From the Dull Mens' Club
Discussion
'This picture shows the lid (aluminium/aluminum foil) of a cup of margarine. The stripe on the side is where it was sealed to the plastic, about 3 mm wide. Some yogurt cups have similar foils. I have been intrigued by the pattern for years and have collected a large number (basically any that is not damaged and that I can get my hands on before my mum throws it away) because I thought that would help me understand the deeper meaning of the pattern, but it doesn't. It looks remotely like ripples caused by water or wind on sand. Do the manufacturers have a mold that produces the same pattern on every lid? I can't find any repetition or symmetry in this pattern. Is the pattern created new and different for every lid? If yes, by what process? What is the advantage of this pattern, other than the aesthetic look, over a flat foil as most lids have?'
Answer in the morning!
From ChatGPT...
The foil covering on a tub of margarine or similar products often has a pattern for practical and manufacturing reasons:
The foil covering on a tub of margarine or similar products often has a pattern for practical and manufacturing reasons:
- Structural Integrity: The pattern, which might look like small dimples or embossed textures, adds rigidity and strength to the thin foil. This prevents it from tearing too easily during packaging and handling.
- Adhesion and Sealing: Patterns help ensure a better seal between the foil and the container. The texture improves the adhesion of the foil to the tub by creating more surface area for bonding, which is essential for keeping the product fresh and airtight.
- Manufacturing Efficiency: Textured foils are easier to handle in automated manufacturing processes. Patterns in the foil prevent it from sticking to machinery, and they can be fed through the equipment more smoothly without wrinkling or tearing.
- Branding and Identification: Some brands use specific patterns as part of their product branding or to make their packaging visually distinctive. These patterns can also help differentiate products on the shelf.
- Safety and Freshness Indication: Patterns can serve as a tamper-evidence feature. If the pattern or texture is disrupted, it may indicate that the foil was punctured or opened before purchase, alerting consumers to potential contamination.
juliussneezer said:
It's subliminal messaging...
Like a QR code; indeed a nice idea.The answer, which happened to come from a Canadian friend which is how I found out about the who thing, is:
'I design machines for processing foil lids (suitably dull) and I can tell you the pattern is produced by passing the foil between two metal rollers that have the pattern chemically etched into them (one positive, one negative). There are few different patterns but the most common is random grub 115 RE 83.
The pattern helps keep the flat foil stiff and reduce curl as well as stopping individual lids from sticking together when they are stacked up ready to be picked and placed onto containers.'
I have no idea what a random grub is - a wood-boring beetle perhaps - but if anyone got within 10 of '115 RE 83' you can have half a point
Gassing Station | Science! | Top of Page | What's New | My Stuff