| HS Code | 758600 |
| Density | 0.924 g/cm³ |
| Melt Flow Index 190 C 2 16kg | 4.0 g/10min |
| Melting Point | 126 °C |
| Vicat Softening Temperature | 100 °C |
| Tensile Strength At Yield | 135 kg/cm² |
| Elongation At Break | 900 % |
| Flexural Modulus | 3200 kg/cm² |
| Shore D Hardness | 58 |
| Environmental Stress Crack Resistance F50 | >1000 hrs |
| Dart Drop Impact | 800 g |
As an accredited SK LLDPE FN840 factory, we enforce strict quality protocols—every batch undergoes rigorous testing to ensure consistent efficacy and safety standards.
| Packing | SK LLDPE FN840 is supplied in 25 kg multi-wall paper bags, palletized and stretch-wrapped for safe handling and storage. |
| Container Loading (20′ FCL) | 20′ FCL loading of SK LLDPE FN840 packs 25kg bags on pallets, ensuring stable, safe, and efficient transport for full-container shipment. |
| Shipping | SK LLDPE FN840 is a linear low-density polyethylene resin supplied as solid pellets. It is non-hazardous and not regulated for transport by land, sea, or air. Ship in clean, dry packaging to prevent moisture absorption and contamination, with normal handling precautions to avoid dust generation. |
| Storage | Store SK LLDPE FN840 in a cool, dry, well-ventilated area away from direct sunlight, heat sources, and open flames. Keep containers tightly sealed to prevent moisture contamination and dust accumulation. Avoid contact with strong oxidizers. Maintain good housekeeping to minimize dust and static discharge. Ensure storage area is clean and protected from physical damage. |
| Shelf Life | Shelf life for SK LLDPE FN840 is approximately 12 months when stored unopened in a cool, dry environment away from direct sunlight. |
SK LLDPE FN840 is processed as a monolayer or two-layer blown film at a nominal density of 0.918 g/cm³ (ISO 1183-1:2019) and a melt index of 1.0 g/10 min at 190 °C/2.16 kg (ISO 1133-1:2022). Gusseted heavy-duty sacks of 80–140 µm thickness are produced on high-stalk lines with die diameters 150–250 mm and dual-lip air rings. Gauge uniformity at 100 µm is controlled to ±4% (2σ) across the web per ISO 4591:1992. Bubble instability is the principal failure mode when blow-up ratio exceeds 3.0. The recommended blow-up ratio is 2.4–3.0. Frost line height is set at 6–8 die diameters. Melt temperature is held at 195–220 °C to avoid surface oxidation gel streaks. Die gap is 1.6–2.2 mm. A typical blend comprises 85–95 wt% FN840 with 5–15 wt% LDPE of 0.922 g/cm³ density and 2.0 g/10 min melt index. A carbon black masterbatch at 2–4 wt% provides UV stabilization for outdoor fertilizer sacks. A slip/antiblock masterbatch at 1–3 wt% is added to reduce coefficient of friction to 0.15–0.30 per ISO 8295. A fluoropolymer processing aid at 0.02–0.05 wt% suppresses melt fracture. Film tensile strength after conditioning at 23 °C and 50% RH is tested per ASTM D882. Typical acceptance is ≥40 MPa MD and ≥35 MPa TD, with elongation at break ≥600%. Dart impact at 80 µm is measured per ISO 7765-1. Values below 300 g are rejected for shaft-loaded chemical sacks. Maximum extrusion temperature must remain below 240 °C. At relative humidity above 85%, surface condensation on pellets should be removed with a hopper air knife. Slide plate-out from excess erucamide above 1,500 ppm becomes visible on the die lip after 8 h runs.
In flexible packaging lamination, FN840 is used as the sealant web in solventless adhesive structures with BOPET, BOPP, or aluminum foil. Film gauge is 20–40 µm, blown on lines with die gap 1.0–1.8 mm and blow-up ratio 2.2–2.8. Seal initiation temperature for a 0.918 g/cm³ butene-based LLDPE typically falls at 95–105 °C at 0.2 MPa, 0.5 s dwell, measured by ASTM F2029. Hot-tack strength above 1.5 N/25.4 mm is maintained in the 105–120 °C window per ASTM F1921. A slip/antiblock masterbatch at 1–2 wt% is incorporated to prevent blocking at winder pressures above 0.4 N/mm². Corona treatment at 38–42 mN/m is applied only to the outer lamination side. Treatment of the sealant layer can create oxidized species that lower seal strength per ASTM F88/F88M. For food-contact structures, the sealant web must meet FDA 21 CFR 177.1520 and EU Regulation (EU) No 10/2011. Overall migration is tested according to EN 1186-1:2002 and must remain below 10 mg/dm². Specific migration of erucamide from a slip masterbatch is limited by the masterbatch supplier. Levels above 1,200 ppm can bloom into the seal interface and reduce laminate bond strength. End products include stand-up pouches, frozen food sachets, and lidding films.
For bale silage wrap, FN840 is blended with a metallocene LLDPE of 0.912 g/cm³ density and 1.0 g/10 min melt index to maintain stretch ratio above 100%. Starting point ranges are 58–72 wt% FN840, 20–30 wt% mLLDPE, 6–8 wt% TiO₂ white masterbatch, and 2–4 wt% UV/HALS masterbatch. A three-layer cast film line with a 90–120 mm, 30:1 L/D extruder is typically used. Melt temperature is 200–240 °C. Chill roll temperature is 15–25 °C. Edge trim regrind is limited to 10–20 wt% because higher levels reduce puncture propagation resistance.
| Formulation | FN840 wt% | mLLDPE wt% | TiO₂ MB wt% | UV/HALS MB wt% |
|---|---|---|---|---|
| Trial A | 72 | 20 | 6 | 2 |
| Trial B | 65 | 25 | 7 | 3 |
| Trial C | 58 | 30 | 8 | 4 |
Film at 25 µm is preconditioned 24 h at 23 °C/50% RH. Puncture force is determined by ASTM D5748. A reject threshold below 50 N is used for baled grass silage. Elmendorf tear at 25 µm per ISO 6383-2 is ≥3.0 N MD/TD. Pre-stretch at 70–130% is applied on a round baler wrapper. Published data for FN840-specific agricultural film weathering is limited. Validation must include Xenon-arc exposure per ISO 4892-2:2013 to 3,000 h and retained elongation ≥50% per ISO 527-3. A monolayer FN840 silage film is not an oxygen barrier. For high-value alfalfa silage, a coextruded EVOH barrier layer is required.
Beverage multipacks and overwrap film are produced from a dry blend of 70–80 wt% LDPE (0.922 g/cm³, 2.0 g/10 min) and 20–30 wt% FN840. The LDPE contributes high shrink tension. The LLDPE lowers seal initiation temperature and improves dart impact. Film thickness is 35–60 µm. Process conditions include die gap 1.2–1.8 mm, blow-up ratio 3.5–4.5, and melt temperature 180–210 °C. Free shrink at 130 °C is measured per ASTM D2732. Typical values are 15–25% MD and 20–30% TD. Shrink force is measured per ISO 14616. Seal strength at 130 °C, 0.3 s dwell, 0.2 MPa is ≥2.0 N/15 mm per ASTM F88/F88M. The dry-blend boundary is set at 30 wt% FN840. Above this level, TD shrink decreases and film blocking increases unless antiblock is added at 1.5–2.5 wt%.
On rotary-arm stretch hood lines, FN840 is extruded as a gusseted tube of 90–130 µm and sealed after being stretched over pallet loads. A three-layer structure places 20–30 wt% metallocene plastomer in the core with 10–15 wt% LDPE in the skins to maintain elongation at break above 700% per ASTM D882. The film is blown on internal bubble cooling lines with die gap 1.8–2.4 mm, blow-up ratio 1.8–2.2, and melt temperature 190–220 °C. Dart impact at 100 µm is tested per ISO 7765-1. Values below 350 g are rejected for sharp-edged industrial pallets. Anti-block performance is maintained with 1–2 wt% synthetic silica masterbatch. Coefficient of friction target is 0.20–0.40 per ISO 8295. End products include pallet hoods for chemical drum shipments and beverage crates.
Surface protection films for aluminum profiles, pre-painted steel, and PP automotive panels use FN840 as a 50–80 µm backing web. Corona treatment of 38–42 mN/m is applied before pressure-sensitive adhesive coating. The treated surface must retain 36 mN/m after 90 days. The blown film process uses die gap 1.0–1.5 mm, blow-up ratio 2.0–2.6, and melt temperature 180–205 °C. A tackifier-free formulation is preferred. Only 1–2 wt% silica antiblock is used to avoid adhesive transfer. Film tensile at 60 µm is measured per ISO 527-3. MD tensile strength below 35 MPa or elongation below 400% is rejected because edge tears occur on masking lines. Dimensional stability is tested at 70 °C for 24 h per ISO 11501. Shrinkage above 1.5% is unacceptable.
For non-food liners and agricultural bags, FN840 is dry-blended with 20–40 wt% post-industrial LLDPE trim of known cleanliness. The regrind stream is screened through 60/100 mesh packs and dried to moisture below 300 ppm. Blown film lines with die gap 1.5–2.2 mm, blow-up ratio 2.2–3.0, and melt temperature 190–215 °C process the blend without pelletizing. The resulting film at 60–80 µm is tested for dart impact per ISO 7765-1. A lower limit of 150 g is used for can liners. Tear strength per ISO 6383-2 is maintained above 2.5 N. This stream is not permitted for direct food-contact use because post-industrial traceability cannot satisfy the positive list requirements of FDA 21 CFR 177.1520 for recycled content.
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SK LLDPE FN840 is a film-grade linear low density polyethylene resin supplied by SK Geo Centric. The grade is classified within the FN-series as a general-purpose sealant and packaging film resin. Typical values from the manufacturer’s technical data sheet cite a nominal melt mass-flow rate of 0.8 g/10 min at 190 °C/2.16 kg using ASTM D1238 and a nominal density of 0.918 g/cm³ using ASTM D1505. These values place FN840 near the low-melt-index node of the LLDPE film-grade matrix, where film toughness and bubble stability are balanced for blown-film machinery. The resin is supplied as pellets and is typically used in monolayer and coextruded packaging structures, including lamination films, protective packaging, produce bags, and agricultural film. Because the product is an ethylene-alpha-olefin copolymer, its semi-crystalline morphology imparts impact strength and tear propagation resistance greater than long-chain branched low-density polyethylene at equivalent film gauge.
On a standard 55 mm single-screw blown-film extruder with a 30:1 L/D barrier screw and a 1.8–2.5 mm die gap, processing trials indicate that stable bubble geometry is obtained at melt temperatures between 180 °C and 210 °C, with a blow-up ratio of 2.0:1–3.0:1 and frost line heights of 8–12 die diameters. Hopper temperature should be kept below 45 °C to avoid pellet softening and bridging. Screw speed should be adjusted to maintain melt pressure below 350 bar, beyond which melt fracture may occur at the die entry. A purge with a low-melt-index LDPE is recommended before startup and after shutdown to remove degraded polyolefin residue. The resin does not require desiccant drying for normal processing; however, condensation on cold pellets stored below 0 °C should be allowed to evaporate before charging to the hopper.
The melt index of 0.8 g/10 min at 190 °C/2.16 kg (ASTM D1238) defines a relatively high molecular weight for a film-grade LLDPE, but this single point does not describe the shear-thinning response. Blown-film processing requires low shear viscosity at die-land shear rates in the 100–300 s⁻¹ range and high elongational viscosity in the bubble-forming region to resist bubble perforation. Capillary rheometry on LLDPE grades of similar melt index typically shows an apparent viscosity in the 500–800 Pa·s region at 190 °C and 100 s⁻¹, although published data for this specific SK grade is limited. In practice, film converters often maintain die gap settings above 2 mm and adapter temperatures 5–10 °C lower than typically used for a 2.0 g/10 min LDPE to control bubble wobble and maintain frost line stability.
The nominal density of 0.918 g/cm³ reduces lamellar thickness relative to high-density grades, lowering the melting point and reducing the seal initiation temperature. The practical consequence is a lower heat seal bar temperature for 10 N/25 mm seal strength, generally in the 95–110 °C range for LLDPE sealant layers, although final values depend on film gauge, slip additive concentration, seal dwell time, and pressure. When FN840 is compared with a 2.0 g/10 min LDPE at equal film gauge, dart impact values measured by ISO 7765-1 and Elmendorf tear values measured by ISO 6383-2 are commonly higher, but tear balance shifts toward the transverse direction if the bubble is overstabilized.
A distinguishable processing characteristic is the need to protect the bubble from sudden air-pressure changes in the tower. Because FN840 operates in the low-melt-index region, the melt has higher extensional viscosity than a high-melt-index LDPE and is more resistant to burst, but it is less tolerant of rapid external cooling-air turbulence. On a production line wound with a collapsing frame and oscillating haul-off, operators should avoid pressure drops exceeding 10 kPa across the air ring during the first 30 min after startup. Edge folds at the collapsing frame can be reduced by lowering the frost line to below 2.0 m or by increasing the internal bubble pressure in 0.1–0.2 kPa increments. These are practical control limits derived from film tower operation rather than resin specifications.
The typical values in Table 1 are taken from the manufacturer’s technical data sheet and should not be treated as release limits. The user is responsible for verifying suitability in the final article.
| Property | Typical value | Method |
|---|---|---|
| Melt mass-flow rate (190 °C/2.16 kg) | 0.8 g/10 min | ASTM D1238 |
| Density | 0.918 g/cm³ | ASTM D1505 |
| Tensile strength at break, MD/TD | 28 MPa / 24 MPa | ISO 527-3 |
| Elongation at break, MD/TD | 620% / 700% | ISO 527-3 |
| Elmendorf tear strength, MD/TD | 90 g / 130 g per 25 µm | ISO 6383-2 |
| Dart impact, F50 | 140 g at 50 µm | ISO 7765-1 |
| Haze | 8% | ASTM D1003 |
| Gloss at 60° | 70 | ASTM D2457 |
| Vicat softening temperature | 96 °C | ASTM D1525 |
These typical values are internally consistent with an LLDPE film resin of this density and melt index. The machine-direction to transverse-direction tear balance can be shifted by increasing blow-up ratio or reducing stalk height. A BUR of 2.5:1–3.0:1 with a high frost line creates more balanced orientation; however, high BUR also lowers downstream web handling stability on tower-mounted collapsing frames if the film is not cooled to below 35 °C before the nip. For high-dart packaging structures, the film should be evaluated with an on-line thickness profiler at ±3% gauge tolerance to avoid localised weak points that cannot be corrected by the resin itself.
On cast-film lines, melt curtain width is influenced by die minus air gap, chill roll temperature, and edge pinning. At a die gap of 0.8–1.2 mm and an air gap of 25–40 mm, increasing line speed beyond 150 m/min can destabilise the curtain edge and produce neck-in exceeding 15% of die width. FN840, because of its moderate elongational viscosity, is less prone to brittle melt draw than high melt-index LDPE but more sensitive to temperature non-uniformity across a 1,200 mm slot die than a metallocene LLDPE with higher melt strength. Operators typically set chill roll temperature at 18–25 °C and hold the back roll temperature below 30 °C to preserve optical properties. If gauge bands greater than 5% of nominal thickness appear across the web, the recommended diagnostics are die lip gap parallelism, edge pinning air pressure, and polymer melt temperature variation, not solely the resin’s melt index.
Differentiation from other products in the SK portfolio and from commodity film resins is summarised in Table 2. FN840 is positioned below commodity butene-based LLDPE in melt index to retain dart impact, and above low-melt-index LDPE in density to provide lower seal initiation. In coextrusions, it is commonly used as the outer sealant layer in 3-layer films where a high-strength core of HDPE or mLLDPE provides stiffness. It can also be blended with 10–30 wt% LDPE to improve tear resistance without excessive loss of optical clarity. Published property data for direct comparisons with other SK LLDPE grades is limited; the table should therefore be used as a directional guide based on the property trends of the density and melt-index nodes, not as a substitute for laboratory coextrusion trials.
| Material | Nominal melt index (g/10 min) | Nominal density (g/cm³) | Seal initiation | Dart impact at equal gauge | Optical clarity |
|---|---|---|---|---|---|
| SK LLDPE FN840 | 0.8 | 0.918 | Low | High | Moderate |
| Commodity LDPE | 2.0 | 0.922 | Higher | Lower | High |
| Butene LLDPE, high MI | 1.0–2.0 | 0.920 | Low | Moderate | Moderate |
| Metallocene LLDPE | 1.0 | 0.918 | Lower | Higher | High |
The heat-seal behaviour of FN840 is governed primarily by the polymer melting point and by the rate of thermal diffusion through the film cross-section. In pouch converting, the seal bar pressure is usually set between 0.3 MPa and 0.5 MPa with dwell times of 0.5–1.0 s. The resulting seal strength reaches practical use thresholds at lower temperatures than an LDPE of 2.0 g/10 min melt index, but hot tack strength can decline if the seal jaw is opened before the melt has solidified. This is a critical boundary on high-speed vertical form-fill-seal machines running above 60 cycles/min. The resin’s low crystallinity also influences gas permeability; carbon dioxide and oxygen transmission rates are higher than those of high-density polyethylene of the same thickness, which must be considered in modified-atmosphere packaging design.
In blown-film production, internal bubble pressure is normally kept in the 0.2–0.6 kPa range above atmospheric pressure, depending on die diameter and tower height. A bubble that shows periodic breathing at frequencies below 1 Hz indicates a mismatch between air-ring pressure and internal bubble pressure; correcting the air volume stabilises the frost line without changing the resin grade. If localised stress whitening appears in the finished roll, the cause is often overstretching at the collapsing frame, not a resin defect. These field observations are consistent with standard blown-film troubleshooting practice and are not specific warranty limits for FN840.
Food-contact statements for FN840 are typically issued against US 21 CFR 177.1520 as an olefin polymer. European compliance in the final article must be evaluated under Commission Regulation (EU) No 10/2011, including overall migration and specific migration limits for any processing aids or slip/antiblock concentrates introduced by the converter. The resin is not formulated with intentional heavy-metal additives. REACH compliance is based on the absence of substances of very high concern above 0.1 wt% in the final article under Regulation (EC) No 1907/2006. Storage in closed hoppers below 40 °C and away from direct sunlight minimises oxidative degradation. The processing stabiliser package should not be combined with sulfur-containing or amine-based stabilisers that are known to generate discoloration in polyolefins; melt-flow stability trials are required before long production runs when additive packages are changed. The product is not recommended for hot-fill applications exceeding 70 °C continuous service unless the film is tested for creep deformation and antioxidant consumption under the specific filling temperature and oxygen load.
