Municipal waste collection sacks in the 100 µm to 220 µm gauge range fail in service primarily by tear propagation from point punctures, not by tensile yield. The base resin is supplied with a density of 0.918 g/cm³ per ASTM D792 and a melt flow rate of 1.0 g/10 min at 190°C/2.16 kg per ASTM D1238. On high-stalk monolayer lines equipped with grooved-feed extruders at 30:1 L/D and die diameters from 400 mm to 800 mm, Braskem LF 118/21 is dry-blended at 60 wt% to 80 wt% with post-industrial LLDPE reclaim and 2 wt% to 4 wt% of a 40% carbon black masterbatch in an LLDPE carrier with melt flow rate below 1.0 g/10 min to minimize viscosity mismatch. The melt temperature at the die is maintained between 190°C and 225°C, the die gap between 1.8 mm and 2.5 mm, and the blow-up ratio between 2.0:1 and 2.8:1; a dual-lip air ring with air temperature controlled to 10°C to 18°C stabilizes the bubble, while frost line height is held at 2.0 to 3.0 die diameters to prevent gauge bands above ±4 µm at haul-off speeds above 80 m/min. Final film is converted on bottom-seal bag machines with impulse seal bars set at 165°C to 195°C, and seal strength is monitored according to ASTM F88/F88M-23. The 100 µm film is specified to survive a falling dart impact of at least 90 g per ASTM D1709-16A and an Elmendorf tear of 250 gf in the transverse direction per ASTM D1922-15; machine-direction tear is lower due to preferential machine-direction orientation and is compensated by increasing gauge rather than by adding more than 20 wt% LDPE, because LDPE dilution suppresses dart impact at blow-up ratios above 2.5:1. The end article is a compacted wheeled-bin liner or industrial can liner for construction and retail waste streams; the formulation is not intended for food contact, and the converter must verify that post-industrial reclaim meets local packaging waste regulations.

What Changes in Tear Resistance Occur When EVA and LLDPE Are Melt-Blended at Sub-190°C Barrel Profiles?

Greenhouse cladding film produced from LF 118/21 as a 70 wt% to 85 wt% base resin, with 10 wt% to 20 wt% of a 14% vinyl acetate EVA and a UV stabilizer package, is extruded on a three-layer blown film line with a 350 mm die diameter and 1.6 mm die gap. Barrel profiles below 190°C in the compression zone leave unmelted EVA domains that appear as periodic haze bands in the finished film, while melt temperatures above 240°C promote gel formation from EVA carboxylate degradation; therefore the melt temperature at the die is limited to 200°C to 215°C and the barrel profile is ramped from 175°C in the feed zone to 205°C in the metering zone. The formulation is stabilized with 0.6 wt% of a high-molecular-weight HALS and 0.25 wt% of a benzotriazole UV absorber, both pre-dispersed in an LLDPE carrier through a 50:1 co-rotating twin-screw masterbatch line; 1.2 wt% glycerol monostearate is added as an anti-fogging agent, and the slip/antiblock package consists of 0.15 wt% erucamide and 0.10 wt% silica. The bubble is run at a blow-up ratio of 2.5:1 and a frost line height of 800 mm to 1,000 mm to balance transverse tear and machine-direction tensile strength. After 3,000 h of QUV exposure under ASTM G154-23, the 150 µm film is specified to retain 70% of initial elongation at break measured by ISO 527-3; total luminous transmittance for photosynthetically active radiation is measured by ISO 13468-1:2019 and is specified above 85% for clear film, while haze is limited to 20% by ISO 14782:2021. The finished tunnel and gutter-connected greenhouse cover is expected to survive three to five growing seasons in temperate zones; exact service life depends on UV radiation dose, sulfur dioxide exposure, and condensation management.

In pallet unitization lines operating at 40 to 70 loads/hour, blown stretch hood film is transported from a gusseted roll to a stretching frame, where it is expanded by 50% to 80% in the transverse direction before being released over a palletized load; the critical downstream requirement is recovery force retention after 24 h at 45°C and 60% relative humidity. LF 118/21 is extruded at 190°C to 215°C through a die with a 1.8 mm gap and run at a blow-up ratio of 3.0:1 to 3.5:1 with a high stalk height of 6 to 10 die diameters to generate transverse orientation and raise dart impact. The formulation contains 65 wt% LF 118/21, 25 wt% of an octene metallocene LLDPE with density 0.912 g/cm³ and melt flow rate 1.0 g/10 min, and 10 wt% of a high-pressure LDPE with density 0.923 g/cm³ and melt flow rate 0.3 g/10 min; the LDPE component increases melt tension and bubble stability, but additions above 15 wt% cause a measurable drop in machine-direction tear propagation resistance. Film thickness is held between 50 µm and 80 µm, and the specified minimum transverse elongation at break is 600% per ASTM D882, with a dart impact above 120 g per ASTM D1709-16A for 50 µm film. After slitting, the film is welded into tubular hoods by ultrasonic sealing at 20 kHz with amplitude of 55 µm to 65 µm; seal area temperature is controlled to avoid burn-through. The finished stretch hood is used for palletized construction materials, block pavers, and appliances; ultraviolet exposure is limited to outdoor storage periods shorter than six months unless an additional UV stabilizer package is incorporated.

Heat-Seal Strength Retention in Frozen-Food Lamination Webs at −25°C Storage

Frozen-food flexible packaging uses LF 118/21 as a 20 µm to 40 µm sealant web laminated to PET or BOPP print webs with a solventless polyurethane adhesive. The sealant web is blown on a monolayer line with a 1.5 mm die gap and a blow-up ratio of 2.2:1 to 2.8:1, then corona treated to 38 mN/m to 42 mN/m before lamination; film melt temperature is held at 190°C to 215°C and the line is operated with chilled air to maintain low web tensions. Seal initiation is observed at 105°C, and the plateau seal strength at 140°C is reached within 0.5 s dwell on standard vertical form-fill-seal machines; the relevant test method is ASTM F88/F88M-23, with a specified average seal strength of 5.0 N/15 mm for 40 µm film after 12 months at −25°C. The cold-temperature seal performance is governed by the density of 0.918 g/cm³ and the narrow molecular weight distribution of the grade, but the converter must limit total slip and antiblock additive loadings to 0.15 wt% because erucamide bloom becomes crystalline at −25°C and deposits on seal jaws, causing intermittent seal leaks. The olefin polymer is covered by FDA 21 CFR 177.1520(c) for food contact olefin polymers, and the finished laminate is subject to European Union Regulation EU 10/2011 Annex I Table 1 with an overall migration limit of 10 mg/dm² using EN 1186-1:2002 extraction; REACH Regulation EC 1907/2006 Annex XVII restrictions apply to the additives and adhesive. The terminal package is used for IQF vegetables, frozen fruit, and frozen meat; seal integrity is additionally verified by dye penetration per ASTM F3039-23 after thermal shock from −25°C to 40°C.

Produced in monolayer form at 50 µm to 120 µm, temporary containment enclosures and concrete curing films fail in service predominantly by puncture propagation from rebar ends and thermal expansion stress after dark-coloured films absorb solar radiation. LF 118/21 is run at 100 wt% or with 5 wt% of a UV-stabilized LDPE carrier containing carbon black at 3 wt% for opacity; the film is extruded through a die with a 2.0 mm gap at 200°C, with a blow-up ratio of 2.0:1 to 3.0:1, and is edge-folded in-line to produce a continuous sheeting layout. Slip and antistatic additive loadings are maintained below 0.05 wt% because surface contamination reduces tape adhesion at seam overlaps; seam adhesion is verified by a 180° peel test at 23°C per ISO 29862:2018. Water vapour transmission is measured by ASTM E96/E96M-22 Procedure B at 23°C and 50% relative humidity; for a 100 µm film the permeance is typically specified below 3.0 g/m²·24 h, but the converter must generate the value from the exact formulation because dust and carbon black content affect the vapour path. Puncture propagation resistance is tested by ASTM D5748-95(2019) using a 0.25 kg dart; the required breakout height is set by the site-specific containment protocol and is not a universal resin property. The end product is used as temporary building enclosure film, concrete curing cover, and lead-abatement barrier; flame-spread classification is outside the scope of the raw resin and must be established on the fabricated film according to regional building codes.

When coextruded silage bale wrap is stretched over a 1.2 m diameter round bale at 55% to 70% extension, the outer layer must resist UV degradation while the core layer maintains cling and puncture resistance against stalk ends and frozen forage. LF 118/21 is extruded as the core layer in a three-layer 25 µm to 35 µm film, with skin layers containing 2.5 wt% polyisobutylene tackifier and 0.5 wt% HALS UV stabilizer; the core layer is run at 100% LF 118/21 or blended with 10 wt% of an octene metallocene LLDPE to raise dart impact. The three-layer line uses a 400 mm die, a 1.5 mm die gap, a blow-up ratio of 2.8:1, and a melt temperature of 200°C to 220°C; film is wound with differential slip additives to avoid blocking in storage at 40°C. Pre-stretch ratio is limited by transverse creep of the butene copolymer; at extension above 70%, the film exhibits stress relaxation after 24 h that reduces bale compression and increases oxygen ingress. Retained cling is measured after 7 days at 40°C and 50% relative humidity by a modified 180° peel test based on ASTM D5458-20, with a specified minimum of 0.8 N/cm between the tackified skin layers; puncture resistance is verified by ASTM D5748-95(2019) on the 25 µm film. The finished wrap is used for round bale silage, haylage, and stalky crop bales; the film is not designed for direct food contact and must be disposed or recycled according to local agricultural plastics collection schemes.