In cast pallet stretch line production using a 90 mm single-screw extruder with an L/D ratio of 30:1 and a variable barrier screw, Clearflex VLDPE FG B0 (nominal density 0.900 g/cm³, melt flow rate 0.8 g/10 min at 190 °C under 2.16 kg) is let down into the cling-layer resin at 20–40 wt% with a C6-LLDPE carrier resin; the core layer may remain 100% C6-LLDPE or include a recycled trim stream. The cling layer is processed at a melt temperature of 190–210 °C, through a coathanger die with a lip gap of 0.6–0.8 mm, onto a chill roll held at 18–24 °C; the air knife is positioned 15–20 mm downstream of the die exit to stabilise edge neck-in and reduce draw resonance. Cling performance is assessed by ASTM D5458, tensile elongation by ASTM D882, and dart drop impact by ASTM D1709 method A. Industrial pallet wrap manufactured from this formulation is typically drawn to 12–23 µm for machine application and 15–20 µm for hand stretch; stretch ratios up to 300% are achievable, but load retention declines if the chill roll temperature exceeds 24 °C because the VLDPE-rich surface remains too amorphous. At addition levels above 40 wt%, roll blocking can occur in warehouse storage above 35 °C, so core-layer LLDPE is externally blended at the hopper to maintain handling stability. For secondary food overwrap, the resin must meet FDA 21 CFR 177.1520 and EU 10/2011 with overall migration tested according to EN 1186-1; for non-food industrial stretch film, REACH 1907/2006 applies. Terminal finished goods include pre-stretched pallet film, hand stretch film, and bundling film for appliance distribution.

Why Does Seal Initiation Temperature Control High-Speed Vertical Form-Fill-Seal Output?

Coextruded VFFS sealant webs position Clearflex VLDPE FG B0 as the sealant skin at 50–100 wt% of the skin layer, with the skin layer occupying 10–20% of total film thickness in a three-layer structure composed of LLDPE core and LDPE outer skin. The resin’s nominal density of 0.900 g/cm³ and DSC melting point near 95 °C shift seal initiation temperature into the 85–95 °C band, which is verified by hot-tack testing under ASTM F1921 at a 0.5 s dwell and 0.3 N/mm² seal pressure, and by seal strength testing under ASTM F88/F88M. Downstream conversion uses high-speed vertical form-fill-seal equipment with seal jaw temperatures set 95–115 °C; the lower seal initiation temperature reduces residence time per seal cycle by approximately 15–20% compared with Ziegler-Natta LLDPE sealants, though exact line-speed gain is machine-specific. The sealant film is produced on blown film coextrusion lines with a die gap of 1.8–2.2 mm, a blow-up ratio of 2.0–2.5, and a melt temperature of 185–200 °C; frost line height is held 300–450 mm above the die to stabilise bubble diameter because the low melt strength of VLDPE increases bubble instability at high stalk heights. Terminal finished goods include frozen food pillow pouches, snack food barrier laminates, flow-wrap lidding films, and stand-up pouch sealant webs. Sustained seal temperatures above 120 °C or retort conditions above 121 °C are outside the product window; converters should specify a higher-density plastomer for those structures.

When frozen vegetable packaging converters require dart impact retention after 24 h conditioning at −25 °C, Clearflex VLDPE FG B0 is incorporated into the core and inner layers of a three-layer blown film at 15–30 wt% with a C4-LLDPE or C6-LLDPE continuous phase; the outer skin is usually a low-density LDPE for printability and thermal sealing. The film is produced on a 75 mm extruder with an L/D ratio of 30:1, a 200–250 mm annular die, and a blow-up ratio of 2.5–3.0, with melt temperatures limited to 180–200 °C because VLDPE-rich formulations oxidise rapidly if melt temperature exceeds 210 °C during extended run times. Impact toughness is tested according to ASTM D1709 method A after conditioning at −25 °C; flex crack resistance is monitored by Gelbo flex testing according to ASTM F392 at 20 cycles/min for 1,000 cycles. For printing, the outer skin is corona-treated to 38–42 mN/m and the film is wound with a maximum reel diameter of 600 mm to limit blocking on the wound roll. The structure meets FDA 21 CFR 177.1520 and EU 10/2011 for frozen food contact, with overall migration below 10 mg/dm² in EN 1186-1 testing. Terminal finished goods include pillow pouches for frozen vegetables, IQF poultry bags, ice cream overwraps, and shrimp block bags; storage temperatures down to −30 °C are specified for mechanical integrity.

Agricultural Silage Wrap Cling Retention and UV Stabilization Thresholds

On cast agricultural silage lines with a 1,500–2,000 mm die width and a 70–90 mm single-screw extruder running at an L/D ratio of 30:1, Clearflex VLDPE FG B0 is let down at 25–35 wt% into the outer cling layer of a three-layer cast film with LLDPE core and a UV-stabilized skin; the UV masterbatch is dosed separately at 2–4 wt% and should contain HALS plus TiO₂ rather than nickel quenchers if the film is later repurposed. Overall film thickness is maintained at 25–30 µm for round bale wrapping, and the cast process uses a melt temperature of 190–210 °C, a die lip gap of 0.5–0.8 mm, and a chill roll setpoint of 16–22 °C to preserve surface tack without excessive blocking. Cling force is measured by ASTM D5458 after 24 h aging at 23 °C; puncture resistance is measured by ASTM D5748; tensile properties are reported according to ISO 527-3. The silage film is supplied in widths of 500 mm and 750 mm, wound on 76 mm cores, for application machines that wrap round bales with 6–8 overlapping layers. Compliance for agricultural use is governed by EN 13207:2001 and national silage film regulations; this application is not intended for direct food contact, and the chosen UV masterbatch must be verified under REACH 1907/2006. Terminal finished goods include round bale stretch wrap, square bale wrap, bale net replacement film, and silage pit cover film.

When Surface Protection Films Require Low Modulus Without Silicone-Coated Release Liners

Surface protection films require a balance of conformability on brushed metal surfaces and clean peel without adhesive residues. Clearflex VLDPE FG B0 is introduced at 10–25 wt% into the cast coextruded skin layer with LLDPE and LDPE as the core; the VLDPE-rich skin provides adhesion by van der Waals interaction rather than by pressure-sensitive adhesive coating, eliminating the need for a silicone release liner. Processing is carried out on cast film lines with a die lip gap of 0.5–0.7 mm, chill roll setpoint of 15–20 °C, and melt temperature of 190–210 °C; draw ratio is kept below 10:1 to avoid orientation-induced stiffness in the skin layer. Peel adhesion is measured by ASTM D3330 using a 300 mm/min peel speed on stainless steel and anodized aluminium panels; tensile behavior is checked by ISO 527-3. The film is laser-cut and wound in widths from 250 mm to 1,250 mm for application by laminating or roll-to-roll machines. Because the adhesion mechanism is substrate-sensitive, published data for this specific configuration is limited; converters should validate peel force on customer-specific surface roughness, residual drawing lubricants, and ambient application temperature. Compliance is governed by REACH 1907/2006 and, where applicable, RoHS 2011/65/EU; the product is not intended for direct food-contact protection. Terminal finished goods include temporary protective film for stainless steel sheet, anodized aluminium profiles, polycarbonate sheet, and PVC window profile surfaces.

Heavy-Duty Industrial Liner Blown Film Formulations and Draw-Down Limits

For heavy-duty industrial liners and FIBC inner liners, Clearflex VLDPE FG B0 is dry-blended at 10–20 wt% with C6-LLDPE and a slip/antiblock masterbatch at 0.5–1.0 wt% to improve environmental stress crack resistance and flex crack resistance during filling and transport of fine powders, resins, and non-hazardous granules. The blown film line uses a 90 mm extruder with a high-output LLDPE barrier screw and an L/D ratio of 30:1, die gap of 2.4–3.0 mm, blow-up ratio of 2.0–2.5, and melt temperature of 180–200 °C; bubble stability is maintained by a dual-lip air ring with chilled air at 10–15 °C because the VLDPE component reduces overall melt tension. Environmental stress crack resistance is evaluated by ASTM D1693 condition B at 50 °C, and flex crack resistance is tested by ASTM F392 method A; tensile modulus is reported by ISO 527-3. For non-hazardous chemical liner applications, chemical compatibility is screened by ASTM D543 at 7 days immersion in the target fluid; UN certification for combined packaging is determined by the outer package class, such as UN 13H4 for FIBCs, not by the liner alone. Compliance for industrial use is under REACH 1907/2006; direct food-contact liners require separate FDA 21 CFR 177.1520 and EU 10/2011 migration testing. Terminal finished goods include drum liners, FIBC inner liners, bulk sack liners, and secondary containment films for logistics hubs.