According to the January 2016 report of the Composites World magazine, the German Aerospace Institute (DLR) Light Production Technology Center has developed an automated production line called EVO, which can produce 100,000 complex composite parts each year.

The EVO was originally designed to make aircraft frames and trusses, which began in 2009 when the next generation of Airbus A320 was planning to use carbon fiber reinforced composites, and the use of hand-paved floors to produce 500 per year was a challenge for Airbus.

Each aircraft has 200 fuselage bulkheads, 500 aircraft each year, that is to say, the production of 100,000 bulkheads every year, so we must develop an automated production line.

The DLR team initially decided to select a supplier to make an integrated production line, but eventually opted for 6 separate splicing lines: prepreg preparation, preforming, precision trimming, RTM (resin transfer molding), ovens, and software.

These vendors can coordinate their work by establishing a standard. The Prepreg prepares the module to roll the fabric and then sends them to the automatic cutting machine, according to the digital cutting file to the different material and the prepreg paving cloth row to cut.

The finished prepreg is stored in a rack system that is checked by the robot and transported by the robot onto the transport counter to the preformed area. On the roof of the workshop, there is a photographic system that provides information to the robot.

The automatic cutting and paving module on the EVo RTM automatic production line the next module uses a vacuum film to pressure the Cascade Prepreg and to draw the gas from under the laminated material, and to activate the powder epoxy binder on the material by infrared heating.

The results show that the preform of the robot is stable during the trimming process.

The Precision trimming module trims the stationary preform into a near-zero-shape piece, which makes the EVO more powerful.

This step can prevent the resin in the preform from wandering, forming a “drypoint.” It is particularly important to emphasize that milling cured parts will expose the fibers to moisture, thus forming micro-cracks in the resin, so that the composite parts are no open edges. All edges must be sealed and put back in the hot pot.

The Precision trimming module robot on the Evo RTM automatic production line is placed in the 4-part RTM mold with all heating channels and preform on the inner die/core mold.

The core die is integrated into the RTM press. All the boxes look alike, but the actual geometry is different, so each mold is required to handle the various parts.

In addition, this process requires the use of the required resin, the resin curing time of more than 90 minutes, so the mold after the closure of the press and then bake after curing.

The Evo can instantly inject and solidify different parts. The first test piece is a 2m-long V-shaped curved frame with varying thickness and curvature in the length direction.

In fact, no part is like this, but the experiment is to collect all the possible problems, so put all the features on a part, people call this part “Frankenframe”.

The Evo production line is capable of processing 2.5mx2mx40cm (height) parts in a 30-40-minute target time.

If you use a faster curing resin, time can be significantly reduced.

In addition, through the improvement of precision trimming area, so that it can be used to make foam milling sandwich parts, but also the use of the diaphragm for curing parts.