Polylactic Acid REVODE110

REVODE110 is an injection-molding grade of polylactic acid supplied as transparent pellets under the REVODE trade name by Zhejiang Hisun Biomaterials Co., Ltd. The polymer backbone is primarily poly(L-lactic acid) with a controlled D-isomer content, a composition that limits crystallinity development during rapid cooling and stabilizes melt behavior in short-cycle cavity filling. Typical melt flow rate is reported as 5–10 g/10 min when measured at 190 °C with a 2.16 kg load according to ISO 1133-1:2022; density is reported as 1.24 g/cm³ by ISO 1183-1:2019. The grade is specified for disposable cutlery, injection-molded lids, cosmetic packaging, household articles, and transparent thin-wall components where controlled gate freeze and surface gloss are process-critical. In comparison with higher-flow PLA injection grades, REVODE110 reduces hot-runner drooling but increases injection-pressure demand in long-flow tools. Because the resin is hygroscopic and undergoes hydrolytic chain scission in the melt, pre-drying is mandatory before any molding operation.

In transparent injection-molded parts, optical quality is governed by crystallite size and flow-induced orientation. Because REVODE110 is an amorphous PLA grade when molded against a cold mold, light transmittance remains high only when the melt temperature and mold surface are controlled within the specified window. Flow-induced birefringence can be minimized by reducing packing pressure and avoiding abrupt changes in flow-channel cross-section. Turbidity or haze increases when the mold surface is above 80 °C, when regrind carries degraded gels, or when moisture remains above 250 ppm. In these cases, the optical defect is not a surface blemish but a bulk refractive-index variation caused by spherulitic growth.

When feedstock moisture exceeds 250 ppm, what changes at the vent port?

At moisture contents above 250 ppm, hydrolysis of the ester backbone during melt residence reduces molecular weight and produces a measurable drop in melt viscosity. The practical consequences on a reciprocating-screw injection machine include unstable vent-flow die pressure, stringing from the vent, white oligomeric deposits around the vent port, and part-surface splay or silver streaks. For REVODE110, desiccant drying at 80 °C for 4 h with a dew point at or below -40 °C is the conventional pre-processing condition, based on the amorphous pellet structure and the need to avoid exceeding crystallization onset in the hopper. If oven drying is used, pellet beds should be no deeper than 5 cm and supplied with dry-air flow above 0.5 m³/h per kilogram of resin. The recommended melt temperature window is 180–210 °C, with feed-zone temperature 170–180 °C, compression-zone temperature 190–200 °C, metering-zone temperature 200–210 °C, and nozzle temperature 195–205 °C. Mold temperature is maintained at 20–40 °C where transparency is required; raising the mold surface above 80 °C induces crystallinity and is normally reserved for parts requiring improved heat resistance at the expense of optical clarity. A general-purpose screw with L/D 20:1 to 24:1 and compression ratio 2.5:1 to 3:1 is employed. Screw speed should be limited to prevent excessive shear heating; back pressure is set at 0.5–1.0 MPa, decompression is set at 2–5 mm of screw retraction, and injection speed is profiled to prevent jetting at gate locations. Residence time in the barrel should not exceed 8 min at melt temperature; longer residence times produce brown specks, acrid vapor, and progressive loss of melt elasticity. If the grade is purged, polypropylene or a commercial purging compound is preferred; leaving REVODE110 in a heated barrel during downtime increases the risk of carbonized residue on screw flights and check rings. The processing window between unmelted material and thermal degradation is narrower than for polyethylene or polypropylene: melt temperature below 175 °C increases screw torque and unmelted granule occurrence, while melt temperature above 230 °C initiates visible yellowing and molecular weight loss.

Differentiation between REVODE110 and adjacent REVODE grades in injection-molding applications is primarily rheological rather than compositional. The manufacturer positions REVODE110 as a standard-flow injection grade; high-flow grades such as REVODE190 are used for thin-wall parts with flow-length-to-wall-thickness ratios above 150:1, while lower-flow grades are specified when melt strength or extrusion stability dominates. Published data for a complete direct property matrix across all REVODE subgrades is limited; therefore grade substitution should be validated by mold-filling simulation using measured melt viscosity curves rather than by melt flow rate alone. A lower melt flow rate of 5–10 g/10 min tends to produce higher pressure drop through hot manifolds but also reduces drooling in valve-gated systems and improves gate blush control. In practice, REVODE110 is selected for nominal wall thicknesses above 0.8 mm; below this section thickness, short shots and flow hesitation may occur unless the tool is designed with generous gate diameters and valve-gate timing controls. The product is an unmodified PLA grade, not an impact-modified compound; applications requiring ductile failure behavior under impact should evaluate toughened PLA grades or polymer blends rather than reducing product wall thickness in REVODE110. Compared with general-purpose polystyrene, REVODE110 has lower heat-deflection temperature and lower notched impact strength; compared with polypropylene, it has higher density and lower elongation at break. These comparisons are structural, not regulatory, and do not imply equivalence in molded-part performance.

Mechanical, thermal, and optical benchmarks under ISO 527, ISO 75, and ISO 306

The data below are drawn from manufacturer technical literature and are typical values for REVODE110; they are not design allowables and must not be used directly for load-bearing finite-element analysis without specimen-specific verification. Injection-molded plaques were conditioned at 23 °C and 50 % relative humidity for not less than 40 h. The values represent short-term static properties on unmodified natural resin and do not apply to colored or filler-modified compounds.

The mechanical values show a steep reduction in impact strength below 10 °C and at moisture contents above 0.5 %; published data for the ductile-to-brittle transition specific to REVODE110 is limited, so cold-condition testing should be performed for freezer applications. Under flexural loading, modulus remains approximately constant between 20 °C and 50 °C, but creep under sustained load becomes measurable near the glass transition region reported for PLA at 55–60 °C. Because PLA exhibits physical aging below the glass transition, tensile modulus and yield stress may increase modestly over the first 50 h after molding, while elongation at break may decrease. For comparable test data, aging time and conditioning must be standardized; ISO 291:2008 class 23/50 is the normal reference. Notched Izod values are sensitive to notch radius and moisture; a 0.25 mm notch radius is specified by ISO 180/A, but vapor-polished or molded-in notches should not be used. The optical data apply only to natural, unpigmented material; the addition of colorants, nucleating agents, or lubricants changes haze and transmission values. Users requiring a defined upper specification limit for optical properties should request a certificate of analysis for the specific production lot, because release testing for optical properties is not universally performed.

Rheological characterization for mold-filling simulation is performed using capillary rheometry according to ISO 11443:2021, with shear-rate sweeps at 180 °C, 200 °C, and 220 °C. Published data for REVODE110 in this geometry is limited in the open literature; however, the manufacturer technical service laboratories supply pressure-volume-temperature data and viscosity coefficients. Simulation should use measured Cross-WLF or Carreau coefficients instead of a single melt flow rate because the shear-thinning behavior of PLA below 100 s⁻¹ is significant. For PLA of this melt-flow class, capillary measurements at 200 °C and 100 s⁻¹ often fall in the order of 200–500 Pa·s, while at 1,000 s⁻¹ the same melt may fall below 100 Pa·s; direct lot-specific curves are required for simulation. Nozzle pressure differentials can exceed 100 MPa in thin-wall tools; clamp force requirements are computed from projected area, and for REVODE110 a clamp force of 3–5 kN/cm² of projected area is used for thin-wall amorphous parts. Gate freeze time, packing pressure profile, and switch-over point from injection to packing must be established with cavity-pressure sensors rather than by screw position alone, because the material transitions from melt to solid with a sharp viscosity increase near the glass transition. Packing pressure is typically 40–60 MPa for transparent amorphous parts; excessive packing can create gate stress and increase birefringence.

Compounding with fillers or impact modifiers is not required for the intended injection-molding applications. If such modifications are necessary, a co-rotating twin-screw extruder with L/D 40:1 and vacuum devolatilization at -0.08 MPa is typical, but compounded formulations are outside the manufacturer release specification and require re-validation for mechanical, thermal, and food-contact compliance. The use of regrind is limited to 20–30 % by weight; regrind above this level can reduce melt stability and increase the variability of tensile elongation. All regrind should be dried with virgin resin and passed through a screen pack to remove degraded gels.

Because food-contact compliance is determined at the final article level, documentation for REVODE110 is typically supplied through manufacturer certificates of compliance that cite the applicable framework for PLA as a thermoplastic. In the European Union, verification against EU Regulation 10/2011 and its amendments is required, with migration testing under the intended food simulants; in the United States, PLA food-contact status is generally addressed under 21 CFR 177.1520 or through a food-contact notification, not automatically by resin grade alone. REACH and RoHS compliance should be confirmed through the Safety Data Sheet and through laboratory test reports for the specific lot; RoHS Directive 2011/65/EU requires declaration of restricted substances at the homogeneous-material level. The processor retains responsibility for verifying that additives, masterbatch, and processing aids do not invalidate the resin compliance status.

The product must not be used in hot-fill or retort applications unless the part is post-crystallized or reinforced; the published HDT of 55 °C at 0.45 MPa means that sustained exposure above 50–55 °C can produce distortion under load. Sterilization by steam is not suitable for unmodified PLA; gamma or electron-beam irradiation may cause chain scission and discoloration, and published data for radiation stability of REVODE110 is limited. Ethylene oxide sterilization at low temperature may be evaluated, but residual absorption and mechanical-property shifts must be tested on the actual molded part. Chemical exposure to esters, ketones, or strong alkali should be avoided; stress cracking has been observed with certain essential oils and solvent-based cleaners on PLA grades of this class, though published data for REVODE110 in these solvents is limited. Storage of unopened bags should be below 35 °C and relative humidity below 60 %; opened material should be re-dried and used within 24 h in humid environments. Incompatibility with amine-based lubricants or certain silicone oils is documented for PLA generally; a production trial is necessary before introducing any mold release or colorant not previously qualified by the manufacturer.