KraussMaffei shows a Proper way to cut weight

WARREN, MICH. — Auto industry people learned about technology trends, like Takata Corp.'s thinner, lighter airbag cover made by overmolding fiber-reinforced sheet, at a one-day conference at Proper Group International headquarters in Warren.

Proper Group, an automotive mold maker and molder, joined with its machinery partner KraussMaffei Corp., to hold the event June 11.

Takata has developed the HyPac “hybrid plastic airbag cover” for the passenger side. The part offers a 37 percent weight reduction over the current cover — which itself is plastic, molded from glass-fiber reinforced nylon, according to Daniel Alt, senior product engineer for safety systems at Takata in Auburn Hills, Mich.

The reason: Using reinforced organo-sheet molded on a KraussMaffei press with the FiberForm process allows Takata to make a thinner airbag cover, Alt said. A thinner cover also can fit easier in the passenger-side space, he said.

Takata, which is looking for customers that want the HyPac cover, uses Lanxess' Tepex sheet, made from fiber-reinforced thermoplastic composites.

KraussMaffei created a work-cell to help develop the airbag cover at its headquarters in Munich. At NPE 2015, and at the event in Warren, KM molded the covers in a CX press with 300 tons of clamping force.

Alt said that working with KM and Lanxess was a key. “It's highly optimized by partner development,” he said.

Alt said the cover is a demanding application. In a crash, the cover has to deform by inner pressure and pull forces, he said.

When Takata designed the organo-sheet cover, engineers used computer simulation to optimize the structure, putting thicker walls where needed and thinning down other areas. Alt said that technique is a common one when trying to reduce part weight — a mandate from the automotive industry, to increase gas mileage.

Alt said Takata validated new Moldflow modeling software for the overmolding of the organo-sheet.

Stephen Beasley, KraussMaffei's regional sales manager for the automotive sector, said the FiberForm technology integrates injection molding and thermoforming. “Today we can offer a composite part out of the mold without secondary operations,” he said

Beasley said the process will be able to make structural automotive parts in the future. He showed attendees a hollow part made of two closed profile sections.

Another speaker, Lanxess senior engineer Vasant Pednekar, said the Tepex sheet comes in thicknesses ranging from 0.5 to 6 millimeters. The fiber direction — using glass, carbon or aramid — is very important to making a good part, he said.

Pednekar said the reinforced sheet makes parts that are lightweight and have very high strength — offering good crash resistance.

He listed some other commercial automotive applications that use Tepex composites, including a plastic-metal hybrid structure on the front end module of the Audi A8, a seat panel on the Astra, the underbody panel on the Mini-Cooper, a brake pedal on the Porsche 918 Spyder, an infotainment carrier on the Audi A6/A7. A concept multimaterial part, used in the tailgate, cuts weight by 40 percent.

Mike Tabbert, Proper's innovation group manager, outlined five technologies the company thinks will be important for the auto industry in coming years:

Core-back with gas counter-pressure in an expansion molding process. A chemical foaming agent is blended in the resin pellets. The gas pressurizes the mold cavity, to counteract the foaming action and give a good surface finish — at lighter weight. Tabbert said the technology is optimal for flat parts that require a high-gloss finish.

Multi-layer injection is a way to mold very thick parts, layer by layer. That avoids the very long cycle time normally required to make thick parts, and the process is catching on for optical-quality parts, Tabbert said.

“Pretty much any OEM is adapting this technology in some shape or form, for automotive lighting,” he said.

Hard-coat shuttle molding that overmolds a very thin polyurethane skin over a polycarbonate/ABS substrate, using a secondary PU mixhead bolted onto the injection molding machine.

Using the MuCell microcellular process, combined with the rapid heating and cooling mold technologies of RocTool or Single, will get light parts with a good surface finish.

In the process, the sheet is first heated, then pre-formed in the molding press. The injection press then does back-injection.

One of the KraussMaffei presses running at the KM/Proper event — the same GHX multicomponent machine KM showed at NPE 2015 — will mold automotive headlamps at Proper's new lighting factory at Pulaski, Tenn. The factory, a $13 million investment, should begin production this fall, said Proper President Joe Grippe.

Grippe said the plant will house 12 to 13 KraussMaffei presses from 110-1,500 tons, and have a vacuum metallizing operation.

Sean Brolley, Tool Stats' business development manager, described the Warren-based company's cloud-based database for companies to store, and update, mold production data. He said that is better than paper documents, CDs or thumb-drives. Tool Stats provides “a real-time updates-platform where you could share the information and have easy access.”

Veteran consultant John Bozzelli gave an energetic talk about the industry's shortcomings. Bozzelli decried what he calls a lack of communication, no standard ways to document the mold process, and even no standard terms for basic things, such as weld lines.