Leverkusen - IVECO, one of the world leaders in commercial vehicles, is using bumpers made from Pocan TP 525-001 (in future Pocan TS 3220) for the third generation of its Eurocargo model. The glass fiber reinforced and elastomer-modified PBT+PET blend from LANXESS has been customized for this application and can be injection molded. The bumper was previously made using sheet molding compound (SMC) technology. “Our thermoplastic enables components to be produced without time-consuming post-molding treatment and is around 20 percent lighter. What’s more, the resultant surface quality is so good that the body part can also be used without a coating,” explains Lars Kraus, head of the Technical Marketing Service in the Semi-Crystalline Products business unit. The bumper is injection molded by Martinplast S.p.A. in San Martino Alfieri, Italy.

SMC components require a great deal of post-molding treatment. For example, burring and flashing need to be removed and holes that have become clogged need to be opened up again. The components also require a coating to achieve good surface qualities. This means they have to be pretreated with primer and often need to be polished, too. Due to the lower mold costs that are found in injection molding, these two drawbacks in production costs can be offset, but only when small numbers of parts are being produced. “Given the relatively high quantities involved, our blend is a much more cost-effective solution. It produces bumpers that require no post-molding treatment with a very low reject rate and short cycle times,” reports Kraus. Two more of the blend’s strengths compared to SMC are its outstanding toughness and good resilience at low temperatures. This makes the component extremely resistant to minor damage. The excellent flowability of the PBT+PET blend comes into its own when manufacturing the very large component, which has external dimensions of 220 x 70 x 30 centimeters.

The blend’s excellent coatability is a further advantage because some Eurocargo bumper models are painted. Thanks to the material’s outstanding stiffness, a tread can be integrated in the component without the need for metal reinforcements. This supports the driver’s entire weight, for example when cleaning the windshield. Another benefit of Pocan TP 525-001 is its good chemical resistance to road salt, fuel, greases, oils, coolant, insect cleaner sprays and other substances typically encountered by motor vehicles.

Customer service for faster component development
LANXESS provided Martinplast with a great deal of assistance when it came to designing and constructing the bumper. It calculated both the thermal expansion and how the bumper deforms under stress. This enabled “critical” areas to be strengthened using targeted localized reinforcements. The mold filling process was also simulated using mold flow analyses to optimize the gating concept and minimize component warpage.

Targeting the commercial vehicle sector
LANXESS sees good prospects for Durethan polyamides and Pocan polyesters in truck engineering applications. To provide potential customers with more targeted information and support, a dedicated key account management team has been set up for this sector. “Our focal points include bodywork applications such as mirror housings, spoilers, handles and bumpers. We also place great emphasis on engine components such as oil pans, blow-molded parts for the cooling system and media hoses designed to transport air, which are subject to very high thermal stresses,” explains new Key Account Manager Juergen Horstmann.