Published moulding data for the specific EcoVid 80TFH High Heat Wood Filled Ingeo PLA compound remain limited to supplier-controlled trials; the following processing windows are conservative industrial starting points derived from filled Ingeo PLA manufacturing practice and must be validated on the intended tool, gate geometry, press, and downstream equipment. Injection moulding of thin-wall appliance enclosures and heat-exposed brackets begins with drying in a desiccant dryer set to 80 °C with a dew point no higher than −40 °C for 4 h; residual moisture above 250 ppm as measured by ISO 15512:2016 drives hydrolysis at melt temperature, producing brittle weld lines and a drop in notched Izod impact strength that is not recoverable by remoulding. Barrel profiles are staged from 35 °C at the throat, 190–200 °C in the compression zone, and 200–210 °C in the metering zone, with a flat profile ceiling of 215 °C because wood extractives degrade into acrid volatiles and gas splay appears on sections thicker than 1.5 mm. Back pressure is set to 3–6 bar hydraulic, screw speed between 50–80 min⁻¹, decompression at 2–3 mm to prevent drool, and shot cushion at 2–4 mm to maintain stable packing. Mold temperature is the only reliable route to high-heat performance: the tool must be held at 95–110 °C and the cavity completely filled before gate freeze, otherwise amorphous skins remain and heat deflection temperature under ISO 75-2 Method B at 0.45 MPa may remain below 85 °C instead of targeting a production minimum of 100 °C. Clamp force should be calculated at 0.6–0.8 kN/cm² of projected area for a 1.2–2.0 mm nominal wall, and the use of poppet-type hot runners is preferred over open hot tips because of the abrasive nature of the wood filler. Finished components include kettle bases, coffee-machine side panels, air-purifier frames, and power-tool clamshell housings where the part must survive internal surface temperatures of 80–90 °C without deformation; compliance targets for these electrical enclosures include IEC 60695-2-11 glow-wire end-product testing at 650 °C, RoHS Directive 2011/65/EU, and REACH 1907/2006 Annex XVII screening for restricted wood-preservative substances.

What restricts wood-filled Ingeo PLA in automotive interior trim?

The limiting variable in automotive interior substitution is not heat resistance in service but volatile emission behaviour under thermal ageing and the combination of scratch sensitivity, grain retention, and low-temperature impact after moulded-in colour. Door trim inserts, seat-back covers, lower pillar cladding, and electric-vehicle centre console trim produced from the compound must pass VDA 278 thermal desorption for volatile organic compounds and fogging; wood fibre and PLA oligomers released during the test can exceed typical OEM limits if the moulded part is not annealed or if regrind above 20 wt% is introduced without emission revalidation. Formulating adjustments are limited with a filled compound, so the converter controls emissions through barrel residence time below 6 min and mould temperature above 100 °C; this crystallises the Ingeo PLA matrix and reduces the amorphous free volume that would otherwise retain low-mass aldehydes and terpene-derived odourants from the wood component. Fogging performance must be evaluated under DIN 75201 Method B; a production-compatible target is 1.0 mg of condensate maximum on the glass plate, although published data for this exact formulation remains limited and batch-to-batch wood moisture shifts the result by 0.2–0.5 mg. Low-temperature ductility is tested at −30 °C through ISO 179-2 notched Charpy; wood-filled PLA grades typically exhibit brittle failure at this condition unless the wall thickness is reduced below 2.2 mm and the part is not constrained by metallic clips that create local stress concentration. Thermal ageing is assessed under ISO 188 accelerated oven ageing at 80 °C for 500 h; tensile retention after ageing is specified at 80% minimum against ISO 527-2. The surface is susceptible to stress whitening under a scratch stylus below 10 N unless an embossed wood-grain texture is tooled at 60–80 µm depth to mask micro-fracture tracks. All wood feedstock must be screened for biocides and substances of very high concern under REACH 1907/2006 and the POPs Regulation (EU) 2019/1021 before the material is accepted for series automotive interior applications.

Melt filtration, die pressure and barrel residence time in wood-plastic profile extrusion

Single-screw profile lines equipped with a grooved feed section and a 30:1–40:1 L/D screw are the preferred conversion route for interior cladding battens, furniture edge mouldings, and decorative window reveal profiles. The wood component in the EcoVid 80TFH compound is abrasive; screen packs must be staged as 20/60/100 mesh and changed when pressure drop across the adapter exceeds 35 bar, because larger chunks of agglomerated wood can tear the melt curtain and create surface slough that is impossible to remove downstream. Melt temperature measured at the die entry is kept at 180–200 °C; higher settings reduce viscosity but accelerate caramelisation of residual sugars in the wood, shifting profile colour from light maple to tobacco within 30 min of residence. The die land length for a 1.5 mm profile wall is held at 15–20 mm to generate sufficient backpressure for melt homogenisation without exceeding 110 bar at the screw tip. Immediately after the die, a water-cooled calibrator at 40–60 °C sets the outer skin; a downstream hot-air tunnel at 100–115 °C for 30 s is then required to complete crystallinity, otherwise the profile will exhibit post-extrusion shrinkage in excess of 0.8% along the extrusion direction when later exposed to 60 °C under intermittent sunlight. The terminal product range includes 6–10 mm decorative edge banding coextruded with an unfilled Ingeo PLA cap layer for surface finish; the cap layer must be limited to 0.2–0.3 mm because thicker cap stock reduces the effective wood content at the surface and alters grain embossing depth during calibrator bending. Fire performance for interior furniture profiles is assessed by EN 13501-1 Euroclass contribution; untreated wood-filled PLA profiles typically reach Euroclass D or E, so end-use placement in public interior applications requires a non-halogen phosphate flame retardant system at 5–8 wt% and revalidation of melt pressure because phosphate additives lower melt viscosity by 10–15% as measured on a capillary rheometer per ISO 11443:2021. Indoor air emission profiles must also be screened under EN 16516 for formaldehyde and acetaldehyde release from the wood-PLA interface, particularly when the profile is cut on site and a fresh edge is exposed.

Fused filament fabrication of EcoVid 80TFH for production tooling, jigs, fixtures, and low-volume interior fascia prototypes requires a calibrated direct-drive extruder with a hardened steel nozzle of 0.6 mm minimum bore; brass nozzles are not recommended because wood fibre enlarges the orifice by 5–10 µm within 200 h of service, increasing the effective extrusion width beyond the slicer offset. Filament must be dried at 60 °C for 8 h in a forced-air dryer before use and printed from a sealed filament box held below 15% RH; moisture regain after 4 h of open-ambient storage at 55% RH elevates die swell and produces a stringing defect that cannot be fully compensated by retraction settings. Retraction distance is held at 1.5–2.5 mm with retraction speed of 30 mm/s and a wipe of 0.5 mm on long travel moves. The extrusion temperature window is tight: 200–215 °C at the nozzle, with a build plate at 90–105 °C and a chamber or enclosure maintained at 35–45 °C to reduce warpage. Layer adhesion is the controlling mechanical factor; tensile properties along the Z axis are 40–55% lower than XY-plane values under ISO 527-2, and the failure mode is delamination along the layer interface because wood particles disturb interlayer polymer diffusion. Printing of 0.2 mm layers at 40–60 mm/s is the practical optimum for high-heat fixtures; speeds above 80 mm/s cause under-extrusion at wood-rich regions and leave surface potholes with depth of 0.1–0.3 mm. Terminal components in low-volume production include vacuum-forming tooling where the printed surface temperature must withstand 80–90 °C sheet contact without soft-creep under 0.1 MPa of clamping pressure, and inspection fixtures that require dimensional stability below 0.2% after thermal cycling from 20 °C to 85 °C according to IEC 60068-2-14 change-of-temperature test logic.

When a 0.8 mm wood-PLA sheet is thermoformed against hot fill and 30 min load

The initial sheet temperature must remain within 85–95 °C at the forming station; higher sheet temperatures above 100 °C cause the wood fibres to scorch at the clamp frame edge and produce brown striations that remain visible after trimming. Extruded sheet for this segment is produced as roll stock with a thickness of 0.8 mm; it is reheated in a forced-circulation oven, not a contact heater, because direct contact above 95 °C accelerates oxidation of the wood-polymer interface and produces a sticky low-molecular-weight exudate on the sheet surface. Female mould temperature is set to 90–100 °C; a plug-assisted pre-stretch at 0.3 MPa is required to distribute wall thickness before final vacuum, otherwise the bottom corners of a 25 mm deep tray thin below 0.4 mm and fail the hot-fill hold. The terminal article is a rigid tray, blister, or cosmetic display insert that must withstand contact with an object at 80 °C for 30 min without visually measurable deformation; this is verified by loading the formed part with a 1 kg steel plate and measuring base deflection against a granite flat plate with a dial indicator of 0.05 mm resolution. Food-contact use is not claimed unless the specific lot is tested under Regulation (EU) 10/2011 for overall migration and the wood source is verified to be free of preservatives; this application is therefore limited to non-food cosmetics, electronic accessory trays, and retail display formats. Post-forming crystallinity is the main quality gate: samples cut from the tray base and sidewall are analysed by differential scanning calorimetry at 10 °C/min according to ASTM D3418-21; cold crystallisation enthalpy above 5 J/g indicates insufficient forming temperature or dwell time and predicts premature deformation under hot-fill conditions.

After extrusion or moulding, thermal annealing converts amorphous skins into a nucleated crystalline matrix

For parts that do not reach adequate crystallinity in the tool or calibrator, a separate annealing step is the only route to the heat resistance implied by the high-heat grade designation. Demoulded parts are placed in a circulating-air oven at 100–115 °C for 20–30 min; the lower bound prevents cold crystallisation from stalling, and the upper bound is fixed by the onset of wood-fibre odour release and dimensional distortion in unrestrained areas. Shrinkage during annealing is anisotropic: the machine direction can contract 0.4–0.7%, while the transverse direction can expand 0.1–0.3% due to fibre orientation and flow-induced residual stress; fixtures must therefore be machined to the expected post-annealed dimensions or the part must cool in the fixture. The crystallinity increase is measured by ASTM D3418-21; the annealed enclosure typically shifts from an amorphous cold-crystallisation exotherm above 5 J/g to a final crystallinity of 40–48% as measured by enthalpy of fusion referenced to 93.6 J/g for polymorphic PLA. This increase in crystallite content raises heat deflection temperature under ISO 75-2 Method B at 0.45 MPa from below 85 °C to above 100 °C, which is sufficient for hot-air ducts, gaming console mid-frames, and vehicle parcel shelf supports. One operational restriction is that annealing must occur after any secondary cutting, hole punching, or ultrasonic welding; if the annealed part is machined later, the machined edge exposes amorphous material and local heat generation can produce stress cracks visibly propagating from the cut line. Ultrasonic welding is further limited by the wood filler, which reduces polymer-to-polymer contact at the weld interface; joint strength must be revalidated by a lap-shear test instrumented with a 10 kN load cell and crosshead speed of 10 mm/min, and a joint overlap below 3 mm is not recommended for load-bearing retaining features.