Sinopec Fujian HDPE DGDA6094 is positioned in the high-molecular-weight blown-film envelope; published technical data sheets list a nominal density of 0.959–0.961 g/cm³ per ISO 1183 and a melt flow rate of 0.35–0.45 g/10 min when measured at 190 °C/2.16 kg under ISO 1133-1. These values exclude the grade from injection moulding and rotational moulding. In high-stalk blown-film conversion of Sinopec Fujian HDPE DGDA6094 into thin-gauge carrier sacks, the melt is conditioned in a grooved-feed single-screw extruder with an L/D 30:1 barrier screw and a screen pack of 120/80/120 mesh, then delivered to a spiral mandrel die with a 1.2–1.8 mm die gap. Melt temperature measured at the die lip is held between 196 °C and 205 °C to avoid both shark-skin melt fracture at low output and thermal oxidation at high residence time. The bubble is opened to a blow-up ratio of 4.0:1–4.5:1; at BUR values below 3.6:1 the film exhibits measurable dart drop anisotropy, while at BUR above 4.8:1 the stalk becomes sensitive to ambient air turbulence and the frost line height oscillates by more than ±100 mm at the collapsing frame. Internal bubble cooling is used with differential pressure limited to 20–30 Pa; higher IBC differentials cool the stalk too rapidly, reduce neck extension, and produce gauge bands between ±8% and ±15% of nominal gauge. For gauge targets of 7–10 µm, up to 10 wt% of a metallocene-catalysed C8-LLDPE with melt flow rate 0.9–1.1 g/10 min is dry-blended to raise dart impact; loadings above 15 wt% reduce bending stiffness below acceptable carrier-bag thresholds and increase blocking tendency on wound rolls. Film tensile properties are measured per ASTM D882, dart impact per ASTM D1709 Method A, and Elmendorf tear per ASTM D1922. Converter internal specifications for 10 µm high-stalk HDPE film commonly require MD elongation at break between 350% and 500%, TD elongation between 300% and 450%, and dart impact of at least 120 g per ASTM D1709 Method A, although published resin-specific data for this configuration is limited and should be verified on the target line. The finished T-shirt carrier sacks are side-sealed and punched on automated converting machines at web speeds of 200–300 m/min; sealing temperatures at the side weld are set 15–25 °C below the polymer melting peak to avoid tearing at the weld root.

The above parameters are line-specific settings recorded on a high-stalk mono-layer line with a 250 mm die and a grooved-feed extruder; they are not resin specification limits and must be shifted for individual tower height, ambient humidity, and die design.

What Prevents HDPE DGDA6094 from Entering Steam-Sterilisable Clinical Waste Sack Lines?

Clinical waste collection sacks made from the grade are extruded at 25–30 µm gauge with a die gap of 1.8–2.2 mm and BUR 3.5:1–4.0:1 to raise dart impact. The film is run on a conventional low-stalk bubble; frost line height is maintained at 250–400 mm to minimise MD tear propagation. Because the sacks must contain sharp waste, dart impact measured per ISO 7765-1 Method A is checked at 200 g minimum for 28 µm film; tensile strength at break per ISO 527-3 shall exceed 20 MPa in both directions. Leakage resistance is tested by filling the sack with 20 L of water and observing for 2 min per EN 13592. The polymer is not suited to steam autoclave cycles above 121 °C: the Vicat softening temperature of the grade is reported near 126 °C under ISO 306 Method A50, leaving a margin of less than 10 K and causing weld creep in bottom-sealed sacks during typical 134 °C prevacuum sterilisation. No antioxidant package change or film orientation alters this upper service ceiling. For outdoor staged clinical waste storage, converters add 2–3 wt% of a carbon black masterbatch carrying 40% carbon black in LDPE; this lowers melt strength and requires reducing die temperature by 5–10 °C to maintain bubble stability. Terminal bags are either tie-handle or star-sealed construction with side weld seals of 2.5–3.0 mm width and a seal bar temperature of 150–165 °C.

Where the resin is converted into frozen food liner film, the line practice is to use 100% virgin DGDA6094 in monolayer form to avoid adhesive migration. The film gauge is typically 20–30 µm; the bubble is run at BUR 3.0:1–3.5:1 with a die gap of 1.4–1.8 mm and melt temperature 195–205 °C. Compliance with food contact requires FDA 21 CFR 177.1520(c)3.1a and EU Regulation 10/2011 as amended. Overall migration is measured under 10 days at 40 °C in 10% ethanol and 3% acetic acid and should not exceed 10 mg/dm². The resin contains a minimal antioxidant package; processing at melt temperatures above 240 °C increases extractable hydrocarbons and odour in the finished liner, so barrel zone temperatures are capped at 215 °C. Water vapour transmission rate for 30 µm film measured per ASTM F1249 at 38 °C and 90% RH typically falls below 5 g/(m²·day); published data for this specific configuration is limited and must be confirmed on the converting line. Low-temperature brittleness is evaluated by ASTM D1790 at -20 °C, with no visible cracking on flexing. The terminal formats include frozen vegetable pouches, ice cream overwrap, and chilled bakery liners; these films are not retortable and should not be exposed to pasteurisation above 95 °C.

Heavy-Duty Liner Film: Melt Fracture, Gauge Control, and Weld Seam Integrity

Conversion of DGDA6094 into heavy-duty construction and demolition liners is carried out at thicknesses from 60 µm to 150 µm on blown-film lines equipped with 350–450 mm dies and L/D 30:1 grooved-feed extruders. The die gap is widened to 2.2–3.0 mm to minimise melt fracture at higher output; melt temperature at the die lip is controlled to 190–205 °C, because temperatures above 220 °C increase oxidation gel formation and temperatures below 180 °C raise the risk of shark-skin melt fracture on the outer bubble surface. BUR is normally 3.0:1–4.0:1, with a low-stalk bubble and frost line height between 150 mm and 300 mm. Impact resistance is measured by ASTM D1709 Method B for film above 75 µm, and tear resistance by ASTM D5884 for tongue tear, because single-sheet Elmendorf values at heavy gauge are less sensitive to field tearing mechanisms. Weld seams are produced by continuous heat-seal bars at 160–180 °C with dwell of 0.6–1.2 s; seams are checked by ASTM F88 seal strength on 25 mm specimens, with values commonly expected above 15 N/25 mm. When black or grey masterbatch is added at 2–4 wt% for outdoor debris containment, the frost line height drops by 50–80 mm due to carbon black nucleation; operators must reduce extruder output 5–10% to maintain gauge uniformity at the collapsing frame. Terminal use covers post-demolition waste sacks, asbestos abatement bags with welded seams, and industrial drum liners; for asbestos containment the film is tested per ISO 7765-1 and no specific permeation is claimed.

In all-polyethylene recyclable laminates for dry powder sachets and courier envelopes, Sinopec Fujian HDPE DGDA6094 is coextruded as the high-stiffness core layer at 40–50 wt% of total structure, with mLLDPE skins occupying 25–30 wt% each, to maintain monomaterial polyethylene content above 90 wt% for recycling stream compatibility under RecyClass assessment. The five-layer structure is blown at a die gap of 1.6 mm, BUR 2.8:1, and melt temperature 200–215 °C; the HDPE core is screened through 100/100 mesh packs to reduce die-lip gels. Film stiffness is determined by ASTM D790 on 25 mm strips, and the presence of the HDPE core raises secant modulus by 35–50% compared with an all-mLLDPE control at equal gauge. Seal initiation temperature is governed by the mLLDPE skins; the HDPE core does not seal below 120 °C, so converters must not attempt to reduce seal temperature below the skin initiation threshold. Terminal formats include stand-up pouches with zipper seam tapes and paper-substitute mailers, both welded on impulse sealing equipment with jaw hold times of 0.8–1.5 s and cooling dwell of 1.0–2.0 s.

If Up to Thirty Percent Post-Industrial Trim Is Reintroduced on the Same Blown Film Line

Recycled internal edge trim from DGDA6094 carrier or liner production is often reintroduced as grind at loadings of 15–30 wt% into the main extruder feed, provided the trim is kept dry and free from paper labels. The regrind fraction has lower bulk density of 0.35–0.45 g/cm³ and uneven particle size, so the grooved feed zone must be maintained at 70–80 °C to avoid unstable throughput. Screen pack differential pressure rises more rapidly; converters change screens when pressure differential exceeds 12–15 MPa to avoid melt temperature spikes. Bubble stability decreases at regrind loadings above 30 wt%, with visible gel counts increasing and dart impact decreasing by more than 20% on 25 µm film. The finished product is typically non-food heavy-duty refuse sacks or industrial liners, not thin-gauge high-stalk film, because particulate contamination risks bubble puncture. Output is typically reduced 5–10% relative to virgin operation to maintain gauge uniformity at the collapsing frame. No published data for this specific closed-loop configuration with DGDA6094 is available; converters should qualify each lot by gel count and dart impact per ASTM D1709.