Multi-material aerospace lay-up: Enhanced A4 gripper for complex geometries and tacky materials

Advanced lay-up for large composite components

To support the growing demand for efficient and precise lay-up of large fiber reinforced structures, Cevotec has further improved its large A4-sized gripper. Based on the design of the previously introduced PV gripper for dome reinforcements of hydrogen pressure vessels, this gripper variant is tailored for fast placement of larger prepreg patches or plies enabling an efficient lay-up of components with surface areas of several square meters. This makes it particularly suited for a range of mid-sized, complexed-shaped aerospace components.

Designed for flexibility and complex geometries

The new A4 gripper extends the capabilities of Cevotec’s Fiber Patch Placement (FPP) technology, especially for complex geometries. Its form adaptive design enables  lay-up on both strongly concave, convex and bi-axially curved surfaces that typically present accessibility and performance challenges for Automated Fiber Placement (AFP). It facilitates the lay-up of both skins of aircraft sandwich structures.

In addition to standard patch placement, the A4 gripper also supports Cevotec’s Post-Placement Push-in feature. This function improves the draping behavior of prepreg patches in geometrically challenging areas, ensuring consistent and high laminate quality.

Advanced Material Handling for All Fiber Types

The gripper’s performance goes beyond the type or nature of materials to be handled; they can be dry or prepreg, glass, carbon or any other technical fiber – even film adhesives.

Depending on the fiber material used, the gripper is available with different contact surface options, e.g. a darker contrast variant for glass fiber prepreg and a lighter one for carbon fiber prepreg. Additionally, the surface texture can be adjusted depending on the material’s tack level.

Smart Features for Efficient, Reliable Production

The new A4 gripper also features a “hot-swap” capability of the foam body. This enables fast switching between different foam body variants on the same gripper and facilitates an easy exchange in case of wear and tear.

A new vacuum chamber architecture enables the handling of small (credit card) to large (A4) sized patches without the need to change the gripper during production. This further improves material-efficient laminate designs with different patch sizes without compromising total lay-up time.

In addition, a new sensor for patch presence detection at the gripper further improves the high level of process control inherent in FPP technology. This real-time verification documents the actual delivery from pick-up to placement position and supports the tight process monitoring requirements of aerospace certifications.

Cevotec has used this enhanced gripper to successfully manufacture large aerodynamic aircraft sandwich structures, proving a maturity level of TRL 6. The new A4 gripper has demonstrated excellent performance, confirming its reliability and efficiency in industrial production settings

Key technical features of the A4 gripper include:

• Patch size range: 40 x 80 mm to 220 x 330 mm, enabled by multiple suction zones
  
• “Hot swap” foam body
  
• Built-in vacuum generation for rapid patch pick-up
  
• Durable surface for reliable patch transfer
  
• Sensor-based patch presence check
  
• Quick connector for automated gripper change

With the new A4 gripper, manufacturers can fully utilize the design flexibility and precision of Fiber Patch Placement technology for larger composite parts at improved productivity. It enables the fully automated lay-up of complex composite structures with difficult-to-handle materials.

Learn more about the A4 gripper and how it can enhance your composite manufacturing process: www.cevotec.com