E-Thesis 358 views 358 downloads
Characterisation of Sustainable Materials for Can Making / EMILY HOLDING
Swansea University Author: EMILY HOLDING
DOI (Published version): 10.23889/SUThesis.69049
Abstract
REACH legislation banning the use of Cr(VI) (hexavalent chromium) in can making initiated a drive to develop safer, more sustainable alternatives. TATA steel developed TCCT, as an alternative to ECCS (Electrolytic Chromium Coated Steel) substrates produced using Cr(VI) electroplating baths. The adde...
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Swansea University, Wales, UK
2025
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| Institution: | Swansea University |
| Degree level: | Doctoral |
| Degree name: | EngD |
| Supervisor: | Jewell, E. |
| URI: | https://cronfa.swan.ac.uk/Record/cronfa69049 |
| Abstract: |
REACH legislation banning the use of Cr(VI) (hexavalent chromium) in can making initiated a drive to develop safer, more sustainable alternatives. TATA steel developed TCCT, as an alternative to ECCS (Electrolytic Chromium Coated Steel) substrates produced using Cr(VI) electroplating baths. The added requirement to remove BPA (Bisphenol A) from food contact materials means that the EP (Epoxy Phenolic) lacquer that is currently used must be replaced with a BPA free alternative, BPANI (Bisphenol A Non-Intent). Both TCCT and BPANI have been characterised using various mechanical and analytical techniques throughout this work.Simulant concentration, substrate surface condition and CrOx (chromium oxide) weight are key influencers on material performance. A CrOx weight of 9-11 mg m-2 is optimal. Water uptake by BPANI is a mechanical rather than chemical mechanism. EP and BPANI are both effective at providing corrosion protection for the underlying substrate.Newer TCCT generations perform similarly to ECCS at lower uniaxial strain. The performance of all substrate types was similar at high strain. At high NaCl concentrations the simulant concentration is the primary influencer over material performance as opposed to strain. The change in surface condition due to strain was more significant for ECCS than TCCT.A method was developed to induce and quantify biaxial strain and test lacquer adhesion. Biaxial strain is more detrimental to the substrate than uniaxial strain. Oxidepin hole identification confirmed that an increase in strain exposes more free metal. A correlation between an increase in copper percentage and a decrease in failure force confirmed that surface condition influences lacquer adhesion.TCCT performance has improved with newer generations. It was concluded that based on the performance of TCCT being similar to ECCS under strain, that the novel TCCT substrate was suitable for use in the can shaping process. Retort and corrosion tests have also demonstrated the suitability of newer TCCT substrate generations for can making applications. The novel BPANI lacquer is heavily influenced by food simulant and retort conditions, more so than the commercially established EP lacquer.Performance of newer generation TCCT generations is acceptable providing the lacquer covers any surface defects and an adequate CrOx layer is present. |
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| Item Description: |
A selection of content is redacted or is partially redacted from this thesis to protect sensitive and personal information. |
| Keywords: |
Coating, lacquer, can making, Cr(III), Cr(VI), REACH, TCCT, ECCS, BPANI, BPA, Epoxyphenolic, |
| College: |
Faculty of Science and Engineering |
| Funders: |
TATA Steel/Eviosys |