CiaoPlas™ PLA212HT02 is a heat-resistant, biodegradable polylactic acid compound supplied in cylindrical pellet form with a nominal diameter of 3.0 mm and a bulk density of 0.78 g/cm³ determined under ISO 60:1977. The grade is formulated for injection moulding, sheet extrusion, and thermoforming applications in which the service temperature of conventional amorphous PLA is insufficient. Melt volume-flow rate, measured at 210 °C with a 2.16 kg load using ISO 1133-1:2022, is 8 cm³/10 min. Density determined under ISO 1183-1:2019 is 1.26 g/cm³. Tensile modulus, tensile stress at break, and nominal strain at break measured on injection-moulded type 1A specimens under ISO 527-2:2012 are 3.6 GPa, 58 MPa, and 3.8 %, respectively. The compound contains a nucleating system and chain-extension chemistry to increase crystallinity after thermal annealing, while retaining the compostability pathways of the base polylactic acid resin.

What Differentiates CiaoPlas™ PLA212HT02 from Unmodified PLA Grades?

The principal distinction is heat deflection behaviour after annealing. Unmodified PLA evaluated under ISO 75-2:2013 method B at 0.45 MPa typically shows a heat deflection temperature of 50–55 °C. CiaoPlas™ PLA212HT02, after a controlled annealing cycle, reaches 95–110 °C under the same load. This improvement is not produced by filler reinforcement alone; the nucleating system reduces the isothermal crystallization half-time from approximately 20 min for neat PLA at 110 °C to below 2 min for the compounded grade. Differential scanning calorimetry at 10 °C/min heating rate on dried pellets shows a cold-crystallization exotherm peak between 88 and 95 °C and a melting endotherm between 165 and 175 °C. Heat resistance therefore develops only after moulding and annealing; as-moulded amorphous parts retain the lower service limits of conventional PLA.

Compared with mineral-filled PLA grades, PLA212HT02 avoids inorganic filler loading above 10 wt%. This keeps density at 1.26 g/cm³ instead of the 1.40–1.50 g/cm³ range typical of talc-reinforced PLA. The lower filler content also reduces abrasion on screws, barrels, check rings, and hot-runner tips. The trade-off is a narrower processing window: PLA212HT02 requires higher mould temperature and a more tightly controlled annealing step than talc-filled grades, which can obtain part of their stiffness through filler reinforcement without reaching high crystallinity. This distinction is operationally significant. PLA212HT02 is selected when a compostable article with lower part mass and lower density is required, not when maximum rigidity per part volume is the sole criterion.

Values shown are representative of moulded and conditioned specimens. They are not batch-release specifications unless provided in a certificate of analysis for a specific lot.

Capillary rheometry under ISO 11443:2014 places the melt viscosity of PLA212HT02 at 320 Pa·s at a shear rate of 100 s⁻¹ and 190 °C. At 1000 s⁻¹, viscosity decreases to 45 Pa·s, corresponding to a power-law index of approximately 0.42 over the measured range. The melt is more temperature-sensitive than semi-crystalline polyolefins: increasing melt temperature from 180 to 200 °C reduces viscosity by approximately 30 %. In production settings where screw speed exceeds 150 rpm on a 35 mm reciprocating-screw machine, viscous heating can shift melt temperature beyond 200 °C. Thermal degradation under these conditions lowers complex viscosity and generates acidic by-products, which may etch unprotected mould steel during extended campaigns.

Drying of CiaoPlas™ PLA212HT02 is performed in desiccant dryers with a dew point of −40 °C or lower. If ambient relative humidity exceeds 60 %, pellet moisture pick-up can reduce molecular weight through hydrolytic chain scission during melt processing. The recommended drying condition is 80 °C for 4–6 h to obtain residual moisture below 250 ppm as measured by Karl Fischer titration under ISO 15512:2016. Production-scale use of a drying hopper without dew-point control has been associated with viscosity loss and black specks in hot-runner systems. On a reciprocating-screw injection-moulding machine with screw diameter 35 mm and L/D ratio 20:1, a reverse temperature profile is maintained from 165 °C in the feed zone to 185 °C at the nozzle to avoid excessive shear heating. Mould temperature is set between 80 and 110 °C. Injection pressure is typically 80–120 MPa, hold pressure is 60–80 % of peak injection pressure, and back pressure is kept below 0.5 MPa. Screw rotation speed for the specified 35 mm screw is 80–150 rpm.

For hot-runner tools, the hot-runner manifold is held at 180–190 °C, and residence time of the melt above 200 °C is kept below 5 min. Prolonged residence in the barrel at 210 °C causes molecular weight degradation, reduced melt strength, and streaking in moulded sections. Moulds designed for polypropylene with small tunnel gates below 0.6 mm can produce jetting, gate blush, and brittleness at the gate. Cold-runner moulds benefit from full-round runners of 5–7 mm diameter and sub-gates of 0.8–1.2 mm diameter.

When Mould Temperature Falls Below 80 °C, Heat Resistance Is Not Retained

This boundary governs the performance envelope of CiaoPlas™ PLA212HT02. If mould temperature is lower than 80 °C, the part cools too rapidly to permit adequate nucleation and crystallinity development. Under such conditions, the as-moulded heat deflection temperature remains near the amorphous PLA range of 50–55 °C, and subsequent annealing cannot fully compensate because spherulite development may be irregular. The recommended annealing protocol is 95–110 °C for 2–4 h in a forced-air oven. Wall thickness above 3 mm requires the longer dwell; thinner sections may develop warpage if heated at the upper limit. Unrestrained parts shrink anisotropically during annealing: flow-direction shrinkage is 0.3–0.6 % and transverse shrinkage is 0.2–0.4 % on 80 mm × 10 mm × 4 mm specimens prepared per ISO 294-4:2018. Dimensional control in production requires annealing fixtures, and tooling shrinkage allowances of 0.8–1.2 % are used depending on gate location and part geometry.

Sheet extrusion of CiaoPlas™ PLA212HT02 is performed on a single-screw extruder with L/D ratio 32:1, a compression ratio of 2.5:1, and a barrier screw. Barrel temperatures from feed to die are set as 170, 180, 190, 195, and 200 °C. The die temperature is held at 195–200 °C. Polished rolls are maintained at 70–85 °C to stabilise sheet thickness before trimming. Thermoforming of this sheet into food-service containers is conducted at sheet surface temperatures between 100 and 115 °C. Infrared heating with zoned ceramic elements is used to avoid local overheating and sheet sag. In production-scale thermoforming trials, sheet temperatures above 120 °C resulted in severe sagging and non-uniform wall thickness; sheet temperatures below 95 °C produced webbing and poor corner replication. Published data for this specific configuration is limited to equipment-specific trials; general PLA thermoforming practice is referenced in machine manufacturer technical bulletins.

Biodegradation Pathways and Regulatory Testing

The polymer matrix is polylactic acid, which undergoes hydrolysis of ester linkages followed by microbial assimilation under industrial composting conditions. CiaoPlas™ PLA212HT02 is intended to be tested for aerobic biodegradation under ISO 14855-1:2012; however, the final article must be certified because thickness, print, barrier coatings, and lamination influence disintegration rate. The product is not designed for home compostability under EN 17427:2022 without additional validation. In marine or freshwater environments, PLA212HT02 does not degrade rapidly and should not be described as marine biodegradable. For US food-contact use, confirmation is required against 21 CFR 175.300 if the material is used as a coating component or against an applicable Food Contact Notification for the base resin and final article.

The operational limits of CiaoPlas™ PLA212HT02 are defined by hydrolysis, thermal ageing, and chemical incompatibility. Continuous service in hot water above 60 °C is not recommended because hydrolytic molecular-weight loss accelerates. Contact with strong acids below pH 4 or strong bases above pH 9 accelerates ester hydrolysis. Avoid combination with amine-based additive masterbatches because basic amine species can catalyse chain scission and reduce melt strength. Storage in unopened bags at 25 °C and 50 % relative humidity is recommended; opened material should be consumed within 8 h unless maintained in dry-air hoppers. The material is not suitable for gamma sterilisation at doses above 25 kGy due to chain scission, and ethylene oxide exposure must be followed by aeration to remove retained gas. No evaluation has been made for long-term implantable medical use; the grade is not tested under the ISO 10993 series.

Typical conversion routes for CiaoPlas™ PLA212HT02 include injection moulding of hot-fill lid stock, thermoforming of shallow trays and cups, and extrusion of profile or sheet with downstream die cutting. Each conversion route requires drying, melt temperature control, and annealing or heated tooling to obtain the heat-resistance benefit. Parts intended for direct food contact are the responsibility of the converter to validate under the relevant migration clauses of EU 10/2011 and any applicable national legislation.