Erie conference covers innovation and emerging plastic technologies

Erie, Pa. — Speakers at a wide-ranging conference at Penn State Erie, the Behrend College, covered everything from low-pressure injection technology and all-electric presses to new uses of foil and film, "smart" actuation of hot runner pins, mold cooling and material blenders — with some Industry 4.0 thrown in for good measure.

Other presentations at the Innovation and Emerging Plastics Technologies Conference detailed molding simulation, remote standardization of injection molds and drying systems.

The conference, June 19-20, drew 210 people to the university in Erie.

Joachim Kragl, director of advanced injection molding systems and processing at Engel Machinery Inc. in York, Pa., outlined how much in-mold decorating has changed during the past two decades. Initially, IMD was used to change colors on basic consumer products, like cellphone covers.

"So what's new in 2019? The original desire to change appearances of the parts did not really change. But what did change dramatically is the amount of functional integration that we now want to do with foils or films," he said.

Kragl passed around parts for a car center console, made with molded-in circuit boards and sensors. "You can integrate connections into the film preform," he said.

In-mold film is vacuum-formed into a preform, then inserted in the mold and back molded. In-mold decorating can be done in a reel-to-reel process and usually does not to be made into a preform, he said.

On automotive consoles, a driver or passenger can change settings with flat-screen buttons or gestures, like a smartphone. The light source goes through the film. A center console may have 200 pieces, but film molding reduces that to a single board, he said.

"What makes it very interesting for automotive is the assembly time of a part like that is reduced by about 90 percent," Kragl said. "You snap it in place. All the contacts are being done as soon as it's snapped in place. There's no connections, there's no fixtures, there's no bolts, and the electrical connection happens as well."

Kragl said film for molding has greatly advanced over the early days. Now you can use film and foil to make a wide range of surface textures — making its touch soft or silky or velvety or sticky — and even multiple textures in different areas of the same part.

Film also plays a big role in scratch-resistant coating of lenses, he said. The coating is on the carrier film, which is peeled off, leaving the coating on the lens.

Kragl said a "holy grail" application is coming: film with special additives to simulate chrome that will feel cold to the touch, not like "plastic" at all.

"There's really limitless possibilities of what can be done with film these days," he said.

Donald Hickel, regional sales manager at Manner USA Inc., described three technologies for actuating hot runner valve pins on high-cavitation molds such as tooling for medical, packaging and personal care products. Manner USA in Lawrenceville, Pa., is part of Otto Männer GmbH in Germany, which is owned by Barnes Group Inc.

"There's a lot going on in the molding process. You have cooling and the cavities, cores; you have the handling of the resin and of the melt," Hickel said. Precisely controlling valve pin gate movement actuation is critical, he said.

"It's very important that all the valves actuate at the same time," he said.

Valve gate systems can be pneumatic with an individual drive, pneumatic with a "common plate" design where a mechanically moving plate engages all valve pins at the same time or use an electrically driven plate.

Hickel said Manner makes all three types, and they all are proven in the market.

"These systems are designed for millions and millions of cycles," he said.

Manner's electrically driven actuator plate is called the e-plate. It can be set for unlimited positioning, with micron-level adjustments.

"Servo drives interface with the proper controls. It's a beautiful thing. You have the ability of working within pre-set limitations of the servos, and you can have fine adjustment of the control, relative to the valve pins," he said. "You can really set these servo drives to do some amazing things."

Conference attendees got a grounding in low-pressure injection molding, thanks to presentations by officials of Milacron Holdings Corp. and Imflux Inc.

Eric Hallstrom said Milacron has rebranded its structural foam and related machinery the Low Pressure Injection Molding unit, or LPIM. He is business manager for LPIM technologies at the equipment manufacturer.

LPIM covers more than just structural foam, although that is the major process done on the machines that boast a large platen filled with holes and nozzles than can run a lot of molds — or mold one very big part. Hallstrom said the LPIM segment includes structural web and gas-assisted molding.

The structural foam process can run a maximum shot sizes of 400 pounds, with an extruder output of 5,500 pounds an hour, all with low pressure.

"What makes the LPIM special? A 500-ton machine is approximately the platen size of a 2,300-ton injection molding machine with high pressure," he said.

The 500-ton is the smallest size Milacron makes. The LPIM line runs up to 2,500 tons.

The big machines are good for running family molds, parts that get assembled together.

"The major markets are material handling, commercial products, infrastructure and recreational vehicle parts," Hallstrom said. He showed a slide depicting parts that included plastic doghouses, manhole covers and collapsible shipping containers.

Hallstrom said Milacron is looking at Imflux to see if that company's technology works on the low-pressure machines. Last fall, Milacron became the first machinery manufacture to mold parts using Imflux at a trade show, during Fakuma in Friedrichshafen, Germany.

Dan Lumpkin, vice president of manufacturing at Imflux, which is part of consumer products giant Procter & Gamble Co., explained how the process differs from traditional high-pressure injection molding.

In traditional molding, the goal is to inject the plastic into the mold as fast as possible under high pressure, then blast it with cold water. He displayed a photo of commuters being crammed onto a Tokyo subway to illustrate his point.

"What other material in the world goes through all these stresses in 10 seconds?" he asked. "Bottom line with conventional injection molding you inject the material as fast as you can. What we're saying is don't do that. Slow it down, fill and pack at the same time and let the cavity tell the mold, go faster, go slower, go really fast or really slow — but keep pressure constant."

Imflux uses constant, low pressure and slow filling — what Lumpkin called "low and slow." Pressure sensors in the machine nozzle and inside the mold at the end of fill, work with Imflux-developed software to give feedback every millisecond to maintain the constant, minimum pressure to fill the mold.

Imflux can cut cycle times, make better parts without molded-in stresses and enable the use of smaller injection presses to make parts, with 35 percent less clamping force than a high-pressure machine, he said.

Another feature, called Auto Viscosity Adjust, allows running of a broader range of materials, include wider-spec resin, Imflux officials say.

"We ramp up to a constant pressure and we hold that for the whole cycle," Lumpkin said. "Our process is all about pressure control and holding that constant at all times." He calls it cruise control.

He reviewed results of a case study that Imflux, of Hamilton, Ohio, did on a flip-top lid for P&G.

You've head of the term scientific molding? Mark Brown is pushing "scientific cooling." His company in Grandview, Mo., Burger & Brown Engineering Inc., does precision machining and injection molding — and six years ago, it added classes in scientific cooling.

Brown, the CEO, said the company has data showing how turbulent flow of water through a injection mold cooling channel is better than laminar flow, where he fluid runs in a straight line.

"Turbulence brings fresh water to the surface of the cooling system, so there's better cooling," he said.

With laminar flow, the outside surface is hot and the inside of the water stream is cool — not the an efficient way to cool down a mold, Brown said.

Jochen Mitzler, director of market intelligence and product management for KraussMaffei Technologies GmbH in Munich, discussed KM's PX all-electric molding press. The PX is designed as a modular machine, allowing customers to mix and match clamping and injection units for their applications.

"It's just a two-piece machine, where we bring the components together. Just like the automotive industry where they have the chassis and the motor," he said.

KraussMaffei also offers an all-electric PX for running liquid silicone rubber, which is growing in the medical market and finding new applications in lenses, Mitzler said. The LSR machine is called the PX SilcoSet.

Alan Landers, director of product development at Conair Group, said blenders are important components to collect data for inventory and quality control. "Blenders are positioned in a unique place in a factory" because they are between the loading system and the molding machine or extruder, he said.

Landers said Conair's TrueBlend gravimetric blender gives inventory reports, shift reports, status reports and other types of production information. Blenders can be linked together — a trend Landers said is poised to explode over the next five years, through Industry 4.0, as all pieces of equipment will connect.

Conair has made a big move to Industry 4.0 with its SmartServices cloud-based platform that can collect all information from plastic processing equipment into a single dashboard.

Two other machinery officials — from Arburg Inc. and Wittmann Battenfeld Inc. — also addressed Industry 4.0.

Wittmann Battenfeld calls its version Wittmann 4.0, and the injection molding machine's controller will act as the center of the network. Tom Betts, regional sales manager, said production data of all equipment — including auxiliaries — is integrated via a Wittmann 4.0 router.

Another feature — the condition monitoring system (CMS) — can tell the operator key information, including oil and water quality, and when the screw tip is wearing and needs to be replaced, Betts said.

Daniel Heinzelmann, application engineering consultant with Arburg, laid out a "road to digitalization" in his Erie presentation.

He said the first "prerequisite" on the way to Industry 4.0 is have standard communication protocols. Heinzelmann cited Euromap 77, a common digital interface that allows injection molding machines from different companies to talk to each electronically.

Euromap, the European machinery association, is working on other standards covering molding machines and temperature controllers, hot runners, robots and other components.

Heinzelmann said the second prerequisite to Industry 4.0 is a system of flexible production that minimizes the time for job setups and teardowns.

"You will get a smart factory. And the machines start to talk," he said. Machinery also will schedule maintenance on an injection molding press and auxiliary equipment, via the number of cycles.

Heinzelmann said Arburg's Gestica controller has the look and feel of smartphones, where an operator can use gestures like swiping on the screen and zooming in.

"The most important thing is you will have the 3D image of the machine inside your controller, he said, adding that this will show where machine components are located on the press and what action is needed.

Heinzelmann said at K 2019 this October, Arburg will show the use of mold filling analyzers within the control system that can make changes, for example, to injection speed if the operator changes molding parameters.

And he said service technicians are getting in on the Industry 4.0 act. Next year, Arburg will launch in the United States a service where the technician hits a button on a cellphone when he or she is in the car driving to a molding factory. Plumbers and pizza delivery drivers don't do that.

Heinzelmann said the biggest interest in Industry 4.0 is in medical molding, where processors need full documentation of production.