The grade designation Sustainable 2001 Tough Injection Molding PLA Blend identifies a compounded polylactic acid system formulated for medium-flow injection molding in which a non-phthalate impact modifier is dispersed at a loading between 8 wt% and 15 wt% to reduce the brittle failure mode of unmodified PLA. The supply specification envelope reports a melt volume-flow rate of 8 cm³/10 min to 14 cm³/10 min at 210 °C under 2.16 kg measured in accordance with ISO 1133-1:2022. The compound is supplied with a density of 1.24 g/cm³ to 1.27 g/cm³ by ISO 1183-1:2019, a notched Izod impact value of 12 kJ/m² to 18 kJ/m² at 23 °C by ISO 180/1A, and a tensile modulus of 2 800 MPa to 3 200 MPa by ISO 527-2/1A. Bio-based carbon content is stated as ≥ 90 % on a total organic carbon basis according to ASTM D6866-24 Method B. These values represent the datasheet specification band under laboratory conditioning at 23 °C and 50 % relative humidity; they are not a substitute for lot-specific certification.

Typical application fields include non-sterile technical housings, point-of-sale display frames, cosmetic packaging components, thin-wall appliance covers, and consumer electronics accessories where lower processing temperatures and renewable carbon content are operational constraints. The grade is not specified for load-bearing gears, continuous service above 55 °C, high-moisture dishwasher exposure, or direct food contact unless supplementary migration testing is completed for the finished article. In capillary rheometry at 210 °C, the apparent melt viscosity is typically between 180 Pa·s and 240 Pa·s at 100 s⁻¹ by ISO 11443:2021. Capillary data for the specific blend configuration is limited outside the manufacturer’s supplied lot ranges, so mold-filling simulations should be calibrated with in-house rheology before tooling release.

What separates Sustainable 2001 from unmodified PLA in injection molding?

Unmodified semi-crystalline PLA grades for injection molding typically exhibit notched Izod impact values from 3 kJ/m² to 5 kJ/m², pronounced notch sensitivity, and brittle failure in thin sections. Sustainable 2001 shifts failure response through controlled dispersion of an impact modifier phase. When the screw plasticating unit provides sufficient distributive mixing, the modifier domains are distributed at a target number-average particle size between 0.5 µm and 1.5 µm. Below this size distribution, toughening efficiency is incomplete; above 3 µm, ductility gains become inconsistent and surface finish can deteriorate. In comparison with a general-purpose ABS grade of 20 g/10 min MFR, Sustainable 2001 processes at a melt temperature roughly 20 °C to 40 °C lower but retains greater melt-temperature sensitivity. Its heat deflection temperature by ISO 75-2/B at 0.45 MPa is 65 °C to 80 °C, whereas impact-modified ABS at the same thickness often exceeds 85 °C. The product therefore does not replace ABS in hot-water, oven-adjacent, or continuous-load thermal applications.

On a 100 t hydraulic injection molding machine using a 25 mm screw with L/D 22:1, stable melt pressure has been observed at a barrel profile of 160 °C rear, 185 °C compression, 195 °C metering, and 200 °C nozzle. Published production-scale data for this specific configuration is limited; process qualification should use cavity-pressure transfer rather than time-based transfer because the blend’s compressibility changes with modifier concentration. Pack pressure between 60 MPa and 90 MPa, with an intensification ratio of 10:1, has maintained gate seal and reduced sink marking at bosses. When cavity pressure at transfer falls below 30 MPa, notched impact performance can drop by approximately 15 %, indicating incomplete packing and orientation-induced weakness at the gate region.

When regrind content rises above 20 wt%, what limits should be applied?

Regrind inclusion is permitted only from uncontaminated production scrap with residual moisture below 250 ppm after re-drying. At 10 wt% regrind, the change in melt flow rate is generally less than 1 g/10 min; at 30 wt%, batch-to-batch notched Izod can fall from 15 kJ/m² to 9 kJ/m² because PLA undergoes chain scission during repeated melt processing. The recommended maximum regrind level is 20 wt%. Blending with virgin polypropylene, ABS, or polyamide is not recommended because the dissimilar melt phases create delamination and reduce weld-line strength. If regrind is unavoidable, the material should be dried at 80 °C for 4 h in a desiccant dryer with a dew point below −40 °C. Open hopper residence in uncontrolled humidity should not exceed 2 h.

Pre-drying is mandatory because PLA hydrolyzes rapidly above its glass transition in the presence of moisture. The grade is supplied in sealed bags with a moisture specification below 400 ppm but should be dried to below 250 ppm before molding. A closed-loop desiccant dryer with a dew point of −40 °C or lower, an air temperature of 80 °C, and a residence time of 4 h to 6 h is the standard preparation. At ambient storage or relative humidity above 60 %, the material can reabsorb surface moisture within 30 min to 60 min. Hopper dryers alone are insufficient unless they supply closed-loop desiccated air. Visible splay, nozzle drool, and a drop in melt viscosity are production indicators of moisture above 300 ppm. Drying in an uncontrolled hot-air oven is not recommended because the equilibrium moisture content may remain above the processing limit and can produce inconsistent lot-to-lot flow behavior.

Thermal stability boundaries and mold-temperature selection are not interchangeable with ABS.

The manufacturer specifies a melt temperature range of 190 °C to 210 °C at the nozzle. Barrel set points above 220 °C should be avoided because lactide regeneration and molecular weight loss accelerate. At 230 °C and a residence time above 5 min, the melt degrades to a low-viscosity state with amber streaks and reduced notched Izod. Mold temperature should be held between 25 °C and 40 °C. Below 25 °C, rapid cooling produces a brittle skin and weakens weld lines; above 50 °C, cycle time lengthens and ejection may become unstable because the heat deflection temperature of the solid is approached. For thin-wall sections below 1.5 mm, mold temperature is often set at 35 °C to 40 °C and injection speed is increased to maintain flow length. A mold temperature of 15 °C can reduce cycle time but lowers apparent ductility and may cause stress cracking at metal inserts or sharp corner transitions.

Electrical and electronic accessory manufacturers evaluate this grade under UL 94 HB at 3.0 mm thickness; the compound is not claimed as a V-0 system unless a dedicated flame-retardant variant is used. Compared with a mineral-filled PLA, Sustainable 2001 has higher practical flow length but lower isotropic stiffness; compared with a nucleated PLA, it has a slower crystallization rate, which improves dimensional stability in cold molds but narrows the auto-desorption window. Cosmetic closures and living hinges should be validated by repeated flexure testing under actual closure torque rather than by datasheet comparison because the modifier phase influences hinge whitening and crack initiation at high strain.

Regulatory boundaries and food-contact evidence requirements

Regulatory documentation for the base compound is generally limited to REACH Regulation (EC) 1907/2006 SVHC confirmation and RoHS Directive 2011/65/EU as amended by (EU) 2015/863. Bio-based carbon content is verified by ASTM D6866-24 Method B. Food-contact evaluation is application-specific; no generic regulatory clearance should be assumed. For the European Union, finished parts must be tested under Regulation (EU) 10/2011 for overall migration, with a limit of 10 mg/dm² for most dry and non-fatty applications unless the food type requires a stricter reduction factor. Specific migration of the impact modifier cannot be covered under a supplier-wide blanket statement because modifier identity and loading may change between production campaigns. For United States food-contact suitability, applicable status is established through food contact substance notifications or specific supplier documentation rather than a single generic FDA clearance.

Mold venting on existing polypropylene tools is often insufficient for this PLA blend because the melt off-gassing from residual moisture and low molecular weight constituents can produce deposit on mold surfaces. Vent lands below 0.02 mm or blocked vents are associated with short shots near the end of fill and burn marks. Storage stability is maintained when unopened bags are kept below 40 °C and protected from direct sunlight. Opened material should be returned to sealed, low-moisture containment or immediately processed, because shelf-life after opening is governed more by ambient humidity than by oxidative degradation. For injection molding sites operating in tropical environments, lot-specific moisture audits should be performed at the hopper inlet rather than relying on supplier bag-level moisture certificates alone.