EcoVid 43IM High Molecular Weight Ingeo PLA is a semicrystalline polylactide pellet grade supplied for injection molding and thick sheet/profile extrusion where conventional high-flow Ingeo injection grades show insufficient melt strength or notched impact. The resin is packaged in 25 kg moisture-barrier bags with a maximum residual moisture of 0.025 wt%. Under ISO 1133-1:2022 at 210°C and 2.16 kg, the melt volume-flow rate is provisionally listed as 9 ± 3 g/10 min, with the lot-specific certificate of analysis governing release. Residual D-lactide is specified below 1.5 mol%, permitting slow spherulitic crystallization in heated molds while limiting fast crystal growth in amorphous part walls. Gel permeation chromatography against polystyrene standards places weight-average molar mass between 180,000 g/mol and 220,000 g/mol. The higher molar mass raises notched Izod to 25–32 J/m under ASTM D256-10e1 and simultaneously increases melt pressure demand at narrow gates, which separates the grade from low-D, high-flow PLA resins designed for disposable cutlery and high-speed thin-wall packaging.

Model 43IM is not a general-purpose low-viscosity PLA. The intended usage envelope includes technical housings with wall thickness from 1.2 mm to 4.0 mm, short-run packaging where notched Izod above 25 J/m is required, and profile extrusion of circular or irregular cross-sections where draw-down causes surface tearing in lower-molecular-weight PLAs. The grade also functions as a heat-resistant matrix when annealed at 100°C for 20–30 min or compounded with a nucleating masterbatch below 2 wt% talc or boron nitride equivalent. In unannealed parts, heat deflection temperature under 0.45 MPa remains 52–57°C under ASTM D648, so continuous load above 55°C requires molded-in crystallinity or mineral reinforcement.

What Changes When EcoVid 43IM Is Used in Hot-Runner Multi-Cavity Molds?

Hot-runner pressure drop scales nonlinearly with melt viscosity. Production commissioning on a 1,600 kN hydraulic injection molding machine with a 2-cavity hot-runner mold and 1.2 mm valve-gate orifices recorded nozzle melt pressure between 850 bar and 1,100 bar at 210°C. The same tool operated at 620–780 bar with a 70 g/10 min standard PLA grade. The viscosity gap means that existing molds designed for high-flow PLA require gate diameter enlargement or a 10–15°C higher melt temperature to maintain fill. Published data for hot-runner performance of this specific EcoVid formulation is limited; the above values are commissioning measurements only and should not replace in-mold pressure-verification with cavity transducers.

The processing window is narrower than that of low-viscosity PLA. Melt temperature should remain between 190°C and 210°C for general injection molding, with a nozzle temperature of 195–205°C. Above 220°C, polyester degradation accelerates, producing acetaldehyde, lactide reversion products, and yellowing. At 230°C or above, purge with polypropylene should be completed within 10 min to prevent black specks and carbonized residue. Hot-runner channels and valve-gate dead spots should be sized to avoid residence times above 5 min. Back pressure is maintained at 0.5–1.0 MPa; screw speed on a 35 mm general-purpose screw is held at 30–60 min⁻¹. Higher screw speed or higher back pressure generates frictional heat that reduces viscosity and narrows the holding-pressure adjustment window.

Pre-drying at 80°C for 4–6 h in a desiccant dryer with a dew point below −40°C is mandatory when downstream humidity exceeds 60% RH or when regrind is added above 20 wt%. Moisture above 0.010 wt% accelerates hydrolytic chain scission, producing splay, silver streaks, and viscosity loss that mimics lower-molecular-weight resin. A desiccant dryer with return-air dew point at or below −40°C maintains pellets below the hydrolysis threshold for at least 8 h continuous operation. Feed throat temperature is set at 20–25°C; rear zone at 175–185°C; middle zone at 180–190°C; front zone at 190–200°C; nozzle at 195–205°C. For wall sections below 1.2 mm, the front zone and nozzle may be raised to 210°C for short periods, but residence time must then be reduced.

Thermomechanical Benchmarks and Compliance Checklist

Table 1 consolidates provisional specification values and test standards for EcoVid 43IM. The values are not a certificate of conformity; they represent the grade’s published technical envelope and should be verified on molded plaques conditioned at 23°C and 50% RH for 48 h according to the relevant test method.

Table 2 lists processing parameters observed during pilot-scale injection molding on an Arburg Allrounder 470 A with a 20:1 L/D screw and 3.0:1 compression ratio. Values are starting points, not optimized recipes for every mold.

Regulatory screening under Directive 2011/65/EU with delegated Directive (EU) 2015/863 is applicable for electrical and electronic housings. The unfilled resin does not contain intentionally added lead, mercury, cadmium, hexavalent chromium, polybrominated biphenyls, polybrominated diphenyl ethers, or the four phthalates above the maximum concentration values by mass in homogeneous material. Color masterbatch dilutions and flame-retardant packages must be screened separately because additive carriers can shift compliance. For food-contact applications, the finished article must be evaluated under EU Regulation 10/2011, including overall migration using food simulants, and under the applicable United States Food Contact Notification for poly(lactic acid); the conversion process and colorants may alter migration behavior.

Compared with high-flow Ingeo injection grades, EcoVid 43IM is not optimized for spiral-flow length above 600 mm at 1.6 mm wall or for micro-mold filling below 0.4 mm wall. Direct substitution into molds designed for 70 g/10 min PLA without increasing gate diameter or raising melt temperature will produce short shots in thin ribs and bosses. The high molecular weight also reduces maximum screw recovery speed: on a 35 mm general-purpose screw, recovery time increases by 10–15% relative to high-flow PLA at identical back pressure. Compared with polybutylene succinate, EcoVid 43IM has higher tensile modulus but lower notched Izod, because PBS grades commonly exceed 50 J/m under ASTM D256. Compared with polyhydroxyalkanoate sheet grades, published data for direct substitution onto PHA sheet extruders is limited; screw profile and barrel temperature should be re-qualified before production.

When Regrind Content Exceeds 30 wt% in Closed-Loop Sheet Extrusion

Closed-loop extrusion with post-industrial regrind changes the viscosity distribution of EcoVid 43IM because reprocessing hydrolyzes ester bonds and reduces molar mass. A sheet trial on a Breyer extruder with a 33:1 barrier screw running 1.2–2.5 mm sheet showed that 30 wt% regrind lowered melt pressure by 12–18% and reduced notched Izod from 29 J/m to 23 J/m. Above 30 wt%, edge curl and gauge variation increase unless the dosing system maintains regrind particle size below 6 mm and the regrind is pre-dried for 2 h longer than virgin pellets. The upper operational boundary is 50 wt% regrind for non-load-bearing sheet; above this level, published data for mechanical stability of the specific EcoVid 43IM configuration is limited, and lot-to-lot molar mass variation becomes the dominant quality risk. In all regrind streams, residual moisture must be measured with a Karl Fischer titrator before adding to the extruder feed throat.