Clariant supplies a bio-based colored 3D printer filament family intended for fused filament fabrication equipment. The product is composed of a bio-derived polyester matrix—predominantly polylactic acid or a related bio-based polyester—compounded with Clariant color concentrates and processing stabilizers. The product designation is order-specific and generated from base-resin type, color code, and filament diameter. No single public model number covers all variants; requests for technical data should cite the lot code on the spool label. The base-resin selection and colorant let-down ratio determine final rheological, mechanical, and thermal properties. Renewable carbon content is quantified using ASTM D6866-21 Method B. PLA-based feedstocks typically exceed 95% renewable carbon before pigment addition; the final renewable carbon fraction depends on the mass fraction of petroleum-derived pigments and additives. Published data for the exact Clariant colored formulation is limited; comparative performance should be established on printed specimens according to ISO 527-2:2012, ISO 178:2019, and ISO 75-2:2013 rather than on injection-molded test bars. The material is not a single universal compound; it is a compounded filament family in which color concentrate loading and base-resin grade are matched to the print application. Dimensional, color, and moisture data are issued on a lot-specific certificate of analysis. The presence of bio-based carbon does not classify the product as biodegradable or industrially compostable without separate certification to EN 13432:2000.

What Dimensional and Rheological Limits Govern Printing?

Commercial filament is available in nominal diameters of 1.75 mm and 2.85 mm. Industrial roundness specifications commonly require diameter deviation no greater than ±0.05 mm; optimized tolling lines using dual-axis laser gauges report lot capability down to ±0.03 mm at 3 sigma. Dimensional data must be taken from the certificate of analysis because pigment loading and base-resin crystallization shift die swell. Melt volume-flow rate for PLA-based compounds is measured under ISO 1133-1:2022 at 210°C and 2.16 kg; typical printing-grade PLA feedstock values fall between 6 g/10 min and 15 g/10 min. Color masterbatch let-down ratios from 1 wt% to 4 wt% can alter MVR by ±2 g/10 min across a production campaign. Capillary rheometry at 190–210°C reveals a shear-thinning pseudoplastic response with power-law index between 0.4 and 0.7 for pigmented PLA compounds; this range indicates that lower print speeds may reduce melt-pressure fluctuation in unheated hot-end configurations. On a co-rotating twin-screw extruder with L/D 40:1 and screw diameter of 25 mm, a barrel profile of 160–190°C is used to disperse organic pigments without exceeding the lactide reformation threshold. Higher shear rates above 1000 s⁻¹ in the printing nozzle may generate viscous heating and reduce melt viscosity by 5–10%, which alters extrusion width in long toolpaths.

Starting parameters for PLA-based bio-based colored filaments commonly span nozzle set points of 190°C to 220°C, bed temperature of 20°C to 60°C, and linear print speed of 30 mm/s to 60 mm/s. A hardened steel or stainless nozzle with internal diameter of 0.4 mm is recommended when inorganic pigments or mineral fillers are present; brass nozzle wear can alter effective extrusion width within 500 g of abrasive filament throughput. Enclosed build chambers are not mandatory, but ambient air temperature above 30°C can reduce cooling-driven dimensional control. Part cooling fans should remain off for the first two layers and then operate at 50–100% depending on overhang geometry. The first-layer height should be maintained at 0.15 mm or greater when colored grades exhibit higher zero-shear viscosity than natural feedstock. Build plate adhesion on unheated glass requires a polyvinyl acetate adhesive film or a dedicated polymer adhesive; heated glass beds above 60°C can cause localized annealing and dimensional drift in tall PLA parts.

Pigment Dispersion Effects on Interlayer Weld Strength

In bio-based colored filament, the pigment and dispersant package influences melt viscosity, surface energy, and weld-line strength. Printed specimens tested under ISO 527-2:2012 often show tensile strength reductions of 5–15% relative to uncolored PLA feedstock when pigment agglomerates exceed 5 µm. High-shear dispersion on a twin-screw extruder with L/D 40:1 reduces agglomerate size below 2 µm, which limits stress concentration. Interlayer adhesion is evaluated by tensile testing perpendicular to layer lines; ISO 527-2 Type 1B specimens printed flat show lower strength than injection-molded bars, and the reduction is more severe for heavily pigmented grades. Nozzle temperature should be increased by 5–10°C within the 190–220°C window when switching from a natural to a colored bio-based compound because colorants raise viscosity. The same effect can reduce oozing and stringing but can also cause under-extrusion if the first-layer height is below 0.15 mm. Weld strength at the layer interface depends on reptation and interdiffusion across the polymer-polymer boundary; higher pigment loading reduces the effective contact area. Additives that migrate to the filament surface can also lower surface energy and reduce adhesion to build plates. A surface energy below 40 mN/m on the printed surface may indicate excessive slip-agent or dispersant bloom.

Thermal degradation of PLA-based compounds is governed by chain scission, lactide regeneration, and colorant decomposition. Residence times above 5 min at nozzle temperatures above 240°C are not recommended. At 230°C, the apparent viscosity of PLA compounds decreases over time; capillary rheometry shows a reduction of up to 15% after 10 min of static residence, leading to over-extrusion at the start of toolpaths. Print jobs requiring nozzle standby periods longer than 3 min should use retraction and nozzle wipe routines to purge degraded melt. Thermogravimetric analysis at 10 K/min under nitrogen typically shows 1% mass loss near 300°C, but the onset shifts lower by 10–20°C when organic red and yellow pigments are present. Processors encountering intermittent nozzle clogging should reduce the retraction distance to 2 mm or less and verify that the heat break cooling fan is operating within specification.

On single-screw filament extrusion lines, melt-pump suction pressure should remain below 50 bar; excursions above this threshold indicate pigment agglomerate filtration or insufficient screw feed. A screen pack of 60/80/60 mesh is typical for colored compounds, but mineral pigments may require a deeper filter to avoid pressure rise. Spool winding tension of 0.5–1.0 N is typical for 1.75 mm filament; higher tension creates memory and can cause dimensional loss during printing. Batch-to-batch variance in colorant dispersion is observable in MVR shift even when the same masterbatch ratio is used, which is why certificate-of-analysis review is required before production runs.

When Moisture Uptake Exceeds 0.4 wt% and Drying Becomes Mandatory

PLA-based colored filaments are hygroscopic; storage at relative humidity above 60% for periods exceeding 24 h can raise moisture content above 0.4 wt%. Moisture degrades printed surface finish and can create microvoids at layer boundaries. Moisture content is determined by Karl Fischer titration under ISO 15512:2019. Pre-drying in a desiccant dryer at 45°C for 4–6 h is recommended before printing if the spool has been stored outside a sealed bag. Vacuum drying at 60°C for 2–4 h is an alternative, but the temperature should not exceed 65°C to prevent spool core softening. The use of a filament dryer with a dew point below −20°C maintains low moisture during long prints. Operators should not rely on heated build chambers to remove moisture from filament; the residence time is too short for effective drying.

Moisture uptake follows non-Fickian diffusion in PLA at room temperature, with the initial mass gain proportional to the square root of time. A spool exposed to 25°C and 70% RH can absorb 0.1 wt% within 4 h. The moisture plasticizes the polymer and lowers the glass transition temperature by approximately 2–5°C, which shifts the optimal bed temperature. Drying at 45°C removes surface moisture within the first 2 h, but core moisture in the filament spool requires longer residence. Re-drying is advised after every 8 h of open-bay exposure. The use of desiccant packs inside a sealed bag with a moisture indicator is insufficient for rewet spools; active drying is required.

Compared with petroleum-based ABS filament, a PLA-based bio-based colored filament typically exhibits higher tensile modulus, lower heat deflection temperature, and lower notched impact strength. Representative literature values place PLA-based compound tensile modulus at 3000–3500 MPa under ISO 527-2:2012 and petroleum ABS at 2000–2600 MPa; HDT B under ISO 75-2:2013 Method B is commonly 50–60°C for PLA-based compounds and 85–100°C for ABS. These values are not Clariant grade-specific but establish the mechanical trade space. Bio-based carbon content should not be confused with compostability: the presence of color concentrates, mineral fillers, or non-PLA impact modifiers can invalidate EN 13432:2000 industrial compostability certification. Renewable carbon is assigned by ASTM D6866-21 Method B, while end-of-life behavior is governed by separate standards. Compared with natural uncolored PLA, the colored grade may require a 5–10°C higher nozzle set point and may produce a measurable decrease in tensile strength. The use of a color masterbatch also reduces the renewable carbon fraction by the mass percentage of petroleum-derived carrier resin and pigment. This trade-off is not visible in a simple bio-based label.

Quality Assurance and Certification Requirements

Each lot should be accompanied by a certificate of analysis that states diameter tolerance, melt flow rate, moisture content, and CIELAB color coordinates. Color difference is measured under ISO 11664-4:2008; a ΔE*ab value below 1.0 is a typical industrial release limit for matched colors. Compliance records for EU REACH and RoHS are maintained by the supplier. Bio-based carbon claims require ASTM D6866-21 documentation. The verification matrix below lists the minimum analytical package for industrial qualification.

Color concentrates based on heavy-metal pigments are not compatible with RoHS restricted applications. The supplier declaration should certify that cadmium is below 0.01 wt%, while lead, hexavalent chromium, mercury, polybrominated biphenyls, and polybrominated diphenyl ethers are below 0.1 wt% in homogeneous materials under EU 2011/65/EU Annex II. For REACH, communication under Article 33 is mandatory when a substance of very high concern exceeds 0.1 wt% in an article. These thresholds are regulatory limits, not performance limits.

Processors should not assume that a bio-based label implies industrial compostability or food-contact status. Colorants and processing aids must be reviewed case-by-case. The filament should be kept away from amine-based additives and strong alkaline cleaning agents because PLA can undergo hydrolytic chain scission. Published data for this specific Clariant configuration is limited; qualification trials on the actual FFF machine and nozzle geometry remain the only reliable method for setting production parameters.