What rotomoulding demands from a material
Rotomoulding is a powder process with no shear and no pressure. A charge of polymer powder tumbles inside a heated mould, sinters against the wall, densifies and then cools slowly. That imposes requirements no other process does: a narrow particle-size distribution around 300–500 µm, good dry flow, low fines, and a resin whose melt viscosity is low enough to coalesce and release trapped air within the cycle. Rotomoulding grades are therefore usually a specific hexene LLDPE, milled and additivated for exactly this.
A recycled polyolefin can be brought into that process, but not by dropping in a pellet. It has to be micronised, screened and flow-tested, and the presence of mineral content changes how the bed sinters. In practice, rotomoulders start with a partial substitution at a share they set themselves, measure wall-thickness uniformity, bubble content and impact on a real part, and move up from there if the part allows it.
Storage bins, crates and containers: the easier win
Many parts that people assume are rotomoulded are in fact injection moulded or extruded: stackable storage bins, logistics crates, pallets, tote lids, bulk container components, cable ducting and drainage parts. These processes are pressure-driven, tolerate filled and recycled feedstocks well, and are where a carton-derived polyolefin is used directly, without micronising.
For this family of parts, the aluminium content is an advantage rather than a complication. It raises stiffness and dimensional stability, which is exactly what a stacking bin or a pallet deck needs, and it lets you thin a wall slightly at equal rigidity. The trade-off is a lower softening point than virgin HDPE (Vicat 90–100 °C) and a darker, non-tunable base colour — irrelevant for grey industrial handling equipment, disqualifying for a white consumer product.
Using it as a compound or masterbatch base
Compounders are the most flexible users of this material because they control the recipe. A carton-derived recycled polyolefin works as a base resin, as a toughening or carrier phase, or as the recycled-content vehicle in an otherwise virgin formulation. Because it arrives with roughly 10% mineral reinforcement already dispersed, part of the filler loading you would normally add is built in.
- Base resin for filled compounds — blend with talc, calcium carbonate or wood-free mineral filler to hit a stiffness target.
- Toughening phase in rigid PP or HDPE compounds where a softer polyolefin improves impact.
- Recycled-content vehicle — dose to reach a specified PCR percentage with documented traceability.
- Profile and sheet compounds for construction, decking, fencing and street furniture.
- Colour and additive carrier where the base darkness is not a constraint.
- Blends with recycled HDPE or PP to raise stiffness and softening point.
Specifying it: what to send us and what you get back
The fastest way to a usable answer is to send the process (rotomoulding, injection, extrusion, compounding), the part and its wall thickness, target mechanical values, colour constraints, the recycled-content percentage you must document, and annual volume. From that we can say which grade applies, whether micronising is required, and what a realistic starting blend ratio is.
What comes back with each batch: a certificate of analysis with MFI, density and ash content, the UNE 53925:2026 conformity statement, and origin traceability from beverage-carton waste through to pellet. Batches are homogeneous 60-tonne lots supplied in 1,000 kg big bags, which matters when you are qualifying a compound and need the next order to behave like the last one.
Where it does not belong
Being direct about limits saves everyone a qualification cycle. This is not a food-contact material: it is post-consumer recyclate without a food-grade decontamination step, so it is excluded from anything with direct food or potable-water contact. It is not a pressure-vessel or structural-certified resin, and it should not go into thin-wall transparent or light-coloured parts because the base is dark grey.
It is also not a like-for-like replacement for a rotomoulding-grade LLDPE at 100% of the charge. Anyone promising that is skipping the powder-flow and sintering work. Where it does earn its place is in industrial durables — bins, crates, pallets, profiles, street furniture, drainage — and in compounds where a formulator is balancing stiffness, price and documented recycled content.
Process suitability at a glance
| Compounding | Direct use as base or toughening phase |
|---|---|
| Injection moulding | Direct use — bins, crates, pallets, components |
| Profile / sheet extrusion | Direct use — decking, ducting, furniture |
| Rotomoulding | Micronise to 300–500 µm, blend share set by the moulder |
| Blow moulding | Case by case, depends on melt strength requirement |
| Food contact / potable water | Not suitable |
| Supply format | Pellet, 1,000 kg big bags, 60 t homogeneous batches |
| Documentation | CoA per batch, UNE 53925:2026, traceability |