--- type: "Article" title: "Optimization of the coating of a can" description: "Case study Optimization of the coating of a can One of our clients wants expertise and optimization of the coating used on the cans it uses to market its beverages. Accueil • Blog • Optimization of the coating of a..." resource: "https://filab.fr/en/blog/2025/12/optimization-of-the-coating-of-a-can/" tags: ["Case study", "Characterization of Materials", "EN", "pll_691f13055daec"] timestamp: "2026-01-06T13:55:44Z" published: "2025-12-02T07:05:35Z" language: "en" author: "bwa" --- # Optimization of the coating of a can Case study # Optimization of the coating of a can One of our clients wants expertise and optimization of the coating used on the cans it uses to market its beverages. [Home](https://filab.fr) • [News](https://filab.fr/?post_type=post) • Optimization of the coating of a can ## The problem? **A beverage manufacturer uses aluminum cans coated internally with a **polymer varnish** to protect the contents (a carbonated beverage) from the aluminum and prevent any chemical interaction or metallic taste.** **The customer approached FILAB because it is committed to continuous improvement and is seeking to optimize the thickness of this coating. Insufficient coating creates defects (pores, discontinuities) and risks of premature **corrosion**. Conversely, excessive coating represents a costly waste of raw materials.** To address this issue, FILAB developed a comprehensive assessment of the integrity of the packaging, including its chemical composition, physical thickness, and electrochemical resistance. ## Summary 01 Issues and comprehensive analytical approach [](#cont-01) 02 Materials and corrosion expertise services [](#cont-02) 03 Conclusion of the study [](#cont-03) 01 ## Issues and comprehensive analytical approach   The customer's initial request to optimize their product quickly evolved into a comprehensive assessment of packaging integrity, encompassing chemical composition, physical thickness, and electrochemical resistance. Our laboratory has developed a comprehensive analysis protocol combining electrochemistry and materials characterization to answer the following questions: - What is the minimum thickness that guarantees the absence of critical defects? - Does contact with the opening tab (made of a different shade of aluminum) introduce a risk of **galvanic coupling**? - How do the coating and metal behave after accelerated aging? ![](https://filab.fr/wp-content/uploads/2025/10/ecovadis-85.png) 02 ## Materials and corrosion expertise services Our laboratory has developed a comprehensive analysis protocol combining [electrochemistry](https://filab.fr/en/our-services/our-expertise-services/electrochemical-characterization.md) and material characterization to ensure packaging integrity. To evaluate the **integrity of the coating**, the analysis began with **electrochemical impedance spectroscopy (EIS)**. This non-destructive technique made it possible to [measure the electrical impedance](https://filab.fr/en/our-services/our-expertise-services/electrochemical-characterization/impedance-measurement.md) of the coating. A high-quality varnish acts as a perfect capacitor with very high impedance, while any drop in impedance reveals and quantifies microscopic **defects and pores**. To understand the physical structure of the coating, we performed micrographing and metallography, allowing us to accurately measure the thickness of the varnish and characterize the metal phases of the can. The [**corrosion rate (LSV)**](https://filab.fr/en/our-services/our-expertise-services/electrochemical-characterization/study-corrosion-speed.md) was measured to establish the kinetics of degradation of the bare metal. This data was supplemented by accelerated aging tests using salt spray (BSN) simulating storage conditions to predict the product's lifespan. ![](https://filab.fr/wp-content/uploads/2025/10/ecovadis-95.png) The analysis then focused on electrochemical interactions. Knowing that the pull tab is often a different color from the body of the can, we studied galvanic coupling. This measurement made it possible to quantify the corrosion current that is created when these two metals come into contact in the presence of the beverage (the electrolyte), which poses a major risk to the integrity of the container. Finally, for surface characterization and chemical analysis, several techniques were used. - The **[ICP](https://filab.fr/en/our-technical-resources/laboratory-analysis-icp-icp-ms-icp-aes.md) (Inductively Coupled Plasma)** was used to **verify the exact composition** of the aluminum alloy. - The **[SEM](https://filab.fr/en/our-technical-resources/laboratory-analysis-sem-scanning-electron-microscopy.md) (Scanning Electron Microscope)**, coupled with **[XPS](https://filab.fr/en/our-technical-resources/laboratory-analysis-xps-esca.md) (X-ray Photoelectron Spectroscopy)**, made it possible to analyze the **chemical nature of the oxides** formed on the surface. - Finally, **[XRD](https://filab.fr/en/our-technical-resources/x-ray-crystallography-laboratory-xrd.md) (X-ray diffraction) identified the **crystallographic phase** of these oxides and any corrosion deposits, providing a complete picture of the degradation phenomena.** 03 ## Conclusion of the stud Thanks to an integrated approach combining **electrochemistry (EIS, galvanic coupling)** and **material characterization (micrography, ICP, XRD)**, the laboratory was able to accurately map the integrity of the coating and metal assembly. The study by **EIS** was essential, as it enabled the parameters of the coating process to be correlated with the presence of **invisible defects (pores)**, leading to the identification of the optimal settings. This optimization generated **substantial savings** in raw materials while ensuring continuous protection. More importantly, the expertise validated two fundamental points: the absence of critical defects in the varnish and the elimination of risks of chemical interaction or galvanic coupling between the can and the pull tab. Need help? Contact our team [](#filab-contact-form) ## Other case studies you may be interested in ### Fracture facies study Inspect a broken metal anchor to identify the cause of the failure. [Learn more +](https://filab.fr/en/blog/2025/12/study-of-metal-anchor-failure-patterns-case-study.md) ### ATG kinetics: simulation of PVC part aging One of our customers wants to evaluate the thermal behavior of 3D-printed parts. [Learn more +](https://filab.fr/en/blog/2025/12/atg-kinetics-simulation-of-pvc-part-aging.md) ### Industrial marking Conduct a cleaning process study in the context of industrial marking [Learn more +](https://filab.fr/en/blog/2025/12/industrial-marking-on-metal-parts-cleaning-process-study-case-study.md) [View all our case studies](https://filab.fr/en/blog-filab.md) ## Services related to the case study [## Free potential measurement (OCV) in laboratory – electrochemical testing](https://filab.fr/en/our-services/our-expertise-services/electrochemical-characterization/free-potential-measurement-ocv.md) [## Galvanic Coupling Test – Electrochemical Test](https://filab.fr/en/our-services/our-expertise-services/electrochemical-characterization/galvanic-coupling-testing.md) [## Impedance measurement in laboratory – electrochemical test](https://filab.fr/en/our-services/our-expertise-services/electrochemical-characterization/impedance-measurement.md) [## Electrochemical testing](https://filab.fr/en/our-services/our-expertise-services/electrochemical-characterization.md) [![avis filab](https://filab.fr/wp-content/themes/astra-child/templates/assets/img/avis-verifies.svg) 5/5 ![note filab](https://filab.fr/wp-content/themes/astra-child/templates/assets/img/stars.svg)](https://www.avis-verifies.com/avis-clients/filab.fr) ## Laboratory specializing in analysis and expertise for industrial companies ![More than 140 people](https://filab.fr/wp-content/uploads/2024/10/collaborateurs-1.svg) More than 140 people at your service ![5200 m² laboratory](https://filab.fr/wp-content/uploads/2024/10/labo.svg) 5200 m² laboratory + 99% of services are provided in-house ![Accredited laboratory](https://filab.fr/wp-content/uploads/2024/10/ISO-17025-1.svg) Accredited laboratory COFRAC ISO 17025 ![+2200 clients](https://filab.fr/wp-content/uploads/2024/10/clients.svg) +2200 clients in France and abroad ### Contact us Our services are reserved for professionals. [![phone](https://filab.fr/wp-content/themes/astra-child/templates/assets/img/form/phone.svg) Call us +33 (0)3 80 52 32 05](tel:+33380523205) [![location](https://filab.fr/wp-content/themes/astra-child/templates/assets/img/form/location.svg) Visit us 80 rue Jean-Louis Auguste Petitjean 21850 - Saint Apollinaire - FRANCE](https://www.google.com/maps/place/Filab/@47.317329,5.076545,15z/data=!4m6!3m5!1s0x47f29e6ab37d6a1d:0xa2cc1016c4f74422!8m2!3d47.317793!4d5.0767354!16s%2Fg%2F1v3gr7f0?entry=ttu) [![mail](https://filab.fr/wp-content/themes/astra-child/templates/assets/img/form/envelope.svg) Contact us contact@filab.fr](mailto:contact@filab.fr?subject=%5BVotre%20demande%20:%20Industrial%20marking%20on%20metal%20parts:%20cleaning%20process%20study%20-%20Case%20study%20en%20%5D) For complaints: all complaints must be sent by mail to contact@filab.fr or by contacting the person who signed the report. The complaint handling procedure is available upon request. In the event of a complaint concerning the laboratory's activities, the customer may be notified of the complaint's handling.