How moulded pulp is made

The raw material is mainly recovered paper, board offcuts and paper-mill production waste. It is pulped in water into a thin slurry in which fibre makes up roughly one per cent. A mesh mould in the shape of the future part is dipped into the slurry and vacuum draws a layer of fibres onto the mesh while the water passes through. The wet part is then taken off the mould and dried in a continuous dryer, or finished in a heated mould under pressure. Finally it is trimmed, and holes are die-cut where needed.

The process water is returned to circulation. The pulp can be dyed or sized before forming, which changes both the appearance of the part and its resistance to moisture.

Because the shape is created on a mould rather than by cutting or folding, the part can have ribs, partitions, cavities and recesses that follow the geometry of the product. For custom retention packs, every new shape therefore requires its own mould.

Types of moulded pulp

The parts differ mainly in how they are dried, and therefore in surface finish and accuracy.

• Rough moulded part – Dried freely without pressing; one side stays rough and the wall is several millimetres thick. Used for trays, dividers, pads and simpler retention parts where appearance does not matter.
• Pressed (thin-walled) part – Finished in a heated mould under pressure. The wall is around 0.5–1.5 mm, the surface is smoother and the dimensions more accurate. Suitable where the product needs a closer fit or where the pack is visible once opened.
• Post-processed part – Water-repellent treatment, coloured pulp, printing, embossed logo or recycling mark, or die-cut openings.

The basic version has a matt surface whose colour depends on the input paper – usually grey or brown.

Applications

• Custom retention packs – The moulded part holds a specific product inside the box, so no loose fill is needed. It is either a single-sided cavity or a pair of parts that clamp the product from above and below. Used for electronics, cosmetics and machine parts, where it replaces foam and plastic inserts.
• Corners and end caps – Fitted over the corners or ends of a larger product to keep it away from the walls of the box.
• Trays and dividers – Cavities for eggs, fruit or bottles and dividers between layers of goods. A common format is the 30-egg tray measuring approximately 300 × 300 mm.
• Pallets – Lightweight one-way pallets with feet formed in a single piece are also moulded from pulp.

What to base the design on

The product, the box the part goes into and the order volume decide.

• Weight, geometry and the most sensitive areas of the product – these determine the cavity and the support points.
• Inner dimensions of the box – determine the outer contour of the part.
• Number of product variants – with a wide range, this often decides whether moulded pulp makes sense, because every additional shape means another mould.
• Stacking and storage – trays and dividers nest inside one another; with custom retention parts, the shape determines how closely empty parts can be stacked.
• Environment – moisture, grease and food contact change the choice of material and treatment.

Points to watch

• Draft and radii – The part must release from the mould, so the walls have a draft of several degrees and the edges are rounded. Vertical walls, sharp edges and undercuts cannot be produced.
• Tolerances are wider than with plastic – The pulp shrinks as it dries, which is taken into account when the mould is designed. Do not design tight fits.
• Moisture – Paper absorbs water and the part loses stiffness. Water-repellent treatment improves resistance, but moulded pulp is not suitable for wet environments.
• Food and grease – Direct food contact requires a suitable material and a declaration of compliance. Grease-resistant treatments used to rely heavily on PFAS; since 12 August 2026 the PPWR has limited their content in food-contact packaging.
• A change to the product means a new mould, not a modification of the existing one.
• Drop test – Before series production starts, test the part with the actual product – in-house or at a test laboratory.

Moulded pulp or EPS

The closest alternative is EPS packaging made from expanded polystyrene. EPS is the better choice when the shipment needs thermal insulation or when a heavy part has to withstand repeated impacts. Moulded pulp suits applications where the goal is paper packaging that the recipient can put into paper recycling without sorting, and for ordinary fragile goods where a moulded part provides enough protection. For flat shapes and simple layering, paper dividers or paper honeycomb are usually sufficient. When the product needs to be visible, a blister is used.

What to send with your enquiry

• A product sample or 3D model, ideally both
• Inner dimensions of the box the part goes into
• Product weight and the areas that must not be pressed
• For trays and dividers: type and size of the goods, number of items per layer and stacking method
• The environment the pack will pass through: moisture, grease, food
• Expected annual quantity and number of variants

Frequently asked questions

What is moulded pulp?

Formed packaging made from pulped, mostly recycled paper. The fibres are drawn onto a mesh mould, and the part is dried and trimmed. It holds the product in position and absorbs shocks. The basic version contains no adhesive and no plastic layer.

Do you supply egg trays?

Yes, trays for eggs, fruit and bottles are part of our range. Please state the number of eggs per tray, their size and the expected quantity.

Can a retention pack be designed precisely for our product?

Yes, custom retention packs are, alongside trays and dividers, the second main group in our range. A mould is made for every new shape; how this is handled for a specific order is stated in our quotation. Send us a sample or 3D model, the box dimensions and an estimate of annual consumption.

How does moulded pulp cope with moisture?

Less well than plastic. Paper softens and loses stiffness in damp conditions. Water-repellent treatment of the pulp improves resistance, but the part will not withstand a permanently wet environment. If the pack will pass through a damp warehouse or a place where condensation forms, please mention it in your enquiry.

Does a used moulded part go into paper recycling?

A part without surface treatment does, provided it is clean and dry. The recipient does not need to separate anything. With treated versions, it depends on the type of treatment.

How long does a custom retention pack take?

The lead time depends mainly on whether a new mould has to be made. Please state your required date in the enquiry and we will tell you in our quotation whether it is achievable.