LLDPE Price per Ton: What Sits Inside a Film-Grade Quotation

A film-grade LLDPE quotation expressed per metric ton is rarely a single market-price observation. It is assembled from base ethylene contract or spot reference, comonomer selection, additive masterbatch loadings, packaging specification, regulatory compliance documentation, and delivery terms. For a converter purchasing blown-film resin, the quotation must be read as an engineering specification rather than as an undifferentiated commodity price. When a buyer requests 0.920 g/cm³ density and 1.0 g/10 min melt index in 25 kg bagged lots, the quoted per-ton value already embeds controlled rheology, pelletizing, stabilizer dosing, silo segregation, and the producer’s lot-to-lot consistency program. The benchmark ethylene price alone does not explain the differences between C4, C6, and C8 film grades.

Why Does Hexene-Based LLDPE Trade at a Premium to Butene-Based Film Resin?

Resin produced with 1-hexene comonomer carries a cost structure different from 1-butene grades because the longer C6 branch produces more effective tie molecules between lamellae at equivalent density. The quotation premium is not created by raw comonomer cost alone; it is driven by measurable film property differences. At 0.918 g/cm³ density and 1.0 g/10 min melt index measured under ISO 1133-1:2022, a C6 film grade may show dart impact values under ASTM D1709 method A of 180 g to 260 g, while a comparable C4 grade can fall below 150 g. That difference permits downgauging on a blown-film line, and the converter may accept a higher per-ton resin price because the film can be reduced from 50 µm to 40 µm while maintaining puncture resistance.

The cost pass-through is also nonlinear. Comonomer incorporation efficiency differs with catalyst type, reactor configuration, and hydrogen response. A C6 film grade may require more costly purification of the comonomer feed and additional gas-phase or solution reactor controls to maintain uniform short-chain branching distribution. The resulting pellet has a different melt-fracture threshold, a different bubble stability window, and a different gel-count profile. These processing variables influence production cost even when the density and melt index are identical on the certificate of analysis. Exact premium levels are contract-specific and are not derived from published benchmark charts alone.

On a 90 mm grooved-feed single-screw blown-film extruder with 30:1 L/D, 250 mm spiral mandrel die, and 2.0 mm die gap, the runnability of a film-grade LLDPE is an economic variable that does not appear on every quotation but directly affects the real cost per ton of usable film. A C6 film grade with nominal 1.0 g/10 min melt index is typically processed at 190–210°C melt temperature and 2.5:1 blow-up ratio. Bubble instability increases when the frost line height exceeds 700 mm for some C6 grades, producing gauge variation that lowers roll yield. Transitioning from a C4 to C6 film resin on the same line can require purging time and off-spec scrap that are not line items in the resin quotation but enter the converter’s true material cost. Therefore, a lower per-ton offer for butene-based LLDPE may not be the lower cost per finished reel if the C6 grade delivers thinner gauge capability and fewer bubble breaks.

Parsing the Additive Line Items in a Film-Grade Quotation

Slip additives such as erucamide or oleamide are dosed at 500–1000 mg/kg in a film-grade formulation. Antiblock agents, typically synthetic silica or talc, are compounded at 1000–3000 mg/kg. A fluoropolymer processing aid may be included at 200–800 mg/kg to suppress melt fracture at high extruder throughput. These loadings appear in the quotation as compounded pellet add-ons or as separate masterbatch recommendations. The coefficient of friction is tested under ASTM D1894 or ISO 8295, and haze is measured under ASTM D1003. Because slip additives migrate to the film surface over time, a coefficient-of-friction value measured 24 h after extrusion will differ from a value measured immediately off-line; the quotation should specify aging interval and conditioning environment.

Antioxidant and neutralizer packages also sit inside the per-ton price. A film-grade resin may be stabilised with phenolic antioxidants at 300–800 mg/kg and phosphite process stabilisers at 400–1000 mg/kg, with oxidation induction time tested under ASTM D3895. These additives protect melt viscosity during multiple extrusion passes and reduce gel formation in recycled edge trim. The quotation cost is not limited to additive unit price; it also includes lot-to-lot dosing accuracy, silo cleaning when switching formulations, and analytical release testing on the finished pellet.

When a Converter Requests Slip, Antiblock, and Processing Aid in a Single Pellet

A fully compounded pellet ask changes the structure of the film-grade quotation. The resin supplier or toll compounder must blend the base LLDPE powder or pellet with the additive concentrate under controlled shear and temperature conditions. This step adds a compounding toll fee, a minimum production lot size, and a loss allowance for start-up material. The converter avoids separate dosing equipment and reduces the risk of poor dispersion, but the per-ton price must then cover the compounding step, not only the base resin and additive weights. Preblending may also reduce flexibility in silo management because the finished compound must be kept separate from non-slip grades.

Specifications in such quotations typically include coefficient of friction, blocking force, haze, dart impact, and gel count. Blocking force may be evaluated under ASTM D3354 or an internal customer method. The supplier may also report migration rate indirectly through coefficient-of-friction change over storage time. Excessive slip loading above 1500 mg/kg can reduce surface treatment adhesion in downstream printing or lamination; therefore, the quotation is not simply a price for “slip included.” It must define the upper tolerance, the polymer carrier system, and the compatibility of the processing aid with the slip package.

Film-Grade Resin Certification and Lot-to-Lot Melt Index Control

Lot-to-lot variation in melt index is a quotation cost item. A film-grade LLDPE with a nominal 1.0 g/10 min melt index may be certified at ±0.2 g/10 min or tighter under ASTM D1238. Tighter limits require more frequent on-line rheometer measurement, silo segregation, and batch-release testing. The certificate of analysis documents density by ASTM D1505 or ISO 1183-2, melt mass-flow rate by ASTM D1238 or ISO 1133-1:2022, and often thermal properties by differential scanning calorimetry. When a structured-product converter requests a narrower melt-index band, the seller may apply a consistency surcharge because off-specification batches must be reworked or downgraded.

Food-contact film grades add regulatory cost. The resin must be manufactured with compliant catalysts and additives, and the converter must receive documentation supporting FDA 21 CFR 177.1520 and EU Regulation No 10/2011. Specific migration testing under EN 1186 may be required for certain food simulants depending on film thickness and contact temperature. These certification packages are part of the quotation because they require third-party analytical work, sample retention, and supply-chain traceability. Claims are not inferential; they are attached to specific product codes and lot numbers.

Delivery terms alter the per-ton price without changing pellet chemistry. A CIF quotation includes freight, insurance, and port charges; an FOB quotation excludes them. Bulk rail-car delivery of 25 t or 28 t lots reduces packaging cost but requires silo capacity and inert handling at the receiving plant. Bagged 25 kg lots add bag material, palletisation, stretch wrapping, and label printing as separate cost drivers. The quotation may also include a seal of quality for resin packaged in moisture-resistant bags or bulk containers. Silo truck delivery can require a minimum unloading rate and a dedicated transfer line to avoid contamination with incompatible polymers such as unmodified polypropylene or recycled mixed polyolefin.

Price formula clauses in contract quotations often link the base resin to a published ethylene contract average plus a conversion adder. The adder is grade-specific and includes comonomer, catalyst, additive, compounding, and quality-control costs. Spot benchmark assessments from market intelligence services may exclude additive packages, logistics, and credit terms. Consequently, two per-ton offers cannot be compared unless the incoterm, packaging form, additive concentration, certificate-of-analysis tolerance, and regulatory documentation scope are normalised.