Metal Molding Makes Play For Smartphone Covers

Add powder injection molding (PIM) to the list of candidate processes for making smart phone covers stronger and less expensive.

Machine builder Arburg and chemicals’ giant BASF formed a joint venture to develop a material and process to produce housing components for smartphones. The concept was first demonstrated at the World PM2016 Congress and Exhibition, held in Hamburg, Germany last October, and more recently at Arburg’s in-house technology fair in Lossburg, Germany, last month.

“The booming international smartphone market offers huge potential for powder injection molding because this process enables the use of materials such as stainless steel, titanium and zirconium oxide, requires much lower material volumes and is significantly more cost-effective than machining,” says Hartmut Walcher, PIM expert at Arburg,

A hydraulic Allrounder 470 S with a clamping force of 10 tons produced the components from a flow-optimized Catamold 17-4 PH Plus from BASF in Hamburg. A lightly larger press was used in Lossburg. A changeable hot runner mold featuring liquid temperature control was designed to produce a closed or four-part frame. Cycle time is about 55 seconds.

The mold temperature is dynamically controlled to help ensure a constant green density throughout the entire part. The polishable surface finish is described as very good. One goal is to minimize part distortion at a wall thickness of only around 1 mm. Part length is 136 mm.

Arburg has manufactured more than 1,000 PIM machines in the past 50 years.

Powder injection molding is a method to mass produce net shape metal or ceramic parts. Powders are mixed with a polymer binder so the material will flow into an injection mold. Parts are first injection molded (called green), and then the binder is removed and parts are “baked” in a sintering oven to remove pores created by the binder.

Photo shows the gripper tool for the mobile phone frame. (Arburg)


Automation/Robotics, Design, Electronics, Europe, Metal Injection Molding, Metal Injection Molding (MIM) , ,

PlastiComp Expands Proprietary CFRP Compounding

PlastiComp, a compounder in Winona, Minnesota, is boosting capacity of an interesting, proprietary process to make long-fiber, carbon-reinforced plastic (CFRP) pellets.

The additional, higher-volume carbon fiber pultrusion line will triple PlastiComp’s capacity for producing long carbon fiber products. “In recent years we have experienced continuous growth in demand for our long carbon fiber reinforced composite materials,” said Eric Wollan, vice president and chief operating officer at PlastiComp. 

The firm brought its initial production line dedicated to producing long carbon fiber composite pellets online in 2014 and operates four other pultrusion lines to manufacture its long glass fiber products.

The pultrusion process used to make long fiber pellets for injection molding processing is different from the standard thermoset pultrusion process used to make lineal shapes such as ladders. Continuous fiber roving/tow (glass, carbon, or other) is pulled through a pressure die where the fiber tow is spread and melt impregnated with thermoplastic polymer. A compounding extruder operates as a melt pump to feed the molten polymer into the die.

Composite strands exit the die and are cooled into thin composite rods, which we cut into 12 mm (one half inch) pellets to facilitate material handling. If pellets are too long, they clog up the feed throat of the injection molding machine.

 PlastiComp makes its own equipment other than the melt pump extruder and the pelletizer

Carbon fiber composites are manufactured by PlastiComp on pultrusion lines located in self-contained areas equipped with isolated electrical and air handling systems.

“From a pultrusion perspective, carbon fiber’s small filament diameter and conductivity makes it a little more challenging to manufacture composite pellets than other types of fiber,” said Wollan.  “Using our specialized equipment, PlastiComp is able to completely melt impregnate continuous tows of carbon fiber with 12,000 to 50,000 filaments.”

Plasticomp says that long carbon fiber reinforced thermoplastic composites provide the strongest and stiffest performance available in flowable materials suitable for injection molding processing.  PlastiComp’s Complēt pellets contain 15 to 50 percent (by weight) long carbon fiber in thermoplastic matrices ranging from polypropylene to PEEK.

CFRPs offer mechanical performance equivalent to aluminum while providing design-dependent weight reductions up to 50 percent.

Thermoplastic materials incorporating carbon fiber reinforcement are conductive (<10E5 ohms-per-square), providing surface and volume resistivity properties and up to 80 decibels (dB) of shielding effectiveness against electromagnetic interference.

The firm also has a long fiber composites line that combines glass fiber and carbon fiber together into a single pellet.

Carbon fiber loaded on spolls feeds into new pultrusion line. (Plsticomp)

Carbon Composites, Carbon Fiber, Glass-Reinforced Composites, North America, PEEK, polypropylene

Toshiba Machine Gets Divorce From Toshiba; Expands Line

Toshiba Machine Co., Tokyo, has extracted itself from the troubled Toshiba Group, and is expanding its lineup of injection molding machinery.

The company is launching the all-electric EC280SXII, featuring a clamping force of 2,744 kN (280 metric tons), and the EC350SXII, featuring a clamping force of 3,430 kN (350 metric tons). They will both be made in China and target a specific application: precision molding of automobile optical parts.

“The EC-SXII series features a wide of array of packages for optical parts such as automobile LED headlight lenses, in-car lighting and displays, and more, for contributing to higher productivity and more stable precision molding,” said Masafumi Ito of the Regional Operating Headquarters (East Asia).

Last month, Toshiba Machine Co. bought back a controlling amount of stock owned by Toshiba Corp. “As a result, they are no longer our top shareholder and we no longer belong to the Toshiba Group,” said Toshiba Machine Chairman and CEO Yukio Iimura at the company’s North American headquarters in Elk Grove Village, Illinois.

Toshiba Machine took the action due to customer concerns about the Toshiba Group’s financial stability in the wake of significant losses in the company’s nuclear power business operated by Westinghouse.

According to Iimura, the transition for Toshiba Machine has been seamless, with no impact to its operations, customers, shareholders, employees or business partners.

Westinghouse field for bankruptcy March 24 because of billions of dollars of cost overruns at four nuclear reactors under construction in the U.S. Southeast. Toshiba shares lost half their value since the nuclear problems became public late last year. The problems also began to affect Toshiba Machine, although it was only 21 percent owned by Toshiba Group.

Toshiba Machine was established in 1938 as a heavy machine tool manufacturer, and has evolved into a diverse business comprised of approximately 48 regional companies and offices supplying global markets with injection molding machines, machine tools, die-casting machines, extruders, robotics and high-precision machines. The company says it has an installation base of more than 60,000 injection molding machines worldwide, owns all of the buildings in which it operates, and employs more than 3300 worldwide.

Toshiba Machine is boosting clamping force of its all-electric injection molding machines with two new models. (Toshiba Machine)

Asia, Automotive, Injection Molding ,

Molded Polyamide Cover Cuts Weight In Toyota Engine Application

Japanese and European car manufacturers continue to push hard for automotive lightweighting.

In a recent example, Toyota has developed an improved method of covering a power transmission timing belt with a complicated plastic enclosure. The timing belt transmits the power from a crank shaft to a cam shaft. The molding is particularly tricky because it holds an oil-sealing gasket that creates problems of heat, pressure and creep.

A metal piece is insert molded into the structure to accept the cam shaft and oil seal.

A U.S. patent application published this week indicates polyamide would be used for the cover and an aluminum alloy for the metal piece.

A molded polyamide enclosure (lower left) reduces weight as a power transmission cover. The cam shaft (3) fits through an insert-molded aluminum ring (13). (USPTO)

Asia, Automotive, Design, Green, Insert Molding, Polyamides , ,

What Can Gene Editing Do For Plastics?

Will industrial microbiologists become more important in the development of plastics than petroleum engineers and geologists?

Maybe. And it may not be all that far off.

There are already hints of this. The earliest bioplastics were natural products like starches. Increasingly, they are highly engineered with microorganisms. DuPont announced four years ago that more than half of its plastics and chemical monomers would be made from renewable resources within the next 17 years. Two years ago, DuPont confirmed it was working on development of whole new families of plastics based on renewable resources as part of the  program.

BASF technicians in a white biotechnology research lab in Germany are working with microorganisms to produce enzymes. (BASF)

Yeast has already been altered to consume plant matter and excrete ethanol, which could pave the way to replacing petrochemicals. There are many other examples.

Now comes the announcement that BASF has reached a global licensing agreement with the Broad Institute of MIT and Harvard for the use of CRISPR-Cas9 genome-editing technology to improve products in agricultural and industrial microbiology applications.

BASF said the technology advances genome editing because it is a simpler and more precise tool for making targeted changes to a cell’s DNA. It may make the production of plastics from plants more efficient and less costly.

“The CRISPR-Cas9 technology is a game changer within the field of genome editing,” says Peter Eckes, president of BASF Bioscience Research. “We are eager to see the new ways it will augment our research and improve multiple products for agriculture as well as numerous industrial applications.”

Bioplastics, Europe, North America , ,

Lightweighting Shines In Europe

Impact on climate change will be the biggest fallout from Donald Trump’s efforts to unwind strict federal limits on greenhouse gas emissions that would have required vehicles to achieve more than 50 miles per gallon on average by 2025.

Another impact will be on advanced plastics manufacturing capabilities in the United States. Efforts to develop improved lightweight composite structures for cars was already more in advanced in Europe than the United States.

Automotive composite technology is advancing faster in Europe than the U.S. (Lanxess)

There is clear danger that America will slip even further behind as a result of EPA rule changes.

In one example, there seemed to be significant energy and technology in the area of lightweighting at the International Congress of Plastics In Automotive Engineering (VDI Conference) held March 29-30 in Mannheim, Germany. Technical focus in the United States seems to be on muscle, talking cars and new levels of glitz—and that was even before the Trump presidency.

 A few examples from the VDI Conference:

  • The Lanxess exhibits featured lightweight, “nearly indestructible” engine compartment trims, tank covers and center tunnel covers. The flat components are polypropylene-based low-weight-reinforced thermoplastics (LWRT) molded with a 0.02-inch thick Tepex blank in a compression molding process.
  • Covestro unveiled a new concept car described as the first vehicle with wrap-around glazing made of transparent polycarbonate.
  • SABIC showed plastic-metal hybrid structural reinforcements for a vehicle body. A SABIC blend of polyamide  and modified polyphenylene ether polymer mates with steel to reduce weight by 2.2 pounds.
Automotive, Carbon Fiber, Compression, Europe, Reinforcing Material , , , , ,

Apple Develops Improved Sealing For Housings

Apple is developing a new injection molding technology to improve the watertight seal of mobile phone housings.

In a U.S. patent application published today, adhesive is placed in pores of an anodized aluminum phone housing. A thermoplastic layer is then insert molded on top of the metal.  The plastic and the adhesive are cured simultaneously, improving bond strength.

The pores in the metal are created by etching, laser etching, aggregate blasting, or nano-molding. The pores are at least one micron in depth or width and are irregularly shaped. The plastic can be transparent or decorated with graphics.

Overmolded plastic attaches to adhesives in irregularly shaped pores of an anodized aluminum housing. (USPTO)

Electronics, Injection Molding, Insert Molding, North America, Telecommunications , ,

Additively Manufactured PEKK Finds Aerospace, Medical Niches

One of former president Barack Obama’s most important legacies in manufacturing policy is America Makes, the National Additive Manufacturing Innovation Institute (NAMII), an initiative to advance additive manufacturing.

The group is thriving, and is much more than a think tank.

One example is Oxford Performance Materials, which demonstrated that additively manufactured PEKK plastic could meet the stringent, mechanical, thermal, safety and other requirements for structural aerospace components as part of an America Makes project. Its partners were Northrup Grumman and NASA.

Now OPM is shipping PEKK parts to Boeing for the Starliner space craft that is designed to transport up to seven passengers, or a mix of crew and cargo, to low-Earth orbit destinations such as the International Space Station.

Starliners are now being built. (Boeing)

OPM’s Aerospace & Industrial Division established performance attributes verified in a B-Basis database that was developed in conjunction with NASA.

“From our earliest discussions with Boeing, they stressed the need to see significant reductions in weight, cost and lead times in order to consider replacing traditional metallic and composite parts with a new technology for their space program,” said Lawrence Varholak, president of OPM Aerospace & Industrial. 

Additively manufacturing PEKK is no ordinary beast, and it clearly shows where America fits in a world of advanced manufacturing.

Most AM uses 3D printing plastics with little engineering pedigree, such as PLA or ABS. PEKK was first synthesized by DuPont in 1962 and was commercially introduced in the late 1980s. It combines good thermal, chemical, fire and other properties. OPM showed that it can withstand a temperature range of -300 to + 300 F as an additively manufactured part. PEKK’s melting point is 639 F.

To make PEKK parts, laser sintering machine builder EOS developed the heavily insulated EOSINT P 800, which is designed for process temperatures of up to 725 F.  The machine includes an integrated Online Laser Power Control module to continuously monitor laser performance. That’s necessary to hit spec requirements spot on.

OPM’s bread-and-butter business is medical parts such as cranial implants that obviously require an exact fit. Parts are certified to fit within one mm of specs in all directions.

OMP is making complex, structural aerospace parts with an EOSINT P 800.

Additive manufacturing, Aircraft, Design, Engineering Thermoplastics, Medical, North America , , ,

Large 3D-Printed Plastic Tools Advance

When Boeing embarked on its ambitious plan to make huge structural sections for the Dreamliner 787 aircraft from carbon composites, big questions remained on manufacturability. The biggest composite parts ever made had been hulls for yachts. Not only were the Dreamliner parts larger, they had to meet the cost and speed demands of series production.

Now 3D-printed plastic tools are emerging as a strong alternative to metallic tooling. This is a far different animal from the small 3D-printed tool inserts produced for injection molding.

The aircraft tools can be huge. The assembly tool being built for the new Boeing 777X passenger aircraft is 17.5 feet long, 5.5 feet wide and 1.5 feet tall. It’s comparable in length to a large sport utility vehicle and weighs approximately 1,650 pounds.

Made from carbon fiber and ABS, the tool was developed by researchers at the Department of Energy’s Oak Ridge National Laboratory (ORNL), using a Cincinnati Inc. Big Area Additive Manufacturing (BAAM) machine. Printing time was 30 hours. The proprietary extruder on the BAAM has a feed rate of 80 lbs/hour. Materials tested include ABS, PPS, PEKK and Ultem.

“The existing, more expensive metallic tooling option we currently use comes from a supplier and typically takes three months to manufacture using conventional techniques,” said Leo Christodoulou, Boeing’s director of structures and materials. “Additively manufactured tools, such as the 777X wing trim tool, will save energy, time, labor and production cost and are part of our overall strategy to apply 3D printing technology in key production areas.”

Vlastimil Kunc, leader of ORNL’s polymer materials development team, added: “Using 3D printing, we could design the tool with less material and without compromising its function.”

Boeing is using the tool in its new composite parts’ production facility in St. Louis. The function of the tool is to secure the jet’s composite wing skin for drilling and machining before assembly. First deliveries of the 777X are scheduled for 2020.

Several partners are working with ORNL to develop tools that can be used in autoclaves. Compounder Techmer PM, for example, developed custom formulated high-temperature carbon fiber-reinforced plastics for tools that endure multiple autoclave cure cycles, withstanding temperatures over 355 F and pressures of 90 psi.

BAAM 3d printer. (Techmer)

The tools were printed on ORNL’s BAAM, machined on a Thermwood 5-axis CNC machining center, and then surface finished by TruDesign.

Other partners include US Naval Air Systems Command (NAVAIR), Boeing, TruDesign, and BASF.

In addition to allowing more design freedom, 3D printed tools are five to 10 times faster and cheaper than metal tools.

3D-printed high-temperature plastic tool. Techmer)

ABS, Additive manufacturing, Aircraft, Carbon Composites, Carbon Fiber, Engineering Thermoplastics, North America, Polyphenylene sulfide, Reinforcing Material ,

Chinese Investor Pumps Some Life Into Liquidmetal

Long-struggling Liquidmetal is now operating under Chinese management, which is injecting capital and new life into the Cal Tech spinoff.

One interesting development from a molding perspective is the addition of metal injection molding (MIM) to its manufacturing lineup. MIM offers a lower cost alternative to the injection molded Liquidmetal parts. MIM production, located in China, is expected to come on stream later this year.

Injection molding and die casting will take place at a new California manufacturing plant. Other projects include development of lower cost metal alloys and molds.

“These efforts allow us to present customers with industry-leading capabilities to address applications, from low cost to very high performance in China, United States and Europe, said Bruce Bromage, EVP at Liquidmetal, in a recent conference call with analysts.

Lugee Li is now the CEO and largest shareholder in Liquidmetal. He is also CEO of Eontec, a vertically integrated Chinese producer of metal parts.

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