TP Composite Surface Texturing: Abrasive Waterjet (AWJ) vs Conventional Methods

In the aerospace industry, surface preparation of thermoplastic (TP) composites is a critical step in ensuring the reliability of structural bonding and paint adhesion. Unlike thermoset resin composites, which naturally accept coatings through chemical affinity, thermoplastics are chemically inert and require a textured surface to achieve mechanical interlocking. BAYAB's Abrasive Waterjet (AWJ) texturing transforms an inert surface into a high-performance bonding interface, consistently yielding cohesive failures in Single Lap Joint tests.

This article analyzes why Abrasive Waterjet (AWJ) texturing is becoming the new technological standard over traditional solutions like manual sanding, laser processing, or chemical treatments.

Complex geometry TP parts textured by AWJ

1. Thermal and Physical Integrity Preservation

Unlike laser treatments that generate a detrimental Heat Affected Zone (HAZ), BAYAB's AWJ is a strictly "cold" process. It fully preserves the physico-chemical properties of the substrate without altering the polymer matrix. This complete absence of thermal stress guarantees that both fibers and resin retain their nominal mechanical characteristics.

Furthermore, abrasive waterjet texturing ensures high processing homogeneity and isotropic adhesion, eliminating any preferential orientation (texture lay) typically caused by sanding.

Compared to manual sanding, AWJ is a non-contact process. It exerts extremely low stress on the component, preserving the structural integrity of the composite substrate with an applied force of less than 2N.

Finally, BAYAB's AWJ texturing is highly tolerant of complex geometries and variations in stand-off distance between the nozzle and the treated surface, drastically simplifying industrial automation.

2. Mechanical Performance: Achieving Cohesive Failure

The industrial standard for evaluating surface preparation before bonding or painting is the water drop test. As shown in the image below, the contact angle (wettability) test yields exceptional results following the AWJ treatment.

Wettability and contact angle test before and after abrasive waterjet surface preparation

This high performance is further validated by mechanical lap shear tests conducted in partnership with ENSTA Bretagne. While untreated samples exhibit poor adhesion and adhesive failure, abrasive waterjet texturing creates an optimized mechanical interlock. The process simultaneously decontaminates the surface under the action of the waterjet and generates a specific micro-roughness via abrasive particle impacts, promoting optimal mechanical anchoring. Our studies prove that maximum joint strength can be achieved, resulting in true cohesive failure during Single Lap Joint testing.

"AWJ optimizes bonding strength compared to conventional methods through controlled, homogeneous roughness combined with deep surface decontamination."

Single lap joint mechanical test showing cohesive failure vs adhesive failure on composite

3. Risk Assessment of Texturing Processes

The matrix below highlights the operational risks associated with each texturing method. Abrasive Waterjet stands out due to:

• Environmental & Health Compliance: Composite dust is instantly confined and captured in the water before filtration.

• Zero Thermal Risk: Absolutely no localized overheating or matrix degradation.

• Seamless Scalability: High adaptability for robotic and automated industrial integration.

Industrial risk matrix comparing manual sanding, laser HAZ, and abrasive waterjet texturing

Conclusion: The Industrial Standard for High-Performance TP Composites

In conclusion, Abrasive Waterjet (AWJ) texturing stands out as the breakthrough technology for thermoplastic surface preparation. Where conventional methods like laser and sanding reach their thermal or mechanical limits, the BAYAB solution guarantees:

• Maximum Adherence: Systematic cohesive failure in Single Lap Joint testing.

• Total Structural Integrity: A cold process with zero HAZ and negligible mechanical stress ($<2\text{N}$).

• Sustainable Operations: 100% chemical-free and a clean, dust-free work environment.

• Process Homogeneity: Straightforward robotization, even on highly complex components.

  
  

Secure your next-generation structural assemblies with a repeatable, high-precision texturing process.