The industry’s challenges, in light of COVID-19 and an uncertain economy, could open the door much wider to greater use of metallic-effect masterbatches, as these significantly lower cost per part. The challenge with masterbatch remains molding parts that do not have visual defects such as flow or weld lines.

PolyOne recently collaborated with a leading global automotive OEM and its injection molder to eliminate paint from a new vehicle’s interior.

To provide customers with additional information on making the switch from paint to molded-in-color parts, PolyOne has created an eBook titled, “Trend Report: Efficient Manufacturing And Molded-In Color.”

“Many car parts are painted, not just metal and thermoplastic exterior parts, but also thermoplastic parts in a vehicle’s interior,” notes Gary Fielding, vice president and general manager, Color and Additives EMEA at PolyOne. “We have successfully helped carmakers transition from paint to MIC for many exterior applications such as skid plates and trims. This recent project is a significant step forward in reducing the cost to manufacture highly visible interior applications.”

KyronMAX can be compounded into any polymer. If an application requires the cost and property balance of nylon 6/6, for example, MCAM can formulate a nylon 6/6 KyronMAX compound that is stronger than anything currently available on the market. This technology ultimately offers customers the flexibility of selecting any polymer they want and combining it with KyronMAX fiber to create the strongest moldable compound in that category.

And though the argument against masterbatch always is about these visual defects, little is said about scrap from paint lines, which can reportedly be more than 20%. Painting is not only more costly, and energy-intensive; it also generates very high levels of non-recyclable scrap.

A quarter-turn latch found in the galley of a commercial aircraft illustrates how even a small weight reduction can have a large impact. Typically made from machined aluminum, this latch is molded using KyronMAX S-6230, a carbon-fiber-reinforced PEI compound. Switching to the thermoplastic provided a 45% weight reduction while still meeting mechanical and flammability requirements. MCAM’s exclusive Sprint technology — a platform for rapid injection molding of functional parts — was used to rapidly prototype components prior to full production.

Until she retired in September 2021, Clare Goldsberry reported on the plastics industry for more than 30 years. In addition to the 10,000+ articles she has written, by her own estimation, she is the author of several books, including The Business of Injection Molding: How to succeed as a custom molder and Purchasing Injection Molds: A buyers guide. Goldsberry is a member of the Plastics Pioneers Association. She reflected on her long career in "Time to Say Good-Bye."

The compounds from Mitsubishi Chemical Advanced Materials are being used to replace aluminum and steel in structural applications.

When it was introduced in 2014, the KryonMAX family of high-strength injection moldable thermoplastic compounds was designed to bridge the gap between traditional thermoplastics and carbon-fiber composites. “KyronMAX combines the best of both worlds by allowing engineers to injection mold high strength, carbon-fiber-reinforced thermoplastics in minutes with strengths that are comparable to metal,” said Dave Wilkinson, Technology Director for Mesa, AZ–based MCAM. “Combining specialized short carbon fiber and proprietary sizing technology produces molded parts that have significantly higher mechanical performance than was previously possible using long-fiber technology (LFT).”

MCAM continues to innovate in materials science, and it now offers materials with tensile strengths that exceed 60,000 psi (414 MPa), as shown in the video. In addition to improved processability, KyronMAX compounds exhibit mechanical properties that surpass conventional glass- and carbon-fiber-filled thermoplastic systems at similar fiber loadings. This allows for a reduction in filler loading, thereby increasing material strain and allowing the molded part to yield rather than fracture. These compounds are now being used to replace aluminum and steel in structural applications.

PolyOne recently collaborated with a leading global automotive OEM and its injection molder to eliminate paint from a new vehicle’s interior. To support the transition to molded-in-color (MIC) parts, PolyOne provided metallic-effect Smartbatch FX masterbatch colorants for two PC/ABS side panels on the center console of a compact SUV now entering commercial production. The parts (two; one on each side of the center console) are C-shaped, 35-cm long, and at their widest point 11-cm wide.

Sprint technology uses additive manufacturing to produce a mold that is injected with the KryonMAX compound in the same manner as a metal tool. These rapid, cost-effective prototypes allow for rapid design iterations while testing under operating conditions.

Transitioning from paint to the use of MIC with Smartbatch FX helps manufacturers in the automotive, appliance, consumer goods and other industries create attractive, durable parts at reduced cost. PolyOne’s metallic-effect masterbatches can be incorporated into pre-colored compounds or dosed at a molding machine.

In January of this year, Mitsubishi Chemical Advanced Materials (MCAM) expanded its KyronMAX product line beyond performance-grade polymers, such as PEEK and PEI, by adding engineering polymers, including polycarbonate, nylon, polyphthalamide (PPA), and even polypropylene. These new compounds unlock a wider range of applications in the automotive and mobility, recreational, electronics, and medical industries.

The key to molding good parts is for OEMs to decide, very early on, that a part will be colored with molded-in color masterbatch; that decision will then support the development of a mold and part suitable for masterbatch.

Transitioning from paint to masterbatch for metallic-effect parts is not new, but it is nowhere near as widespread as one would expect according to some auto industry observers. Inertia — We’ve always done it that way — and legacy investment in paint lines, supports the continued use of paint.

“KyronMAX compounds can significantly change the way engineers approach part design, manufacturing, and assembly,” said Wilkinson. “The combination of KyronMAX’s performance with MCAM’s proprietary high-pressure molding technology is now able to produce the highest strength structural components made from injection molded thermoplastics.”

Stephen has been with PlasticsToday and its preceding publications Modern Plastics and Injection Molding since 1992, throughout this time based in the Asia Pacific region, including stints in Japan, Australia, and his current location Singapore. His current beat focuses on automotive. Stephen is an avid folding bicycle rider, often taking his bike on overseas business trips, and is a proud dachshund owner.

“Typically, you do not want a bunch of holes or sharp curves in a part if you intend to use metallic-effect masterbatch. Too often, a mold is made for molding of parts that will be painted, and then — when it is time for a facelift — the OEM decides it wants to save some money and shift from paint to masterbatch. However, without investing in a new mold, the existing mold design often makes it very difficult for masterbatch to be successfully used.

Metal replacement has become a strategic element in most major OEM strategies for lightweighting and sustainability. KyronMAX technology has raised the bar for performance of injection moldable plastics and provides customers the opportunity to replace metal parts with plastic, said MCAM. KyronMAX parts that replace metal components on vehicles contribute to lower overall weight, which translates into a reduction of fuel consumption and CO2 emissions. Part cost can also be significantly reduced through the consolidation of several metal components into a single thermoplastic part by eliminating secondary operations during assembly.

Paint adds a great surface finish to automobile parts, but painting always adds cost, time, and additional logistics requirements according to PolyOne. By using Smartbatch FX metallic masterbatches, the molder was able to produce parts ready for assembly with no secondary processing required. Suitable for standard injection molding machinery, Smartbatch FX reduces the cost per part by 30 percent or more compared to painted parts. Lowered energy requirements versus painting and the reduction of VOCs also make this masterbatch a more environmentally sustainable solution.