TPU – 68D is a high-hardness thermoplastic polyurethane that combines flexibility, durability, and strong impact performance with a Shore hardness of 68D. It is suited to functional parts that require greater rigidity than soft TPU while retaining high elongation and energy absorption.
Design Advantages
High Shore hardness for semi-rigid parts that still require flexibility and recovery
Published X/Y elongation greater than 650% for highly deformable designs
Strong impact performance for protective, energy-absorbing, and wear-resistant components
Fast processing capability with reduced stringing compared with many softer TPU grades
Material Specifications
Item
Published Value
Material family
Thermoplastic polyurethane
Shore hardness
68D
Filament diameter
1.75 mm
Published density
1.26 g/cm3
Water solubility
Insoluble
Appearance and odor
Solid filament; odorless under normal handling
Material Properties
Physical and Thermal Properties
Property
Test Method
Published Value
Density
ISO 1183
1.26 g/cm3
Melt index
210 °C at 2.16 kg
21.8 ± 0.3 g/10 min
Melting temperature
DSC at 10 °C/min
183 °C
Glass transition temperature
DSC at 10 °C/min
Not reported
Crystallization temperature
DSC at 10 °C/min
Not reported
Vicat softening temperature
ISO 306 and GB/T 1633
Not reported
Heat deflection at 1.8 MPa
ISO 75
Not reported
Heat deflection at 0.45 MPa
ISO 75
Not reported
Saturated water absorption
25 °C and 55% RH
1.20%
Mechanical Properties
Property
Test Method
Published Value
Young’s modulus X/Y
ISO 527 and GB/T 1040
1,190 ± 0.4 MPa
Young’s modulus Z
ISO 527 and GB/T 1040
600 ± 0.5 MPa
Tensile strength X/Y
ISO 527 and GB/T 1040
22.4 ± 0.6 MPa
Tensile strength Z
ISO 527 and GB/T 1040
11.2 ± 0.5 MPa
Elongation at break X/Y
ISO 527 and GB/T 1040
>650%
Elongation at break Z
ISO 527 and GB/T 1040
31%
Flexural modulus X/Y
ISO 178 and GB/T 9341
Not reported
Flexural modulus Z
ISO 178 and GB/T 9341
Not reported
Flexural strength X/Y
ISO 178 and GB/T 9341
Not reported
Flexural strength Z
ISO 178 and GB/T 9341
Not reported
Impact strength X/Y
ISO 179 and GB/T 1043
124.3 kJ/m2
Impact strength Z
ISO 179 and GB/T 1043
9.6 ± 0.3 kJ/m2
Representative values from standardized specimens. Actual part performance depends on geometry, orientation, wall thickness, processing parameters, conditioning, and service conditions.
Processing
Recommended Processing Window
Setting
Recommended Range
Drying before printing
Forced-air drying oven at 70 °C for 8 h
Printing and storage humidity
Below 20% RH; sealed with desiccant
Nozzle size
0.4, 0.6, or 0.8 mm
Nozzle temperature
220 to 240 °C
Build surface
Textured PEI or smooth PEI with glue
Bed temperature
30 to 35 °C
Cooling
Part-cooling fan on
Printing speed
Below 250 mm/s
Retraction
0.8 to 1.4 mm at 20 to 40 mm/s
Chamber temperature
25 to 45 °C
Overhang and bridging
Approximately 70 degree maximum overhang; 20 mm maximum bridge
Supports
Enable where required by geometry
Representative Specimen Conditions
Parameter
Source Condition
Nozzle temperature
230 °C
Bed temperature
35 °C
Printing speed
130 mm/s
Infill density
100%
Pre-test conditioning
Annealed and dried at 70 °C for 12 h
Chemical and Handling Characteristics
Characteristic
Published Information
Composition
Thermoplastic polyurethane
Odor and skin hazards
Odorless; source documentation reports no skin hazard
Chemical stability
Stable under normal storage and handling conditions
Water solubility
Insoluble
Acid and alkali resistance
Not resistant
Organic solvent resistance
Not resistant to some organic solvents
Oil and grease resistance
Resistant to most kinds of oil and grease
Flammability
Flammable
Combustion products
Water, carbon oxides, and nitrogen oxides; pungent odor
Design and Validation Considerations
Account for strong anisotropy: published tensile strength is 22.4 MPa in X/Y and 11.2 MPa in Z, while elongation is greater than 650% in X/Y and 31% in Z.
Use X/Y-oriented load paths where high elongation, toughness, and impact performance are critical.
Dry and store material below 20% RH with desiccant to support consistent extrusion and mechanical performance.
Do not assume chemical compatibility from the generic resistance statements; validate the actual fluid, concentration, temperature, exposure time, and stress state.
Annealing is generally not recommended because complex parts may deform. Do not use a microwave or household kitchen oven for drying or heat treatment.
Published Data and Qualification
The values in this sheet are based on standardized specimen testing documented by the material source and are provided for design reference and material comparison. Lucent Additive has not independently generated every published value. Final-part performance can differ substantially from standardized specimens because of geometry, orientation, process settings, conditioning, and service environment.
Lucent Additive provides manufacturing expertise and application support; this document does not create a material warranty or replace qualification of the customer’s finished component.
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