Heavy-duty industrial liners in the 100 µm–200 µm gauge range are produced from Braskem HF2007 on a 75 mm grooved-feed single-screw blown film extruder with L/D 30:1 and a 400 mm diameter low-pressure spiral die. The resin has nominal density 0.918 g/cm³ and melt index 1.0 g/10 min at 190°C/2.16 kg under ASTM D1238. Melt temperature is held between 195°C and 215°C at the adapter. Die gap is set at 2.0 mm. Blow-up ratio is maintained between 2.5:1 and 3.0:1. Frost line height is fixed at 8 to 10 die diameters. For bubble stability on high-speed winders, HF2007 is blended with 15–20 wt% high-pressure LDPE having melt index below 0.30 g/10 min. The blend provides improved melt strength and reduced bubble flutter but dart impact measured under ASTM D1709 declines if LDPE exceeds 25 wt%. The film is converted into side-gusseted FIBC inner liners, drum liners and bulk box liners. Seams are impulse heat sealed at 125°C–140°C and seam strength is evaluated by ASTM F88. Compliance for non-food industrial use relies on REACH 1907/2006 Article 33 and EU Directive 94/62/EC heavy-metal concentration below 100 mg/kg in packaging components. Pre-drying is not required, but surface condensation from cold warehouse transfer must be avoided because free moisture on pellets can generate bubble instability at the die. On lines without automatic air ring control, ambient air temperature swings above 10°C can shift frost line height and create gauge variation exceeding 5%.

How Does Seal Initiation Temperature Shift in 30 µm Frozen Food Packaging Films?

In mono-layer frozen food packaging produced on a 55 mm extruder with L/D 24:1 and a 150 mm die, Braskem HF2007 is processed at 190°C–205°C melt temperature with die gap 1.8 mm and blow-up ratio 2.2:1 to 2.5:1. The melt index of 1.0 g/10 min under ASTM D1238 supports stable bubble formation. A 5–10 wt% addition of high-pressure LDPE further stabilises the bubble at line speeds above 80 m/min. Food-contact qualification is performed under FDA 21 CFR 177.1520(c) 3.2a and EU No 10/2011. Overall migration testing for frozen aqueous food uses 10% ethanol simulant at 20°C for 10 days. The blown web is converted into pillow pouches and side-seal bags for IQF vegetables and frozen meat portions. Seal initiation on VFFS jaw is controlled by heat transfer through the web; the low melt index reduces thin-down at the seal edge, but seal bar temperature must be raised by 5–10 K compared with high-slip blown LDPE grades. Hot tack is measured by ASTM F1921 and seal strength by ASTM F88. The film’s low density of 0.918 g/cm³ maintains flexibility at freezer temperatures; published data for this exact configuration is limited and should be confirmed by ASTM D882 tensile testing at -20°C. Film with gauge below 25 µm risks pinholing in draw-down after frost line, and should be produced only with automatic gauge control and cold air ring at 10°C to 15°C.

Silage Film Oxygen Permeability and Tear Retention in a 150 µm Coextruded Structure

Agricultural bale wrap in 150 µm thickness uses a three-layer coextrusion die with skin layers carrying 2–4 wt% HALS/UV masterbatch and a core layer containing Braskem HF2007 blended 70/20/10 with high-pressure LDPE and a metallocene LLDPE. Melt temperature is kept at 200°C–220°C. Die gap is set at 2.4 mm. Blow-up ratio is held between 2.5:1 and 3.0:1. The collapsing frame is positioned to minimise surface tension wrinkles. Oxygen transmission rate is measured by ASTM D3985 at 23°C and 0% RH. Processors use an internal reference of 4,000 cm³/m²·day·atm at 50 µm, but this value must be confirmed because OTR scales inversely with thickness only when the web is free of pinholes. Tear retention after 12 months of weathering is monitored by ASTM D1922 in machine direction. A loss below 50% of initial tear indicates UV stabiliser depletion. The finished blown bale wrap tube is slit to 750 mm widths for round-bale wrappers. Regulatory compliance for non-food agricultural film does not require FDA food-contact clearance; REACH 1907/2006 Article 33 and EN 13206 are the relevant references. High UV masterbatch loadings above 6 wt% can reduce bubble stability due to carrier resin incompatibility and should not be entered without stabilizer compatibility testing. In multi-layer structures, the core layer remains unstabilised if the skin layers provide complete UV shielding; incorrect layer distribution below 15% core can expose HF2007 to UV and accelerate embrittlement.

Because post-consumer PE recyclate at 30–40 wt% reduces bubble strength and narrows the HF2007 processing window on a 55 mm extruder, refuse sack producers lower melt temperature to 185°C–200°C and install a 100/80/60/100 mesh screen pack upstream of the die. The recyclate fraction is a washed and regranulated blown film fraction with melt index between 0.7 g/10 min and 1.5 g/10 min. Drawn film gauge is 20 µm to 30 µm. Die gap is set at 1.2 mm. Blow-up ratio is held at 2.0:1 to 2.5:1. The finished sacks are star-sealed or drawstring sealed and must meet EN 13592 for household refuse sacks. Dart impact is tested under ASTM D1709 and Elmendorf tear under ASTM D1922. Compliance follows REACH 1907/2006 Article 33 and EU Directive 94/62/EC. Screen pack gel capture must be balanced against melt temperature rise; excessive head pressure above 350 bar can degrade the recyclate fraction and form gel streaks in the bubble. Batch-to-batch variation in recyclate melt index above 0.5 g/10 min can require die gap adjustment or output reduction to maintain film gauge.

When 50 µm Film Enters Vertical Form-Fill-Seal Lines for Pulses and Cereals

At 50 µm thickness, mono-layer HF2007 web is slit to 350 mm and converted on vertical form-fill-seal machines running 60–90 packages per minute. The coefficient of friction is controlled with slip additive masterbatch at 0.5–1.0 wt% added at the extruder throat. Target kinetic COF under ASTM D1894 is 0.15–0.30. Film is processed at 190°C–210°C melt temperature, with die gap 1.8 mm and blow-up ratio 2.0:1 to 2.4:1. Bubble cooling air at 15°C improves gauge uniformity to ±8% or better. Compliance for dry food contact requires FDA 21 CFR 177.1520(c) 3.2a and EU No 10/2011. The selected erucamide or oleamide slip masterbatch must satisfy the applicable specific migration limit in EU No 10/2011 Annex II. Terminal products include 1 kg pulse pillows and 500 g breakfast cereal pouches. Seal strength after filling is measured by ASTM F88 and hot tack by ASTM F1921. Dusty product fines on the seal area require positive air purge at the jaw; otherwise accumulated fines can create a continuous dust layer and lower seal strength. Gauge bands outside ±8% produce seal jaw pressure variation; if seal pressure drops below 0.3 MPa, bottom seal failures increase in high-speed drop filling.

Pallet Hooder Holding Force Decay at Sub-Ambient Temperatures

Stretch hood film in 90–120 µm gauge is produced from HF2007 with a 10–20 wt% addition of high-toughness mLLDPE or high-pressure LDPE to increase melt strength and elongation at break. The film is drawn over pallets at 55–70% pre-stretch on elastic recovery equipment. Elastic recovery is measured by ASTM D5459 and holding force by machine-specific instrumentation. At -10°C warehouse conditions, elastic recovery must remain above 90% at 70% stretch to prevent pallet load shift. If more than 30 wt% high-pressure LDPE is used, loss of recovery may exceed 15% after 24 h. Processing on a 65 mm extruder with L/D 30:1 uses melt temperature 200°C–215°C, die gap 2.2 mm, blow-up ratio 2.5:1–3.0:1, and double-bubble air ring configured for high frost line 10 die diameters. The terminal product is a tubular hood film sealed at the top with axial seals, used for pallets of cement, paper rolls, beverage cans and white goods. Compliance is limited to REACH 1907/2006 Article 33 and RoHS 2011/65/EU for non-consumer goods. No food-contact declaration is made unless the specific structure is qualified. At warehouse temperatures above 35°C, holding force decay accelerates; film rolls stored in direct sunlight may show width shrinkage above 2%.

Evaluating Sealant Web Bond Strength in Extrusion Lamination

Following corona treatment to 42–46 mN/m measured under ASTM D2578, blown HF2007 film at 30–60 µm is used as a sealant web in duplex or triplex laminates for liquid and dry food sachets. The web is combined to aluminum foil or PET through a 15 g/m² LDPE extrusion tie layer at 320°C. Lamination bond strength is measured by ASTM F904. The sealant layer must maintain heat seal strength above 15 N/25 mm after 0.5 s dwell at 140°C. If sealant web is stored above 40°C or exposed to sunlight, corona treatment decay reduces bond strength. Processing of the sealant web itself uses die gap 1.8 mm, blow-up ratio 2.0:1, melt temperature 190°C–210°C, and inline slitting to 650 mm rolls. Compliance is governed by FDA 21 CFR 177.1520(c) 3.2a and EU No 10/2011. For fatty food simulant D2, overall migration must remain below 10 mg/dm². Finished terminal products include stand-up pouches for sauces and stick packs for drink powders. High extrusion lamination temperatures can retract the sealant web at the nip if line speed drops below 50 m/min; thermal shrinkage is measured by ASTM D2732.