Hybrid process offers opportunity for lighter interior parts
German carmaker Daimler AG has developed a manufacturing process for the series production of very light trim parts for motor vehicles that combines injection and compressions molding. The so-called KIS technology (derived from the German for ‘consolidation in injection molding tool’) combines intelligent compression and injection-molding processes to achieve weight reductions of up to 50 percent with suitable materials.
No other economically viable series production technology offering higher weight- saving potential exists at present according to Daimler. This opens up the prospect of the process becoming the standard technology for interior trim parts in the space of a few years.
The KIS technology combines the advantages of compression- and injection-molding processes: pressed components allow a marked reduction in weight, while injection-molded components enable the incorporation of ribs to ensure the necessary stability and strength as well as opening up broad scope for shaping to enable the realization of many different components.
In the new manufacturing process, ribs and attachment points are injected directly onto the pressed carrier while it is still hot. The starting material for the carrier takes the form of hybrid bonded-fiber fabrics consisting of thermoplastic and reinforcing fibers. Use of the same materials for the bonded-fiber fabric and the injection-molding process results in an optimum bond. In this way, the KIS technology enables both simple functional integration and thin wall thicknesses.
When the full scope of potential is exploited in the interior, weight savings of over five kilograms per vehicle are reportedly attainable with the KIS technology. This substantial reduction in weight is accompanied by reduced material input. Consequently, substantial reduction in CO2 emissions from the component manufacturing process are also attainable. No other process suitable for use in large-volume production operations is capable of realizing potential for CO2 reduction on a comparable scale according to Daimler.
A further advantage is that the new components can be produced without any increase in costs in comparison to the injection-molding process, due to the reduced material input and the use of suitable materials. Furthermore, in comparison to the compression molding process, costs can be reduced by up to ten percent.The first parts for pillar and door trims to be produced with the KIS technology will go into series production in one of the next Mercedes-Benz model lines.
The process has been nominated for the 2013 Baden-Württemberg Umwelttechnikpreis (‘Environmental technology award’) in the “Material efficiency” category. This award has been presented since 2009 for environmental technologies and products from Baden-Württemberg which make a substantial contribution to the efficient use resources and to the protection of the environment.