SABIC LLDPE 222NJ is transferred from bulk silo storage into loss-in-weight feeders on a co-rotating twin-screw compounding line where it functions as the carrier resin for pigment concentrates and additive masterbatches. The nominal melt flow rate of 22 g/10 min at 190 °C/2.16 kg under ISO 1133-1:2022 and density of 0.922 g/cm³ under ISO 1183-1:2019 lower melt-phase viscosity enough to wet particulate surfaces without high wax or metal stearate additions. In carbon black masterbatches, carrier fraction is typically 45–60 wt%; in titanium dioxide white concentrates the carrier fraction falls between 40 wt% and 55 wt%; organic pigment concentrates generally require 60–75 wt% carrier because of higher specific surface area and dispersion energy demand. The downstream production process uses a 36:1 to 44:1 L/D co-rotating twin-screw extruder with downstream side stuffing, atmospheric venting at zone 7, and vacuum venting at −80 kPa to −90 kPa. Melt temperature is held between 190 °C and 210 °C to prevent pigment thermal degradation while retaining pellet stability. Strand pelletizing is run with water bath temperature at 25–40 °C; higher water temperature reduces pellet surface porosity in high-filler grades. Finished product types include color masterbatch granules let down at 1–4 wt% in blown film, 2–6 wt% in injection molding, and 0.5–2 wt% additive concentrates in extrusion coating. An operational boundary appears when filler loading exceeds 72 wt%: the low melt-phase torque from a 22 g/10 min MFR carrier can destabilize gravimetric side-feeder control, and feed surge above ±3% of set point is observable on production-scale lines. Regulatory compliance for masterbatch use follows REACH Regulation (EC) No 1907/2006, Article 33 for SVHC communication, RoHS Directive 2011/65/EU Annex II for electrical and electronic packaging, and EU Packaging and Packaging Waste Directive 94/62/EC with EN 13428:2004 for heavy metal limits. Food-contact masterbatch is not automatically compliant at the concentrate stage; final-article migration must be tested under EU (EU) No 10/2011 Annex I Table 2 and FDA 21 CFR 177.1520 because compliance is article-specific.

What Process Limits Appear When Molding a 22 g/10 min Butene LLDPE at Sub-1 mm Wall Sections?

Thin-wall food packaging molded from SABIC LLDPE 222NJ requires narrow control of shot speed, hold pressure, and cooling time because the melt transitions from fluid to freeze-off rapidly in wall sections below 0.8 mm. The material is processed either as 100 wt% for lids and flexible bowls, or in a 70–80 wt% blend with an HDPE component having MFR between 8 g/10 min and 20 g/10 min to increase stacking stiffness. The injection machine is typically an all-electric press with clamp force of 80–150 t, a barrier screw diameter of 25–35 mm, and a hot-runner valve-gate system with gate land diameter not below 0.6 mm. Nozzle melt temperature is kept at 200–225 °C; mold surface temperature is held at 15–30 °C to accelerate solidification. Injection velocity is set at 120–180 mm/s, holding pressure at 25–45 MPa for 0.5–1.5 s, and cooling time at 3–6 s. Melt temperature above 230 °C creates flash at split lines and gate blush because the narrow-MWD grade loses melt integrity; below 190 °C, short shots occur in walls thinner than 0.8 mm because the flow front freezes before cavity packing. End-use articles include dairy cup lids, non-stacking thin-wall bowls, takeout containers, and overcaps for portion packs. Compliance for food contact depends on migration testing on the finished article under EU (EU) No 10/2011 Annex I Table 2 with overall migration limit of 10 mg/dm², and FDA 21 CFR 177.1520 for olefin polymers. The upper service temperature is constrained by Vicat softening under ISO 306/A50; continuous hot-fill above 60 °C is not recommended unless the article is requalified with a higher-heat polyolefin blend. Production-shop observation on 32-cavity lid tools indicates that hold-time variation of ±0.2 s can change part mass by more than 1.5% because of low melt viscosity.

Post-consumer LLDPE/LDPE film re-granulate with melt flow rate of 0.5–1.0 g/10 min can be shifted into injection molding or thick-section extrusion by blending 15–30 wt% SABIC LLDPE 222NJ. This addition ratio raises combined MFR to 2–5 g/10 min, which is generally required for spiral-flow distances above 300 mm in non-food recycled parts. The production route starts with dry film flake after NIR sorting with polypropylene rejection at ≤2 wt%, conveyed to a recycling extruder with 36:1 L/D, melt filtration through dual slide-plate screens of 120–180 μm mesh, and two-stage vacuum degassing at −85 kPa to −95 kPa. Melt temperature is limited to 190–210 °C to avoid gel formation and odor reformation. The 222NJ component is dosed through a side gravimetric feeder after the screen changer, downstream of the primary melt seal, to preserve molecular weight and avoid unnecessary thermal history. Finished product types include non-food waste bins, stackable transport trays, collation trays, garden pots, and industrial spill pallets. Compliance is governed by EN 15344:2021 for recycled plastics traceability and REACH Regulation (EC) No 1907/2006 for substances of very high concern. If food-contact use is projected, only a recycling process authorized under EU (EU) 2022/1616 can justify use; blending 222NJ into non-authorized recyclate does not create food-contact approval. An operational boundary arises when regrind surface moisture is present from storage at relative humidity above 60%; pre-drying at 70–80 °C for 1–2 h is required to prevent splay marks and melt-pressure fluctuation.

When 222NJ Displaces High-Pressure LDPE in Closure Liner Compounds

Closure liner and gasket compounds using EVA/LDPE systems can incorporate SABIC LLDPE 222NJ at 10–35 wt% to reduce melt viscosity and improve low-temperature seal conformability. The formulation typically includes an EVA with vinyl acetate content of 9–18 wt%, a high-pressure LDPE, and optionally a butyl elastomer where residual tack is needed. Compounding runs on a co-rotating twin-screw extruder at screw speed 300–500 min⁻¹, melt temperature 160–200 °C, with liquid additives injected at 5–8 wt% through a side port. Strand pelletizing is followed by injection or compression molding into pre-formed cap shells; in in-mold liner processes, nozzle melt temperature is 190–210 °C, mold temperature 15–25 °C, and liner shot weight is 0.2–0.8 g. Finished closure types include lined caps for carbonated soft drinks, still water, dairy, aseptic juices, cosmetic jars, and pharmaceutical closures where foil seal is not required. Compliance for food and pharmaceutical contact is article-specific: FDA 21 CFR 177.1520 for polyethylene, FDA 21 CFR 177.1350 for EVA copolymers, EU (EU) No 10/2011 Annex I Table 2, and USP ⟨661.1⟩ for pharmaceutical plastic packaging when the closure is intended for drug product. Sensory carryover in dairy and beverage applications must be tested according to ISO 13302:2003. Use of 222NJ above 35 wt% can reduce elongation under the cap and lower recovery after sterilization; retort and steam sterilizing regimes above 80 °C require requalification because the linear resin may not maintain seal compression set under sustained thermal load.

Injection-molded overcaps and snap-on lids for personal-care and household-chemical packaging use SABIC LLDPE 222NJ at 100 wt% where the cap must flex over a retention bead without stress whitening, or in a 50–60 wt% blend with an HDPE of MFR 12–30 g/10 min to raise top-load stiffness. The production process is high-cavitation stack tooling with 24–96 cavities, unscrewing cores or collapsing cores, and cycle time of 5–9 s. Barrel zones are set from feed to nozzle at 180–220 °C; injection velocity is 80–150 mm/s depending on thread detail; hold pressure is 30–50 MPa for 0.4–1.0 s; mold cooling water is held at 10–18 °C. Finished products include flip-top overcaps for spice bottles, snap-on lids for cosmetic jars, pump bases, and flexible outer shells over rigid PP cores in child-resistant packaging. Regulatory compliance follows FDA 21 CFR 177.1520 and EU (EU) No 10/2011 for food or cosmetic contact, and REACH Annex XVII restrictions when the packaging enters the EU market. Torque failure in unscrewing tools is a known production limit; because 222NJ has lower modulus than HDPE, caps below 0.8 mm thread height may strip at application torques above 1.5 N·m, requiring thread redesign or an increase in HDPE fraction.

Carbonate-Filled PE Sheet: Viscosity Control and Edge-Tear Resistance Limits

Calcium carbonate–filled polyethylene sheet compounds used as thermoforming feedstock incorporate SABIC LLDPE 222NJ at 5–15 wt% of total compound to correct the low MFR of virgin or recycled HDPE filled at 30–60 wt% CaCO₃. The compounding step runs on a co-rotating twin-screw extruder with 40:1 L/D, side feeding of coated calcium carbonate at barrel 5 or 6, and melt temperature 190–205 °C. The sheet line uses a single-screw extruder with 30:1 L/D, a gear pump, and a polished three-roll stack with roll temperatures of 55–70 °C. Sheet thickness is typically 0.8–2.0 mm; thermoforming is performed at 120–150 °C surface temperature. Finished products include thermoformed food trays, egg trays, plant propagation trays, and industrial separator sheets. Compliance for food trays requires EU (EU) No 10/2011 Annex I Table 2 overall migration 10 mg/dm² and FDA 21 CFR 177.1520; industrial sheets require RoHS Directive 2011/65/EU compliance when used within electrical and electronic equipment packaging or fixtures. A technical limitation occurs at CaCO₃ loadings above 60 wt%, where edge-tear sensitivity rises in trim tooling. Increasing 222NJ beyond 15 wt% can reduce Vicat softening temperature enough to distort stacked trays at 60 °C warehouse conditions. Published comparative data for this exact grade at calcium carbonate loadings greater than 60 wt% is limited, so thermoforming trials on production tooling are required before final formulation lock-in.