Ecosam

The Development of a Novel Hexavalent Chrome-Free Environmentally Sustainable Pre-Treatment for Plastic Surfaces using Molecular Self-Assembly Nano-Technology

Ecosam’s main objective was to develop a novel surface pre-treatment method for chrome plating on a broad range of plastics. The majority of industries worldwide use a hexavalent chrome-based pre-treatment. Its major disadvantage is that hexavalent chromium (Cr(VI)) is carcinogenic.

Thus, the project aimed to develop a new process based on a molecular self-assembly technology (SAM) developed at laboratory level in Spain, in the manufacture of organic sensors, that eliminates the need for chemical etching and electroless nickel plating, and which provides a stable and secure surface suitable for subsequent chrome plating operations.

Specific objectives of the project were:

• Eliminate carcinogenic chromic acid from the pre-treatment process
• Decrease processing time and the number of plating/rinsing tanks
• Offer greater product flexibility, as the process will not be limited to a single polymer such as acrylonitrile-butadiene-styrene (ABS)
• Reduce waste water and chemicals due to fewer process steps
• Reduce the cost of the plating process by elimination of the expensive palladium catalyst and electroless nickel coating operations
• Increase process stability compared to classical wet chemical metallisation
• Maintain performance whilst lowering the cost of the chrome plating process

Organisational Information

Budget: €1M
Funding: €545k
Start Date: October 2006
Finish Date: December 2008
Duration (in months): 27
Lead Partner (Co-ordinator): Smithers Rapra, UK

Participants

		Avanzare SL

Results – What happened next?

The Ecosam process was developed and adjusted to allow the successful coating of polyamides, Poly(oxmethylene) (POM), poly(vinyl chloride) PVC and poly(ethyleneterephthalate) PVC-PET. However it was not possible to find suitable conditions by which to plate poly(cyclohexyleneterephthalate)PCt .

Injection processing parameters were optimised in order to facilitate good adherence in the metallic layer, given that, by and large this depends on the processing conditions of the polymer as well as the nature of the base plastic material.

Moreover, residual stress was minimised to achieve a good surface appearance with adjustment to the parameters. Failure to control the residual stress in the plastic samples can lead to poor adherence on plating.

Project website: www.ecosam.eu