Sinopec Qilu DGDA6098 is processed on monolayer high-stalk blown-film lines dedicated to thin-gauge T-shirt carrier sacks. The resin is charged to a grooved-feed extruder with a barrier screw of 24:1 to 30:1 L/D and a die gap of 0.8 mm to 1.2 mm. The bubble is set at a blow-up ratio of 4.0:1 to 5.0:1 and the stalk height is held at 6 to 8 die diameters. Melt temperature measured at the die lip is controlled from 200 °C to 230 °C; sustained excursions above 240 °C produce oxidation gels and die-lip deposits in the tack-down seal area of the film. Film thickness is drawn to 8 µm to 15 µm. Tensile properties are recorded to ASTM D882, dart impact to ASTM D1709 Method A, and Elmendorf tear to ASTM D1922. The converter seals T-shirt sacks at 130 °C to 155 °C with a dwell time of 0.2 s to 0.4 s. The end products are retail carrier sacks, produce bags, and laundry bags. The dominant processing failure is MD/TD orientation imbalance: high-stalk operation raises MD tensile strength but depresses MD tear in thin film, so seal bars are set along the TD axis where elongation is more uniform. For food-contact retail use, FDA 21 CFR 177.1520(c) and EU Regulation 10/2011 migration testing must be verified for the finished structure. Incoming pellet surface moisture is kept below 0.05 wt%; when condensation appears on cold pellets, hopper-air purging at 70 °C for 1 h to 2 h is applied before extrusion.

What Changes When DGDA6098 Is Coextruded With LLDPE in Refuse Sack Film?

When 20 wt% to 40 wt% LLDPE is coextruded as skin layers over a DGDA6098 core, the structure is run on a three-layer blown-film line with separate core and skin extruders. The LLDPE skins are processed at 185 °C to 210 °C, while the HDPE core is maintained at 200 °C to 225 °C. If the melt temperature differential between the core and skin streams exceeds 25 °C, interfacial instability appears at the die as wavy gauge bands near the frost line. The core is metered at 60 wt% to 80 wt% and the skins at 20 wt% to 40 wt%. The resulting refuse sack film is produced at 20 µm to 40 µm. Dart impact is tested to ASTM D1709 Method A, slow puncture to ASTM D5748, and seal strength to ASTM F88. The HDPE core supplies yield stress and stiffness; the LLDPE skins contribute TD tear and heat-seal strength. The terminal products are drawstring refuse sacks, star-seal kitchen bags, and higher-gauge garbage sacks. The known limitation is that HDPE-rich structures can exhibit lower dart impact at frost-line heights above 8 die diameters, so the air ring and chilled-air flow are adjusted to maintain the frost line within the high-stalk window. Compliance for heavy-metal content is screened against EU Directive 94/62/EC packaging standards for the final converted sack.

Calcium carbonate masterbatch is let down into DGDA6098 at 5 wt% to 25 wt% on monolayer film lines fitted with a static mixer or cavity transfer mixer in the metering section. The filler suppresses film necking, increases opacity, and improves dead-fold in opaque retail packaging. During the trial, the density of the filled film is measured to ASTM D1505 and is expected to rise from the unfilled resin value of 0.949 g/cm³ to the range of 1.05 g/cm³ to 1.20 g/cm³ at 25 wt% CaCO₃, depending on masterbatch carrier resin and particle size. Haze and opacity are evaluated under ASTM D1003 and ISO 14782. Filler addition also raises melt pressure and torque on the extruder main drive; the screen pack is typically upgraded to a 60/100/60 mesh configuration to trap undispersed filler agglomerates. At loadings above 30 wt%, dart impact measured to ASTM D1709 and MD tear measured to ASTM D1922 commonly decline below retail bag acceptance limits in thin-gauge film. End products are opaque retail packaging, mailers, laundry bags, and industrial covers where paper-like stiffness and low light transmission are required. Food-contact status again requires verification under 21 CFR 177.1520(c) and EU Regulation 10/2011; the masterbatch additives must be specified in the migration test because CaCO₃ itself does not automatically confer compliance.

If Production Scrap Is Reintroduced Above 20% in Non-Food Liner Film

Post-industrial edge trim and start-up film are recycled back into non-food liner film on lines with a screen changer and a gear pump. The reinjection ratio of regrind to virgin DGDA6098 is held at 10 wt% to 20 wt% for standard runs. If the ratio exceeds 20 wt%, the melt flow rate is monitored to ISO 1133-1:2022 condition 190 °C/2.16 kg because repeated heat history increases the MFR and narrows the bubble stability window. The regrind must be ground to a uniform particle size below 8 mm to avoid uneven feeding; dust and fines are removed with a cyclone. A continuous screen changer with 100 µm or 150 µm screen packs is required to remove gel contamination. The resulting film is specified at 30 µm to 60 µm for non-critical trash can liners and industrial waste bags. Quality tests are limited to visual gel rating, gauge profile, and puncture resistance to ASTM D5748. Because the reincorporation of regrind can increase gel formation, converters must not use this stream for food-contact or high-speed T-shirt sack applications without additional melt filtration and migration testing.

Heavy-duty industrial liners and can liners are converted from DGDA6098 film in the gauge range 50 µm to 100 µm. The process uses a lower blow-up ratio of 3.0:1 to 3.5:1 to reduce the TD orientation and increase the film's carrying strength along the machine direction. Die gap is widened to 1.2 mm to 1.5 mm to maintain melt homogeneity at higher gauge. Secant modulus at 1% strain is measured to ASTM D882; this value is used as the release criterion for down-gauge projects. Puncture propagation tear is tested to ASTM D2582 on a high-speed puncture apparatus fitted with a 50 mm/min crosshead. The film is slit and sealed into heavy-duty liners, construction debris bags, and agricultural bulk packaging. The key processing constraint is the frost line: as gauge exceeds 60 µm, the bubble must be cooled with a dual-lip air ring and internal bubble cooling to prevent blocking at the collapsing frame. Additive packages should not exceed 1,500 ppm of total slip and antiblock, because higher concentrations produce plate-out on the collapsing shields and reduce film adhesion. The converted liners are tested for seam strength to ASTM F88 and for loaded burst resistance under factory-specific vacuum-lift trials.

Lamination Webstock and Envelope Window Film Performance Limits

For lamination webstock and garment-bag construction, DGDA6098 film is treated by corona discharge to a wetting tension of at least 38 mN/m, measured to ASTM D2578. The corona treater is placed on-line between the collapsing frame and the winder; treatment intensity is adjusted according to line speed and film gauge. The film is then printed with flexographic or gravure presses, and the ink adhesion is checked with tape-pull tests referenced to ASTM F2252. The HDPE film is used as an outer web in envelope windows, garment bags, and publication mailers because of its moisture resistance and dead-fold. The lamination adhesive is selected from polyurethane or acrylic grades; an epoxy-cured polyurethane system is not recommended where amine migration could generate interlayer delamination at the heat-seal jaw. The finished laminate is tested for bond strength under ASTM F904 on a tensile tester with a 200 N load cell. End products include envelope windows, garment bags, and non-food printed mailers. The known limitation is that corona treatment decays with storage; the web must be printed or laminated within 7 days of treatment, or retreatment is required. Film thickness is held at 12 µm to 25 µm for window and garment applications.