Z. Yang, C. Goode, J. Venter
Cirrus Materials Science,
New Zealand
Keywords: plating on polymer, metallization, coatings, sustainable, cost effective, benign chemistry
Summary:
The authors present a newly developed eco-friendly technology to metallize advanced polymers via a novel chemical bond that directly addresses the global need to decarbonize and improve energy efficiency through light-weighting of components in the automotive, electronics and aviation industries. Rapid development of advanced polymer substrates, especially engineered composite polymers, offers lighter, cheaper, and easier to manufacture components; however, these often require metallic coatings to provide improved UV performance, chemical resistance, electrical conductivity, and EMI shielding. Prior technology development has attempted to replace widely used toxic chromic acid etches, eliminate expensive palladium catalysts, and reduce the number of processing steps; however, these newly developed technologies typically only support a limited range of substrate materials and the proposed alternatives to palladium catalyst are challenging to scale. Furthermore, mechanical interlocking still dominates metallic coating adhesion mechanism produced from those technologies, thus producing adherent surfaces often relies on appropriate design of component and polymer design. A novel plating on plastic technology proposed by Cirrus Materials Science requires few process steps, operates at low to moderate temperatures, uses benign and cost-effective permanganate chemistry and adopts inexpensive Ag or Cu catalysts. The resulting metallic surfaces produced on ABS exhibit excellent adhesion, classified as 5B following ASTM D3359 with an average peel strength of 19 N/cm following ASTM B533. Moreover, Cirrus has successfully applied the technology to metalize hard-to-plate polymers, including PETG, phenolic resins and both glass and carbon fibre reinforced PPS, achieving 5B adhesion in tape testing. Unlike most polymer plating technologies, the Cirrus process creates a chemical bond between the metal layer and the polymer matrix which may simplify the design of composite polymer and facilitate improved coatings on intricate or 3D printed components. This presentation discusses aspects of the Cirrus’ PoP technology and presents examples of metal coatings achieved using the technology.