Reducing setup times in CFRP post-processing

Two tables with shuttles instead of just one: By switching to new CNC machining centers, ACE has significantly reduced setup times for milling operations on CFRP components. Machine downtime now amounts to a maximum of only three percent, down from up to 45% previously.

The TIER 1 supplier primarily manufactures carbon fiber reinforced plastic (CFRP) parts for premium automotive manufacturers. They primarily source Class-A quality visible parts and structural components made of CFRP from ACE, which require milling of contours and trims prior to painting. For this purpose, the company from Lake Constance utilizes three 5-axis CNC portal milling machines of the type P-S-F (20-25)/S from HG GRIMME SysTech.

Easy Switching Between Identical Machines

ACE acquired the identical machining centers, each with two tables and a shuttle as well as a Siemens 840d sl control system, between 2016 and 2024. Consistent operation and machine tables with the same hole pattern and a fixed zero point also contribute to short setup times. Furthermore, ACE can post-process the CFRP parts on all machines from HG GRIMME SysTech interchangeably and without any quality limitations.

CFRP Dust is Extracted

The milling systems are suitable for workpieces with external dimensions of up to 2,000 x 2,500 x 650 mm, which can be machined with exceptional dynamics thanks to rapid traverse speeds of 80 m/min in X/U/Y and 30 m/min in Z.

Double tables and shuttles result in a machine length of just under 11 meters and a width of slightly less than six meters. This simultaneously provides sufficient space for good accessibility to the machine table and milling head from all sides.

The components to be machined are up to 2,000 x 2,500 mm in size, with thicknesses between 1 and 3 mm, and batch sizes usually vary between 500 and 10,000 pieces.

Around two-thirds of the products are visible parts, predominantly for car bodies, particularly fenders and hoods. The remaining parts are structural components such as monocoques for the drivetrain, battery trays for electric vehicles, and paneling for B-pillars and center struts.

Given the significant dust generation during CFRP milling, CNC machining centers from HG GRIMME SysTech are completely encased, and an extraction system removes many airborne particles directly within the enclosure. Furthermore, the components are manually cleaned again with high pressure after machining.

ACE manufactures most CFRP components using the closed RTM process

ACE manufactures ninety percent of the CFRP components and assemblies using the closed RTM process. In this process, textile preforms are cut and prepared into layups, which are then placed in presses, injected with resin, and cured into shells. The edges of the two, or less frequently three, shells still need to be milled before they are subsequently bonded together to form the carbon fiber part.

After contour and trim milling, the bonded and painted components are inspected before ACE delivers them to its customers' assembly lines. This includes well-known brands such as Lamborghini, Porsche, Aston Martin, Bugatti, BMW, Mercedes, AMG, Audi, and Volkswagen. The most important customers from the aerospace industry are Airbus and Boeing.