| HS Code | 850003 |
| Polymer Type | Linear Low Density Polyethylene |
| Comonomer | Butene-1 |
| Density | 0.918 g/cm³ |
| Melt Flow Rate 190 C 2 16 Kg | 1.0 g/10 min |
| Melting Point | 120 °C |
| Vicat Softening Point | 94 °C |
| Tensile Strength At Yield | 9 MPa |
| Elongation At Break | 700% |
| Dart Drop Impact F50 25 µm Film | 120 g |
| Film Clarity | High clarity |
As an accredited SHELL LLDPE 18F1B factory, we enforce strict quality protocols—every batch undergoes rigorous testing to ensure consistent efficacy and safety standards.
| Packing | SHELL LLDPE 18F1B is packaged in 25 kg polyethylene bags, palletized and shrink-wrapped for transport. |
| Container Loading (20′ FCL) | 20′ FCL container loading of Shell LLDPE 18F1B uses palletized bags, secure bracing, even weight distribution, and dry, ventilated conditions for safe transit. |
| Shipping | SHELL LLDPE 18F1B is a non-hazardous, non-regulated linear low-density polyethylene resin. Ship in clean, dry, moisture-protected containers or lined bulk hoppers. Avoid contamination, excessive heat, and direct sunlight. Standard plastic bags, gaylords, or bulk tankers are suitable. No dangerous goods declaration is required, but proper product documentation and traceability must accompany the shipment. |
| Storage | Store SHELL LLDPE 18F1B in a cool, dry, well-ventilated area away from direct sunlight, heat, and ignition sources. Keep containers tightly sealed to prevent moisture absorption and contamination. Avoid high stacking or rough handling that could damage packaging. Maintain stable ambient temperatures and follow the manufacturer’s safety data sheet for specific storage conditions. |
| Shelf Life | Store in a cool, dry area away from sunlight and heat. Shelf life is typically 12 months from date of delivery. |
In three-layer coextruded blown film for food-contact sealant applications, Shell LLDPE 18F1B is dry-blended with an autoclave high-pressure low-density polyethylene at a ratio of 70/30 by weight in both the sealant layer and the outer skin layer; the sealant layer constitutes 20 wt% of the total structure, yielding a total 18F1B addition of 14 wt% per 50 µm film when the skin layer is not counted. Where a separate skin layer is coextruded at 20 wt% of the total, the total 18F1B loading rises to 28 wt% because the skin layer is formulated at the same 70/30 blend. The core layer contains a polyamide-based oxygen barrier or a medium-molecular-weight high-density polyethylene moisture barrier, and it is not formulated with 18F1B in standard barrier film. Direct-food-contact regulatory status is governed by FDA 21 CFR 177.1520(c) for olefin polymers and by European Commission Regulation (EU) No 10/2011 as amended by Regulation (EU) 2020/1245; Chinese shipments are tested under GB 4806.7-2016. Overall migration testing under EU 10/2011 is to be conducted with food simulants at 10 mg/dm² limit, while hot-tack and seal-strength performance are measured under ASTM F1921 and ASTM D882-18.
On a production-scale three-layer blown-film line configured with a 200 mm spiral mandrel die and internal bubble cooling, the sealant-layer extruder is run at 210–225 °C melt temperature, the barrier core at 220–240 °C, and the outer skin at 205–220 °C; die gap is maintained at 1.8 mm, and blow-up ratio is kept between 2.5:1 and 2.8:1. A dual-lip air ring with chilled air at 10–15 °C stabilizes the bubble, and frost line height is held at 500–700 mm above the die face. For 50 µm film, seal initiation temperature measured by hot-tack testing is reduced relative to high-pressure LDPE by about 10–15 °C when the 18F1B loading in the sealant layer exceeds 70 wt%; below 60 wt%, the seal-strength plateau narrows by 5–8 °C. Batch-to-batch pellet melt index variation of ±0.05 g/10 min under ASTM D1238-23 at 190 °C/2.16 kg requires gravimetric hopper dosing with ±0.25 wt% accuracy to avoid layer-thickness drift. The converted film formats include frozen vegetable pillow bags, fresh-cut produce bags, bakery bread bags, and case-ready overwrap.
For heavy-duty industrial liner extrusion, 18F1B is compounded with 10–15 wt% bimodal high-density polyethylene (density 0.952 g/cm³, MI 0.25 g/10 min) and 3–5 wt% carbon black masterbatch to raise stiffness and ultraviolet resistance. The blend is processed on a monolayer blown-film extruder with a 65 mm grooved-feed barrel, L/D 30:1, barrier screw with Maddock mixer, and 250 mm diameter die; melt temperature is maintained at 200–215 °C, die gap at 2.2 mm, and blow-up ratio between 2.8:1 and 3.2:1. Below 2.5:1, machine-direction tear measured by ASTM D1922-23 decreases by approximately 15–20% because lower transverse orientation reduces the balance of film lamellae; above 3.2:1, bubble instability becomes apparent on high-stalk configurations with gauge variation exceeding ±8% on 125 µm film. Product compliance for construction and demolition debris liners follows ASTM D4397-22 for polyethylene sheeting for construction, and tensile properties are measured under ASTM D882-18. The 18F1B dosage is held at 80–85 wt% to retain low-temperature flexibility; HDPE levels above 20 wt% produce a measurable drop in Elmendorf tear and dart impact under ASTM D1709-22 because of increased stiffness and reduced tie-molecule density.
Finished stockkeeping formats range from 100–200 µm rubble sacks, 75–150 µm temporary construction opening covers, 50 µm non-hazardous industrial waste liners, and 150 µm geomembrane underlay. Operational boundaries are narrow for filled systems: if carbon black masterbatch moisture uptake exceeds 0.1 wt%, predrying at 80 °C for 2 h is required, and a continuous screen changer with 125 µm mesh is specified to remove agglomerated carbon black particles that otherwise cause bubble instability on 2.2 mm die gaps. Published data for 18F1B in combination with high-loading flame-retardant masterbatches are limited; those formulations are not recommended without pilot-line validation because the butene-rich matrix can lose impact strength rapidly when mineral filler loading exceeds 15 wt%.
Because ultraviolet resistance and low-temperature flexibility govern field performance, agricultural silage and greenhouse film production imposes different demands on 18F1B than industrial packaging. For silage bale wrap, the formulation is 60–70 wt% 18F1B, 20–30 wt% metallocene LLDPE, and 5–10 wt% tackifier masterbatch; the metallocene component raises dart impact and puncture resistance, while 18F1B provides melt strength and cost control. For greenhouse cladding, the blend is 70 wt% 18F1B, 15 wt% high-pressure LDPE (MI 1.8 g/10 min), 15 wt% EVA with 12–18% vinyl acetate, and 5–8 wt% HALS-based ultraviolet stabiliser masterbatch. Compliance falls under EN 13206:2017 for thermoplastic films used in agriculture and horticulture; mechanical values are evaluated by ISO 527-3 for tensile, ISO 6383-2 for tear, and ISO 7765-1 for impact resistance. Accelerated weathering is verified under ISO 4892-3, and the dosage of UV masterbatch is confirmed by xenon-arc exposure, not by resin supplier data alone.
Film is produced on blown-film lines with a 250 mm die, 2.0 mm die gap, blow-up ratio 2.5:1–3.0:1, and thickness between 25 µm for mulch and 180–220 µm for greenhouse covers. Melt temperature is controlled at 195–215 °C to avoid EVA degradation in greenhouse formulations; for silage wrap without EVA, melt temperature can be raised to 220 °C without film gel formation. End-use formats are 150 µm silage pit covers, 25–40 µm round bale wrap, 180 µm greenhouse cladding, and 30 µm mulch film.
| Application sector | Primary compliance reference | Mechanical/thermal test designation | Line-scale control variable |
|---|---|---|---|
| Food-contact sealant layer | FDA 21 CFR 177.1520(c); EU Regulation (EU) No 10/2011 | ASTM F1921; ASTM D882-18 | Melt temperature 210–225 °C |
| Heavy-duty industrial liner | ASTM D4397-22 | ASTM D1709-22; ASTM D1922-23 | Blow-up ratio 2.8:1–3.2:1 |
| Agricultural silage/greenhouse film | EN 13206:2017; ISO 4892-3 | ISO 527-3; ISO 6383-2 | Melt temperature 195–215 °C |
| PCR-loaded carrier bag film | REACH EC No 1907/2006; EN 15343:2007 | ASTM D1922-23; ASTM D1709-22 | Screen pack 100 µm |
| Frozen-food deep-freeze packaging | FDA 21 CFR 177.1520(c); EU Regulation (EU) No 10/2011 | ASTM F392-20; ISO 7765-1 | Frost line height 300–450 mm |
Post-consumer recyclate (PCR)-loaded carrier bag film requires a virgin backbone resin with adequate melt strength and a stable melt-filtration window. 18F1B is dry-blended at 50 wt% with 40 wt% PCR LDPE/LLDPE-rich regranulate and 10 wt% bimodal HDPE; the HDPE fraction offsets the loss of modulus caused by low-molecular-weight fractions in PCR. The PCR feed must be melt-filtered through a 100 µm continuous screen pack before pelletising, and the final blend is processed through a 65 mm grooved-feed extruder with L/D 30:1 and gear pump to damp pressure fluctuations. Melt temperature is set at 210–230 °C, die gap at 2.0 mm, and blow-up ratio at 2.5:1; film thickness for retail carrier bags is 25–60 µm. Compliance is determined by REACH EC No 1907/2006 Article 33 for substances of very high concern in recycled feedstock, EU Directive 94/62/EC packaging-waste requirements, and EN 15343:2007 for recycled-content traceability. If the PCR contains more than 5 wt% polypropylene contamination, gel count and melt-pressure variability increase measurably; a continuous belt filter with 80 µm screen is then required.
Converted film products include retail carrier bags, small-parcel mailers, and non-hazardous waste sacks. The addition ratio is bounded at 50 wt% 18F1B; higher virgin loadings above 60 wt% make the film economical only in thin-gauge applications, while lower loadings below 40 wt% reduce melt stability and tear strength under ASTM D1922-23. Published data for 18F1B-specific PCR compatibility are limited to commercial trials, and any replacement of the PCR fraction should be validated through gel index testing and ASTM D1709-22 dart impact before bulk production.
In frozen-food deep-freeze packaging, low-temperature flex-crack resistance becomes the critical failure mode when packages are handled at -18 °C or below. 18F1B is blended at 80–90 wt% with 10–20 wt% high-pressure LDPE or metallocene LLDPE to improve dart impact and flex-crack resistance without raising film haze above the opaque range typical for butene LLDPE. The blown-film process is set with a 1.8–2.0 mm die gap, blow-up ratio 2.5:1–3.0:1, and melt temperature 200–220 °C; frost line height is lowered to 300–450 mm to reduce oriented stress and improve low-temperature crack resistance. Compliance for direct food contact is assessed under FDA 21 CFR 177.1520(c) and EU Regulation (EU) No 10/2011; mechanical durability is measured by ASTM F392-20 Gelbo flex testing, ASTM D1709-22 dart impact, and ISO 7765-1 instrumented impact. Typical end-use formats include frozen meat bags, seafood bags, ice cube bags, and IQF produce bags.
Below 35 µm gauge, flex-crack pinhole count under ASTM F392-20 increases sharply for monolayer structures; where thinner film is required, 18F1B should be replaced or diluted in a coextruded structure with a tougher metallocene-rich outer layer. Published data for 18F1B in sub-35 µm deep-freeze packaging are limited, and end-use validation under the intended freezing regime is required. Pre-drying is not normally required for 18F1B; only when surface condensation is present after cold-storage transfer is hot-air hopper drying at 70 °C for 2 h recommended.
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SHELL LLDPE 18F1B is a film-grade linear low-density polyethylene produced by low-pressure coordination copolymerisation of ethylene with a butene α-olefin. The resulting polymer contains short-chain branches that reduce crystallinity and density without introducing the long-chain branching characteristic of high-pressure low-density polyethylene. Nominal base resin properties listed in supplier technical data sheets include a melt flow rate of 1.0 g/10 min measured at 190 °C under 2.16 kg load according to ISO 1133-1 and a base density of 0.918 g/cm³ determined according to ISO 1183-1. The grade designation 18F1B identifies a film-grade resin with a nominal melt index near 1.0 and a nominal density near 0.918 g/cm³; the B suffix is conventionally associated with a formulated slip and antiblock additive package, but the exact additive composition must be verified against the current supplier certificate of analysis because formulations differ by production site.
The combination of 0.918 g/cm³ density and 1.0 g/10 min melt flow rate places the resin in a viscosity range that can be processed on conventional blown film equipment while retaining enough melt viscosity for bubble stability in monolayer and coextruded structures. The butene comonomer content lowers the melting peak relative to high-density polyethylene and expands the heat-sealing range relative to high-density grades, although seal initiation is a film-system property rather than a pure resin constant. The resin is not hygroscopic, and routine pre-drying is not required unless surface condensation has formed during storage or transport.
Production-scale blown film extrusion of Shell LLDPE 18F1B is normally performed on single-screw extruders with screw diameters between 60 mm and 90 mm and length-to-diameter ratios from 24:1 to 30:1. Grooved feed sections and barrier screws with mixing elements are preferred because LLDPE can develop higher viscosity at extrusion shear rates than high-pressure LDPE of equivalent melt index, increasing melt pressure at the die lip. Barrel profiles are usually run from approximately 150–170 °C in the feed zone to 210–220 °C near the die. Melt temperature at the adaptor is generally controlled between 180 °C and 230 °C, and die temperature is commonly held between 190 °C and 220 °C. These values are processing guidelines rather than absolute product limits; excessive dwell time at high temperature can consume the stabiliser system and increase the tendency for gel formation.
The die-gap range is critical. Spiral mandrel dies with die gaps from 1.6 mm to 2.5 mm are commonly selected. When the gap is reduced below approximately 1.2 mm, the die-lip shear stress can exceed the critical value for sharkskin surface melt fracture in linear polyethylene, producing film surface roughness. Widening the die gap above approximately 2.8 mm can lower shear stress but may reduce transverse orientation and negatively affect film haze. Bubble geometry is normally maintained at a blow-up ratio from 2.0:1 to 3.0:1, with frost line heights between 2 and 5 die diameters. Dual-lip air rings and internal bubble cooling are commonly required on lines originally designed for high-pressure LDPE because Shell LLDPE 18F1B does not have the long-chain branching that stabilises high-pressure LDPE bubbles.
On such lines, output is generally cooling-limited rather than extruder-limited. Bubble instability, film thickness variation, and web handling defects appear before the melt-viscosity limit of the resin is reached. Published data for this specific configuration is limited; therefore, optimal output must be established by a designed trial on the target line. The main processing boundaries are excessive melt temperature above 240 °C, inadequate die-gap for the selected output, and low frost line height that quenches the bubble before the required molecular orientation is developed. These boundaries are not product specifications but process thresholds relevant to monolayer and coextruded films.
| Process parameter | Typical band | Equipment or measurement point |
|---|---|---|
| Melt temperature at adaptor | 180–230 °C | Adaptor thermocouple |
| Die temperature | 190–220 °C | Spiral mandrel die body |
| Die gap | 1.6–2.5 mm | Spiral mandrel die lip |
| Blow-up ratio | 2.0:1–3.0:1 | Bubble geometry |
| Frost line height | 2–5 die diameters | Air ring and internal bubble cooling |
| Extruder length-to-diameter ratio | 24:1–30:1 | Single-screw extruder |
The table does not replace a process specification; it summarises the practical window observed on equipment of conventional design. Batch-to-batch variation in melt flow rate and additive levels may require small adjustments within these bands.
In heavy-duty sacks, carrier bags, freezer packaging, agricultural film, and industrial liners, Shell LLDPE 18F1B is converted at thicknesses from 30 µm to 120 µm. In coextruded structures, the resin is used as a sealing layer or a toughness layer, often at 15–30 wt% of the total structure. The slip and antiblock package is intended for winding and converting operations; coefficient of friction is measured according to ASTM D1894 and blocking force according to ASTM D3354. Because slip additives migrate to the film surface over time, online slitting and bag-making trials should be performed after a conditioning period of at least 24 h after extrusion to obtain stable frictional behaviour.
Mechanical performance of the final film is not defined only by the base resin. Specimens are generally conditioned at 23 °C and 50% relative humidity for at least 40 h according to ISO 291. Tensile properties are measured by ISO 527-3 or ASTM D882, dart drop impact by ISO 7765-1 or ASTM D1709, Elmendorf tear by ISO 6383-2 or ASTM D1922, and haze by ISO 14782 or ASTM D1003. Published data for this specific configuration is limited; film property targets should therefore be derived from production-line capability studies rather than bibliographic values alone.
For printing, lamination, and coating, surface treatment is required. The dyne level of untreated polyethylene film is below the threshold for most ink and lamination systems, and corona discharge is normally applied at production speeds to achieve a surface energy of 38–42 mN/m or higher according to ASTM D2578. The decay in surface energy with storage time is influenced by the slip additive package; therefore, converters should schedule corona treatment and printing close together.
In coextrusion, the die gap and melt temperature profile of Shell LLDPE 18F1B must be compatible with the coextruded high-viscosity or barrier layers. The resin is generally processed in the seal or skin layer with a melt temperature from 200 °C to 230 °C, and the die may be fed from a satellite extruder. Melt-pressure mismatch at the feedblock can cause layer-to-layer interfacial instability; this is controlled by adjusting the melt temperature of the higher-viscosity layer rather than by exceeding the recommended temperature of the LLDPE layer.
Replacing high-pressure LDPE with Shell LLDPE 18F1B changes the failure mode of the film. High-pressure LDPE has long-chain branching and a broad molecular weight distribution, which provides high melt strength, high bubble stability, and comparatively high optical clarity, but its film strength is lower at equivalent thickness. Shell LLDPE 18F1B, as a linear butene-based resin, generally offers higher puncture resistance, higher Elmendorf tear strength, and higher tensile elongation at break. However, the same linear architecture reduces melt strength and can make the bubble more sensitive to air currents and gauge variation. Complete substitution is therefore uncommon on older LDPE lines; many converters use a blend containing 10–30 wt% high-pressure LDPE to restore bubble stability while retaining much of the LLDPE toughness. The blend ratio is not a fixed recipe and depends on die design, cooling capacity, and the required optical appearance.
Compared with octene-based LLDPE, Shell LLDPE 18F1B has shorter α-olefin branches. At equal density and melt flow, longer octene branches can increase tie-molecule formation and improve dart impact and tear resistance, particularly in films below 50 µm. Hexene-based LLDPE occupies an intermediate position. The butene-based Shell LLDPE 18F1B is therefore usually selected for general-purpose packaging and agricultural applications where the mechanical demands do not justify the higher cost of an octene grade. The difference is not a simple superiority relationship; it is a cost-performance trade-off that depends on film gauge, sealing requirements, and downstream abuse conditions.
From a morphology standpoint, butene comonomer in Shell LLDPE 18F1B creates short-chain branches that interrupt crystallite formation and decrease density. Octene and hexene comonomers produce longer short-chain branches that can participate in tie-molecule formation across crystalline lamellae. Because the butene branch is shorter, it is less effective at forming load-bearing tie molecules at low temperatures and high deformation rates. This explains the performance gap in dart drop impact and tear resistance when compared with higher α-olefin LLDPE grades. However, in thick films and in blends with LDPE, the butene grade may still meet the required abuse resistance at lower material cost.
In converter trials, the optimum loading of Shell LLDPE 18F1B in blend films is often determined by plotting Elmendorf tear against melt pressure and haze. A small addition to high-pressure LDPE, typically 10–20 wt%, raises tear resistance significantly while keeping haze within acceptable limits for many industrial films. At levels above 50 wt%, the converter may need to change the air ring or die gap because the blend no longer has sufficient long-chain branching to maintain the same bubble stability. This transition point is equipment-specific and must be confirmed on the production line.
Compared with metallocene-catalysed LLDPE, Shell LLDPE 18F1B typically shows a broader molecular weight distribution. This can result in lower extruder backpressure at a given output, easier gauge control, and a wider processing window on conventional equipment. Metallocene grades may provide higher hot-tack strength, lower extractables, and improved low-temperature impact, but they can demand more stable bubble control and higher extrusion pressures. The selection between Shell LLDPE 18F1B and metallocene LLDPE is therefore based on the film’s required sealing performance, organoleptic limits, and equipment capability.
| Film performance attribute | Shell LLDPE 18F1B | High-pressure LDPE | Octene-based LLDPE | Metallocene LLDPE |
|---|---|---|---|---|
| Dart impact at equal film gauge | Moderate | Lower | Higher | Higher |
| Elmendorf tear resistance | Moderate | Lower | Higher | Higher |
| Bubble stability on conventional dies | Lower than LDPE | High | Moderate | Lower to moderate |
| Optical clarity | Moderate | Higher | Moderate | Higher |
| Material cost position | Low to moderate | Moderate | Higher | Higher |
Regulatory status is not inferred from the grade designation. For food-contact use, polyethylene grades may comply with U.S. FDA 21 CFR 177.1520 and European Commission Regulation (EU) No 10/2011 when the supplier certifies the specific grade and the final article meets overall migration and specific migration limits. The B suffix additive package may contain migratory slip agents such as fatty acid amides. For food-contact packaging, the user must verify that the specific slip agent and its concentration fall within the positive list and specific migration limit of Regulation (EU) No 10/2011. The base polyolefin may meet the compositional requirements of U.S. FDA 21 CFR 177.1520, but the final film must be tested for overall migration under EN 1186-1 or the relevant national method. These migration values depend on film thickness, storage time, and food simulant, and cannot be assigned to the pellet alone.
Pellets should be protected from direct ultraviolet exposure during storage because long-term outdoor storage can degrade the antioxidant package and shift colour. Silos and hoppers should be purged with dry air in high-humidity regions; the resin does not require desiccant drying, but surface moisture can create visual defects. Incoming inspection should verify melt flow rate and density, and film producers may also test the coefficient of friction after one pass through the extruder because reprocessing can partially consume the slip additive.
On high-speed form-fill-seal lines, seal performance is evaluated by hot-tack and seal-strength tests under ASTM F1921 and ASTM F88. Seal initiation temperature is not a fixed resin constant; it depends on jaw pressure, dwell time, film thickness, and the presence of migrated slip additives. In multi-layer polyethylene structures, Shell LLDPE 18F1B is used in the sealing layer where its density and molecular architecture provide a measurable balance between seal initiation relative to high-density polyethylene and hot-tack strength relative to high-pressure LDPE.
Operational boundaries include storage below the dew point or exposure to ambient relative humidity above 60%, which can deposit surface moisture and cause bubble defects; in such circumstances a hopper dryer at 50–60 °C for 2–4 h is a practical corrective measure. Avoid combining the resin with copper-based pro-oxidant systems or highly acidic additive packages unless the formulation has been explicitly validated by retained-melt-stability testing, because these additives can accelerate stabiliser consumption and change film appearance. Unvalidated addition of highly polar antistatic or antifog additives may disturb slip migration and surface coefficient of friction.
For outdoor applications such as silage bags and agricultural films, ultraviolet stabilisation is not normally provided by the base resin. UV masterbatch must be added according to the exposure region, and weatherability is evaluated through accelerated weathering methods such as ASTM D2565 or ISO 4892-2. Published data for this specific configuration is limited; field life depends on film thickness, antioxidant package, exposure angle, and climate.
