Plastic Wheel: Is It In Your Car’s Future?

Plastic automotive wheel rims may be getting closer to prime time. And the payoff could be big in overall vehicle weight savings.

BASF this month was awarded a U.S. patent for a new concept that overcomes problems with previously developed plastic wheels.

From the patent: “It is already known from DE-U 297 06 229 to produce rims for a motor vehicle from a fiber-reinforced plastic. However, on account of the great forces that are transmitted at the rim, the plastic of the rim does have a tendency to creep, which leads to deforming of the rim.”

The patent drawing depicts attachment of a plastic wheel to a wheel mounting such as brake drum (not shown). The fastener is shown as 9. (USPTO)

The patent drawing depicts attachment of a plastic wheel to a wheel mounting such as brake drum (not shown). The fastener is shown as 9. (USPTO)

Too much fiber loading creates cracks in the rim, which may lead to rupturing.

One of the keys in the new approach is the use of an adaptor for fastening the rim to the wheel mounting. The goal of the design is to transmit force directly from the wheel mounting to the adapter, avoiding formation of damaging stress peaks in the plastic. In the BASF invention, “The force is transmitted to the plastic more uniformly, whereby the risk of damage to the plastic, in particular crack formation, is minimized.”

The rim could be made of any of a number of plastic compounds. The preferential compound comprises a blend of at least two types of polyamides and a high loading of random long glass fibers (45 to 65 percent by weight). One candidate is already commercially available: BASF’s Ultramid Structure, which consists of PA6 and PA66 grades as well as specialty polymers with long glass fiber-reinforcement of 40 to 65 percent.

The adaptor, which could be insert molded, could be titanium, ceramic or some other material. The preferred production method is injection molding or casting.

BASF’s first public venture into plastic wheels was in 2011 when smart and BASF exhibited the first all-plastic wheel rim in the smart forvision, a concept vehicle. The wheel was shown at the International Motor Show (IAA) in Frankfurt/Main and at the plastics trade fair Fakuma in Germany.

The smart all-plastic wheel rim was said to be over 30 percent lighter than a standard production aluminum wheel. Savings are even greater compared to a steel wheel

Automotive, Design, Europe, Injection Molding, Polyamides , ,

GM Targets SLS For Conformally Cooled Molds

General Motors is developing new mold making technology that reduces skill levels required to design optimum conformal cooling channels as well as improves cooling times.

The technology is interesting for several reasons, including the automaker’s plan to use selective laser sintering (SLS) to produce conformal cooling channels, presumably to mold large interior parts. Use of direct metal SLS in mold making has been slow to develop because of the cost of the equipment and the lack of expertise in its use. Its potential value has never been in question.

Fins (functioning as structural stanchions and designated as 56) are shown in coolant flow cavities. (USPTO)

Fins (functioning as structural stanchions and designated as 56) are shown in coolant flow cavities. (USPTO)

GM’s new approach is outlined in U.S. Patent Application 20160052185 published Feb. 25. The inventors are Jeff Konchan, engineering group manager at GM and Julien Mourou, lead engineer-Advanced Vehicle Development at General Motors.

Layout of conformal cooling channels is traditionally determined by trial and error, a time-consuming process highly dependent on the skill of the mold designer. GM says it has developed an optimization algorithm that can accurately predict where the channels should be located for best cooling performance to reduce cycle times. The method is based on the calculated temperatures of the tool surface elements.

One of the interesting design elements of the invention is the use of “fins” or pillars that act as a structural support for the tool and bear pressure loading during the molding process. They are positioned to establish the coolant flow paths and are sized to ensure that tensile stress, shear stress, and deflection of the tool element are below predetermined maximum limits.

The capability to produce such intricate internal features is only possible with additive manufacturing processes such as SLS.


Additive manufacturing, Automotive, Molds & Moldmaking, South America , , ,

Apple Eyes Expanded Use of Molded Metal Parts

Increased use of molded specialty metal parts appears very much to be in Apple’s future.

In the biggest buzz, Apple will use metal injection molded hinges in a new ultra-thin MacBook, according to sources citing DigiTimes. The report has the business going to Amphenol, which operates metal injection molding in divisions in China and Korea. Business at the China division increased 20 fold since being acquired by Amphenol in 2005.

Meanwhile, Apple continues to impressively ramp up its intellectual property in the bulk amorphous metals technology it licenses from Liquidmetal. Surface topology is manipulated in one new patent application (20160102391) that tackles issues with the difficult processing technology in high aspect ratio parts such as thin sheets. The lead inventor is Chris Prest, director of product design engineering at Apple.

In another interesting new technology in U.S. Patent 9,302,319, Apple describes a process to use a bulk metallic glass feedstock with a dissimilar sheath. The goal of the inventions seems to be the better preservation of the mechanical properties of Liquidmetal finished parts.  


Amorphous Metals, Electronics, Metal Injection Molding (MIM), North America , ,

Igus Expands 3D Printing Services To Include SLS

Igus, a privately owned company based in Cologne, Germany, is rapidly expanding its 3D printing product offerings and services—all focused on its core business of bearings and other motion control products.

The company, a major captive injection molder and specialty plastics compounder, is introducing a new tribological grade of plastics for selective laser sintering (SLS) and will offer printing services on the machine for outside customers starting this summer. The new plastic for wear resistant applications, designed iglidur I3-PL, is said to have at least three times higher abrasion resistance than other SLS materials.

Igus already owns four FDM (fused deposition modeling) printers, and formally launched its FDM services a year ago at Hannover Messe.

3D printed worm gear. (igus)

3D printed worm gear. (igus)

“The laser sintering is known in 3D printing for a much higher precision compared to the FDM process,” says Tom Krause, product manager at igus. “Another advantage of our new material is also that the parts can achieve a much higher strength due to the pressure in the SLS method.”

No support structures are needed in SLS because powder not melted by the laser provides support. As a result, less finishing work is required.

Igus is already offering prototypes and small volume production for four FDM grades of material: iglidur I180-PF, iglidur I180-PF BL, iglidur I170-PF and iglidur J260-PF. Two more materials will be introduced at this month’s Hannover Messe.

Igus operates more than 10 3D printers, some of which are used for internal purposes. One of its machines is an Arburg FreeFormer, which can make complex parts from standard plastics as well as the company’s own proprietary formulations.

One of the company’s applications for its new 3D capabilities is a right-abrasive filament allowing lubricant and maintenance-free movement in a racing car.

A printed component enables new positioning of the suspension stabilizer in a race car developed by a student team at a Bavarian technical high school.

“The teams in the race series ‘Formula Student’ try every season to optimize their cars by new designs and improvements in their vehicles to get advantages over competitors,” says Krause. “By attempting in their race car to run the chassis for the first time through the empty hood the student team how the rod of the suspension stabilizer may be attached. In order to keep the workload and the weight of the car as low as possible, while ensuring the necessary tolerances, the students opted for a solution from the 3D printer.”

Additive manufacturing , ,

IMM Shipments Rose 6.4% In 2015

Dollar-based shipments of injection molding machinery in the United States jumped 18.2 percent in the last three months of 2015 compared to the same quarter in 2014, according to the SPI Committee on Economic Statistics (CES). Shipments for the year rose 6.4 percent.

Factors contributing to strong results include low interest rates and energy prices, as well as rising wages and household incomes resulting from stronger employment levels, according to Bill Wood, former chief economist for Plastics World who provides analysis to the CES.

Headwinds include the strong value of the U.S. dollar, which makes imported plastics goods less expensive.

The strongest market sectors in 2016 are expected to be medical and appliance manufacturing, according to a survey by the SPI CES.

The total value of all primary equipment shipments measured by the CES, which includes some Canadian business, in 2015 was $1.29 billion, up 4.8 percent compared total from 2014. The CES report does not include all plastics machinery manufacturers.

Injection Molding

New RocTool System Cuts Costs, Cycle Times

RocTool, a 16-year-old French company, is rolling out a new molding technology that does not require a molding machine. The goal is to reduce costs to make large composite parts for aerospace and various transportation applications.

Light Induction Tooling (LIT) includes a light tooling structure with integrated induction heat technology. Cooling units are external.  “With this new Out-Of-Press and Out-Of-Autoclave (OOA) technique, manufacturers can now increase their capabilities without investing in large tonnage machines and the OEM can extend their supply chain for such composite parts,” says Mathieu Boulanger, CEO of RocTool, Le Bourget du Lac, France.

Boulanger said that cycle times are under three minutes because of the reduced thickness of tooling.

RocTool LIT

Aircraft, Compression, Europe ,

Panasonic: New Polypropylene Extends Life Of LEDs

The rapid transition to LED lighting may be facilitated by a new resin development from Panasonic, Osaka, Japan.

The company announced this week that it has developed a light diffusion type polypropylene (PP) resin molding compound, called Full Bright PP. The goal of the invention is to extend the operating life of LEDs.

The material can be used for injection stretch blow molding as well as injection molding.

Pansonic says the material can produce more complex shapes and can be molded with walls as thin as 0.5 mm. The previous best material from the Japanese company generated a hole when a product was blown to a 0.5 mm thickness. Improved chemical resistance is also claimed.

Light resistance stats are interesting: under an environment of 90°C+ UV, there is discoloration after 90 days of exposure (approx. 2000 hours).

According to a report from the U.S., Department of Energy, the market share of LED lighting is expected to reach 84 percent of lumen-hour sales by 2030, reducing lighting energy consumption in that year alone by 40 percent.

Panasonic, a global electronics company formerly known as Matsushita Electric Industrial Co., has developed an interesting portfolio of intellectual property on polypropylene. Last year, Panasonic was awarded a U.S. patent for a high-molecular oriented crystal polypropylene with improved mechanical strength.

PP is of particular interest because of its recyclability.  


Asia, Blow molding, Consumer Goods, Electronics, polypropylene

3M Targets Ultrasonic Assist To Mold Complex Optical Parts

3M has developed a technology that uses ultrasonic energy applied to a plastic-filled mold to relieve flow-induced stresses in a still-forming precision optical part.

The technology addresses the growing use of molded plastics in precision optical

Patent drawing shows a polarizing beam splitting (PBS) prism that would benefit from the new ultrasonic-assisted molding approach. The surfaces help guide light emitted from a light-emitting diode source through a lens (not shown in the drawings). (USPTO)

Patent drawing shows a polarizing beam splitting (PBS) prism that would benefit from the new ultrasonic-assisted molding approach. The surfaces help guide light emitted from a light-emitting diode source through a lens (not shown in the drawings). (USPTO)

applications as manufacturers move away from heavier and more expensive glass components. Another issue is that complexity of the parts has grown substantially.

Previously used practices to mold newly designed precision optical parts are proving insufficient, according to 3M. These methods include coining, injection compression, variothermal response molding, and slow servo-driven injection for simple parts such as screens, diffraction gratings, and some lenses or mirrors.

New parts feature significant compound curvature with thick and thin wall sections. Dimensional tolerances have also tightened.

Patent drawing shows the ultrasonic system (214, 216 and 218) fit into the mold assembly. The sprue entering the mold cavity is 222. (USPTO)

Patent drawing shows the ultrasonic system (214, 216 and 218) in a mold assembly. The sprue entering the mold cavity is 222. (USPTO)

Here’s how the 3M systems works: 1) The mold is heated to a temperature of 104-116ºC; 2) Plastic is injected into the mold cavity; 3) When plastic at the gate has solidified, ultrasonic energy is applied to the mold without remelting the solidified plastic in the gate until the temperature increases to 116-122ºC; and 4) Then the mold is cooled to a temperature of 101-107ºC and subsequently reheated to 116-122ºC. The mold is then cooled and the part is ejected.

The source of ultrasonic energy is an ultrasonic transducer, optionally including at least one of a resonant horn, a booster, and a waveguide.

The types of parts that 3M is targeting include lenses, prisms, mirrors, light pipes, beam splitters, polarizers and diffraction gratings used in several industrial and consumer products. One key application is electronic display devices, such as liquid crystal displays and projectors, televisions, computer monitors, e-readers, cellular phones, and MP3 players.

Specific goals of the 3M ultrasonic-assisted molding process include substantial removal of birefringence, residual stresses, sink marks, knit marks, weld lines, and voids in acrylic plastics.

There are interesting discussions in the 3M patent describing the causes of optical problems in parts and the role of ultrasonics in easing the stresses and reducing the cooling time. One example: “Because ultrasonic energy helps relieve the thermal shock associated in going from a heated barrel into a cold mold cavity, it is, in some exemplary embodiments, possible to reduce the cooling time requirement needed for before ejection of a substantially defect-free precision molded article from the mold.”

The lead inventor is Stan Rendon, who is the Global Technical Service and R&D Operations Manager at 3M. Three years ago he was listed as one of the inventors of a process to ultrasonic injection mold on both sides of a carrier web.

Optical Systems, which includes film and molded products, is a major business group at 3M, which is based in St. Paul, Minnesota. 3M Optical Systems Manufacturing is based in Shanghai.

Figure shows an example of a timing diagram for an ultrasonic-assisted molding process. (USPTO)

Figure shows an example of a timing diagram for an ultrasonic-assisted molding process. (USPTO)

Acrylic, Consumer Goods, Electronics, Injection Molding, North America , , , ,

Korean Firm Will Produce Mirel PHAs

Metabolix, a struggling developer of innovative bioplastics, is receiving a lifeline from a Korean manufacturer that is building a 10,000 tons per year plant in Fort Dodge, Iowa to produce the company’s proprietary PHAs (polyhydroxyalkanoates).

Under a memorandum of understanding (MOU), Metabolix will buy specialty PHAs from CJ CheilJedang Corp., and then sell the materials to its customers. The companies also expect to define a framework for longer term expansion of the collaboration for larger scale PHA production and related commercial activities.

“The MOU with CJ provides a path to establishing the first tranche of commercial production capacity for our specialty PHA biopolymer materials,” said Joseph Shaulson, CEO of Metabolix. “In addition to the significant investment in manufacturing at Fort Dodge, CJ brings impressive engineering capabilities and operating expertise that will be critical to the success of this project.”

“Metabolix’s specialty PHA materials are well aligned technically and commercially with our strategic plan to diversify the products and as CJ’s first biopolymer product, a-PHAs will be a stepping stone for further expansion of the biochemical portfolio,” said Hang Duk Roh, head of CJ CheilJedang BIO. “The shift Metabolix has made to focus on a-PHA as a performance additive as well as other specialty applications of PHAs is very promising.”

Metabolix initially planned large-scale production of PHAs as a biodegradable packaging material as part of a joint venture with Archer Daniels Midland. The six-years-old JV, called Telles, was terminated by ADM in 2012 because of poor sales and high capital costs. Mirel PHA was significantly more expensive than fossil fuel-based packaging plastics, such as polyethylene.

Corporate research efforts shifted to ways to use the company’s PHAs as a polymer modifier, a move that has paid off for PVC and PLA applications. In 2015, Metabolix launched a-PHA (amorphous PHA) pilot production.

CJ BIO operates world-scale fermentation facilities in the United States, China, Indonesia, Malaysia and Brazil.  CJ CheilJedang is a Korean-based food, feed, and bioscience company, and a subsidiary of the CJ Group.

The manufacturing agreement is a positive development for Metabolix, which still faces some financial issues. The following statement was included in its just-released 10-K annual report: “The company held unrestricted cash and cash equivalents of approximately $12.3 million at December 31, 2015. Our present capital resources are not sufficient to fund our planned operations for a twelve-month period, and therefore, raise substantial doubt about our ability to continue as a going concern. Our independent registered public accounting firm included an explanatory paragraph in its report on our financial statements as of and for the year ended December 31, 2015 with respect to this uncertainty.”

The company’s stock was trading at around $2 per share this morning, down from a high of $167 in 2007.

Asia, Bioplastics, North America

Chinese Investor Poised to Take Control of Liquidmetal

One of the jewels of American advanced materials’ technologies is on the verge of a potential takeover by a Chinese manufacturer.

Liquidmetal Technologies, a Caltech spinoff based in California, disclosed this month in a flurry of filings with the Securities and Exchange Commission that a Chinese investor has the right to buy up to 405 million of the company’s stock at a price starting at just eight cents per share and to name three directors to its board, which is expanding to seven. At the same time, employment contracts with its CEO and other top officers were rewritten allowing their termination next year.

Since the 1990s, Liquidmetal has been attempting to commercialize metal alloys that retain their amorphous atomic structure and do not develop crystalline grains generally associated with metals. Liquidmetals exhibit superior strength and other superior performance characteristics compared to crystalline metals.

Liquidmetal first made a foray into golf clubs that was unsuccessful, and has struggled since to find a commercial application. There has been significant interest. The high cost and novelty of the technology seem to be the primary barriers.

In an effort to raise cash to stay afloat, Liquidmetal was forced to sell exclusive market licenses to Apple and Swatch, which has announced a few uses for the alloy. Significant new Apple uses are almost constantly rumored.

An important breakthrough came when machine builder Engel agreed to develop a special injection molding machine that would allow mass production of net shape parts. Engel began aggressively marketing the technology in Europe in the past year.

Liquidmetlal’s cash flow has remained a significant issue as development costs have mounted and management’s promises of success have not borne fruit.

Interest by the Chinese investor was not publicly known.

He is Yeung Tak Lugee Li, 56, the founder, chairman, and majority stockholder of DongGuan Eontec Co. Ltd., a Chinese company listed on the Shenzen Stock Exchange that makes precision die-cast products and is involved in the research and development of new materials. Li founded Eontec in 1993. He is also the founder and sole shareholder of Leader Biomedical Limited, a Hong Kong company involved in the advancement of biomaterials and surgical implants. Medical is a potentially significant market for Liquidmetal. So are automotive and defense. Li serves as an analyst for the Institute of Metal Research at the Chinese Academy of Sciences and teaches at several universities in China.

Executed simultaneously with Li’s Purchase Agreement was the award of an exclusive license to Eontec for Liquidmetal development in China and the rest of Southeast Asia, including the Koreas and Thailand.

The stock purchase agreement is subject to the approval of a special meeting of Liquidmetal shareholders to be held before the end of May. Share prices rose almost immediately after the announcement from eight cents to 13 cents.

In the world of global economic growth and advancement of materials’ technologies, this is good news. Liquidmetal needed a deep-pocketed investor who believes in the technology and will invest in it.

Is this a technology with potentially significant military applications? I would feel comfortable if the U.S. government took a close look at the deal.  





Aircraft, Amorphous Metals, Asia, Automotive, Consumer Goods, Defense, Electronics, Europe, Medical, Metal Injection Molding (MIM), North America , , ,