EVERYDAY MATERIALSAtlas
Packaging / object study

Egg carton

A single moulded fibre shape protects several fragile shells.

Original conceptual vector illustration. Construction varies by product.
A familiar object, opened up

A moulded-fibre egg carton supports each egg separately while keeping the group easy to handle. Cups, posts, a lid and a closing edge are formed from a wet fibre mixture and dried into a shaped article. This example follows a recovered-paper carton. Its four components are functional regions of the moulding, not four glued layers, and they differ from the construction of plastic or foamed-polystyrene egg packs.

4 assemblies1 linked materials
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OBJECT 97 / COMPONENT INDEXSELECT A NUMBER ↗
Explore the components of Egg cartonConceptual illustration, not to scale. The numbered component index is adjacent; markers are navigation points, not exact disassembly locations.1234

Original conceptual illustration. Numbers open the component index; their positions are illustrative, not a disassembly guide. Equivalent text follows beside the diagram.

1Individual egg cups

Each moulded cup supports an egg over selected contact regions instead of letting it roll freely. The fibre structure and shape provide some compliance. Cup dimensions and clearances must suit the intended eggs; simply adding more material would not guarantee better protection.

Paper & paperboard

2Separating posts and ribs

Raised posts and ribs keep neighbouring eggs apart and help support the closed pack. Their shape creates local stiffness from a relatively thin wall. These features work as part of the whole moulding, so damage to a connecting rib can affect more than one compartment.

Paper & paperboard

3Protective lid

The lid covers the egg tops and can provide a surface for printed information or a separate label. Its geometry must avoid pressing directly on fragile shells. Printing, colourants and labels are additional choices, even when recovered fibre supplies most of the pack's mass.

Paper & paperboard

4Hinge and closing edge

A thin connecting region allows the lid to fold, while formed tabs or edges keep the pack shut. Repeated opening bends the fibre structure locally. This region is designed for packaging service rather than the indefinite cycling expected from a mechanical metal hinge.

Paper & paperboard
Designed differences

Why these materials?

Moulded fibre gains much of its usefulness from three-dimensional shape. A wet fibre suspension is formed against a mould, water is removed and the article is dried into its supporting geometry. The resulting walls do not need to be perfectly rigid: modest deformation can help cushion contact, while posts and ribs carry stacking loads. Protection therefore depends on fit, clearances and how the closed carton transfers force around the eggs. A damaged or wet pack can lose that intended balance.

One object, many versions.

Egg packaging also uses clear plastic and expanded-polystyrene constructions, whose collection routes differ from moulded paper. Fibre cartons can be coloured, printed or labelled, and food-contact specifications depend on the particular product. Recovered fibre content does not by itself establish compostability, hygiene suitability for reuse or acceptance by every paper recycler.

What happens after use?

Keep the carton dry while it is protecting eggs. Once empty, follow local guidance for moulded-fibre packaging and remove incompatible additions if requested. Food contamination can change the appropriate route. Do not put plastic or foam cartons into paper collection because they share the same shape, and do not assume every printed fibre carton is suitable for home composting.

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