| HS Code | 891546 |
| Density | 0.920 g/cm³ |
| Melt Flow Index 190 C 2 16 Kg | 20 g/10 min |
| Tensile Strength At Yield | 12 MPa |
| Tensile Strength At Break | 18 MPa |
| Elongation At Break | 600% |
| Flexural Modulus | 260 MPa |
| Shore D Hardness | 52 |
| Izod Impact Strength Notched 23 C | 4.0 kJ/m² |
| Melting Point Dsc | 122 °C |
| Vicat Softening Temperature | 95 °C |
| Heat Deflection Temperature 0 45 Mpa | 75 °C |
| Brittleness Temperature | -60 °C |
As an accredited Union LLDPE 7144 factory, we enforce strict quality protocols—every batch undergoes rigorous testing to ensure consistent efficacy and safety standards.
| Packing | Union LLDPE 7144 is supplied as resin pellets in 25 kg moisture-resistant polyethylene-lined bags. |
| Container Loading (20′ FCL) | 20′ FCL container loading of Union LLDPE 7144: 25 kg bags, palletized, secure, dry, ventilated, safe transport. |
| Shipping | Union LLDPE 7144 is a non-hazardous linear low-density polyethylene resin supplied as free-flowing pellets. Ship in clean, dry containers, sealed bags, or bulk railcars/trucks. Protect from direct sunlight, moisture, and excessive heat. Avoid exposure to dust accumulation. Standard handling and storage practices for plastic materials apply. |
| Storage | Store Union LLDPE 7144 in a cool, dry, clean, well-ventilated area away from direct sunlight, heat, open flames, and ignition sources. Keep in original sealed packaging to prevent moisture uptake and contamination. Avoid stacking pallets excessively high. Protect material from dust, dirt, and mechanical damage. Proper storage maintains resin quality and safe handling. |
| Shelf Life | Union LLDPE 7144 has a shelf life of at least one year when stored in original, unopened packaging away from heat and moisture. |
Union LLDPE 7144 is converted on single-screw blown-film towers fitted with grooved-feed extruders of 45–90 mm diameter and 25:1–30:1 L/D to manufacture heavy-duty shipping sacks, woven-bag outer plies, bulk-bin liners and FIBC insert films. Compliance for non-food industrial packaging is governed first by REACH Annex XVII restrictions on additives, while any food-contact inner ply must satisfy FDA 21 CFR 177.1520 and EU No 10/2011, including an overall migration limit of 10 mg/dm² under Annex II. The grade is blended at 80–95 wt% with 5–20 wt% LDPE or post-industrial recycle to raise bubble stability; slip and antiblock masterbatches are added at 300–1,500 ppm erucamide and 1,000–3,000 ppm synthetic silica, respectively. On a 150–350 mm die with a 1.8–2.4 mm die gap, typical melt temperature is 190–215 °C, BUR is held at 2.0–2.5:1, and frost-line height is maintained at 5–8 times the die diameter to preserve impact strength. When BUR exceeds 2.8:1, the rapid transverse molecular orientation creates a property cliff: Dart impact under ASTM D1709 Method A may fall by 30–50% compared with a 2.0:1 BUR operation, while Elmendorf tear under ASTM D1922 becomes directionally unstable. Conversely, die gaps below 1.6 mm increase melt fracture, visible as herringbone surface defects at the nip. The finished product types include heavy-duty shipping sacks, valve sacks, FIBC liners, dunnage air bags and temporary containment covers. Pre-drying is not required unless surface condensation is visible; if condensation occurs, warm-air drying at 60–70 °C for 2 h removes surface moisture without altering stabilizer performance.
The most frequently recorded production fault on commercial towers is bubble whip when the frost line is raised above 8 die diameters; the collapsed film then exhibits gauge bands of ±10–15% from nominal thickness. Operators typically respond by reducing take-off speed below 35 m/min or increasing internal bubble cooling air flow. Extruder barrel profile is normally set in four zones from 160–170 °C in the feed zone to 205–215 °C at the adapter and die; melt pressure at the screen changer is maintained below 350 bar to limit shear heating and gel formation. At ambient relative humidity above 60%, condensation on pellets may introduce surface moisture that appears as splay unless pre-warming is used. The matrix below lists the incoming resin and finished sack film test methods.
| Stage | Standard | Condition |
|---|---|---|
| Resin melt flow rate | ASTM D1238-20 | 190 °C, 2.16 kg |
| Resin density | ASTM D1505-18 | 23 °C gradient column |
| Film tensile | ASTM D882-18 | MD/TD, 500 mm/min |
| Dart impact | ASTM D1709-22 | Method A, 100 µm film |
| Tear resistance | ASTM D1922-15 | Elmendorf, 100 µm film |
| Food-contact compliance | FDA 21 CFR 177.1520, EU No 10/2011 | Overall migration limit 10 mg/dm² |
During production of wide-width silage cover and bale-wrap film, Union LLDPE 7144 is extruded in monolayer or three-layer configurations with target thicknesses from 75 µm to 150 µm. The governing standard for silage film is EN 13207:2001, which sets mechanical strength after weathering, thickness tolerance and storage stability; REACH-registered UV stabilizers and color concentrates are required, and EU food-contact regulation does not apply unless the film is later repurposed for feed-contact packaging. Formulation for black or white silage film contains 80–90 wt% Union LLDPE 7144, 10–20 wt% LDPE for drawdown stability, 2–5 wt% carbon black or 5–8 wt% titanium dioxide, and 500–2,000 ppm hindered amine light stabilizer. Production uses a 1,200–2,400 mm blown-film die, 2.2–2.8 mm die gap, BUR of 2.5–3.5:1, and internal bubble cooling at a throughput of 350–650 kg/h. The process conflict is that high BUR improves MD tear propagation but reduces dart impact and increases cross-web curvature after slitting; converters typically set BUR at 3.0:1 as an upper limit for 125 µm silage film. Terminal products are bale wrap, pit cover, clamp film and silage bags.
For frozen-food films, Union LLDPE 7144 is specified as a sealant layer because its short-chain branching gives a lower heat-seal initiation than standard LDPE and it retains flexibility below −20 °C as verified by ASTM D1709 Method A cold-condition impact testing. Food-contact compliance requires FDA 21 CFR 177.1520 for olefin polymers and EU No 10/2011, including the declaration of compliance under EU 2023/2006 Good Manufacturing Practice; specific migration limits for each monomer and additive must be evaluated on the final packaging configuration. In a three-layer blown-film structure, the resin is used at 60–80 wt% of the sealant layer, with 10–20 wt% LDPE and 5–15 wt% polyolefin plastomer to lower seal initiation temperature to 95–110 °C; slip and antiblock are added at 300–800 ppm and 1,500–4,000 ppm, respectively. Film is produced on coextrusion towers with 100–250 mm dies, 1.5–2.0 mm die gap, melt temperature 190–220 °C, and chill air at 5–10 °C to stabilize the bubble. The production limitation is hot-tack failure rather than melt fracture: if seal temperature is pushed below 95 °C, hot-tack strength can drop below 1 N/25 mm under ASTM F1921, and filled bags open during vertical form-fill-seal at speeds above 60 packs/min. Terminal finished types include frozen vegetable pouches, ice cream overwrap, frozen fish laminate webs, and IQF food bags.
Pallet-load containment through cast stretch-hood film subjects Union LLDPE 7144 to a different strain history from blown film because the web is pre-stretched by 60–75% during application. The resin is used in the core layer at 60–80 wt%; skin layers are modified with 10–30 wt% metallocene LLDPE or VLDPE to reduce stress whitening and increase puncture retention. Mechanical compliance references ASTM D882 for tensile elongation, ASTM D5458 for peel cling, and ASTM D5748 for stretch wrap cling; REACH and local packaging waste regulations apply for export pallets. On a cast-film line with 0.8–1.5 mm slot-die gap, 15–25 °C chill-roll temperature and 300–600 m/min line speed, the film is wound at 20–40 µm thickness. The main process conflict is draw resonance at low melt temperature: when melt temperature drops below 200 °C, edge instability and gauge variability exceed ±5%; raising temperature above 240 °C increases oxidation gel formation and reduces cling. Published data for Union LLDPE 7144 in this specific cast-stretch configuration remains limited, so the above parameters must be confirmed on the target line using the resin’s measured melt flow rate under ASTM D1238. Finished product types include machine stretch film, stretch-hood film, and core-layer webs for hand wrappers.
In flexible laminate structures, Union LLDPE 7144 is coextruded as a sealant web at 20–60 µm thickness onto aluminium foil, metallized OPP or metallized PET for coffee pouches, snack laminates and medical device overwrap. Food-contact compliance for laminates requires FDA 21 CFR 177.1390 for adhesives and FDA 21 CFR 177.1520 for the polyolefin layer, plus EU No 10/2011 overall migration and specific migration testing on the final laminate. The recommended formulation is 80–90 wt% Union LLDPE 7144, 10–20 wt% LDPE or plastomer to reduce seal initiation, 400–800 ppm slip and 1,500–4,000 ppm antiblock. The extrusion coating line uses a 90–150 mm single-screw extruder with 30:1 L/D, 200–230 °C melt temperature, 150–200 mm air gap and 15–20 °C matte chill-roll chilling; corona treatment is maintained at 38–42 dyn/cm to ensure adhesion to primers or tie resins. The critical boundary is oxidation: at melt temperature above 230 °C and air gap beyond 200 mm, surface oxidation can reduce heat-seal strength below 15 N/25 mm unless nitrogen blanketing is applied. The finished product types are coffee lidding film, snack bag laminate, and peelable medical pouch web where seal integrity is verified under ASTM F88.
When Union LLDPE 7144 is compounded with calcium carbonate, the resin functions as the matrix for moisture-permeable hygiene backsheet film. The governing standards are REACH for the filler and polymer additives, plus ISO 10993-5 and ISO 10993-10 only if the film is used as a medical device component; hygiene nonwovens normally use manufacturer-specific biocompatibility data. The formulation contains 45–55 wt% surface-treated calcium carbonate with 1–3 µm particle size, 40–50 wt% Union LLDPE 7144, and 1–5 wt% compatibilizer; processing aid is added at 200–600 ppm. The film is cast through a slot die at 15–40 µm thickness, quenched at 15–20 °C, then uniaxially stretched in a machine-direction orienter at 2.0:1–3.0:1 ratio to initiate interfacial debonding around the filler particles. Water vapour transmission rate is tested under ASTM F1249 at 38 °C and 90% RH; typical filled films reach 1,000–4,000 g/m²/day depending on stretch ratio and filler content. The process conflict is that excessive stretch ratio above 3.0:1 can generate pinholes and reduce hydrohead below 1,000 mm H₂O under AATCC 127, while insufficient stretch leaves WVTR below the target for diaper backsheet. The terminal products are breathable diaper backsheet, adult incontinence film, feminine hygiene film, and medical protective clothing film when laminated to nonwoven carriers.
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Union LLDPE 7144 is a linear low-density polyethylene pellet grade identified by a nominal density near 0.922 g/cm³ and a melt flow rate of 4.0 g/10 min at 190 °C under a 2.16 kg load. The density is generally controlled within 0.921–0.925 g/cm³ under ISO 1183-1:2019, and the melt flow rate is controlled within 3.6–4.4 g/10 min under ISO 1133-1:2022. The material is an ethylene-α-olefin copolymer; the specific comonomer—butene or hexene—should be verified from the certificate of analysis for the production campaign because it affects the balance between dart impact and stiffness. The standard pellet form does not include slip, antiblock, or processing aid unless ordered as a compounded formulation.
| Property | Test method | Reported typical range |
|---|---|---|
| Density | ISO 1183-1:2019 | 0.921–0.925 g/cm³ |
| Melt flow rate | ISO 1133-1:2022 | 3.6–4.4 g/10 min |
| Tensile yield strength | ISO 527-2:2012 | 11–14 MPa |
| Elongation at break | ISO 527-2:2012 | 600–900 % |
| Melting peak | ISO 11357-3:2023 | 122–126 °C |
| Vicat softening point A/50 N | ISO 306:2022 | 100–108 °C |
| Flexural modulus | ISO 178:2019 | 260–320 MPa |
Warehousing at ambient relative humidity below 60 % does not require hopper drying. In coastal processing sites where silos remain above 70 % relative humidity, surface moisture uptake can occur within 48 h and produce splay in cast film or injection moulding. The corrective procedure is a desiccant dryer set to 70–80 °C for 2–3 h at an air dew point of −30 °C or lower. Dwell time in the dryer should not exceed 6 h because discolouration can develop in stagnating hopper zones.
On production blown film towers with 45–75 mm grooved-feed extruders operating at 24:1–30:1 L/D, the grade is usually processed with barrel settings between 180 °C and 210 °C and a die temperature of 210–225 °C. At melt temperatures below 190 °C, screw motor amperage rises because the crystalline fraction retains pellet morphology; above 225 °C, oxidative gel accumulation on the die lip becomes measurable within 4–6 h of continuous operation. The practical stable melt-temperature window is therefore narrow, approximately 35 °C.
Bubble stability constraints are more restrictive than thermal stability. The melt flow rate of 4.0 g/10 min lowers melt strength relative to 1.0 g/10 min film grades. At blow-up ratios above 3.0:1, bubble oscillation is observed when the frost-line height exceeds 10 die diameters unless chilled air at 10–12 °C is used. Field data from air-cooled systems with die gaps of 1.8–2.4 mm indicate that draw-down ratios above 3.5:1 generate edge tear and gauge bands exceeding ±12 %.
Mechanical property retention in 30 µm monolayer film should be measured on-line because thickness variation dominates tensile data. Under ISO 527-3:2018, machine-direction elongation at break is typically above 500 %; transverse-direction elongation is lower. Dart impact of 25 µm film tested under ASTM D1709-22 method A is generally reported between 80 g and 120 g, but the value collapses above 12 % gauge non-uniformity.
In cast film extrusion through a 90 mm single-screw extruder and a 2.0 mm die gap, melt temperature can be set to 230 °C for a 20 µm film. Chill roll temperature is held at 28–32 °C; at roll temperatures above 45 °C, blocking increases unless an antiblock masterbatch is added at 5–10 wt%. The lower melt elasticity of Union LLDPE 7144 reduces neck-in, but the curtain is more sensitive to ambient air currents than high-pressure LDPE. Stable line speeds up to 120 m/min are possible; above this, edge weave becomes the limiting variable.
The melting peak of Union LLDPE 7144 lies between 122 °C and 126 °C when analysed by differential scanning calorimetry at 10 °C/min under ISO 11357-3:2023. The first-heating crystalline fraction typically falls between 35 % and 42 % using a reference heat of fusion of 293 J/g for perfectly crystalline polyethylene. This crystallinity range contributes to a flexural modulus near 260–320 MPa under ISO 178:2019 for compression-moulded plaques, but the exact value depends on cooling rate.
Repeated processing of regrind above 30 wt% shifts the oxidation onset time downward. Inspection of the die lip after 8–12 min of continuous extrusion at 230 °C can reveal gel build-up generated by crosslinked oxidized regions. The use of antioxidant masterbatch is required for closed-loop regrind systems, and filter pressure rise across a 150 µm screen pack should be monitored as a lot-specific control limit.
The substitution of Union LLDPE 7144 for high-pressure LDPE changes the extensional viscosity and melt-tension response of the curtain. High-pressure LDPE derives strain hardening from long-chain branching; 7144, as a linear LLDPE, exhibits less strain hardening and therefore requires a narrower die-to-laminator distance. On a pilot extrusion coating line running 12 µm coatings at 150 m/min, the neck-in measured between die exit and laminator nip is typically 8–12 % of die width for 7144, compared with 15–20 % for a conventional LDPE coating grade at the same output. Published data for this specific configuration is limited, and the neck-in value depends on the air gap and die-lip geometry.
For heat-seal layers in flexible packaging, 7144 can be blended with high-pressure LDPE at 20–30 wt% LDPE to recover bubble stability and maintain hot-tack force. Hot-tack strength measured under ASTM F1921-18 is typically highest when the seal bar temperature is between 105 °C and 115 °C, whereas the hot-tack plateau of 7144 alone may be narrower. Seal initiation temperature is generally between 95 °C and 105 °C, but film gauge and dwell time shift the curve by up to 5 °C.
| Parameter | Union LLDPE 7144 | High-pressure LDPE | Butene LLDPE film grade |
|---|---|---|---|
| Nominal density | 0.921–0.925 g/cm³ | 0.917–0.922 g/cm³ | 0.918–0.920 g/cm³ |
| Melt flow rate | 3.6–4.4 g/10 min | 0.8–2.0 g/10 min | 0.8–1.2 g/10 min |
| Tensile yield strength | 11–14 MPa | 9–12 MPa | 10–13 MPa |
| Elongation at break | 600–900 % | 400–600 % | 700–1000 % |
| Dart impact, 25 µm film | 80–120 g | 50–90 g | 90–130 g |
| Seal initiation temperature | 95–105 °C | 90–100 °C | 100–110 °C |
The comparison rows in Table 2 are drawn from typical commercial data for the indicated resin classes. They are not lot-specific guarantees for Union LLDPE 7144; the current certificate of analysis should be used for release testing. Compared with metallocene-catalyzed LLDPE grades of similar density, 7144 may exhibit a broader molecular weight distribution and a lower dart impact at equivalent gauge because of conventional Ziegler-Natta active-site heterogeneity. Published data for this specific configuration is limited, and the comparison should be validated on the actual lot.
Direct conversion from high-pressure LDPE to Union LLDPE 7144 should be planned around die swell and melt-pressure differences. A purge charge of 8–12 kg is usually sufficient for a 75 mm extruder, but the die gap should be reset for 7144 before starting the purge to avoid initial gauge variation. The first 15 min of stable output should be scrapped as transition material, particularly when the previous resin contained slip or antiblock additives. Melt pressure should be recorded at the breaker plate; a pressure drop across the screen pack above 25 % of the starting value indicates gel accumulation and requires screen replacement.
Injection moulding of thin-wall containers from Union LLDPE 7144 uses melt temperatures of 210–240 °C and injection velocities of 150–250 mm/s. Mould temperatures are held at 25–40 °C. Parts with wall thickness of 0.8–1.2 mm fill readily because of the 4.0 g/10 min melt flow rate, but shrinkage measured under ISO 294-4:2018 can reach 1.8–2.2 % in the flow direction; this is higher than high-pressure LDPE and must be accommodated in gate and rib dimensions. Ejector pin marks can deepen if demoulding occurs above 60 °C surface temperature.
In three-layer coextruded film structures where Union LLDPE 7144 forms the outer plies and a tie layer bonds EVOH or polyamide, the melt temperature of the 7144 layer should not exceed 225 °C to preserve interfacial viscosity matching. When the EVOH layer requires 240 °C, processing aid masterbatch addition at 2–3 wt% may be necessary to prevent unstable layer distribution. The use of maleic anhydride-grafted tie resins does not degrade the seal performance of 7144 at dwell times below 1 s and seal pressures of 0.3–0.5 N/mm².
In thick-section components such as industrial container lids and pallet boxes, the flexural modulus of Union LLDPE 7144 is typically 260–320 MPa under ISO 178:2019. The notched Charpy impact at 23 °C is usually above 40 kJ/m² when tested under ISO 179-2:2020; at −20 °C, the retained value may fall to 20–30 kJ/m², indicating a ductile-to-brittle transition that limits use in deep-freeze industrial containers unless a lower-density comonomer-rich grade or elastomer modifier is blended. The specific transition temperature for 7144 should be generated on finished parts because weld lines and moulded-in stress shift the curve by as much as 10 °C.
Rheological measurements at 190 °C show a shear-thinning index in the range of 0.55–0.65 when the viscosity at 100 s⁻¹ is compared with that at 10 s⁻¹. This moderate shear thinning is lower than that of long-chain branched LDPE and explains the more uniform filling of thick sections at moderate injection speeds. The batch-to-batch variance of this index is typically below 5 % for product released under ISO 9001:2015 lot certification.
When the grade is pulverized for rotational moulding of 3–6 mm wall chemical tanks, oven dwell time should be adjusted to keep peak internal air temperature near 220–240 °C. The melt flow rate of 4.0 g/10 min is suitable for complex mould filling, but the low melt strength can produce sag in large flat panels. A mould release cycle at 80 °C part surface temperature reduces warpage. The exact suitability of Union LLDPE 7144 for rotomoulding must be stated by the supplier because stabilizer packages differ between film and rotomoulding grades.
For regulated packaging and moulded food-contact parts, converter compliance should not be inferred from the commodity resin data sheet alone. The base olefin polymer may be compliant with 21 CFR 177.1520(c) and the food-contact conditions of EU 10/2011, but the finished article must be evaluated for overall migration and specific migration of degradation products. SVHC declarations under REACH 1907/2006 and heavy-metal limits under RoHS 2011/65/EU should be obtained for the purchased lot, particularly when regrind or colour masterbatch is added at the converter. No specific statement about the absence of per- and polyfluoroalkyl substances can be made without targeted analytical screening because the supply chain may introduce external contaminants.
