Skip to content
MTECHPLAST
Send a drawing
MTECHPLAST
Send a drawing for a quote

Recycled polyethylene: HDPE vs LDPE and where each is used

Published:

HDPE and LDPE are two different polyethylenes. HDPE (high-density polyethylene) is rigid and dense — canisters, crates, caps and pipes are made from it. LDPE (low-density polyethylene) is soft and flexible — mostly film and bags. Recycled granules are chosen the same way: HDPE for rigid products, LDPE for film and soft parts, with the melt flow index matched to the process.

Milky-white and dark grey polyethylene granules on a steel table, a white canister and a roll of film behind

How HDPE differs from LDPE

The difference lies in the structure of the molecules: HDPE chains have almost no branches and pack tightly, while LDPE chains are heavily branched. In Ukraine and other post-Soviet markets the two are often named after the production pressure, which can confuse: HDPE is called low-pressure polyethylene, LDPE high-pressure.

In practice this means:

  • HDPE — a density of about 0.94–0.97 g/cm³, rigid, strong in tension, chemically resistant; marked 2 or PE-HD;
  • LDPE — a density of about 0.91–0.93 g/cm³, soft, elastic, clearer in thin film; marked 4 or PE-LD.

What recycled HDPE is used for

Canisters and bottles for technical fluids and household chemicals, crates, buckets, caps, household goods, non-pressure and cable pipes. HDPE blow moulds well, so it is often chosen for canisters, and it is also injection moulded and extruded.

What recycled LDPE is used for

Mostly film: bin bags, technical and construction film. Soft parts are moulded from it too — for example, lids that fit tightly onto a container. Used film, including stretch wrap from warehouses, is a common feedstock for recycled LDPE.

Can HDPE and LDPE be blended

Both are polyethylene, and a blend processes together. But the blend has intermediate properties: an HDPE part becomes softer, LDPE film becomes stiffer. For consistent products it is better to buy granules of one type, and if you blend, keep a fixed ratio chosen with trial shots.

What to ask the supplier

To make sure the granules suit your production, ask about:

  • the type of polyethylene — HDPE or LDPE, and for HDPE whether it is for injection moulding, blow moulding or extrusion;
  • the melt flow index (MFI): blow moulding and pipes need a low flow, injection moulding a higher one;
  • the colour and whether it stays the same from batch to batch;
  • whether there is polypropylene or other plastics in it;
  • how clean the feedstock is: granules from poorly washed waste give off a smell and leave inclusions in the part.

Recycled polyethylene from MTECHPLAST

We produce recycled polyethylene granules from injection moulding rejects that we buy and recycle. Ask which polyethylene is available now and in what volume for your request in the Plastic section: in total we produce 5 to 40 tonnes of granules a month. You can also order a blow mould for canisters or bottles from us.

Granule types and availability

Questions

Frequently asked questions

HDPE or LDPE — which is stronger?

HDPE is stiffer and stronger in tension, which is why canisters, crates and pipes are made from it. LDPE is softer and stretches better — it is the right choice where flexibility is needed, for example in film.

How can you tell HDPE from LDPE?

By the marking: HDPE is 2 or PE-HD, LDPE is 4 or PE-LD. An HDPE part is rigid, an LDPE one is soft and feels waxy. HDPE film rustles like a carrier bag, while LDPE film is smooth and stretches easily.

Can recycled polyethylene be used for food packaging?

Materials in contact with food have stricter rules: recycled plastic is allowed there only under special conditions and with the right documents. For technical and household containers, recycled polyethylene is widely used.

Need polyethylene granules?

MTECHPLAST is a producer of recycled plastic granules: polypropylene, ABS, polycarbonate, polyethylene and polystyrene. We produce 5 to 40 tonnes a month, depending on your request. Ask about availability and supply terms for each material.

Granule types and availability

Other articles

  • Clear, white and blue plastic granules on a steel table, sacks on a pallet behind

    Recycled plastic granules: how they differ from virgin

    Recycled granules are plastic reprocessed from production waste or used products. They cost less than virgin material, but their properties depend on the feedstock and processing, so for each task you need to know the polymer, the melt flow index and the colour. Below is where they fit and what to check before buying.

  • Dark grey polypropylene granules in a steel tray, shredded plastic beside them and a plastic crate behind

    Recycled polypropylene: properties, uses and how to choose granules

    Recycled polypropylene (PP) is granulate reprocessed from polypropylene waste: injection moulding rejects, runners, used crates and containers. It is light, chemically resistant and cheaper than virgin material, so it goes into crates, buckets, housings and technical parts. Before buying, you need to know the melt flow index, the colour and whether the granules contain other plastics.

  • Moulding rejects and runners sorted by colour in sacks, blue shredded plastic on a steel tray

    Plastic waste: how to sell moulding rejects

    Moulding rejects, runners and other production plastic waste are bought by recyclers who turn them into granules. Clean waste of one plastic type and one colour fetches the best price. Below is what to prepare to sell your waste for more.

Send a drawing