On a 65 mm grooved-feed blown film line with a 30:1 L/D screw, a 250 mm die, and a dual-lip air ring, Braskem LL118/21 — specified at nominal density 0.918 g/cm³ and melt flow rate 1.0 g/10 min under ISO 1133-1:2022 — is processed as the primary load-bearing layer in heavy-duty industrial sacks. The converter-level formulation places Braskem LL118/21 at 80–85 wt%, LDPE at 15–20 wt%, and an antiblock masterbatch at 0.5–1.0 wt%; this ratio maintains dart impact under ASTM D1709-16ae1 while preventing blocking at film thicknesses of 200–250 µm. The production process is monolayer blown film extrusion with a die gap of 2.0 mm, a blow-up ratio of 2.0:1, a melt temperature between 200°C and 210°C, and internal bubble cooling engaged above 180 kg/h output. Compliance for export lot release is anchored to ISO 8367-2:1993 for thermoplastic sack dimensions, ASTM D4976-20 for the material designation, and EU 94/62/EC for heavy metals; direct food contact is not implied unless the converter separately validates the finished article under 21 CFR 177.1520(c). Terminal finished product types include 25 kg polymer granule sacks, mineral powder sacks, animal feed sacks, and insert liners for FIBC constructions rated at 500–1000 kg. At thickness above 250 µm, collapsing frame surface temperatures must be maintained below 35°C to avoid blocking bridges; on similar high-output lines, exceeding 220 kg/h without internal bubble cooling is known to increase film thickness variation to more than ±8%.

When Does Low-Temperature Seal Strength Override Film Yield in Frozen Food Packaging?

Film structures intended for frozen vegetable, seafood, and ice cream packs are run at 30–80 µm, where the low-temperature ductility of Braskem LL118/21 becomes the controlling property rather than tensile yield. In this segment, the polymer fraction is blended at 85–90 wt% Braskem LL118/21, 10–15 wt% LDPE, 0.5–1.0 wt% antiblock masterbatch, and 0.08–0.12 wt% erucamide slip; slip loading above 0.15 wt% is avoided because migration to the sealant surface narrows the hot-tack window on high-speed vertical form-fill-seal equipment and can transfer to filling jaws. The compliance matrix for this segment includes 21 CFR 177.1520(c) for US food contact, EU Regulation (EU) No 10/2011 with an overall migration limit of 10 mg/dm², and GB 4806.7-2016 for China-bound packs; water vapor transmission rate is measured under ASTM F1249-20 at 38°C and 90% RH, while tear propagation is recorded under ASTM D1922-15. Processing is performed on a 50 mm grooved-feed single-screw extruder with a 200 mm die, a die gap of 1.8 mm, a blow-up ratio of 2.5:1, and a melt temperature of 190–200°C; secondary air cooling at 5–10°C reduces blocking during roll formation. Terminal finished products include pre-formed frozen vegetable pouches, individually quick-frozen seafood bags, ice cream bags, and frozen bakery overwrap. A known processing boundary is bubble chatter when the frost line is held below 300 mm, which produces gauge bands that fail downstream leak and seal integrity tests.

Stretch Hood Pallet Wrap Puncture Propagation and High-Stalk Bubble Stability

Palletizing lines for bagged cement, construction blocks, and ceramic products impose puncture and tear loads that cannot be satisfied by monolayer LDPE alone; Braskem LL118/21 is therefore blended at 60–70 wt% with C6-LLDPE at 20–30 wt% and LDPE at 10–15 wt%. A fluoropolymer processing aid is added at 0.02–0.05 wt% on lines equipped with a 350 mm die, a die gap of 1.8 mm, a blow-up ratio of 3.0:1, and a high-stalk bubble configuration; the stalk length is held at 700–900 mm with internal bubble cooling to stabilize the bubble against ambient air turbulence. Puncture resistance is recorded under ASTM D5748-19, tensile under ASTM D882-18, and propagation tear under ASTM D1922-15. Export consignments to the EU require heavy metals assessment under EU 94/62/EC, with combined lead, cadmium, mercury, and hexavalent chromium below 100 mg/kg in packaging. Terminal finished product types are stretch hoods of 60–100 µm for pallet loads of cement bags, brick stacks, appliance cartons, and chemical drums. Exceeding 35 wt% C6-LLDPE creates measurable melt-pressure oscillation and raises dart drop absolute variation above 15%; this configuration is not recommended where pallet loads present sharp steel-edge or strapping contact.

On three-layer coextrusion lines running black silage cover film at outputs above 180 kg/h, Braskem LL118/21 is used in the core and inner layers at 85–90 wt% of the total polymer fraction, with LDPE at 10–15 wt% and a carbon black masterbatch at 2–4 wt%. The carbon black loading is not cosmetic; it provides weather resistance for silage covers that must remain intact over 12–24 months of outdoor exposure. A hindered amine light stabilizer is added at 0.3–0.6 wt%, and a fluoropolymer process aid at 0.03 wt% controls melt fracture without altering surface tension to levels that compromise winding. The relevant agricultural film standard is EN 13206:2017; when exported to EU member states, the final article must also demonstrate compliance with REACH Regulation (EC) No 1907/2006, Annex XVII restrictions for polycyclic aromatic hydrocarbons, and the packaging waste directive EU 94/62/EC. Extrusion is performed with a layer distribution of approximately 30/40/30, a die gap of 2.2 mm, a blow-up ratio of 2.0:1, and a melt temperature of 200–215°C. The film is wound at 150–200 µm, and thickness tolerance is held at ±5% because variation above this range produces localized thinning under bale wrap edge pressure. Terminal finished products include bale wrap, bunker silage covers, and tube-stored silage bags used in dairy and biogas operations. When carbon black masterbatch exceeds 4 wt%, screen pack pressure rises above acceptable thresholds on 80 mm extruders, and tear propagation resistance under ASTM D1922-15 declines; this is the primary formulation ceiling for this application segment.

If Adhesive Lamination Converters Run Thin Sealant Webs Above 300 m/min, Corona Retention Becomes the Controlling Variable

Adhesive lamination converters processing sealant webs for stand-up pouches and stick packs use Braskem LL118/21 as a 20–40 µm blown film layer in duplex or triplex laminates. The polymer fraction in this segment is 92–95 wt% Braskem LL118/21, 5–8 wt% LDPE, and 0.5–1.0 wt% antiblock masterbatch; slip additive is kept at 0.1–0.2 wt% because higher slip levels can reduce the initial peel strength of solventless polyurethane adhesive bonds to PET and BOPP. US food contact status is assessed under 21 CFR 177.1520(c), and EU status under EU Regulation (EU) No 10/2011 with overall migration below 10 mg/dm²; converters must validate migration under the food simulant and time-temperature conditions assigned in Annex III of the regulation for the specific food category. Processing conditions for the blown sealant web are a die gap of 1.2–1.5 mm, a blow-up ratio of 2.5:1, a melt temperature of 195–210°C, and corona treatment to 38–42 mN/m. Lamination is then performed at line speeds above 300 m/min; at these speeds the interval between corona discharge and adhesive application is the main variable controlling bond durability. Terminal finished product types include stand-up pouches, stick packs, sachets, and lidding film. Surface energy below 36 mN/m after 30 days of roll storage is a common failure boundary; converters storing film rolls beyond this interval in RH > 60% conditions should re-check dyne level or apply atmospheric plasma retreatment before lamination.

Bag-in-Box Liner Film Is Extruded at 40–70 µm With Flex-Crack Cycle Requirements

Bag-in-box filling lines for 3 L, 5 L, and 10 L liquid packaging require a monolayer blown film tube that survives repeated flexing during transport and spout insertion. In this application Braskem LL118/21 is blended at 85–90 wt% with metallocene LLDPE at 10–15 wt% and LDPE at 5–10 wt%; this ratio improves flex-crack resistance while retaining bubble stability on a 55 mm grooved-feed extruder. Food contact compliance for wine, dairy, and liquid food service is evaluated under 21 CFR 177.1520(c) and EU Regulation (EU) No 10/2011, with overall migration not exceeding 10 mg/dm²; flex durability is measured under ASTM F392-93 using the A or B test mode selected by the converter and accepted by the brand owner. The tube is extruded at 40–70 µm through a 1.5 mm die gap with a blow-up ratio of 2.5:1 and a melt temperature of 190–205°C. After collapsing, the tube is perforated for spout insertion, heat-sealed at the top and bottom, and leak-tested by air inflation prior to loading into corrugated cases. Terminal finished product types include bag-in-box liners for wine, dairy concentrates, post-mix syrup, and non-hazardous liquid chemicals in 3 L to 20 L formats. At film thickness below 40 µm, pinhole counts in flex-crack testing increase sharply; for wine bag-in-box liners a minimum of 50 µm is common because oxidative ingress through pinholes compromises shelf life.

Household refuse sack production is the most cost-sensitive segment in this group; formulations are adjusted continuously against post-consumer recycled LDPE availability. Braskem LL118/21 is added at 70–80 wt% of the virgin polymer fraction, with LDPE at 20–30 wt%, colored masterbatch at 1–2 wt%, and calcium carbonate masterbatch at 5–10 wt% only when downgauging below 40 µm is not part of the product specification. The applicable standard is EN 13592:2017 for household refuse sacks, with dart impact under ASTM D1709-16ae1; EU packaging waste compliance is demonstrated under EU 94/62/EC with combined heavy metals below 100 mg/kg. Processing on a monolayer line with an 80 mm grooved-feed extruder, a 400 mm die, a blow-up ratio of 3.0:1, and melt temperature 190–205°C yields 20–60 µm film at high output. Terminal finished product types include drawstring refuse sacks, bin liners, and heavy-duty trash bags for municipal collection. Calcium carbonate loadings above 10 wt% reduce dart drop and increase melt pressure; screen packs are set at 60/80/100 mesh to remove agglomerates that would otherwise generate pinholes at the collapsing frame.