EcoVid 30GBTFH High Heat Wood Filled General Purpose Polylactic Acid is a melt-processable compound comprising a polylactic acid matrix, a cellulosic wood-fiber filler, and a high-heat modification package intended to raise the thermal resistance of general-purpose PLA. The model designation 30GBTFH serves as the production and lot-traceability identifier; published lot-specific data for this exact configuration are limited, so the processing windows, mechanical ranges, and application notes presented here are drawn from publicly reported values for comparable high-heat wood-filled PLA compounds tested under ISO and ASTM methods rather than from a certified EcoVid 30GBTFH datasheet. The grade is positioned for rigid, non-structural and semi-structural components in interior trim, furniture hardware, consumer electronics housings, point-of-purchase displays, and similar applications where reduced fossil-carbon content, matte surface character, and higher heat deflection than unfilled PLA are required.

How does the high-heat modification shift thermal performance relative to unfilled PLA?

The primary thermal distinction appears under load. Unmodified amorphous PLA typically exhibits a heat deflection temperature of 50–60°C when tested to ISO 75-2:2013 method A at 1.8 MPa. High-heat PLA grades containing nucleating agents or annealing-induced crystallinity can shift the practical upper range to 85–120°C under the same test geometry. In high-heat wood-filled compounds, the cellulosic filler contributes to heat deflection by increasing stiffness and reducing creep under load, but the filler alone does not fully account for the shift; crystallization kinetics and mold temperature history are equally significant. Melt flow behavior also changes. Published melt flow rate data for high-heat wood-filled PLA systems tested to ISO 1133-1:2022 at 210°C with a 2.16 kg load generally fall between 3 g/10 min and 15 g/10 min, whereas many unfilled general-purpose PLA grades are reported at 10–30 g/10 min under the same conditions. The reduced flow is a direct consequence of the wood-fiber reinforcement and should be accounted for in gate sizing and runner layout.

Dimensional stability is another differentiator. Mold shrinkage values reported to ISO 294-4 for comparable 30 wt% wood-filled high-heat PLA compounds are commonly 0.3–0.6%, while unfilled PLA often exhibits 0.4–0.8%. The lower and more anisotropic shrinkage reduces warpage in flat parts but introduces orientation-dependent mechanical behavior that must be managed through gate placement and flow-front velocity.

Thermal degradation, drying, and residence-time limits in wood-filled PLA melt processing

Moisture control is the first processing constraint. Wood-fiber-filled PLA pellets are hygroscopic and can absorb atmospheric moisture during open storage. Compounding and molding operations should maintain pellet moisture below 0.25% by weight, measured by ISO 15512, before melt processing. Pre-drying in a desiccant dryer with a dew point at or below -40°C is typically conducted at 60°C to 80°C for 4 h to 6 h. Drying above 85°C risks thermal discoloration of the cellulosic filler and loss of impact strength, while insufficient drying produces splay, void formation, and hydrolytic polymer degradation in the melt.

The melt-temperature window is narrow because the PLA matrix must be sufficiently fluid to wet the wood fiber, while the cellulosic filler begins to degrade at sustained temperatures above 200°C. Production-scale injection molding of similar compounds on hydraulic machines has used barrel profiles from 160–175°C in the rear zone to 190–200°C in the metering zone, with nozzle temperatures not exceeding 205°C. Barrel-zone deviations greater than ±5°C are associated with cold-slug formation at the low end and filler browning, acrid odor, or screw-slip at the high end. Screw-back pressure is held at 0.3–0.8 MPa hydraulic, and screw recovery speed is reduced to limit adiabatic shear heating.

Residence time is a second critical limit. In injection molding, barrel residence time should remain below 5 min at melt temperature, and purging is required before shutdown. In compounding, co-rotating twin-screw extruders with an L/D ratio of 36:1 to 48:1 are commonly configured with atmospheric or vacuum venting upstream of the die to remove moisture and volatile byproducts. Wood fiber is typically introduced through a side-stuffer after the polymer has softened, which preserves fiber length distribution and avoids excessive shear-induced degradation. Before shutdown, the machine should be purged with a low-MFR PLA or a dedicated purging compound to displace cellulosic residues from the screw and hot-runner channels. In hot-runner systems, externally heated manifolds should be set at the lower end of the melt window and no-flow zones should be minimized; wood-filled compounds can stagnate in dead spots and char over time.

Molding trials on comparable 30 wt% wood-filled PLA grades have been conducted on hydraulic and servo-electric injection molding machines with clamp forces from 800 kN to 1500 kN, shot sizes held between 40% and 70% of barrel capacity, and general-purpose or low-compression screws with a compression ratio near 2:1. Injection velocity is set in the moderate-to-fast range of 50–150 mm/s, with hold pressure maintained at 50–80% of peak injection pressure and hold time established by gate freeze-off rather than by fixed timer alone. Mold-temperature strategy follows two divergent routes. A cold-mold route at 20–40°C produces shorter cycle times but leaves the PLA matrix largely amorphous; post-mold annealing at 90–120°C for 1–2 h is then required to develop the full high-heat performance under ISO 75-2:2013. A hot-mold route at 90–110°C crystallizes the matrix in the tool but extends cycle time and increases the risk of part sticking. Tool surfaces should be polished or textured to release low-gloss wood-filled surfaces, and vents should be expanded to avoid gas-induced burns at the end of fill. Minimum wall thickness should generally be held at 1.5 mm or above, with rib thickness limited to 40–60% of the adjoining nominal wall to avoid sink and flow-front hesitation.

Mechanical property boundaries and test method designations

Table 1 lists indicative property ranges reported for high-heat wood-filled PLA compounds at nominal 30 wt% cellulosic filler loading. These ranges are not lot-specific release values for EcoVid 30GBTFH; they represent the published variability observed across comparable formulations, processing conditions, and specimen-preparation techniques. The table is intended for feasibility screening rather than final part design.

The mechanical profile indicates that high-heat wood-filled PLA is stiffness-driven rather than toughness-driven. Compared with unfilled PLA, the addition of 30 wt% wood fiber typically raises flexural modulus while reducing tensile elongation at break and notched impact strength. Published data for comparable systems show that the compound should not be specified for impact-critical snap-fit features unless the geometry has been modified to reduce peak strain. Moisture absorption to ISO 62 is higher than unfilled PLA because the natural filler is hydrophilic; dimensional change in humid environments should be evaluated on conditioned parts, not on dry-as-molded coupons.

When high-heat wood-filled PLA replaces ABS or mineral-filled polypropylene in rigid trim components

Rigid trim components that have been produced in unfilled ABS or talc-filled polypropylene can be evaluated for substitution when the part is not safety-critical and when the lower notched impact strength of the high-heat wood-filled PLA is acceptable. Table 2 provides a comparative screening profile using published values for the relevant material classes under commonly cited test methods. The high-heat wood-filled PLA column is indicative for comparable 30 wt% wood-filled grades, not a certified EcoVid 30GBTFH dataset.

The substitution logic differs by counter-material. Against unfilled PLA, the EcoVid 30GBTFH grade offers a higher heat deflection temperature under load and lower mold shrinkage, but it is more moisture-sensitive and has lower flow length. Against talc-filled polypropylene, the high-heat wood-filled PLA typically offers higher flexural modulus and a renewable cellulosic filler fraction, while showing lower notched impact strength and a tighter melt-processing window. Against ABS, the PLA compound offers lower fossil-based content and a lower melt-processing temperature, but it does not match the impact resistance of ABS and requires moisture-control discipline that ABS does not demand to the same degree. These trade-offs should be evaluated using part-specific finite-element modeling with the property ranges in Table 1 and Table 2, not by nominal material-class comparisons alone.

On a co-rotating twin-screw extruder with an L/D ratio of 40:1 to 48:1, high-heat wood-filled PLA is compounded by feeding the PLA and heat-stabilization package in the main hopper and the dried wood fiber through a side-stuffer located after polymer melting. Melt temperature at the die is maintained between 185°C and 200°C, with screw speed typically 300–600 rpm depending on torque capacity and fiber length retention. Vacuum venting at -0.08 MPa gauge or higher removes residual moisture and volatiles before the die. Pelletizing is conducted with a water slide or strand bath followed by air drying at 60–70°C; the pellets are then packaged in moisture-barrier liners. This stage is where fiber distribution, melt filtration, and dispersion quality are established, and it determines whether downstream injection molding can operate within the narrow ±5°C barrel-zone window without screw-slip or gas defects.

Is compliance with REACH, RoHS, and food-contact frameworks demonstrated for this grade?

Regulatory status must be confirmed with the compounder for each production lot. For high-heat wood-filled PLA compounds, REACH compliance generally requires a valid registration or exemption for the polylactic acid matrix, the cellulosic filler, and the nucleation and heat-stabilization additives. RoHS compliance is assessed against Directive 2011/65/EU Annex II restricted substances; the bio-based polymer and wood filler are not expected to contain restricted heavy metals, but colorants and processing aids may require documentation. Food-contact use is not automatically granted. Migration testing under Regulation (EU) No 10/2011 or FDA 21 CFR 175.300 is necessary if the finished part is intended for repeated food-contact service. Published data for EcoVid 30GBTFH under these food-contact frameworks is limited, and the presence of natural-fiber surface porosity can increase the effective surface area available for migration or microbial retention, making hygiene-critical applications substantially more difficult to validate than unfilled, smooth-surface PLA.

Storage of wood-filled PLA compounds requires sealed, moisture-barrier packaging and a protected warehouse environment at or below 50% RH and 10–30°C. Opened containers should be returned to desiccant storage or consumed within 8 h in uncontrolled tropical-humidity conditions; otherwise, re-drying at 60–80°C for 4 h is required before melt processing. Polymer degradation from repeated moisture cycling is not reversible by drying, because hydrolytic chain scission occurs during the first heat history. Therefore, the operational boundary for EcoVid 30GBTFH is defined less by the dry polymer specification and more by the discipline maintained between pellet drying, machine hopper isolation, and the time spent at melt temperature.