PE Resin Supplier China | HDPE, LDPE, LLDPE Pellets

How to compare PE density branches

Polyethylene is specified by density first, melt index second. Density sets stiffness and stress-crack behaviour; melt index (MI, ISO 1133 at 190 °C / 2.16 kg) sets how the resin flows in your extruder or mould. Same density, different MI — different settings.

Branch	Density	What it gives you	Where it is used	Confirm before ordering
HDPE	0.941–0.965 g/cm³	Highest stiffness, hardness and chemical resistance in the PE family	Blow-moulded bottles, pipe, crates, caps, tanks	MI window, ESCR value, UV or carbon-black package
MDPE	0.926–0.940 g/cm³	Balance of flexibility and crack resistance	Gas and water pipe, squeeze packaging, geomembranes	Pressure rating, slow crack growth resistance
LDPE	0.910–0.925 g/cm³	Soft, easy to extrude at high output	Shrink and greenhouse film, extrusion coating, foam, cable	Slip, antiblock and processing-aid package; coating adhesion
LLDPE	0.915–0.925 g/cm³	Puncture and tear resistance at thin gauge, good sealability	Stretch wrap, heavy-duty sacks, liners, agricultural film	Comonomer type, dart impact, seal initiation temperature

Specifications to put in your RFQ

Density branch plus MI window — quote a range so the supplier can offer ex-stock material, not a special run
Comonomer — butene, hexene or octene for LLDPE; it changes tear strength and seal behaviour
Conversion route — blown or cast film, blow moulding, injection, pipe extrusion, rotational moulding or coating
Additive package — antioxidant, UV stabiliser, carbon black for pipe, slip and antiblock, antistatic
Regulated end use — food contact, drinking water or gas distribution, with the destination market named
Pack, Incoterm and volume — 25 kg bags, big-bags or bulk; annual tonnage and call-off pattern decide contract versus spot pricing

Documents to request before you pay

Certificate of Analysis for the actual lot: density, MI, tensile and impact, tied to a traceable batch number
Technical Data Sheet for the exact grade code, not the family brochure
Food-contact declaration against EU 10/2011 or FDA 21 CFR 177.1520 where the part touches food
Drinking-water approval for the receiving market — for example NSF/ANSI 61 in North America or WRAS/KTW listings in Europe
Pipe material classification — PE80 or PE100 with the MRS rating, plus the relevant pressure-pipe product standard
REACH SVHC statement and RoHS declaration, and a Safety Data Sheet in the language of the receiving country

Common sourcing mistakes

Enquiring for generic “PE” without the density branch — HDPE and LDPE are not substitutes in a mould or an extruder
Copying one MI across processes: film, pipe and rotational moulding need low MI, thin-wall injection needs much higher
Skipping environmental stress-crack resistance when the container holds detergent, oil or surfactants
Forgetting UV protection outdoors, then blaming the resin for early failure

Frequently Asked Questions

What is the difference between HDPE, LDPE and LLDPE?

Density and chain branching. HDPE is almost linear, so it is stiff and strong. LDPE is highly branched, so it is soft and easy to extrude. LLDPE is linear with short branches, which gives film its puncture resistance. HDPE vs LDPE sets out the numbers.

Which melt index should I specify?

Ask your converter, not the resin seller. Low MI grades hold melt strength for film, pipe and rotational moulding; high MI grades fill thin-wall injection. Give a window, not a single value.

Can PE be used for food contact and drinking water?

Yes, but approval is grade- and market-specific. Request the food-contact declaration for the exact code, and for water service the listing recognised in the destination market. Pipe buyers should also confirm PE80 or PE100 — PE100 vs PE80 explains what the rating covers.

Is recycled PE available from Chinese suppliers?

Both post-industrial and post-consumer PCR PE are traded, mostly into film, pipe cladding and non-food packaging. Colour, odour and gel count are the usual constraints. See recycled plastics and require the PCR percentage in writing.

How is PE resin priced?

PE tracks ethylene feedstock and regional capacity, so long fixed prices are rare. Agree a validity window or an index-linked formula, and state ex-works or a named Incoterm.