On a high-stalk blown-film line equipped with a 90 mm grooved-feed extruder and a 300 mm spiral mandrel die, Chevron Phillips Chemical HDPE HMN TR-942 is processed into T-shirt grocery sacks at a final film gauge of 10–15 µm. The grade is supplied at a nominal density of 0.942 g/cm³ under ASTM D1505; specific lot values, including the 190 °C/21.6 kg high-load melt index under ASTM D1238, are governed by the supplier certificate of analysis. In this segment, the formulation typically contains 2–5 wt% of a 50% HDPE-based white masterbatch and 0–25 wt% of pre-sorted in-house HDPE trim regrind; exceeding 30 wt% regrind reduces dart impact and raises gel counts because the melt filtration screen pack is limited to 60–80 mesh by the high melt viscosity of the resin. The downstream process sets the stalk height at 6–10 die diameters and the blow-up ratio between 3.5:1 and 5.0:1; heat sealing in the bag converter is held at 150–175 °C. Compliance testing on finished film uses ASTM D1709A dart impact and ASTM D1922 Elmendorf tear, with the retail packaging waste directive applying to the finished bag. Terminal product types include die-cut handle grocery sacks, flat-bottom takeout bags, and wicket-mounted retail bags.

What Limits Regrind Loading in Blown Can Liner Film When HMN TR-942 Supplies the Virgin Backbone?

Post-consumer HDPE regrind is added at 20–40 wt% to HMN TR-942 in 55-gallon can liner production; above 40 wt%, the dart impact and tear propagation resistance degrade non-linearly because the recycled fraction carries oxidized gel domains and low-melt-flow contaminants that cannot be fully dispersed in a single-screw extruder configured with a 1.2–1.8 mm die gap. The formulation may also include 2–6 wt% carbon black masterbatch and 200–500 ppm of a fluoropolymer processing aid to manage die lip deposit; predrying of regrind at 80 °C for 2–3 h is recommended when outdoor storage exposes the flakes to RH above 60%. The blown-film process operates at a lower blow-up ratio of 2.5:1–3.5:1 and a frost line height of 4–7 die diameters; melt temperature at the die lip should not exceed 220 °C to limit oxidative gel formation. Compliance is verified through EN 13592 for refuse sacks, ASTM D882 tensile properties, and ASTM D1922 tear resistance; end-use can liners and compactor bags are typically non-food-contact, so FDA clearances are not invoked. Terminal product types include high-density can liners for 55-gallon drums, compactor bags, and contractor refuse sacks.

Slip-agent migration in produce roll bag film determines the coefficient of friction between film layers once the web is wound under tension on 100–150 mm diameter paper cores. HMN TR-942 in this application is extruded at a thickness of 6–10 µm with 0.5–1.5 wt% of an erucamide/antiblock masterbatch; the erucamide migrates over 24–72 h post-extrusion, and the coefficient of friction measured under ISO 8295 typically falls to 0.15–0.30 after this conditioning window. The downstream blown-film line uses a 2.0:1–3.0:1 blow-up ratio and a low stalk height of 3–5 die diameters to preserve MD tear resistance, because produce roll bags are perforated along the cross-machine direction and an MD tear propagation resistance under ASTM D1922 of at least 15 g/µm is required for clean detachment. Compliance is food-contact-driven: the film must comply with FDA 21 CFR 177.1520 for polyolefins and EU No 10/2011 for plastic materials intended to contact food. Conversion includes in-line perforation, roll slitting, and heat sealing of the bag bottom at 140–165 °C. Terminal product types include produce roll bags mounted on retail axle dispensers, bakery tissue-overwrap liners, and short-length wicket bags for handled produce.

When HMN TR-942 Functions as the Sealing Ply in Dry-Food Multi-Wall Liners

Coextruded or adhesively laminated inner liners for multi-wall paper sacks require a polyolefin sealing ply that combines low seal initiation temperature, low organoleptic contribution, and a stable melt curtain at thicknesses of 40–60 µm. HMN TR-942 is used as the virgin HDPE layer at 100 wt% in the sealing ply, with a polymeric processing aid addition not exceeding 0.05–0.20 wt%; the specific additive package of the 942G designation must be cleared for food contact under the intended end-use. The downstream process applies the blown film as the innermost ply of a pasted or stitched multi-wall paper sack, or extrusion-laminates it to kraft paper at 200–260 °C melt temperature. Sealing of the finished liner is performed on vertical form-fill-seal equipment at jaw temperatures of 135–155 °C. Compliance requires the base resin to meet FDA 21 CFR 177.1520(c) and the finished plastic layer to meet EU No 10/2011 overall migration limits of 10 mg/dm²; organoleptic tests under ISO 13302 are often used to confirm low taint transfer. Terminal product types include dry-food liners for flour, sugar, rice, dried pet food, and seed, as well as mineral additive inner liners where paper dust must be isolated from the fill product.

Heavy-duty industrial sack film derives puncture resistance from layer-ratio control in three-layer coextrusion rather than from a single-material gauge increase. A typical structure places HMN TR-942 at 60–80 wt% of the total polymer mass in the core layer, with hexene LLDPE skins making up the remaining 20–40 wt%; this combination allows a total film thickness of 60–120 µm without the bubble instability observed when the high molecular weight HDPE is run alone at blow-up ratios above 3.0:1. The coextrusion line uses a 250 mm die, internal bubble cooling, and a die gap of 1.8–2.5 mm; the HDPE layer is processed at a melt temperature of 200–220 °C, while the LLDPE skins are kept 10–15 °C lower to prevent surface degradation and die lip oxidation. Compliance testing uses ISO 527-3 tensile properties on film, ASTM D1709A dart impact, and ISO 6383-2 Elmendorf tear. Published dart impact values for the exact three-layer structure using HMN TR-942 are limited, so converter trials should establish a lot-specific control window; the operational boundary is defined by the onset of bubble pumping at the frost line when output exceeds 180 kg/h on the specified die diameter. Terminal product types include FIBC inner liners, heavy-duty debris sacks for construction waste, and industrial shipment covers.