The product designation Ensinger TECAFIL PA6 GF30 black, 2.85 mm filament, identifies a melt-compounded polyamide 6 monofilament containing 30% by weight chopped glass fibre. The black grade is supplied in sealed vacuum packaging to limit atmospheric moisture uptake before first use. Diameter control is specified at ±0.05 mm with an ovality tolerance below 0.05 mm according to supplier documentation; these values are measured by laser micrometry. The composite density is approximately 1.35 g/cm³ when tested to ISO 1183-1, compared with 1.13 g/cm³ to 1.14 g/cm³ for unfilled nylon 6. The glass fibre is dispersed in the PA6 matrix during twin-screw compounding at shear rates sufficient to reduce fibre bundle agglomeration, but retained fibre length after pelletising and filament extrusion typically falls below 300 µm. Because the glass loading is 30% by mass, it reduces the equilibrium moisture uptake of the composite relative to unfilled PA6; however, the nylon 6 matrix remains hygroscopic and requires drying.

From a processing standpoint, the material is extruded at nozzle set temperatures between 250 °C and 280 °C, with a heated bed maintained between 80 °C and 110 °C. Build chamber temperature is used when available; a chamber setpoint of 60 °C to 80 °C reduces premature solidification and warpage in parts with continuous fibre orientation along the print plane. Direct-drive extruders with hardened feed gears and dual-drive idlers are preferred because the glass-filled compound exhibits higher melt viscosity than unfilled PA6 and transmits more feed-path resistance. Print speed is generally limited to 30 mm/s to 60 mm/s for nozzle diameters of 0.4 mm to 0.6 mm, but published data for maximum volumetric throughput in this specific product configuration is limited.

Glass fibre loading and the thermal stability of the PA6 matrix

Melt compounding of 30% glass fibre into a nylon 6 matrix reduces mould shrinkage and elevates short-term thermal load capacity. Representative published values for dry-conditioned fused filament fabrication coupons tested in the XY plane are summarised in Table 1. The glass fibre orientation follows the deposition path, producing anisotropic mechanical properties; the Z-direction tensile strength may be 40% to 60% lower than XY-direction values when interlayer fusion is incomplete. Short-term heat deflection temperature measured at 1.8 MPa according to ISO 75-2 Method A is substantially higher than unfilled PA6, but continuous service temperature must be limited by creep and oxidation effects rather than by HDT alone. The supplier indicates that the glass-filled PA6 range is generally compliant with RoHS Directive 2011/65/EU Annex II and REACH SVHC requirements; batch-specific certification should be confirmed for the black pigmented grade.

Values in Table 1 are representative and depend on print orientation, layer height, extrusion multiplier, chamber temperature, and conditioning. Supplier datasheets should be reviewed for batch-specific results before load-bearing component qualification.

What separates the 30% glass fibre grade from unfilled nylon 6 and carbon-fibre-filled PA6?

Comparative data for dry-conditioned printed coupons show that the glass-filled grade shifts the mechanical response from ductile yielding to quasi-brittle failure. Unfilled nylon 6 filament absorbs more moisture at equilibrium and displays higher elongation but lower modulus under ISO 527-2. The 30% glass fibre grade raises tensile modulus into the range of 7,000 MPa to 8,000 MPa and reduces creep strain under sustained load, although notched impact strength is significantly lower than that of unfilled PA6. Compared with carbon-fibre-filled PA6 compounds, TECAFIL PA6 GF30 black is electrically non-conductive and generally lower in stiffness, while avoiding carbon fibre’s galvanic coupling risk with aluminium and magnesium counterfaces in wet environments. Compared with glass-filled PA12, the PA6 matrix offers higher short-term strength and temperature capability but greater moisture sensitivity and dimensional change with humidity. The product is therefore used in rigid fixtures and housings where dimensional stability under moderate sustained stress is prioritised over ductility or conductivity.

When hardened steel nozzle hardware becomes a process requirement

At nozzle temperatures of 260 °C to 280 °C, chopped glass fibres produce accelerated bore wear in brass nozzles, causing uncontrolled changes in extrusion width and melt leakage around the heater block. Hardened tool steel, tungsten carbide, or ruby-tipped nozzles with a minimum orifice diameter of 0.4 mm are specified for stable dimensional output over multi-spool runs; 0.5 mm to 0.6 mm orifices reduce clogging and nozzle pressure drop. Because hardened steel has lower thermal conductivity than brass, nozzle set temperature may require an increase of 5 °C to 10 °C to maintain the same melt temperature, verified by hand-held melt thermocouple measurements on the nozzle block. The feed path should avoid tight bends and use wide-radius PTFE guide tubes. In production environments, filament dust from glass fibre should be controlled with local extraction to prevent accumulation on linear rails and drive gears.

Controlling moisture uptake before and after printing

Storage in sealed foil with desiccant is required once the primary spool is opened. At 50% RH and 23 °C, unfilled PA6 reaches equilibrium moisture content near 2.5% by mass according to ISO 62; the 30% glass fibre reduces that value on a composite basis, but moisture still degrades layer strength and creates surface splay if the filament is printed wet. Pre-drying at 80 °C for 4 h to 8 h in a dry-air dryer with a dew point below -30 °C is recommended; vacuum drying at 80 °C for 6 h to 12 h can also be used. After printing, moisture re-equilibration acts as a plasticiser: tensile modulus decreases and Charpy impact increases as the part approaches ambient humidity. Dimensional growth of 0.4% to 0.8% can occur in thin sections after humid ageing. For maximum stiffness and HDT retention, parts should be tested in the dry-as-moulded state or stored in sealed barriers until immediately before measurement.

Chemical exposure limits for PA6 GF30 black are dictated by the polyamide matrix rather than the glass reinforcement. The material is generally resistant at room temperature to aliphatic hydrocarbons, greases, and many commercial lubricants, but hydrolytic degradation can occur in hot aqueous acid or strong alkaline media. Resistance should be evaluated by immersion testing to ISO 175 for the specific chemical and service temperature; supplier data for the black glass-filled grade is not exhaustive for every process fluid. The black pigment system may also be unsuitable for food-contact or medical use unless explicit FDA or EU 10/2011 compliance documentation is supplied for the exact grade. Parts that require machining after printing should be milled with carbide tooling because glass fibres cause rapid flank wear in high-speed steel tools.

In tooling and fixture applications where dimensional stability at elevated temperature is critical, the TECAFIL PA6 GF30 black filament is typically deposited in a heated build chamber and printed with the outer shell lines parallel to the primary load path. Robotic gripper jaws, drilling templates, and assembly nests machined from printed blanks are typical uses where the fibre-filled material reduces creep under clamping force. The limiting factors for operational use are the interlaminar Z-direction strength, moisture-induced dimensional change, and the maximum continuous service temperature of the PA6 matrix under oxidative conditions, which is generally below the short-term HDT value reported in Table 1. No end-use deployment should proceed without testing coupon-level mechanical data generated on the same printer, chamber, and nozzle configuration used for production parts.