In thin-wall injection moulding of EcoVid 43IM for single-serve foodservice articles, the resin lot release record includes melt mass-flow rate measured under ISO 1133-1:2022 at 210°C with 2.16 kg load, because lot-to-lot variation in the high-molecular-weight tail changes downstream fill pressure more than it changes extruder motor load. The material is pre-dried in a desiccant-bed dryer at 80°C for 4 h to a free-moisture ceiling of 250 ppm; excursions above 250 ppm generate hydrolytic viscosity loss that appears as gate blush and short-shot variability on a 120-ton hydraulic clamp injection machine. Barrel temperatures from feed to nozzle are profiled at 175°C, 190°C, 205°C, 210°C, and 210°C, with nozzle temperature held at 205°C to avoid droplet formation during screw recovery. A 20:1 L/D reciprocating screw with 2.5:1 compression ratio and a spring-type non-return valve is used; melt residence time is capped at 8 min because the high molecular weight fraction has a narrow thermal-oxidative tolerance after initial degradation. When pigmented, a 2–3 wt% masterbatch is introduced at the feed throat; otherwise the formulation is neat resin. EU No 10/2011 Annex I total migration limit of 10 mg/dm² and an FDA Food Contact Notification for PLA homopolymer define food-contact compliance for cutlery, single-serve coffee pods, cup lids, and cosmetic scoops. Where a cold runner is retained, regrind from sprue and runner can be reincorporated at up to 10 wt% after closed-loop drying; where a hot runner is used, regrind is excluded to avoid residence-time accumulation in the manifold. End-part thickness below 0.8 mm requires peak injection pressures above 900 bar when the flow-path-to-wall-thickness ratio exceeds 180:1, and gate freeze-off restricts pack holding to the first 0.2–0.5 s after velocity–pressure switchover. Published data for this specific configuration is limited, so production trials using in-mould pressure transducers are required to fix the switchover point. Tool temperature is held at 25–40°C to balance crystallization rate against cycle time.

What Limits Regrind Reincorporation in Compostable Sheet Extrusion and Thermoforming?

EcoVid 43IM sheet extrusion operates on a 30:1 L/D single-screw extruder with a vacuum vent at −0.08 MPa, because residual volatile content at the calendar determines whether the melt bank collapses during rolling. The pre-dried resin is metered at 80°C for 4 h to below 300 ppm moisture, then processed through a barrier screw with melt temperatures of 190–210°C and a positive-displacement melt pump set to 60–80 bar to damp screw-induced surge. Formulation for food-contact clamshells and deli trays uses 80–100 wt% virgin EcoVid 43IM, 0–20 wt% post-industrial regrind from trim and rejected sheet, 1–3 wt% anti-block masterbatch, and 0.5–1.0 wt% slip masterbatch; impact modifier addition above 10 wt% is avoided because it lowers the heat-deflection temperature below the 45°C continuous service limit required for stacked cold-chain containers. The sheet is calendered at 40–60°C on a three-roll stack, then thermoformed on a high-speed contact-heat machine with sheet surface temperature at 90–110°C and forming-air pressure at 4–6 bar. Compliance tracks EN 13432, ASTM D6400, EU No 10/2011, and the same FDA Food Contact Notification for PLA homopolymer; migration testing under 10/2011 Annex I uses 10 mg/dm² total migration limit with food simulants A and B. End products include cold beverage cups, clamshells, portion trays, bakery window boxes, and insert trays for fresh produce. A processing boundary appears when regrind exceeds 20 wt%: the viscosity drop from repeated thermal history narrows the thermoforming window and increases sheet sag in the oven; at 25 wt% regrind, tear resistance measured by ASTM D1004 declines enough to cause trim fracture on perforated clamshell hinges.

Monofilament extrusion for fused filament fabrication is controlled by melt-pump inlet pressure stability rather than by extruder screw speed alone, because the high molecular weight fraction in EcoVid 43IM raises die entrance pressure and creates a non-linear relationship between screw rpm and mass throughput. The resin is pre-dried at 80°C for 4 h to below 250 ppm moisture, then processed on a 25 mm single-screw extruder with a 24:1 L/D barrier screw and a melt pump maintaining 65–75 bar before a 2.0 mm die. Melt temperature at the die is held at 195–215°C; the filament is quenched in water at 45°C and drawn through a dual-axis laser micrometer array to a diameter of 1.75 mm or 2.85 mm, with ovality maintained below 0.05 mm and spool-to-spool length variation below 0.5%. For pigmented filament, 1.0–2.0 wt% pigment masterbatch and 0.5–1.0 wt% internal lubricant masterbatch are compounded in a twin-screw side feeder; if a filler-grade carbon black is used above 2 wt%, the melt pressure drop across the screen pack rises and the melt pump inlet pressure drops below 25 bar, causing diameter oscillation. Compliance standards applied to the final filament are ISO 527-2:2012 for tensile properties, ISO 1133-1:2022 for melt flow consistency, and ISO/ASTM 52900 for additive manufacturing feedstock classification; RoHS Directive 2011/65/EU and REACH Candidate List screening are applied to the pigment and lubricant additives. End products are certified spools for fused filament fabrication printers, prototype tooling aids, and vacuum-forming patterns. Open-air storage at relative humidity above 60% for more than 24 h induces moisture regain above 0.25%, producing steam bubbles at the die and diameter spikes; sealed desiccant packaging with a moisture indicator is used on all certified spools.

Melt-Spun Nonwoven Attenuation and Calender Bonding Window

EcoVid 43IM enters melt-spun nonwoven production at spinneret temperatures of 210–230°C, where the high-molecular-weight fraction resists draw resonance but also raises die pressure across a 0.35 mm hole-size spinneret. Pre-drying at 80°C for 4 h to below 350 ppm moisture is required because hydrolysis at these temperatures reduces filament tenacity before attenuation; the resin is extruded through a single-screw spinning beam with a 30:1 L/D screw, filtered through 40 µm screen packs, and quenched by two-sided air at 15–20°C and 0.4–0.6 m/s. Spin finish is applied at 0.5–1.5 wt% on fiber weight, not in the resin, to avoid screw slip in the feed zone. Calender bonding takes place at 70–90°C and 40–60 N/mm line force; these conditions create point-bonded nonwoven fabric with the required tensile strength under ISO 9073-3. Compliance for industrial wipes and packaging interleaves follows ISO 9073-2, ISO 9073-3, and EU No 10/2011 where the nonwoven is used as a food-contact separation layer; the loading ratio in the fibre itself remains 100 wt% EcoVid 43IM with 0–2 wt% additive masterbatch for color or UV stabilization, while the spin finish is excluded from the polymer formulation. Downstream production includes spunbond web formation, hot calender bonding, edge-trim in-line recycling at 5 wt%, and slitting to roll widths of 500 mm and 1000 mm. End-product types include industrial cleaning wipes, biodegradable packaging void fill, agricultural crop covers, and filtration support layers. A process limitation arises in the calender bonding stage: increasing line speed above 350 m/min shortens contact time and reduces bond-point strength; published data for this specific configuration is limited, so production trials with ISO 9073-3 tensile stripping are required for each calender pattern.

When EcoVid 43IM is extrusion-coated onto kraft board for ambient-moisture food contact structures, the high-molecular-weight melt permits a 12–20 µm coating layer to neck in less than 3 mm on a 600 m/min line, using a matte chill roll and downstream corona treatment. Pre-drying at 80°C for 4 h to below 250 ppm moisture is maintained; melt temperature at the coat-hanger die is 200–220°C, and the molten web is nipped onto the board at 15°C chill roll temperature. Compliance tracks EU No 10/2011, FDA Food Contact Notification for PLA homopolymer, and EN 13432; the formulation uses 100 wt% virgin EcoVid 43IM with 2–4 wt% slip masterbatch for release at the slitter, and no regrind is used in direct food-contact layers. End products include cold-beverage paper cups, sandwich boards, and bakery sheets. The process boundary is board moisture: a board moisture content above 8% causes steam blistering at the coating nip.

When High-Molecular-Weight PLA Replaces Polystyrene in Biaxially Oriented Label Film

Sequential biaxial orientation of EcoVid 43IM label film is viable only when the sheet has been conditioned to 300 ppm moisture or below, because the preheating zone at 60–70°C in the machine-direction orienter and 70–80°C in the transverse stenter produces a humidity-dependent crystallization exotherm that can shift the stretch ratio by 5–10%. The resin is processed at 210–230°C through a 30:1 L/D single-screw extruder, cast onto a 40–60°C chill roll, and thinned to a cast sheet from 200–300 µm; the sheet is stretched 3.0× in the machine direction and 4.0× in the transverse direction to produce a 20–30 µm film. Formulation for label facestock uses 95–100 wt% EcoVid 43IM, 1–3 wt% anti-block masterbatch, and 1–2 wt% slip masterbatch; plasticizer is omitted to preserve the ISO 527-3 tensile modulus above 3,000 MPa. Compliance for labeling applications is anchored to ISO 527-3:2018, ASTM D882, and EU No 10/2011 where the film is used as a food-contact label on the non-food side; end products include shrink-free label facestock, roller-fed wraparound labels, and window carton film. A critical process limitation is storage: film held at relative humidity above 60% develops curl and blocking because PLA absorbs water and relaxes surface orientation, so slit rolls are sealed immediately after production.