EcoVid 43TF is supplied as a compound of Ingeo PLA and a lignocellulosic wood flour. The base resin is a poly(lactic acid) produced through microbial fermentation of plant-derived dextrose followed by lactide ring-opening polymerization. The 43TF model designation identifies the product within the EcoVid series; the supplier’s certificate of analysis is the authoritative source for filler loading, residual lactide, moisture content, and melt flow rate, because published data for this specific configuration is limited. Representative wood flour–PLA compounds in the commercial 40–50 wt% filler range exhibit density values of 1.24–1.32 g/cm³ measured by ISO 1183-1:2019, tensile modulus values of 3.8–6.2 GPa measured by ASTM D638-14, and flexural modulus values of 4.0–6.8 GPa measured by ASTM D790-17. The compound is intended for injection molding, sheet extrusion, and thermoforming where higher stiffness-to-weight ratio, lower mold shrinkage, and reduced fossil-polymer content are required. These properties are not automatic and depend on drying, melt residence time, screw design, mold temperature control, and the presence or absence of a coupling agent.

What distinguishes wood flour filled Ingeo PLA from mineral-filled and unfilled grades?

Compared with unfilled Ingeo PLA, the incorporation of wood flour changes the rheological and mechanical signature. At 210°C and 2.16 kg, the melt flow rate of filled systems measured by ISO 1133-1:2022 or ASTM D1238-23 is typically lower than unfilled PLA; commercial wood flour compounds in the 40–50 wt% range may fall below 10 g/10 min, while unfilled Ingeo PLA grades frequently exhibit values from 6–30 g/10 min. Water absorption increases significantly with lignocellulosic filler. Under ASTM D570-22, 24 h water uptake for wood flour filled PLA often ranges from 1.5–4.0%, compared with 0.2–0.4% for unfilled PLA. Compared with 20 wt% talc-filled PLA, the wood flour grade is generally less abrasive to screw elements and barrel liners but more hygroscopic and more thermally sensitive. Mineral-filled PLAs often exhibit higher density of 1.32–1.42 g/cm³ and more consistent nucleated crystallization, which can produce heat deflection temperatures above 90°C at 0.455 MPa when nucleated; wood flour variants typically require annealing or a nucleating agent to reach equivalent thermal resistance.

Data in the table are representative published ranges for wood flour–PLA systems and mineral-filled PLA; compound-specific values from the EcoVid certificate of analysis must govern part qualification.

Melt temperature and moisture limits are interdependent at 200–230°C

Before processing, pellets should be dried to 250 ppm (0.025%) moisture or less. Ingeo PLA processing literature recommends desiccant drying at 80°C for 4 h with a dew point of -40°C or lower. At ambient relative humidity above 60%, pre-drying is essential because absorbed moisture hydrolyzes the polyester backbone at melt temperatures above 190°C. In a vented 40:1 L/D co-rotating twin-screw extruder, barrel settings for wood flour filled PLA commonly follow a flat-to-mild reverse profile from 165°C at the feed throat to 210–230°C at the die, with vacuum venting below -0.08 MPa gauge. The processing window is narrow: melt temperatures above 230°C accelerate molecular weight loss and release acetic acid, while temperatures below 190°C can create excessive torque, screw stall, or unmelted filler agglomerates. Melt residence time should be minimized. Industrial practice on injection molding machines in the 1,500–2,500 kN clamp force class indicates that total barrel residence time beyond 8 min at 210°C can produce visible darkening and reduce notched Izod impact by more than 20%. Additives containing primary or secondary amines should be avoided because they accelerate hydrolysis of PLA and can cause surface exudation.

Injection molding trials on hydraulically clamped machines in the 1,200–2,500 kN class typically use barrel temperature profiles of 180–220°C, mold temperatures of 25–60°C, and back pressure of 0.5–1.0 MPa. Injection speed should be set to prevent jetting; for thin-wall parts below 2.0 mm, fill times of 0.5–0.8 s are commonly used. Screw decompression should be limited to 3–5 mm to avoid air entrapment and moisture uptake at the feed throat. Mold shrinkage measured by ASTM D955-21 is generally in the 0.3–0.6% range. Warpage caused by anisotropic filler orientation is reduced by locating the gate near a thick section and maintaining a uniform mold temperature within ±5°C; unbalanced cooling circuits in production tools can double measured flatness deviation on parts longer than 150 mm.

Sheet extrusion with EcoVid 43TF requires a polished three-roll stack set at 40–60°C. The die lip gap is normally set to 0.8–1.2 times the desired final sheet thickness because the filled melt exhibits lower die swell than unfilled PLA. If the sheet is drawn from the die at a ratio greater than 2.5:1, edge tearing and transverse modulus imbalance may occur. Thermoforming plug assist temperatures of 80–120°C and mold temperatures of 25–50°C are used. Sheet surface temperature should be checked with an infrared pyrometer to remain above 100°C during drawing to prevent brittle cracking at the corners. Thermoformed parts may show wall-thickness distribution variance of ±0.15 mm when using a plug depth of 70% of cavity depth. Line speed should be reduced if sheet moisture exceeds 0.3%.

When a 43 wt% lignocellulosic filler is compounded at L/D 40:1

This configuration requires a side stuffer or loss-in-weight feeder capable of delivering wood flour with tapped bulk density of 0.25–0.45 g/cm³. The main polymer feed should be flood-fed at the first barrel, with filler introduced downstream after polymer melting to limit barrel wear and moisture entrapment. Screw design uses 2–3 kneading blocks with staggered angles of 30°–90°; the first mixing zone disperses the filler, while the second distributes the coupling agent and removes volatiles through a downstream vacuum vent. Specific mechanical energy input typically ranges from 0.15–0.30 kWh/kg. Higher SME leads to thermal degradation; lower SME yields poor dispersion and anisotropic mechanical properties. Filler particle size distribution should be controlled: retention on a 180 µm sieve should be below 5 wt% to avoid surface defects in molded parts, while fines below 45 µm can increase water absorption but improve surface finish. A high-shear dispersive zone combined with weak coupling can produce a 10–15% difference in tensile strength between replicate batches; batch-to-batch variation in wood species, moisture, and particle aspect ratio is a known production-scale bottleneck.

Regulatory and supply-chain certification boundaries

Compliance statements for EcoVid 43TF must be obtained from the supplier’s technical data sheet and certificate of conformance. The base Ingeo PLA resin is commonly manufactured under food-contact clearances such as FDA 21 CFR 177.1520 and EU No 10/2011 for specific conditions, but the addition of wood flour and processing aids requires separate migration testing under the EN 1186 and EN 13130 series methods. Heavy-metals and REACH compliance should be verified by REACH EC 1907/2006 Article 33 declarations; RoHS compliance is typically limited to EU 2011/65/EU Annex II substance restrictions. Industrial compostability is not automatically conferred. Disintegration and ecotoxicity must be tested according to EN 13432:2000 or ASTM D6400-23, with 90% mineralization within 180 days under controlled composting conditions. For food-contact applications, migration of wood-derived aldehydes and residual lactide should be assessed under the EU No 10/2011 total migration limit of 10 mg/dm². For outdoor applications, water swelling and UV exposure should be characterized by ASTM D570-22 and ISO 4892-2:2013; published data for this specific configuration is limited.