JEC COMPOSITES MAGAZINE - Issue #77 - December 2012 - 49

Fig. 2: Sequence of automatic handling, 3D pre-draping and pre-fixing of textiles over the preforming tool

Fig. 3: System for automatic inspection by artificial vision and outputs showing the virtual 3D reconstruction of the preform containing the real preform 3D geometry, as well as the fabric positioning and orientation for quality control

preforming cycle time, to increase process capacity, repeatability and quality control, while reducing energy consumption and the consumable materials involved in the process. The main innovations and functionalities integrated in this advanced preforming cell are 1) a fully automated handling/pre-draping end effector, 2) a fast, energy-efficient selective activation system based on direct resistance heating combined with 3) a flexible compaction system that can cover different geometries, and 4) an automatic inspection system based on artificial vision.

specific PLC. The fabric is captured by the vacuum grippers, which can be adjusted in position automatically as a function of the specific shape of the 2D pattern.
Fig. 4: Mould with integrated electrodes and compaction setup for direct Once the fabric heating/activation by Joule effect during the final compaction phase is captured, it is transported to the cell can perform on-the-fly inspection of deposition table where the preforming tool the plies using an advanced stereoscopic is located. At that point, the fabric is placed visual inspection system. This system can over the preforming mould. For depoautomatically detect typical errors (wrinsiting the fabric over complex geometries, kles, position or fibre orientation errors) the pick-and-place system modifies the and alert operators so that corrections can configuration of the vacuum grippers to be made where needed. These inspections adapt and pre-drape it onto the 3D mould can be performed on the fly between the deposition geometry. To avoid undesired placement of each ply, or as a final step in movements, deformations or deviations the preforming process. of the plies, the end effector can tack some locally activated areas with a special Fast, energy-efficient activation vacuum gripper having additional degrees and final preform compaction of freedom while reference points in the Once the pre-programmed number of plies periphery are still fully fixed on the tool. has been laid down, the activation, consolidation and de-bulking step is performed Automatic automatically. For this step, an innovative one-shot system using a reusable highinspection elongation membrane system especially by artificial vision Once the fabric pattern is placed over the adapted for complex shapes was developed preforming tool, the cell proceeds to the to apply the necessary pressure/vacuum automatic inspection step using an artificial while thermally activating the binder vision-based device (Figure 3) to guarantee (Figure 4) for overall compaction of the that the deposition was done correctly. The preform. A selective advanced heating

Automatic handling, pre-dra ping and pre-fixing of textiles
Through the use of the robot and end effector, the system automates all the typical manual fabric preparation steps carried out by human operators, such as fabric handling, adaptation/folding to 3D geometry and fixing to the preforming tool. First, 2D fabric patterns are placed on a table for sequential capture of the different fabric layers by the pick-and-place system. This system is based on an anthropomorphic robot and an end effector (Figure 2) with several vacuum grippers, each gripper having different degrees of freedom and independent movement possibilities. These movements are implemented by electromechanic actuators and controlled via a

No77 December 2012

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JEC COMPOSITES MAGAZINE - Issue #77 - December 2012

Table of Contents for the Digital Edition of JEC COMPOSITES MAGAZINE - Issue #77 - December 2012
