This article describes the Appearance standard for coloured can ends and offers technical recommendations.
❓ Why do I observe minor abrasions (scuffing) on my coloured can ends?
Scuffing refers to minor surface abrasions or wear on the coloured lacquer coating of the can end, typically observed in the curl area.
This is a natural and unavoidable phenomenon that occurs across the industry due to the high-speed mechanical processes involved in manufacturing and packaging.
Scuffing occurs during the following processes:
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End Making: As a normal part of the end manufacturing process.
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Conveying: During the transport and stacking of shells and ends.
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Filling and Seaming: The mechanical action required to seal the can and the presence of aluminum particles can cause abrasion.
⚠️ Acceptance Standard and Responsibility
Minor scuffing on the coloured lacquer is an expected visual characteristic and does not compromise the functional integrity or the hermetic seal of the can.
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Supplier Notification: Our supplier has informed us that coloured ends will scuff during the production and/or filling and seaming processes.
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Customer Agreement: Customers acknowledge and agree that NOMOQ is not responsible or liable for damages or replacement ends when scuffing occurs up to an expected level.
🛠️ Recommendation to minimize abrasion on black or coloured ends during the seaming process
General Information
- The seaming roll profiles can become contaminated with Aluminium particles after prolonged use. This contamination is coming from:
- Lacquer abrasion carried over from the end itself
- Abrasion particles which get released between the ends because of the separation process in the end feeding system
- Aluminium abrasion coming from the end "brake system" within the end handling system.
- Aluminium particles can arise in the end feeding system while transporting the end to the seamer due to too tight radius bends used in conveying ends to the system. Recommend min 600 mm min radius corners.
- Due to the nature of the end movement process the existence of these particles and associated accumulation is inevitable. This accumulation upon the seamer rolls can adversely change the seam profile geometry and consequently has a cumulative effect on the double seam appearance due to abrasion. Therefore it is recommended to clean the seaming roll profiles on a more frequent basis.
Following measures should be checked and carried out to improve the quality of seam, reducing the abrasion, as well as increasing the shelf life of the seaming rolls.
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The seaming rolls should rotate easily and exhibit no axial movement.
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The seaming lever and the shaft of the chuck must be checked for axial movement.
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The chucks and rolls may not come into contact with each other! This needs to be checked especially after any adjustments of the seam profiles.
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The seaming tools have to be in good condition.
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All critical seam parameters have to be in specification.
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To clean the seaming roll profile the following procedure is recommended:
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Spread a textile rode with diamond paste (e.g. Ferrum article number 314504) and pull the rode through the seaming roll profile until the abrasion is removed.
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Using this process the quality of the tooling will be retained and shelf life will be increased.
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This cleaning can be carried out in the machine as well.
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This process is also recommended by the seamer suppliers such as Ferrum for example.
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- Interval of cleaning: It is recommended to clean at least once a week and can be combined with a CIP for example thus reducing downtime.
🖼️ Visual Standard Reference
The images below illustrate the typical and acceptable level of scuffing that may be observed on coloured ends:
Loose Ends
End Before Seaming
End After Seaming
🤝 Need more information ?
Feel free to book a meeting with our Head of Customer Service: https://calendly.com/nomoqfl/customerservice