TPU 92A (Thermoplastic Polyurethane, Shore 92A) for FDM

April 29, 2026

Material Profile: TPU 92A (Thermoplastic Polyurethane, Shore 92A) for FDM

FDM Engineering Material Technical Report Series

Compiled from manufacturer technical datasheets and peer-reviewed literature

Abstract—TPU 92A is a slightly softer thermoplastic polyurethane than the more common 95A grade — Shore 92A on the durometer scale. The reduced hardness comes from a higher proportion of soft polyol segments versus hard urethane segments. The result is improved rebound, softer touch, and greater flexibility, balanced against modestly more difficult printing (the filament is more prone to buckling in Bowden extruders). Suppliers include Recreus FilaFlex 92A, Polymaker PolyFlex™ TPU90, NinjaTek Edge (90A), and Filaflex Conductive (92A).

Index Terms—additive manufacturing, FDM, thermoplastic polyurethane, TPU 92A, soft elastomer.

I. MATERIAL IDENTIFICATION

This section establishes the canonical names and commercial designations under which the material is supplied.

A. Designation

Trade name: TPU 92A (generic). Examples: Recreus FilaFlex 92A, NinjaTek Edge 90A (very close in hardness), Filaflex Conductive 92A.

B. Full Chemical Name

Thermoplastic polyurethane — segmented block copolymer with ~30–35% hard urethane segments and ~60–65% soft polyol segments (lower hard fraction than 95A).

C. Aliases and Alternative Designations

Alias	Origin / Usage
TPU 92A	Standard descriptor
FilaFlex 92A	Recreus grade
NinjaTek Edge	Approximately 90A, comparable performance
Soft TPU	Industry descriptor (vs 95A medium-hardness)

II. COMPOSITION AND MOLECULAR STRUCTURE

A. Empirical Chemical Formula

Idealised: [-CO-NH-R-NH-CO-O-R'-O-]ₙ. Hard segment fraction reduced by ~5% vs 95A; soft segment fraction increased correspondingly.

Fig. 1. Repeating unit / structural schematic of the polymer matrix.

Fig. 2. Schematic of the single-phase polymer (no reinforcement).

B. Composition Breakdown

TABLE I
COMPOSITIONAL BREAKDOWN OF TPU 92A (TYPICAL / PER SUPPLIER DATASHEET)

Constituent	Mass fraction	Function
Hard segment (urethane / isocyanate)	≈ 30 – 35 wt%	Reduced versus 95A → softer grade
Soft segment (polyether / polyester polyol)	≈ 60 – 65 wt%	Higher fraction → more flexibility, higher rebound
Stabilisers, antioxidants, processing aids	< 2 wt%	UV / thermal protection
Total	100 wt%	—

III. MECHANICAL PROPERTIES — XZ PRINT DIRECTION

In the XZ orientation the tensile load is applied parallel to the deposited rasters; for fibre-reinforced grades this is the strongest orientation because the fibres align preferentially along the extrusion direction.

TABLE II
MECHANICAL PROPERTIES — XZ ORIENTATION (TPU 92A)

Property	Value (XZ)	Test method / source
Tensile strength, ultimate	≈ 35 – 45 MPa	ASTM D638
Tensile strength, yield	Not applicable (elastomer)	Elastomers do not exhibit conventional yield
Elastic limit	~ 5 % strain (estimate)	Engineering estimate
Young's modulus	≈ 15 – 22 MPa	ASTM D638 (lower than 95A)
Elongation at break	Up to ~ 900 %	ASTM D638
Izod impact, notched (23 °C)	No break (elastomer)	ASTM D256

IV. MECHANICAL PROPERTIES — ZX PRINT DIRECTION

In the ZX orientation the tensile load is applied perpendicular to the print layers, so failure occurs through inter-layer (Z) bonds. Properties are markedly lower than in XZ — this anisotropy is intrinsic to FDM.

TABLE III
MECHANICAL PROPERTIES — ZX ORIENTATION (TPU 92A)

Property	Value (ZX)	Test method / source
Tensile strength, ultimate	≈ 22 – 28 MPa (estimate)	Engineering estimate
Tensile strength, yield	Not applicable	Elastomer
Elastic limit	~ 4 % strain (estimate)	Engineering estimate
Young's modulus	≈ 14 – 20 MPa (estimate)	Engineering estimate
Elongation at break	≈ 350 – 500 % (estimate)	Engineering estimate; layer adhesion governs
Izod impact, notched (23 °C)	No break (estimate)	Engineering estimate

Like 95A, anisotropy primarily affects elongation rather than modulus or hardness. The lower hard-segment fraction makes inter-layer welding marginally more sensitive to print parameters.

V. RECOMMENDED PRINT PARAMETERS

Values summarised below give consensus operating windows from public datasheets. Specific suppliers may differ within ±10 °C; the supplier datasheet always supersedes this table.

TABLE IV
RECOMMENDED PRINT TEMPERATURE RANGES FOR TPU 92A

Parameter	Range	Notes
Nozzle temperature	220 – 240 °C	Slightly higher than 95A to ensure complete melt of soft segments
Build plate temperature	30 – 60 °C	PEI / glass with adhesive
Chamber temperature	Ambient	Not required
Print speed	15 – 25 mm/s	Slower than 95A; direct-drive strongly recommended
Pre-print drying	50 °C × 4 – 6 h	Mandatory; even more hygroscopic than 95A

VI. GLASS TRANSITION TEMPERATURE (TG)

Reported / typical Tg: ≈ -35 °C (soft segment); hard segment Tg ≈ 70 – 90 °C.

Soft segment Tg is slightly lower than 95A (more polyol content), giving better low-temperature flexibility (down to -40 °C). Upper service limit is correspondingly slightly lower (~70–80 °C) due to reduced hard-segment fraction.

VII. HEAT DEFLECTION TEMPERATURE (HDT)

Heat deflection temperature is the temperature at which a standard bar deflects 0.25 mm under a specified flexural load (ASTM D648 / ISO 75).

TABLE V
HEAT DEFLECTION TEMPERATURE OF TPU 92A UNDER STANDARD TEST LOADS

Test load	HDT	Standard / source
0.45 MPa	Not typically reported (elastomer)	ASTM D648 — generally inapplicable to elastomers
1.82 MPa	Not typically reported	ASTM D648 — generally inapplicable

VIII. DISTINGUISHING CHARACTERISTICS AND STANDARDS

A. Softer, higher rebound than 95A

The 3-point lower Shore A hardness translates to substantially higher elastic rebound and a more 'rubbery' tactile feel. Specifically suited to applications where a 95A part feels too hard or where higher cushioning is required.

B. Conductive variants available (e.g., FilaFlex Conductive 92A)

Recreus offers a conductive 92A variant where the polymer is loaded with conductive carbon black to enable wearable electronic and sensor applications. Volume resistivity ~10² Ω·cm in the conductive grade.

C. Print difficulty trade-off

The increased flexibility comes at the cost of harder printing — the filament buckles more easily in Bowden tubes and requires a direct-drive extruder for reliable feeding. Print speeds typically 5–10 mm/s slower than 95A.

D. Chemical and abrasion resistance

Similar to 95A: resistant to oils, greases, fuels, alcohols. Slightly more sensitive to high-temperature chemicals due to reduced crystallinity in the hard segment.

IX. REPRESENTATIVE APPLICATIONS

TPU 92A is typically deployed in the following applications:

1) Soft-touch consumer product surfaces: Phone case grips, electronic device covers, ergonomic handles.

2) Wearable / conductive sensor components: FilaFlex Conductive 92A — flexible electrode and EMG sensor pads.

3) Higher-rebound vibration damping: Anti-vibration mounts where 95A is too stiff for the application frequency band.

4) Custom-fit insoles and orthotics: Greater conformability than 95A; closer to traditional shoe-insole rubber durometer.

(Source : Unionfab)

5) Soft sealing surfaces and bellows: Where 95A is too rigid to deflect under low-pressure differentials.

Photographs of representative parts in these applications are not reproduced here for copyright reasons; the table below provides direct manufacturer / case-study URLs where original imagery and project descriptions can be viewed.

TABLE VI
SUGGESTED IMAGE / CASE-STUDY SOURCES

Application area	Source URL
TPU 92A wearable / electronic device cover	https://recreus.com/en/12-filaflex
TPU 92A custom orthotic / insole	https://www.ninjatek.com/products/ninjatek-edge/