and microgrids is $17 billion per year.Target customers include remote and island communities; oil & gas, mining, agriculture, and telecommunications firms; disaster relief organizations; and military bases. In 2013, Altaeros successfully tested a BAT prototype in 45-mph/72-kmh winds and at a height of 500 ft/152.4m at its test site in Maine, and is currently working on rotor and nacelle designs for commercial full-scale BAT deployments. Glass says the first commercial product will be about 30kw, and future scale-ups could reach 100 to 200kW. The commercial units will be slightly larger in size than the Alaskan proof-of-concept.

Posted by: Ginger Gardiner

18. April 2014

SMTC has launched DYNATECH thermoplastic sandwich panels for transportation interiors based on FITS technology. SOURCE: SMTC

Honeycomb-cored sandwich panels have been used in aircraft interiors since the 1970s. Passenger rail is more conservative and cost-sensitive, but in Europe, aluminum-cored composite panels have become fairly common. Fiberglass-faced (aircraft and rail) or metal-faced (rail) honeycomb is used in baggage bins (stowbins), lavatories, galleys, tables, trays, partitions, doors and trolley carts. Compression molded cored panels are also used in shaped sidewall and overhead panels. Sara Black’s 2006 CT article, “Advanced materials for aircraft interiors” is a good primer on standard materials and processes used. 

A new material has been launched for this market by SMTC (Bouffere, France), a manufacturer of transportation interiors using composite panels since 1983. The company announced at JEC Europe 2014 its launch of  DYNATECH thermoplastic sandwich panels, based on its acquisition of Foamed In-situ Thermoformable Sandwich technology from FITS Technology (Driebergen, The Netherlands) inventor and CEO, Martin de Groot (see my article “Thermoformable Composite Panels, Part II” in CT June 2006).

FITS technology was developed to reduce weight and cost in aircraft and other transport interiors. SOURCE: Fits Technology

DYNATECH encompasses an automated panel-making process that enables polyetherimide (PEI) to be in-situ foamed as a core (with a vertical cell structure) and then receive fiber-reinforced PEI skins that are “welded” onto the core inline, as both are thermoplastic. This thermoplastic panel stock is then easily thermoformed into shapes and angles, edges are easily sealed and inserts do not require potting. FITS inventor de Groot asserts that 25 percent of a Nomex honeycomb panel’s weight comes from potting, exterior decorative layers (e.g., Declar) and connections.

 

DYNATECH panels reportedly offer weight and labor savings via automated processes for thermoformed edges and fastener installation. SOURCE: FITS Technology

The concept of a lightweight cored panel made using a belt press and reinforced thermoplastic faceskins was patented by DuPont in 1990 based on its polyetherketoneketone (PEKK) polymer. CW reported on Fokker’s use of carbon fiber/PEI skins on Nomex honeycomb for the G650 load floors (see “Thermoplastic composites: Inside story”, in HPC Feb 2009). And SABIC (Pittsfield, Mass., USA) has been marketing its Ultem PEI foam for applications like aircraft baggage bins since 2008.

What makes DYNATECH different is that all of the pieces have been put together, including core, skins, thermoforming shapes, edge-finishing, insert installation and now automated panel manufacturing through SMTC’s commercialization of the product. Also, SMTC is an established supplier of interiors, with customers like Bombardier, Alstom, Sogerma and Zodiac Aerospace. Hence, it knows the cost and performance targets and already has supplier relationships in place. Interestingly, a representative from interiors giant Zodiac Aerospace was at the JEC Europe 2014 press conference, and SMTC said it has already discussed qualification with several OEMs.

I’ve asked de Groot for test data showing the reported acoustic and thermal insulation benefits of DYNATECH vs. honeycomb-cored panels, and also for the calculations used to assert the 20 to 40 percent weight savings and 10 to 30 percent cost savings possible. The PEI foam core is higher in density than Nomex honeycomb, but SMTC and de Groot are claiming the structures can be made much thinner. That alone is intriguing as airlines and OEMs look for more interior space.

Also, the big topic at Airbus and Boeing now is “multifunctional,” where interior structure is integrated with other functions such as ventilation, lighting, electrical power, etc., into walls, ceilings and bins. It might be possible to embed a variety of structural components and/or functional elements (e.g., fiber optics) within DYNATECH's core. De Groot also claims that unique design advantages can be exploited — for example, a box-type reinforcement achieved from folding and thermoforming skins up around the panel edges and welded or thermoformed local reinforcements.

The FITS Technology website features a page of videos demonstrating the concepts for automated edge finishing and insert installation. Illustrations for corner and edge reinforcements are also shown.

SMTC says pilot production will begin this summer with high-volume production slated for 2016.

Posted by: Ginger Gardiner

15. April 2014

RocTool demonstrated its 3iTech high-speed composites molding technology at
JEC (right) powered by two 50kW induction generators (left), which it also produces.

RocTool (Savoie Technolac, France) is an anomaly in the composites industry, not because of its astronomical growth — from revenues of $700,000 in 2010 to $7 million in 2013 — or its previous 10 years of R&D without revenues, but because it has truly achieved innovation in high-speed composites production — now claiming a mold heating world record of 60° to 160°C (140° to 320°F) in 5.3 seconds — and has succeeded, against all predictions, with its technology licensing business model, one which is difficult even for Microsoft. It is accomplishing all of this with a headquarters-based core staff of 30.

Founded in 2000, RocTool has 80 patents in 20 technology families with roughly 40 licensees worldwide, mostly major OEMS and Tier 1 suppliers. It astutely anticipated the opportunity in consumer electronics and via Taiwan-based licensee Ju Teng, now boasts use of its technology in one of the world’s largest smartphone and tablet parts factories in China, outputting around 10,000 parts per day. It also claims license agreements with five of the world’s top 10 manufacturers of 3C products (computers, communication and consumer electronics).

In fact, RocTool and Ju Teng were recognized, along with partner Complam (Taichung, Taiwan), with the JEC 2014 Innovation Award in Consumer Electronics, presented to Motorola Mobility (Libertyville, Ill., USA) for its MotoX and Ultra products. The MotoX rear housing is a molded polycarbonate (PC) composite reinforced with thermoplastic polyester (PET) fiber featuring a high-quality surface finish while the Ultra employs a 3-D unibody from the same composite but with Kevlar fiber added. The JEC award claims that combined production for both models exceeds 50,000 units per day.

RocTool was included in a second Innovation Award, this one to Expliseat (Paris, France) for its new Titanium Seat, claimed to be the lightest commercial aircraft seat on the market, weighing 4 kg (9 lb) per passenger place. The design, qualified for Boeing 737 and Airbus A320 aircraft, features titanium and composite tubes and uses RocTool’s 3iTech molding system to process TenCate (Almelo, The Netherlands) TC1100 polyphenylene sulfide (PPS) unidirectional composite tape reinforced with HexTow AS4 12k carbon fiber from Hexcel (Stamford, Conn.).

RocTool President Alexandre Guichard predicts the company's bespoke licensing agreements will number 100 within five years. However, he claims growth for its own sake is not RocTool’s priority, but instead it is focused on profitability first, and then technical support for worldwide licensees, including plans for subsidiaries in Germany and Japan as soon as possible.


In RocTool's CAGE system, inductors (right) are positioned in two halves outside of the mold (left). They form a cage when electrically connected, instantaneously heating only the tool surface at a very rapid rate.  CAGE is ussed for high-temp production of complex shapes (e.g., part at bottom). SOURCE:  RocTool

RocTool’s intellectual property (IP) strength comes from very fast heating and cooling via induction heating, seen in its Cage System and 3iTech technologies.  In the Cage System, inductors are positioned in two halves outside of the mold, forming a cage when they are electrically connected. At this instant, the tool surface and only the tool surface heats rapidly. Cage is touted for production using high temperature, complex shapes and molds with moving features. 3iTech also uses inductors but placed inside the mold, similar to heating cartridges, but much faster and with a fraction of the energy consumption. Again, heating is within seconds and is for molding using localized or one-side only heating, seen especially with parts needing cosmetic and high-quality surfaces. RocTool also sells its induction generators, which range in power from 50kW to 300kW and may include cooling devices and automated remote control.


RocTool's 3iTech system uses inductors placed inside the mold,
again heating in seconds, but offering localized or one-side only heating
for parts requiring cosmetic surface finish. SOURCE: RocTool

RocTool demonstrated its 3iTech technology at JEC Europe (Mar. 11-13, Paris, France) by molding boomerangs from three different material combinations:

  • Flax/polypropylene (PP)
  • Recycled carbon fiber/glass fiber/PP CoDEP (fibers and thermoplastic co-deposited into a felt-like material) from MIT RCF (Asheville, N.C., USA)
  • Glass fiber/ Thermoplastic polyurethane (TPU) from Bond-Laminates (Brilon, Germany).

The standard 100-ton press by Wabash MPI (Wabash, Ind., USA) achieved induction heating via copper coils inside the mold fed by two 50kW high-frequency induction generators, one for the top mold and one for the bottom. The molds could be heated and cooled — using a typical water system at 20°C (68°F) — from 50° to 400°C (122 to 752°F) and molded the boomerangs in 2.5 minutes. This type of system could be easily adapted for tools up to the size of an auto hood and has made cell phone parts. When asked about the timeframe from licensing to production, RocTool explained that engineering typically requires 2 to 4 weeks, followed by a few months for the mold tools to be fabricated and then a few weeks to establish production at the licensee’s site — i.e. less than six months for a simple, single-site installation.


RocTool demonstration of 3iTech molding technology with 2.5 minute cycle time at JEC Europe. SOURCE: CompositesWorld

RocTool has perhaps another trump card to play, an advantage few others in composites seem to offer: high-speed production using hybrid materials. Its technology and expertise spans composites, plastics and metals. Guichard gave an example in that Samsung and LG prefer “all-plastic” tablet and phone bodies while Apple and Lenovo have favored metal. In automotive, Volkswagen has avowed a hybrid approach including all three materials but favoring none. Guichard notes that metal has certain advantages but it is difficult to achieve fine thicknesses without extensive and costly surface finishing operations. He asserted that RocTool would have no problems finding customers for a technology which could produce metal parts less than 1mm (.04 inch) thick and a cosmetic surface quality. Perhaps that is one of their 10 dedicated R&D programs. In any case, there is little doubt that much more is to come from this small powerhouse with an ever-increasing global reach.

Posted by: Mike Musselman

14. April 2014

Materials data for UHT Unitech's carbon fiber.

The carbon fiber market, once the relatively unchanging — not to mention unassailable — preserve of a small, elite group of fiber manufacturers, is in the midst of a massive sea change. The advent of the Boeing 787, Airbus A350 XWB and other commercial aircraft with composite airframes forced Japan's Toray, Teijin and Mitsubishi Rayon (all based in Tokyo) and U.S.-based Hexcel (Stamford, Conn., USA) and Cytec Industries (Woodland Park, N.J., USA) to commit to capacity increases that, previously, had been viewed as patently insupportable because of the enormous capital investment. Zoltek (St. Louis, Mo., USA) — at long last — and DowAksa (Instanbul, Turkey) joined the club, with commercial-grade fiber, aimed at wind and transportation markets — especially, hoped-for automotive applications.

When the realization of the vertically integrated SGL/BMW carbon fiber supply chain for its i3 and i8 electric cars silenced many doubters, the stage seemed set: SGL's commisioning of its carbon fiber plant in Moses Lake, Wash., USA, stimulated a round of partnership announcements between fiber producers, auto OEMs and others interested in repeating the carbon fiber aerocomposites windfall in the world of autocomposites (see, for example, "Ford, Dow join forces to research carbon composites for production autos").  And a flurry of announcements by new carbon fiber sources: Saudi Basic Industries Corp. (SABIC, Riyadh, Saudi Arabia),  Hyosung (Gyeonggi-do, Korea), Alabuga Fiber LLC (Tartarstan, Russia), to mention a few. The once exclusive club has become a larger and more competitive fraternity.

Given all that, the rumor of yet another new PAN-based carbon fiber manufacturer wasn't high on CW's "must see" at this year's JEC Europe event in Paris. In fact, the rumor proved untrue. But CW found that the subject of the rumor, carbon fiber converter UHT Unitech Co. Ltd. (Zhongli, Taiwan), proved unexpectedly intriguing.

Established in 2011, UHT Unitech offers not a new fiber but a graphitization service for composites fabricators who purchase T700-grade PAN-carbon fiber from existing manufacturers. Unitech’s president, Ben Wang, gave a presentation at JEC, describing the company’s business model. Briefly, Wang’s process unspools PAN carbon fiber (3K to 48K) purchased from other sources, burns off the factory-applied sizing, then graphitizes it in Unitech’s — and here's the intriguing part — Wang's patented 2000°C/3632°F microwave ovens. Processed fibers are resized (Wang says he specializes in sizings compatible with thermoplastic resins for sporting goods and industrial applications) and re-spooled.

The result? Wang quips that “no one believes it” but he says he can deliver  T800- or T1000-grade fiber at 15 to 30 percent lower cost, because his microwave technology reportedly consumes 30 percent less energy and processes fiber 50 percent faster than conventional graphitization ovens. Further, he claims his process generates no water or air pollution. But most compelling, he claims that test results conducted by the Taichung, Taiwan, branch of independent testing organization SGS SA (Geneva, Switzerland) indicate that his UT30S and UT1000 products are roughly equivalent to the high-end fibers now on the market (see chart). Wang goes farther: Graphitization by conventional means, he says, typically increases the modulus (stiffness) but slightly degrades fiber strength. He claims, however, that his microwave-based process not only increases fiber modulus by 20 to 30 percent but also adds 2 to 5 percent to its strength.

Wang says he’s working with interested parties in the composites manufacturing community, both inside and outside Taiwan. And he says his technical team also works with customers to adopt and adapt UHT Unitech's fiber in their manufacturing processes. Wang offers help, for example, by formulating both prepregs and injection-moldable thermoplastic compounds for use in sporting goods and industrial applications. 

Currently capable of producing a total of 300 metric tonnes (roughly 661,380 lb) of fiber per year, UHT Unitech isn't a big threat to the "bigs" in the carbon fiber market. In any case, Wang says he has no intention of threatening anyone: He emphasized that he’s not planning to engage in spinning or carbonization of raw PAN fiber. More importantly, he would he happy to partner with carbon fiber manufacturers who are interested in adopting his less-expensive microwave process for their high-tonnage lines. 

It's important to point out, here, that microwave technology is not new to the composites industry. In 2009, no less than GKN Aerospace (Isle of Wight, U.K.) acquired a Hephaistos microwave curing oven from heating systems specialist Vötsch Industrietechnik GmbH (Reiskirchen-Lindenstruth, Germany). GKN’s experience has shown that microwave technology consumes about 80 percent less energy than a comparable autoclave, with a 40 percent savings in cycle time (see "Microwave: An alternative to the autoclave?"). 

Given all the excitement surrounding massive production line expansions and new players in the  carbon fiber sector, a UHT Unitech could — but should not — go unnoticed. The perennial cry — particularly from the auto industry — is that cost of carbon fiber is the principal deterrent to its widespread application in volume production. A technology that might reduce carbon fiber cost by double-digit percentage points is probably worth a look.

Ben Wang, president, UHT Unitech.

 

 

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