Braskem LL6801N is supplied as a butene-copolymer linear low-density polyethylene with a nominal density of 0.918 g/cm³ per ASTM D1505-18 and a nominal melt index of 1.0 g/10 min per ASTM D1238-20 at 190 °C and 2.16 kg. In heavy-duty form-fill-seal sack production for dry construction chemicals, polymer resin, and mineral filler export, the resin is introduced into the middle layer of a three-layer blown-film structure at 70–85 wt%, with the remaining 15–30 wt% comprising high-pressure LDPE with a melt index of 0.2–0.8 g/10 min to raise melt strength and stabilize the bubble. The coextrusion line is run on grooved-feed extruders with a length-to-diameter ratio of 30:1 and barrier screws; melt temperature is held between 200 °C and 230 °C, die gap is set from 1.8 mm to 2.5 mm, and blow-up ratio is controlled at 2.2:1–2.8:1. When the blow-up ratio exceeds 2.8:1, the butene branching architecture of LL6801N provides insufficient melt tension compared with hexene or octene LLDPE, producing frost-line height oscillation and gauge variation unless LDPE is raised by at least 5 wt% above the 15 wt% floor. Film verification follows ASTM D1709-15a for dart impact, ASTM D1922-15 for Elmendorf tear, and ISO 527-3:2018 for tensile properties. Sacks intended for products classified as dangerous goods are qualified under the UN Model Regulations for flexible plastics packagings; non-hazardous export sacks typically undergo drop testing under ASTM D5276-19 and gross leak detection under ASTM F2096-11. Terminal finished products include gusseted FFS sacks, side-gusset bags, valve sacks, and pinch-bottom sacks for dry mortar, calcium carbonate, polymer pellets, and granular chemical intermediates.

What Is the Practical Addition Window for LL6801N in Frozen-Food Sealant Webs?

Frozen-food laminate webs built around LL6801N position the resin in the core layer at 60–80 wt% of the total film, while the heat-seal layers contain LDPE at 20–30 wt% to reduce seal initiation temperature and maintain hot-tack on vertical form-fill-seal machines running at 40–80 packages/min. Melt temperature on three-layer coextrusion blown-film lines is set between 190 °C and 215 °C, die gap is adjusted from 1.5 mm to 2.0 mm, and blow-up ratio is held at 2.0:1–2.5:1. Corona treatment is applied inline to raise surface energy to 38–42 mN/m for subsequent printing or lamination, but excessive treatment above 44 mN/m can reduce heat-seal strength through surface chain oxidation. A core film of LL6801N reduces side-gusset splitting compared with a high-stiffness HDPE structure, yet the butene comonomer cannot supply the same low-temperature impact resistance as an octene LLDPE; films thinner than 30 µm are therefore blended or coextruded with a metallocene LLDPE skin when dart impact must exceed 150 g per ASTM D1709-15a. Food-contact suitability falls under FDA 21 CFR 177.1520(c); within the European Union, compliance is assessed under Regulation (EU) No 10/2011, with an overall migration limit of 10 mg/dm² or 60 mg/kg depending on the food-contact configuration. Terminal finished products include pillow pouches for frozen vegetables and seafood, bakery overwrap, side-gusset bags for frozen fruit, and clear ice bags.

Dart Drop, MD Tear Propagation, and Core-Layer Ratio in Agricultural Silage Wrap

When LL6801N is compounded into agricultural silage wrap for bale coverage, the resin is blended at 75–90 wt% with a metallocene LLDPE or plastomer at 10–20 wt% to raise puncture resistance at bale shoulders, where film is pulled over high-friction stalk ends. A polyisobutylene-based tackifier masterbatch is added at 2–6 wt%, and a UV/HALS additive masterbatch is incorporated at 2–4 wt% because the wrap must retain tear resistance during outdoor storage beyond 30 days while the silage fermentation cycle completes. On high-stalk blown-film lines equipped with internal bubble cooling, die gap is set between 2.0 mm and 2.8 mm, melt temperature from 200 °C to 230 °C, and blow-up ratio from 2.0:1 to 2.5:1; film gauge is controlled between 25 µm and 30 µm. In baler application, the film is pre-stretched at 50–70% around the bale, and butene-LLDPE stress relaxation can generate wrinkles at the bale shoulder if tackifier migration has not reached the surface or if frost-line height is set too low. Test methods referenced for incoming film include EN 13207:2018 for thermoplastic silage films, ISO 527-3:2018 for tensile properties, ASTM D5748-95(2019) for puncture propagation resistance, and ISO 4892-2:2013 for accelerated weathering. Terminal finished products include 750 mm width silage bale wrap rolls and pre-stretched round bale covers for maize silage, grass hay, and alfalfa. Published data for this specific configuration is limited at tackifier loadings above 6 wt%, where excessive migration may reduce laminate integrity and complicate unbalanced cling on roll edges.

On high-output monolayer blown-film lines with internal bubble cooling, LL6801N serves as the base polymer at 80–100 wt% in institutional can liners and refuse sacks, with post-industrial reclaim incorporated at 10–30 wt% only when the end-use specification permits recycled content and the waste collector does not mandate a virgin-only declaration. Extrusion is run at melt temperatures of 190–220 °C, die gaps from 1.8 mm to 2.4 mm, and blow-up ratios from 2.0:1 to 3.0:1; at the upper blow-up ratio, operators commonly add 10 wt% LDPE or reduce line speed to limit bubble flutter at the frost line. Finished film thickness spans 20 µm to 50 µm, with dart impact tested under ASTM D1709-15a and Elmendorf tear tested under ASTM D1922-15. For sacks sold into European household and municipal waste collection, EN 13592:2017 is applied to verify dimensions, load capacity, and closure strength. Terminal product forms include flat-packed janitorial liners, star-sealed refuse sacks, and heavy-gauge can liners for wet and dry institutional waste. Since butene LLDPE has lower melt strength than LDPE, maximum LL6801N loadings are better suited to sack configurations that accept a wider gauge tolerance rather than high-speed printed film applications requiring very low gauge variability and precise flexographic registration.

When Pre-Stretch Levels in Machine-Grade Pallet Wrap Expose Butene LLDPE Relaxation Limits

In blown stretch wrap, LL6801N is formulated at 65–80 wt% as the base polymer, with a metallocene plastomer at 10–20 wt% and a tackifier masterbatch at 2–5 wt% to provide cling after rotational pre-stretch. The blown-film process uses die gaps from 2.0 mm to 2.5 mm, melt temperatures from 200 °C to 230 °C, and film thickness between 15 µm and 23 µm. Machine-grade film is pre-stretched to 150–250% on rotary and inline pallet-wrapping equipment; near the upper end of this window, butene LLDPE exhibits stress relaxation that lowers retained load force on pallet corners. Converters compensate by increasing the metallocene plastomer fraction by 5 wt% or by selecting a tackifier with lower surface migration temperature. Cling force is measured under ASTM D5458-95, peel cling under ASTM D5459-95, and puncture propagation resistance under ASTM D5748-95(2019). There is no single harmonized regulatory standard for non-food pallet wrap; compliance documentation typically consists of REACH article declarations, heavy-metal limits under CONEG, and optional process control under ISO 9001:2015. Terminal products include 500 mm machine-grade rolls for rotary and inline wrappers, pre-stretched hand film, and high-cling industrial wrap. Published data for this specific configuration is limited above 250% pre-stretch; converters operating above that threshold generally select cast-film grades with a higher melt index and lower density.

Evaluating Seal Strength and Flex-Crack Resistance in Non-Hazardous Liquid Pouches

Non-hazardous liquid pouch structures use LL6801N in the sealant layer at 70–85 wt%, with LDPE at 15–30 wt% to reduce seal initiation temperature and enhance hot-tack on impulse and heat-jaw sealers. The sealant layer is coextruded with tie resins and a polyamide or EVOH barrier core in five-layer or seven-layer blown-film configurations when the packaged liquid requires oxygen or aroma barrier properties; for less sensitive aqueous emulsions, a three-layer configuration may be sufficient. Melt temperature is controlled at 200–230 °C, die gap from 1.8 mm to 2.5 mm, and blow-up ratio from 2.0:1 to 2.5:1. Seal strength is verified under ASTM F88/F88M-21, leak detection under ASTM D3078-02, and flex-crack resistance under ASTM F392/F392M-11. Since the application is non-food, resin compliance is established through REACH article declarations and CONEG heavy-metal limits; LL6801N alone does not provide a barrier sufficient for aggressive solvents, strong oxidizers, or filled liquids requiring high-temperature sterilization. Terminal finished products include bag-in-box liners for water-based inks, liquid detergent concentrates, lubricant additive systems, non-hazardous aqueous emulsions, and other liquid packaging from 5 L to 1000 L capacity.