Exact 3024 is a very low density ethylene-α-olefin copolymer with a nominal density of 0.905 g/cm³ by ASTM D1505-20 and a melt index of 4.5 g/10 min by ASTM D1238-23 procedure A at 190 °C and 2.16 kg. In multilayer cast-film production for dry and frozen food packaging, Exact 3024 is introduced as the sealant-layer resin in 3-layer, 5-layer, and 7-layer coextruded structures. A typical sealant layer comprises 20–40 wt% Exact 3024 blended with a linear low-density polyethylene having a density of 0.918 g/cm³ and a melt index of 1.0 g/10 min by ISO 1133-1:2022. The blend is processed on a cast-film line equipped with a 90 mm barrier screw extruder, automatic screen changer with 250 µm mesh filtration, and a coat-hanger die with a die gap of 0.4–0.75 mm. Melt temperature is held between 200 °C and 240 °C, while chill-roll temperature is maintained at 15–25 °C to reduce post-crystallisation haze. The sealant layer thickness is normally 8–18 µm in a total film gauge of 40–70 µm. Seal performance is evaluated by ASTM F1921/F1921M-23 for hot tack and ASTM F88/F88M-23 for heat-seal strength after conditioning at 23 °C and 50% RH. Compared with an LLDPE-only sealant, a 30 wt% Exact 3024 blend commonly reduces seal initiation temperature by 8–15 °C at a seal pressure of 0.5 N/mm² and a dwell time of 0.5 s, although production line data for this specific film configuration is limited. Terminal packages include frozen vegetable pouches, shredded cheese packs, dry soup mixes, and powdered beverage sachets.

Food-contact use of the sealant layer is grounded in FDA 21 CFR 177.1520 for olefin polymers and, for the EU market, Commission Regulation (EU) 10/2011 Annex I. Specific migration is assessed according to EN 1186-1:2002 and EN 13130-1:2004 with food simulants selected for the intended contact. Fatty foods use simulant D2 or 95% ethanol; aqueous foods use simulant A or 10% ethanol. Exact 3024 does not require pre-drying under standard warehousing conditions. However, exposure to relative humidity above 60% can increase surface moisture sufficiently to generate micro-voids during extrusion and should be managed with a dehumidifying hopper or controlled storage. The resin is not recommended as a barrier layer because its oxygen transmission rate is significantly higher than EVOH or PA; its function is limited to sealing, flex-crack resistance, and package integrity.

What Changes When Exact 3024 Replaces a Heterophasic Copolymer in Impact-Modified Polypropylene?

In injection-moulded polypropylene compounds, Exact 3024 is introduced as an impact modifier at 10–25 wt% via a co-rotating twin-screw extruder with an L/D of 40:1. The compounding line uses a screw profile with two kneading blocks downstream of the feed throat and a vacuum vent at -0.08 MPa to remove low-molecular-weight volatiles. Barrel temperatures are optimised from 180 °C at the feed zone to 230 °C at the die; screw speed is set between 300 rpm and 500 rpm. Polypropylene feedstock is typically a homopolymer with an MFR of 12 g/10 min by ISO 1133-1:2022 or a heterophasic copolymer with an MFR of 8 g/10 min. Exact 3024 is fed either by gravimetric metering into the main feed throat or by side feeding after polypropylene plastication. Side feeding at 120–140 °C reduces excessive droplet coalescence and preserves the elastomeric particle size required for low-temperature impact resistance. Morphology is monitored by scanning electron microscopy on cryo-fractured surfaces; effective modifier dispersion typically yields elastomer domain sizes below 1.0 µm. Notched Izod impact is measured by ASTM D256-23 at 23 °C and -20 °C; flexural modulus is measured by ISO 178:2019; heat deflection temperature is measured under 0.45 MPa load by ISO 75-2:2013. The ductile-brittle transition shifts from 10 wt% to 20 wt% addition in applications requiring sub-zero impact without excessive modulus loss.

A limitation appears at addition levels above 25 wt%. The flexural modulus of a 20 wt% modified compound may decline by 25–40% relative to the neat polypropylene depending on the polypropylene crystallinity and processing conditions. Compounds intended for rigid automotive interior parts therefore require balancing against ISO 178:2019 modulus targets. Injection moulding of these compounds is performed on hydraulic or electric machines with a clamping force selected from 3,500 kN to 16,000 kN depending on part size. Melt temperature is maintained at 220–240 °C and mould temperature at 30–60 °C. Shrinkage anisotropy measured on a 60 mm × 60 mm × 2 mm plaque is typically 1.0–1.4% in flow direction and 0.8–1.1% transverse, but published data for Exact 3024 in this specific formulation is limited. Processing incompatibility exists with peroxide masterbatches above 0.05 phr, where undesired viscosity shifts may occur. Typical end-articles are door panel lower retainers, appliance housing brackets, and electrical enclosure covers.

Extrusion coating and lamination with Exact 3024 is used where a low-density metallocene-grade sealant or adhesive tie layer is required on paperboard, aluminium foil, or oriented polypropylene. Typical coat weights are 10–20 g/m² for liquid packaging board and 6–12 g/m² for sachet foil. A single-screw extruder with a 120 mm diameter screw, 30:1 L/D, and Maddock mixing section discharges through a flat die at 290–310 °C; the polymer melt is drawn down into a nip at 250–400 m/min. Poor drawdown or edge neck-in is controlled by maintaining melt index of the coating layer within 3.0–5.0 g/10 min by ASTM D1238-23 procedure A. Exact 3024 may be blended with LDPE at 30–70 wt% to adjust neck-in and promote adhesion. Adhesion to aluminium foil is tested by ASTM F904-16 on laminated pouches; hot foil seal strength is measured after sealing at 150–180 °C for 0.3–0.7 s. Board adhesion is tested by ASTM D3359 tape-peel on coated samples. Because the resin has a lower melting point than conventional LDPE, melt temperature is set 10–20 °C lower to prevent film splitting at high draw speeds. Terminal uses include liquid carton board, coffee stick pack laminates, and pharmaceutical sachet substrates.

Low-density olefin foam expansion using butane and isobutane physical blowing agents

Exact 3024 is foamable in tandem extrusion lines when blended with LDPE at 30–70 wt%. The first extruder, typically 150 mm diameter with 30:1 L/D, plasticates the blend at 180–200 °C before physical blowing agent injection. Isobutane is injected at 6–12 wt% of polymer feed using a high-pressure metering pump; the gas-laden melt enters a second cooling extruder, typically 120 mm diameter with 36:1 L/D, where melt temperature is reduced to 105–115 °C. The die gap is 0.4–0.8 mm. Expansion at the die lip produces foam densities in the range 30–60 kg/m³. Exact 3024 contributes narrow cell-size distribution and high foam resilience, measured by compressive creep at 23 °C and 50% RH following ASTM D3575-20. Density is verified by ISO 845-2006. Foam with less than 5 wt% Exact 3024 may show irregular cell collapse in thin sheet below 2 mm gauge. At addition above 70 wt%, available melt strength may become insufficient for stable bubble growth, depending on screw cooling configuration and die pressure. Published data for this specific grade in plank foam is limited; sheet foam data is available from extrusion line trials but is not systematically standardised. Terminal products include cushion packaging, wine bottle protective sleeves, and foam pouches for automotive painted trim.

Adhesive compounding with Exact 3024 provides a low-density base polymer for packaging hot-melt formulations. In a sigma-blade mixer, Exact 3024 is charged at 10–35 wt% with a C5 hydrocarbon tackifier at 30–45 wt%, paraffin or microcrystalline wax at 10–25 wt%, and a hindered phenolic antioxidant at 0.3–0.5 wt%. Mixing is carried out at 130–160 °C under a nitrogen blanket to suppress thermo-oxidative degradation. Melt viscosity is measured with concentric-cylinder rheometry at 177 °C by ASTM D3236-15; viscosity values for formulations with Exact 3024 typically fall between 800 mPa·s and 2,500 mPa·s at 20–30 wt% polymer load, depending on wax type and tackifier softening point. For carton closing, the adhesive is applied by slot die or spray application at 150–170 °C; open time is 2–5 s. Fibre tear on corrugated board is measured at -10 °C, 0 °C, and 23 °C using TAPPI T 812 or an equivalent internal method. Indirect food-contact compliance for packaging adhesives is grounded in FDA 21 CFR 175.105 and 177.1520; for the EU it is covered by Regulation (EU) 10/2011 when the adhesive is part of a final article. The practical limitation is that Exact 3024 has a lower ring-and-ball softening point than EVA with 28% vinyl acetate, so formulations intended for high-clarity packaging tape require tackifier selection with a softening point above 90 °C to maintain shear adhesion failure temperature. Terminal applications include corrugated box closing, paperboard carton assembly, and lamination of polypropylene film to paper stock.

When seal initiation temperature is driven below 90°C in high-speed form-fill-seal lines

Blown-film coextrusion for form-fill-seal sealing layers uses Exact 3024 to lower seal initiation temperature without sacrificing hot-tack strength. The film is produced on a 7-layer blown line with die diameter 350 mm, die gap 1.4 mm, BUR 2.5:1, and frost line height 900 mm. The sealant layer is composed of 80 wt% Exact 3024 and 20 wt% of an LLDPE with density 0.918 g/cm³; skin layers use LLDPE with density 0.926 g/cm³. Melt temperature at the die is 190–210 °C, because temperatures above 230 °C produce die-lip drool and reduce bubble stability. At 0.5 s dwell and 0.5 N/mm² sealing pressure, the seal initiation temperature by ASTM F1921/F1921M-23 is commonly 5–10 °C lower than an LLDPE-only control; published data for this specific grade configuration is limited. Hot-tack strength measured at 80–95 °C determines the speed ceiling of the packaging line. The practical processing window is constrained at the lower end by seal bar contamination from low-molecular-weight fractions if seal temperature exceeds 120 °C for more than 10 s during line stops. Terminal packages are frozen ready meals, fresh-cut produce, and ice cream multipacks.

Non-implantable flexible medical packaging and tubing uses Exact 3024 as a blend component when EVA-like softness and polyolefin cleanliness are required. A typical tubing formulation contains 70 wt% Exact 3024 and 30 wt% LLDPE or polypropylene-based elastomer. Extrusion is performed on a single-screw tube line with 45 mm screw, 24:1 L/D, and a crosshead die with a 3.2 mm mandrel and 0.5 mm wall gap. Zone temperatures from hopper to die are 150–190 °C; melt temperature at the die is 180–200 °C. Cooling is via a closed-loop water trough at 20–25 °C. The tube is cut in-line and tested for shore hardness by ISO 868:2003, tensile stress at break by ISO 527-2:2012, and dimensional stability after 24 h at 40 °C. For medical packaging film, Exact 3024 is coextruded as an inner sealing layer on a 3-layer cast film line at 20–30 wt% with LLDPE. Biocompatibility is not an intrinsic resin property; every finished medical article must be evaluated under ISO 10993-5:2009 for cytotoxicity and ISO 10993-10:2010 for skin sensitisation. The resin is not suitable for implantable or blood-contact devices unless a full biological risk assessment demonstrates compliance with the applicable device standard. Terminal products include diagnostic kit overpouches, disposable pipette bulb tubing, and non-sterile barrier wraps.