Early in 2002, RKT Kunststoffe GmbH (D-73257 Köngen), has launched the production of front ends for different types of VW Golf and VW Polo at a further site located in Curitiba / Brazil. These fitting frames for front end modules are heavy-duty functional parts which the company produces, also at the new location, using the direct compounding and compression molding process. The frames are made from a polypropylene blend reinforced with 38 % by weight long glass fibers, in one heat, i.e. dropping the cost-intensive step with a semi-finished product. The technology of direct processing of long fiber reinforced thermoplastics (D-LFT) has been jointly developed by RKT Kunststoffe and Coperion Werner & Pfleiderer GmbH & Co. KG, (D-70466 Stuttgart; www.kwpc.com)It has proved its success since 1999 at the German location in Peine and, since mid 2001, at the locations in Puebla / Mexico, Curitiba / Brazil and Bilbao / Spain.

For all RKT´s worldwide production sites, a total of 8 D-LFT plants for fitting frames and other structural car components has been supplied by Coperion Werner & Pfleiderer. The working principle of a D-LFT plant is that – starting from the raw materials, additives and glass fibers – the melt is compounded and extruded in the form of a continuous sheet. The sheet is cut into individual blanks which are stockpiled for feeding into the press. The core component of the system is a ZSK 70 Megacompounder with a maximum plastification capacity of 650 kg/h. Its screws have been optimized especially for compounding of the melt and for gentle incorporation of the long glass fibers. In the first process zone of the compounding extruder, the gravimetrically fed raw materials and additives are melted and a homogeneous melt is produced. Endless glass fibers are then pulled in from rovings by the rotation of the screws, impregnated with melt, cut to length and dispersed. The compound thus produced is continuously discharged as a flat strand into a heated confectioning unit and cut into individual blanks which are stacked and then picked up by a robot with gripping needles and placed in the press mold. The weight of a finished fitting frame for the VW Golf A4 is 3.8 kg; worldwide production capacity is about 1.2m units per year.

Regarding production in Brazil, the direct process offers the invaluable advantage that polypropylene and glass fibers from national suppliers can be used. These products are available at low cost and are not subject to additional charges like transport cost and high import duties. Only some additives that are required in small quantities need be imported. Under the prevailing conditions imposed by the economic and financial policy of the Brazilian government, direct processing is the only production method for front ends that is practical in terms of profitability.

RKT Kunststoffe GmbH has emerged from Rütgers Kunststofftechnik in 2001 and, today, is a company of the AKsys group, Worms. RKT is a global partner of the automotive industry for systems, focussing on structural components and underbody systems, including the necessary acoustic components.