The instrument panel carrier of the 2017 Mini Countryman from BMW Group is this year’s winner in the Body Interior category of the Automotive Innovation Awards, an annual competition now in its 47th year and run by the Society of Plastics Engineers (SPE). The Tier 1 supplier on this program is International Automotive Components (IAC) Group. The toolmaker is Siebenwurst.
An innovative process combined with lightweight-enabling materials from Sabic has helped reduce the part’s weight by about 15 percent versus a comparable solid plastic component. The injection-molded part uses a high flow concentrate long glass fiber-reinforced polypropylene (LGFPP) material (Stamax resin) from Sabic and a dedicated masterbatch solution in a structural foaming process with core-back technology.
|Structural foaming process with core-back technology realizes a 15% weight saving in the instrument panel carrier of the 2017 Mini Countryman.|
In this approach, the material injects into and completely fills the mold. The mold then opens to allow for foaming on the core side of the mold. This foaming part of the core-back technique increases the wall thickness of the part from 1.9 mm to 4 mm. This delivers the required strength and rigidity characteristics without adding weight. This foamed solution with Stamax resin also typically requires less material during processing and enables shorter cycle times.
“Congratulations to BMW Group and all those involved in this collaborative effort,” said Scott Fallon, Sabic’s global automotive business leader. “This award is well deserved in that success with this foaming technique does not come easily. Designing the tool and optimizing the process for the best results requires skill, knowledge and persistence from all parties. We take pride in our ability to step in and provide the support required to help develop and validate this lightweight solution.”
Sabic performed extensive CAE warpage analysis to predict warpage behavior of the part. This evaluation, early in the development process, provided valuable insights for the design of both the part and the mold, which enabled building the mold correctly the first time.
“This sort of computer simulation is standard practice when it comes to solid plastic parts, but the industry is still in the early stages of developing simulation tools for foamed plastic parts,” explained Fallon. “As evidenced through this program, we have predictive capability that we can apply today. We continue to work on new material formulations and improved ways to predict the properties of foamed parts.”