Essentium TPU 80A-Z Additive Manufacturing Filament is an unfilled thermoplastic polyurethane supplied for high-speed extrusion platforms in 1.75 mm ± 0.05 mm diameter. The grade carries a Shore A hardness of 80 under ASTM D2240 and a specific gravity of 1.17–1.20 under ASTM D792. It is positioned below Shore A 95 TPU in stiffness and above it in recoverable elastic deformation, which makes the Z grade applicable to parts that must absorb cyclic impacts, conform to irregular mating surfaces, or retain sealing force after repeated compression. Published supplier data report tensile strength at break in the 30–38 MPa range under ASTM D638 and elongation at break in the 500–620% range. The material is processed on direct-drive additive manufacturing machines with heated beds between 20 °C and 60 °C, although published data for this specific configuration is limited for Bowden-tube setups operating above 80 mm/s. Field experience on production high-speed extrusion lines indicates that uncontrolled moisture absorption is the primary cause of nozzle-pressure fluctuation, surface pits, and interlayer delamination; spools exposed to plant air at 60% relative humidity for more than 8 h require pre-drying at 80 °C for 4 h in a desiccant dryer with a dew point no higher than −40 °C.

What Are the Supplier-Published Mechanical Property Values and Their Test Context?

The property envelope below is generated on conditioned specimens under ISO 291 standard atmosphere at 23 °C and 50% relative humidity. Because thermoplastic polyurethane is viscoelastic, tensile strength and elongation depend strongly on strain rate, specimen geometry, and print orientation. The values should not be used for design without validation on production geometry.

When the filament is dried to a residual moisture content below 0.05 wt%, extrusion is stable at nozzle temperatures between 220 °C and 245 °C. On a direct-drive high-speed extrusion platform with a 0.8 mm hardened steel nozzle and a chamber ambient of 35 °C, a linear print speed of 30–60 mm/s produces continuous melt deposition without unsteady backpressure. At layer heights above 0.3 mm with the same nozzle diameter, interlayer wetting improves because the larger molten bead retains heat longer, but sidewall sag becomes measurable above 240 °C. The process window narrows to ±5 °C when cooling fans above 70% duty are used; excessive fan speed rapidly quenches the surface and can reduce interlayer adhesion by 15–25% relative to quiescent cooling, as measured by Z-direction tensile pulls. Bed adhesion is acceptable on polyimide tape, heated glass, and polypropylene-coated polyvinyl chloride plate at 40–60 °C; below 30 °C, edge lifting on parts longer than 150 mm is common.

When the 80A-Z Grade Is Run on Unheated Bowden Machines, What Limits Interlayer Strength?

When the 80A-Z grade is run on unheated Bowden machines, interlayer strength is limited by filament buckling in the guide tube. Because Shore A 80 TPU has low column stiffness, retraction distances above 2 mm induce hysteresis and varying feed pressure; production trials have measured an interlayer tensile drop of 20–30% compared with direct-drive extrusion at equivalent nozzle temperature. The recommended start parameters for a Bowden configuration are therefore limited to 20–35 mm/s linear speed, 225–235 °C nozzle temperature, and retraction distance no greater than 1.5 mm. If retraction is set above 2 mm or travel speed exceeds 120 mm/s, stringing and ooze defects form because the filament cannot be retracted cleanly through the melt zone. Published data for this specific configuration is limited for some printer models; operators should run a standard retraction tower printed at 220–240 °C in 5 °C increments before production.

Extruder backpressure serves as a practical moisture diagnostic in high-speed toolpaths. A melt-pressure transducer mounted at the nozzle entry on an industrial direct-drive tool indicates a stable reading for dry feedstock under steady feed rate; a pressure oscillation above 2 MPa from baseline is associated with water vaporization, partial plugging, or feed-wheel slip. When the same transducer signal is stable but the extruded bead shows periodic thickness variation, the feed wheel tension is reduced to below 15 N because excessive compression flattens the flexible filament and introduces variable feed length. On production machines, placement of the filament spool below the extruder and use of a filament guide with a ≥50 mm bend radius lowers feed resistance and reduces cold-zone deformation.

Support removal for Shore A 80 TPU is mechanical rather than chemical. The material welds to itself at layer interfaces; a support separation gap below 0.20 mm makes removal difficult, while a gap above 0.35 mm degrades underside surface quality. For internal channels, a breakaway support printed with a 0.4 mm nozzle and a 0.25 mm separation gap is recommended, with support roof density above 60% to prevent sagging. The material is not compatible with solvent-based support removal processes that use limonene or acetone; these solvents cause surface swelling without dissolving the TPU. Water-soluble polyvinyl alcohol supports are generally ineffective because TPU self-adhesion is stronger than the PVA interface unless the PVA is printed at 190–200 °C and the TPU at 220 °C. Operators on production machines have noted that support removal time can be reduced by chilling printed parts to −20 °C for 20 min before mechanical separation.

Differences from Shore A 95 and Rigid Polyurethane Grades

Compared with a Shore A 95 TPU, the 80A-Z grade exhibits lower hardness and lower 100% tensile modulus, which produces softer contact stress and better recovery in compression seals. Supplier data place the 80A-Z elongation at break roughly 100–200 percentage points higher than a comparable Shore A 95 ether-based TPU, but tear strength is typically 10–15% lower under ASTM D624. Compared with a Shore D 74 rigid TPU, the 80A-Z grade trades abrasion resistance and creep modulus for cold-temperature flexibility and impact damping; a Shore D 74 material is inappropriate for soft-jaw robotic gripper applications where contact stress must remain below 0.5 MPa. The Z suffix in the supplier designation is associated with Z-direction fusion stability in high-speed extrusion; measured interlayer tensile strength in printed parts is above 70% of XY tensile strength when the extrusion temperature is within the 220–245 °C window and cooling fans remain below 50% duty.

For functional sealing applications such as compressed-air connector gaskets, the material is printed at 0.15 mm layer height and annealed at 80 °C for 2 h after printing to reduce residual stress before mounting. The material is resistant to hydrolysis in neutral aqueous service, but continuous contact with strong polar solvents, including ketones and chlorinated hydrocarbons, produces swelling; immersion test data show mass uptake above 10% after 24 h in methyl ethyl ketone under ISO 175. Contact with phthalate-plasticized polyvinyl chloride is incompatible because plasticizer migration softens the TPU surface and creates tack. Continuous service above 70 °C is not recommended; compression set under ASTM D395 at 70 °C and 22 h rises to 50–60%, reducing seal recovery. The unfilled formulation is RoHS 2011/65/EU compliant and is supplied with REACH SVHC statements on request, but food-contact status under FDA 21 CFR 177.1680 must be verified for the complete finished article, not assumed from the pellet feedstocks.

Thermal annealing at 80 °C for 2 h in air reduces residual stress and marginally increases tensile modulus by 5–10%, but annealing above 90 °C causes dimensional shrinkage of 1–2% in the Z direction and must be accounted for in part scaling. Published data for this specific configuration is limited; validation on production geometry is necessary. The 80A-Z grade is also distinct from PLA, PETG, and ABS in that its flexural modulus is lower by approximately two orders of magnitude, its elongation at break is roughly 100–300 times that of PLA, and its glass transition is below −20 °C, which permits cold-weather flexing but reduces dimensional precision under load. Those differences require direct-drive feed paths, low retraction distances, and mechanically assisted support removal in industrial additive manufacturing cells.