How to Select a Polyethylene Grade for Your Application

Choose by application before comparing HDPE, LDPE and LLDPE

HDPE means high-density polyethylene; LDPE means low-density polyethylene; LLDPE means linear low-density polyethylene. Each family contains grades for different processes and requirements.

The table gives typical starting points, not Zenith stock or confirmed specifications. Manufacturer guidance shows that several families can serve one process. Confirm the exact grade for your line.

Scroll across the table to compare all columns.

Reference: LyondellBasell: cast-film applications · LyondellBasell: extrusion blow moulding · LyondellBasell: extrusion coating

Compare melt flow under the same test conditions

Melt mass-flow rate (MFR), often called melt index for polyethylene, measures material flow under specified laboratory conditions and is commonly reported in grams per ten minutes. Record the test temperature, load, method and units with the number. Results measured at different loads are not a like-for-like comparison.

ISO 1133-1:2022 distinguishes mass-flow from volume-flow measurement and notes that these quality-control tests do not always predict processing behaviour. A higher MFR is not an overall quality score or proof that a grade will run better on your equipment.

Reference: ISO 1133-1:2022: melt-flow measurement

Check density, additives and the producer's data sheet

Record density, units and test method, then read it alongside the application properties. Density and melt flow alone do not describe the resin's complete behaviour. Two grades with similar headline values can differ in molecular structure, additives and finished-product performance.

Ask which additives are included: for example, slip, antiblock, stabilisers or processing aids when relevant. Slip affects film friction; antiblock helps limit sticking between film surfaces. Additives and line conditions can influence sealing and surface behaviour, so assess printing, lamination and sealing requirements together.

• Identify the producer, grade code and current technical data sheet (TDS) revision.
• Separate typical data-sheet values from any expressly agreed contractual limits.
• Declare colour, virgin or recycled content requirements and any blend or masterbatch.
• Use agreed tests for the finished product rather than relying only on resin-family descriptions.

Reference: LyondellBasell: polyolefin film extrusion guide · ExxonMobil: producer product and safety data sheets

Trial the exact grade before approving an alternative

Write a trial brief identifying the resin, batch, equipment, settings and finished-product acceptance criteria. Assess conversion performance as well as laboratory results.

For film, example checks include stable running, thickness, defects, mechanical behaviour and sealing. A moulded-container trial can assess dimensions, appearance and product-specific tests. These are examples, not universal limits. Approve an alternative as a technical change rather than assuming equivalence.

Reference: ISO: limits of melt-flow data as a processing predictor · LyondellBasell: film-process and performance guidance

Verify documents and any regulated end-use claim

The TDS describes technical properties; the safety data sheet (SDS) supports handling and hazard communication; a contracted lot COA reports identified test results. Ask which properties are tested on each lot and what acceptance evidence will be supplied. These documents serve different purposes.

For United States food-contact use, FDA considers individual components, applicable authorisations and intended conditions of use. An effective food-contact notification can be manufacturer-specific. A generic PE label, SDS or reference to FDA is insufficient to establish compliance for your finished article. This United States example was reviewed on 13 October 2026; obtain applicable producer declarations and specialist confirmation for the actual destination, additives, food type, temperature and contact conditions. No food-contact approval is implied for Zenith's range.

Reference: ExxonMobil: distinct product and safety documentation · FDA: determining food-contact regulatory status

Hypothetical example: choosing a liner-film resin

A converter shares its blown-film process, thickness, sealing method and acceptance tests for a non-food industrial liner. It compares named grades under matching melt-flow conditions, checks additives and trials the material before approving an order. The LDPE or LLDPE label alone does not decide suitability. This is a planning example, not a customer case or guarantee.

What to send for a polyethylene grade quotation

Zenith's polyethylene page supports enquiries by family and application grade. Confirm producer, grade, quantity, packing, documents and delivery scope in the offer; this guide does not establish availability.

• Finished product, destination market and conversion process; relevant equipment or line constraints.
• Current approved grade or reference TDS, and whether alternatives may be considered.
• MFR with temperature, load and method; density, additives, colour and content requirements.
• Finished-product acceptance tests, trial quantity and any regulated end-use declarations.
• Requested TDS, SDS, lot COA, traceability and contracted shipping or origin documents.
• Order quantity, pack requirements, destination, requested shipment period and Incoterms® rule with named place.
• Write “Not sure” for unknown technical details rather than guessing a grade or melt-flow value.