INZEA F27 is a rigid polylactic acid (PLA)-based thermoplastic compound designated for injection molding and rigid extrusion of short-life articles. The renewable carbon share is 70% as determined by radiocarbon analysis according to ASTM D6866 or EN 16640:2017. The remaining fraction consists of a proprietary biodegradable copolyester and processing stabilizers. The grade is supplied as pellets and is intended for disposable cutlery, thin-wall rigid packaging, cosmetic jars, horticultural clips, trays, and non-food housings. It is not positioned for applications requiring continuous service above 55 °C under load or for impact-modified, film-forming, or heat-resistance-critical functions.

Processing and Rheological Envelope for Thin-Wall Injection Molding

Pellet handling before melt processing is governed by the hydrolytic instability of PLA. Pellets should be dried in a desiccant dryer with a dew point at or below −40 °C and an airflow of 3.0–4.0 m³/h per kg/h of polymer throughput. Drying should be conducted at 70–80 °C for 4–6 h until residual moisture is below 250 ppm, with a target of 100 ppm for thin-wall molding. Moisture verification should be performed by Karl Fischer titration according to ISO 15512. Pre-drying remains mandatory when ambient relative humidity exceeds 60%; failure to dry the resin promotes hydrolytic chain scission, visible splay, reduced melt strength, and loss of notched impact strength.

The melt flow index is typically quoted in the range 20–30 g/10 min at 190 °C under a 2.16 kg load in accordance with ISO 1133-1. This places INZEA F27 in the higher-flow segment of rigid PLA compounds, but shear sensitivity should not be confused with thermal stability. A general-purpose injection screw with an L/D ratio of 20:1 to 25:1 and a compression ratio of 2.0:1 to 2.5:1 is appropriate. Barrel start values from rear to nozzle are 160–180 °C, 190–210 °C, 190–210 °C, and 190–205 °C. Melt temperature should not exceed 210 °C for more than 10 min cumulative residence time because lactide regeneration and molecular weight loss accelerate above this boundary. Mold temperatures between 25 °C and 60 °C produce largely amorphous, transparent parts. Injection pressure commonly falls between 80 MPa and 120 MPa, with hold pressure at 50–80% of injection pressure. Back pressure should be limited to 0.3–0.7 MPa to avoid excessive shear heating.

Hot runner manifolds and nozzles should be maintained at 190–210 °C and designed without dead spots or stagnant zones. Regrind may be used up to 20 wt% when dried and free of contamination. Higher regrind fractions may reduce notched Izod impact and increase lot-to-lot variation; published data for higher regrind fractions in this specific formulation are limited. Purge after processing interruptions with a low-melt-index polyethylene or a commercial purging compound. Polycarbonate and polyester-based purge materials should be avoided because residual transesterification products can degrade the PLA matrix and block narrow gate regions.

For thin-wall cutlery and trays with nominal wall sections of 1.0–1.5 mm, gate and vent design are critical. Edge gates with a land length of 0.8–1.2 mm and a gate width equal to 60–80% of the part wall section reduce jetting and improve surface filling. Vent depths of 0.01–0.02 mm prevent gas burn marks. Draft angles of 0.5–1.0° are recommended for release. Flow-parallel mold shrinkage is typically 0.3–0.5% when molded at 25–60 °C. Anisotropic shrinkage can increase warpage when wall thickness changes exceed 25% across a part.

The cooling profile determines morphology and post-molding performance. Rapid cooling below the glass transition temperature of 55–60 °C produces amorphous parts with clarity and limited dimensional change during ordinary service. A mold temperature above 90 °C permits crystallization, which may raise heat deflection but also increases cycle time, shrinkage, and warpage. This is a critical processing threshold: crystallized parts can exhibit improved heat resistance, while sink mark severity and part deformation may increase. For wall sections below 1.5 mm, the amorphous route is usually preferred unless off-mold annealing is performed.

When 70% Renewable Carbon Content Is Interpreted Correctly

The designation 70% renewable refers to the share of organic carbon derived from contemporary biomass, not necessarily 70% of total compound mass. Radiocarbon analysis per ASTM D6866 or EN 16640:2017 distinguishes fossil-derived carbon from biomass-derived carbon. This distinction is operational and comparative: some unfilled PLA grades exceed 90% renewable carbon, while certain PBAT/PLA blends may fall below 50%. A renewable carbon value of 70% does not by itself establish compostability, because industrial compostability depends on aerobic biodegradation, disintegration, and ecotoxicity behavior of the final formed article. Conversely, a lower renewable carbon fraction does not automatically imply non-compliance with EN 13432 or ASTM D6400.

The compound should not be described as “home compostable” unless a recognized home compost certification is explicitly cited for the finished article. INZEA F27 is intended for industrial composting environments where thermophilic conditions are actively maintained. In cold soil, marine, or anaerobic landfill environments, PLA degradation is typically slow or incomplete. These end-of-life boundaries must be communicated in disposal specifications and are not masked by the renewable carbon value.

What Distinguishes INZEA F27 from Other PLA and Rigid Compostable Compounds?

Compared with plasticized PLA film resins, INZEA F27 exhibits low elongation at break and high tensile modulus. This combination supports rigid, non-impact applications but limits use in snap-fit closures and hinged geometries unless generous radii and properly located gates are used. Compared with PBAT/PLA blends, the material provides higher flexural modulus and lower notched impact strength. Compared with mineral-filled PLA or stereocomplex PLA, it does not claim elevated heat deflection above 60 °C without post-crystallization or annealing. The 70% renewable carbon share also distinguishes it from fully biobased PLA grades and from partially renewable PBAT/PLA compounds with lower renewable carbon fractions.

These values are screening benchmarks rather than specification limits. The relevant certificate of analysis and the supplier’s current technical data sheet should be referenced before mold design or application validation. Property retention after conditioning at 23 °C and 50% relative humidity can differ from dry-as-molded values because PLA is moisture-sensitive.

For industrial compostability, the finished article must be tested or certified according to EN 13432:2000 or ASTM D6400. The standard pass criteria for EN 13432:2000 include a minimum of 90% ultimate aerobic biodegradation within 180 days, disintegration leaving no more than 10% of initial dry mass on a 2 mm sieve after 12 weeks, and absence of ecotoxicity according to OECD 208. Composting requires an active thermophilic environment at 58 °C and 50–60% relative humidity. The material should not be described as home compostable unless a separate home compost certification is explicitly cited for the final article.

Food-contact status is not an inherent property of the resin alone. The finished food-contact article must be evaluated under Commission Regulation (EU) No 10/2011 for overall migration and specific migration limits. For United States submissions, the appropriate FDA Food Contact Notification or predicate clearance for polylactic acid should be cited. No claim of food-contact compliance should be transferred from raw material documentation without article-specific migration data. Electrical and electronic articles containing INZEA F27 should be assessed under RoHS Directive 2011/65/EU for restricted substances, and REACH Regulation 1907/2006 applies to the final formulation.

Washing, sterilization, and hot-fill exposure should be excluded unless post-crystallization or annealing has been validated. The material is not recommended for continuous service above 55 °C under mechanical load, for microwave reheating, or for contact with boiling water. Unstabilized PLA should not be specified for long-term outdoor weathering without testing under ASTM D4329 or ISO 4892-2. In high-humidity environments above 60% relative humidity, moisture uptake plasticizes the matrix and accelerates environmental stress cracking in stressed molded parts. Alkaline fillers and amine-based colorants should be avoided because they can promote hydrolytic chain scission in the polyester backbone. The formulation is also sensitive to contamination from polyvinyl chloride and polyethylene terephthalate residues, which can generate corrosive degradation by-products and gate blockage.