TERRAMAC TE-8210 is a polylactic acid injection-molding grade positioned for rigid parts requiring elevated heat deflection and high bending stiffness. The product is supplied as pellets and is formulated around a semicrystalline polylactic acid matrix with a crystallization-promoting additive package. Published manufacturer data identify the grade as a high-heat/high-rigidity injection material, with processing behavior distinct from amorphous polylactic acid grades. The following sections specify the property envelope, drying and molding windows, and comparative placement against unfilled amorphous polylactic acid and glass-fiber-reinforced polylactic acid systems.

When Mold Temperatures Exceed the Cold-Crystallization Onset

Mechanical performance of TERRAMAC TE-8210 cannot be separated from mold thermal history. On an electric injection molding machine with a 35 mm screw and a mold temperature held at 100°C, the grade develops sufficient crystalline fraction to shift the heat deflection temperature under 0.45 MPa to a reported 140°C when tested to ISO 75-2:2013. If the same material is molded into a cold tool at 40°C, the part remains largely amorphous and the 0.45 MPa heat deflection temperature falls to the 55–60°C range associated with non-nucleated polylactic acid. This thermal-history dependence is the principal processing boundary for the grade: high mold temperature is not a recommendation but a requirement for the high-heat property claim.

Published property data for TERRAMAC TE-8210 include flexural modulus measured to ISO 178:2019 at 6.0 GPa, flexural strength near 115 MPa, tensile strength at break to ISO 527-2:2012 at 68 MPa, and tensile elongation at break of 2.5%. Notched Izod impact strength according to ISO 180/1A:2023 is approximately 3.2 kJ/m², indicating limited ductility in notch-sensitive geometries. Mold shrinkage parallel and normal to flow is typically 0.3–0.5% under ISO 294-4:2018 conditions. The tabulated values below represent the manufacturer-published typical property set for the grade.

Moisture management is decisive for this grade. Polylactic acid undergoes hydrolytic chain scission during melt processing if pellet moisture exceeds 250 ppm; wet material produces silver streaks, unstable screw recovery, and measurable loss in ISO 527-2 tensile strength. TERRAMAC TE-8210 requires closed-loop desiccant drying at 70–80°C for 4–6 h at a dew point no higher than -40°C. At relative humidity above 60%, drying time should be extended to 8 h, and open bags should be re-dried before molding. Hot-air ovens are not an adequate substitute when ambient moisture is high because the required dew point is not reached.

Barrel profiles are typically set with rear zone 160–180°C, center zone 190–210°C, front zone 200–220°C, and nozzle 195–215°C. The measured melt temperature should not exceed 230°C. Screw speed and back pressure should be set to limit shear heating: stable screw recovery on a 50 t electric injection molding machine with a 22 mm screw has been reported at back pressure 0.5–1.5 MPa and screw speed 60–100 rpm. At melt temperatures above 230°C or residence times beyond 5 min, melt flow rate increases and notched Izod strength declines, consistent with random chain scission. Screw configurations should use 20:1–24:1 L/D ratios with compression ratios of 2.2–2.8:1, and the screw and barrel should be purged with polypropylene or low-density polyethylene before shutdown.

What Distinguishes TE-8210 from Unfilled Amorphous PLA and Glass-Filled Compounds?

The difference between TERRAMAC TE-8210 and standard amorphous injection polylactic acid is not primarily chemical identity but crystallization behavior in the tool. Unfilled amorphous polylactic acid grades typically show 0.45 MPa heat deflection temperatures near 55–60°C and flexural moduli near 3.5 GPa. TERRAMAC TE-8210 shifts both values upward only when the mold temperature is held above 100°C. The grade does not use glass fiber or mineral filler to achieve rigidity; therefore screw and barrel wear is lower than with 20% glass-fiber polylactic acid compounds and density remains close to 1.26 g/cm³. However, the absence of fiber also means that notched impact and tensile elongation remain in the brittle range.

The comparative table uses representative literature values for unfilled amorphous polylactic acid and glass-fiber polylactic acid compounds; these are not supplier specifications for a single commercial grade. Published creep data for TERRAMAC TE-8210 under sustained load is limited. Design should not rely on short-term flexural modulus alone when replacing glass-filled polyester or polybutylene terephthalate in structural applications. Continuous service temperature should be derived from ISO 899-2 creep data or prototype testing under the actual mechanical load, not from the 0.45 MPa heat deflection temperature.

Tooling design must account for the grade's crystalline shrinkage and low elongation. Gates should be located away from high-stress areas; direct sprue gates and tab gates are preferred over pinpoint gates for thick sections because the material does not tolerate high shear at the gate. Venting depth of 0.015–0.025 mm is recommended along the parting line to avoid burn marks caused by trapped air. Ejector pins should have sufficient area because the hot mold reduces green-part stiffness during ejection; typical ejection temperatures of 80–100°C are needed to avoid part deformation. Hot runner systems are usable but must avoid dead spots and shear-induced heating above 230°C.

Post-mold annealing at 100–120°C for 2–4 h can further raise the 1.8 MPa heat deflection temperature, but uncontrolled annealing causes warpage in parts with variable wall thickness. The grade is not recommended for continuous hot-water service above 60°C or for applications requiring notched Izod impact strength above 5 kJ/m² unless toughness modification is validated with part-level testing.