The compounds deliver light weight, attractive aesthetics, and sustainability benefits for automotive interiors.

Sabic has introduced a specialized portfolio of Sabic PP compounds for foam injection molding (FIM). New mineral-reinforced Sabic PPc F9005, PPc F9007, and PPc F9015 grades can help deliver attractive aesthetics for visible automotive interior parts with complex geometries, such as door panels and trim, seat and trunk cladding, A/B/C/D pillar covers, and center consoles.

Unlike standard FIM materials, which typically exhibit surface defects, the new advanced PP compounds feature uniformly high surface quality similar to solid injection molded parts. Compared with solid components, foamed parts made with Sabic PP compounds offer significant weight savings that can help cut emissions. According to a cradle-to-grave life-cycle assessment study (pending third-party review), the advanced materials can help OEMs lower carbon dioxide (CO₂) emissions by as much as 15%.

“The automotive industry continues to look for new weight-out strategies that can advance energy efficiency and sustainability goals,” said Sabic’s Abdullah Al-Otaibi, General Manager, ETP & Market Solutions. “Although foam injection molding produces desirable lightweight parts, manufacturers have been forced to sacrifice aesthetics . . . until now. We applied our extensive expertise in foaming technology to develop these new compounds to help resolve the issue of surface quality and open new application opportunities for foamed parts.”

Solving the FIM aesthetics challenge

Previously, the FIM process was essentially limited to non-visible parts, restricting its usefulness in automotive applications. Foaming can underperform in surface aesthetics — silver streaking, swirl lines and dimples are common defects. Sabic PP compounds for foamed interior parts deliver low-gloss textured (grained) surfaces with uniformly high quality and eliminate streaking and swirling. Talc filler in these grades acts as a nucleator that promotes the generation of finer bubbles, which contribute to a consistent surface appearance. For enhanced aesthetics, these grades are currently available in selected automotive interior colors. Custom coloring is also available.

Optimizing weight-out benefits

Weight reduction results with Sabic PP compounds depend on several factors, including the type of FIM technique used.

Short-shot molding, which uses the same tooling as an injection molded part, can reduce weight by up to 10%. Sabic PPc 9007 is formulated for short-shot FIM and low-impact applications.

Core-back molding, which requires part redesign and new tooling, can lower weight by as much as 30%. Both Sabic PPc 9005 and PPc 9015 grades are formulated for core-back molding and deliver medium stiffness and impact.

The choice between the short-shot and core-back techniques, with their different tooling requirements, also helps to determine whether FIM with Sabic PP compounds is cost neutral or delivers cost savings. Additional cost savings are possible through cycle time reductions from flow improvements inherent in FIM.

Another consideration is the foaming process, which can use chemical or physical agents. The new Sabic PP compounds are good candidates for use with chemical blowing agents, which are typically preferred for visible foamed parts. These agents are introduced to the molding machine in the form of a masterbatch, along with the plastic pellets, and activated during the melt phase to release gases for foaming.

Sabic fully supports its new PP compound portfolio with extensive expertise in foamed part design, development, and processing, as well as predictive engineering. For instance, the company can provide guidance on the selection of the appropriate chemical blowing agent for each grade. Sabic’s technical team will collaborate with customers to achieve desired aesthetics at the lowest possible part weight.

To drive future developments in polymer foams, Sabic operates a Foam Innovation Center in the Netherlands. This center, which is equipped with foam process capabilities as well as analytical equipment, enables the company to develop new foam solutions and technology innovations and collaborate with customers.

The new Sabic PP compounds have launched in Europe, with upcoming availability in the Americas and Asia/Pacific.

Source: https://www.plasticstoday.com/automotive-and-mobility/sabic-debuts-pp-compounds-foam-injection-molding

Less range anxiety for consumers and reduced production costs are among the advantages.

As electric vehicle (EV) production ramps up and developing charging infrastructures make longer journeys more feasible, the onus is on automakers to further reduce vehicle mass. One of the remaining relatively untapped applications is the battery housing. Several alliances and individual companies are vying to develop commercial solutions.

Lanxess and Kautex Textron, for example, are experimenting with direct long-fiber thermoplastic (D-LFT) and polyamide 6 (PA 6) resins in a feasibility study. Aimplas, meanwhile, is developing sustainable structural battery casings for lightweight vehicles based on reusable, recyclable long-fiber thermoplastic composites. Discharged battery packs will be hot-swappable. In other developments, the Vestaro Consortium is adopting a novel approach based on lightweight sheet molding compounds for high-voltage battery module housings.

Shifting to PA 6

Inroads are also being made in peripheral EV battery components, with Lanxess again at the fore. According to the nylon supplier, PA 6 and PA 66 are materials with very similar properties, yet they are frequently in competition with one another. Recently, the tense pricing situation for PA 66 and its temporarily limited availability have resulted in it being replaced with PA 6 even in traditional applications. However, new developments in components that typically have been made from PA 66 are now increasingly being directly implemented in PA 6.

One current example is the cover for an on-board battery charger used in an EV compact vehicle made by a German car manufacturer. It is composed of Durethan BKV50H3.0 from Lanxess, which is highly reinforced with 50% by weight of short glass fibers. The manufacturer of the system consisting of the cover and charger is Leopold Kostal GmbH & Co. KG (Luedenscheid, Germany), a global system supplier of automotive, industrial, and solar electrics as well as electrical connector systems.

This large-scale application underlines the fact that PA 6 compounds do not necessarily have to be hydrolysis-stabilized to be used in cooling applications with glycol-water coolants in electric vehicles. “We assume that in the future, polyamide 6 products of this type will become very common in the mass production of covers and other thermal management components for electric vehicles. That is especially the case for applications such as fluid connectors or control units in the cooling system,” explains Dr. Bernhard Helbich, Technical Key Account Manager at Lanxess’ High Performance Materials business unit.

Thermal management requirements differ in electric powertrains

Plastic components in the cooling circuit of combustion engines have long been the domain of PA 66. This is because the thermoplastic is highly resistant to hot coolants such as water-glycol mixtures. However, the requirements in the thermal management of purely electric powertrains are shifting toward lower temperatures. For all-electric vehicles, the long-term thermal resistance of polyamide 6 compounds to water-glycol mixtures is sufficient for most of the parts, even for the significantly longer stress times in some cases. Thus, the cover permanently withstands temperatures up to 85°C during vehicle operation without any problems and burst loads up to 10 bar are achieved. Long-term tests on samples also revealed that the mechanical properties of the compound in water-glycol mixtures hardly diminish. even after 1,500 hours of storage at 110°C and a pressure of 1.5 bar. As a result, the material meets the technical requirements of a major German carmaker for water-cooled components of electric vehicles.

At around 29 cm long and 12 cm wide, the cover has a considerable flange length. The cover, together with a seal, is screwed to the aluminum housing of the charger. The high strength and stiffness shown by the PA 6 compound ensures that the cover meets strict leak tightness requirements. Helbich comments, “To that end, we optimized the mechanical component properties in close collaboration with Kostal and, by simulating filling, we determined how minimum values for shrinkage and warpage can be achieved in injection molding processing.”

In addition, Durethan BKV50H3.0 employs copper-free H3.0 thermal stabilization that does not result in electrical corrosion occurring on metallic parts in the cooling circuit. It is resistant to media typically found in EV operation, such as oils, greases, battery electrolyte, and road salt.

Source: https://www.plasticstoday.com/automotive-and-mobility/plastics-make-their-case-battery-housings