Natureplast PLRE 002 is supplied as a recycled transparent polylactic acid grade intended for rigid packaging, thermoformed trays, clear lids, and consumer serviceware where industrial compostability is required. The designation PLRE 002 places the material in the supplier’s recycled PLA range; it is delivered in pellet form and is formulated to retain visible-light transmission while incorporating post-industrial or post-consumer PLA feedstock. Because the recycled fraction can include scrap from extrusion trims, thermoforming skeletons, and sorted post-consumer articles, the product is specified less as a single fixed formulation than as a controlled recyclate stream with defined melt flow and optical limits. Class-typical data for transparent recycled PLA of this type include a density of 1.22–1.26 g/cm³ under ISO 1183-1:2019, a melt flow index of 2–8 g/10 min at 210 °C and 2.16 kg under ISO 1133-1:2022, and tensile modulus in the range of 3,000–3,500 MPa under ISO 527-2:2012. These values are class-typical, not a certificate of analysis for a specific lot. The material can be processed on conventional PLA extrusion, injection molding, and thermoforming equipment, but the recycled origin imposes stricter incoming quality control and drying protocols than are required for virgin PLA.

What Processing Limits Are Observed When PLRE 002 Is Extruded at Production Scale?

Pre-drying is mandatory before melt processing because PLA undergoes hydrolysis at melt temperatures when moisture exceeds 250 ppm. A desiccant dryer with a dew point of ≤ -40 °C is specified; drying at 80 °C for 4 h is typical for virgin PLA, but recycled lots exposed to ambient air at relative humidity above 60 % may require 6 h to reach the same moisture ceiling. Moisture content should be verified by Karl Fischer titration under ISO 15512:2019, not by weight loss alone. On a 30:1 L/D single-screw extruder or a 36:1 L/D co-rotating twin-screw extruder, the melt temperature should be held between 190 °C and 210 °C. The processing window is narrow: melt-temperature excursions above 220 °C for more than several minutes can produce measurable loss of molecular weight and a 20–50 % increase in melt flow index after a single additional thermal cycle when moisture control fails. Residence time above 200 °C should therefore be kept below 30 min. Lot-to-lot MFR variation in recycled PLA is wider than in virgin PLA; incoming QC should include melt flow testing under ISO 1133-1:2022 before setting extruder screw speed and barrel profile. In recycled PLA extrusion, a 200-mesh screen pack is often installed upstream of the die to remove particulate contamination; increasing screen pack pressure is an early indicator of feedstock contamination or gel build-up. Injection molding is carried out with barrel temperatures of 190–210 °C and a mold temperature of 20–30 °C when amorphous transparency is required. Mold temperatures above 60 °C promote crystallization and increase haze, although they can improve heat resistance in technical parts. Thermoforming sheet produced from PLRE 002 is typically heated to 90–110 °C surface temperature before forming; uneven sheet temperature produces wall-thickness variation and localized haze. The grade should not be compounded with strongly alkaline or amine-based additives because these catalyze PLA chain scission and raise melt flow rate during compounding or downstream processing.

Mechanical and Optical Data Anchored to ISO 527-2 and ISO 13468

Because recycled transparent PLA grades retain the rigid amorphous character of virgin PLA, tensile modulus and strength are governed primarily by molecular weight retention, moisture history, and contamination level. Representative ranges for rigid transparent recycled PLA of this class are shown in the table below. These ranges should be confirmed with lot-specific data from the supplier before setting article test plans or mold design assumptions.

The haze range reflects feedstock quality. Post-industrial scrap can produce haze values near 5 %, whereas post-consumer flake with residual ink, label adhesive, or thermal history can push haze toward 20 %. Tensile elongation at break below 3 % indicates excessive molecular weight loss; lots with MFR above 8 g/10 min may fail to maintain die-melt strength during sheet extrusion and may suffer torn trim edges or sagging across the die. Light transmittance of 85–90 % at 2 mm is sufficient for many clear packaging applications, but it is lower than the 90–95 % transmittance typical of virgin PLA; crystal nucleation from residual additives or contamination further reduces transparency. These results are sensitive to plaque preparation conditions under ISO 293:2004; visual inspection should be performed against a sealed reference plaque because surface scratches and flow marks can be misread as optical property failures.

Certification of PLRE 002 under EN 13432:2000 or ASTM D6400-23 does not automatically confer food-contact approval. Industrial compostability requires ≥ 90 % biodegradation within 180 days under 58 ± 2 °C aerobic composting conditions, disintegration of the final article within 12 weeks, and absence of negative effects on compost quality and plant germination. The organic recovery claim applies to industrial composting facilities only; the material should not be described as home compostable unless the supplier provides a specific certification such as TÜV Austria OK compost Home or NFT 51-800 compliance. For food-contact applications, the finished article must be evaluated under EU Regulation 10/2011 or US FDA 21 CFR conditions of use; recycled feedstock can introduce non-intentionally added substances that require migration testing under EN 1186-1:2002 and EN 13130-1:2004. Where articles are exported, REACH and RoHS compliance must be verified against the specific lot and supplier safety data sheet. Published data for this specific recycled configuration’s food-contact status is limited; a migration test plan is therefore recommended before commercial use. This compliance boundary distinguishes PLRE 002 from some virgin PLA grades that carry clearer food-contact documentation. In addition, the industrial compostability certificate does not imply aerobic or anaerobic degradation in marine, freshwater, or soil environments unless separate testing under ISO 17556:2019, ISO 14851:2019, or equivalent has been performed.

When Recycled Transparent PLA Replaces Virgin PLA or rPET in Rigid Packaging

Substitution of virgin PLA with PLRE 002 in clear serviceware and packaging reduces virgin polymer demand but changes optical, mechanical, and processing trade-offs. Compared with virgin PLA, the recycled grade may exhibit a 10–20 % reduction in tensile strength and a 5–15 % increase in haze, depending on feedstock quality and extrusion history. This does not necessarily disqualify the material from packaging use, but it requires wider incoming QC limits and may require higher wall thickness to compensate for reduced tensile elongation. Compared with recycled poly(ethylene terephthalate) (rPET), PLRE 002 is industrially compostable under EN 13432:2000, whereas rPET is not. However, rPET offers higher heat deflection temperature, typically 70–85 °C at 0.45 MPa, and lower oxygen transmission. PLA articles soften near 55–60 °C and are unsuitable for hot-fill above 60 °C unless they are crystallized, which reduces transparency. Compared with PBAT or PBS biodegradable polyesters, PLRE 002 is stiff: tensile modulus is approximately 3,000–3,500 MPa, whereas PBAT grades often fall below 100 MPa with elongation at break above 400 %. PLRE 002 is therefore selected for rigid transparent applications, not flexible film. Within the recycled PLA range, transparent grades such as PLRE 002 differ from opaque recyclates because they require a cleaner feedstock; black or colored pellets, metal fragments, and crosslinked gel particles are more apparent in the final article. This feedstock constraint raises cost and sorting complexity but enables use in see-through lids, trays, and blister packs. Operators replacing virgin PLA with PLRE 002 may need to reduce the draw ratio in sheet extrusion or increase melt temperature by 5–10 °C within the 190–210 °C band to compensate for lower melt strength.

Storage Moisture Uptake, Shelf-Life Boundaries, and Batch Variation Control

Moisture uptake follows Fickian diffusion kinetics in PLA; pellets stored in opened bags at 23 °C and 50 % RH can reach moisture levels above 250 ppm within 24–48 h. At 80 % RH, the time to reach this limit shortens substantially, and drying before processing becomes non-negotiable. Unopened bags should be stored below 30 °C and protected from direct UV exposure. Under those conditions, PLA recyclates generally retain processability for 12 months; however, the recycled fraction may exhibit greater acid number and lower thermal stability than virgin PLA after prolonged storage. Incoming QC should include moisture by ISO 15512:2019, melt flow index by ISO 1133-1:2022, and visual haze on a 2 mm compression-molded plaque under ISO 293:2004. Lot acceptance limits should be based on the supplier’s certificate of analysis and internal process capability. Where MFR exceeds the upper control limit, the lot may be restricted to lower-shear extrusion applications rather than injection molding. Conversely, lots with MFR at the low end may require a 5–10 °C increase in melt temperature, within the 190–210 °C band, to achieve adequate fill. Recycled feedstock variability means that a single set of processing parameters cannot be assumed stable across all production campaigns; process adjustments should be driven by measured melt viscosity and not solely by barrel set points. Blending of multiple recycled lots may be necessary to stabilize melt flow and color; however, blending should be performed before drying and with documented lot traceability to maintain compliance with organic recovery certifications.