TPU print parameters — temperature, bed, cooling and drying

TPU Flex 98A is the flexible material for parts that have to bend and spring back — seals, dampers, cases, wheels. The manufacturer rates it as hard, with a slow print speed, and recommends a direct drive extruder. Impact resistance: very high, the only such rating in the entire table.

The manufacturer's FDM parameter table has two flexible entries: TPU Flex 98A and Easy Flex. Easy Flex is classified completely differently — difficulty level very easy, print speed high, cooling 100% and a declared resistance of 80–100 °C. Both parameter tables side by side below.

Full parameters for TPU Flex 98A and Easy Flex

Parameter	TPU Flex 98A	Easy Flex
Nozzle temperature	230–260 °C	240–260 °C
Bed temperature	40–60 °C	0–60 °C
Recommended nozzle diameter	0.4 mm	0.4 mm
Cooling (fan)	40–70%	100%
Drying	2–4 h at 40–60 °C	2–4 h at 30–40 °C
Enclosure (chamber)	open frame, no enclosure	open frame, no enclosure
Recommended printers	direct drive extruder recommended	all desktop-class FDM printers
Bambu AMS compatibility	Not recommended	Not recommended
Print difficulty level	hard	very easy
Print speed	slow	high
Detail resolution	0.2 mm and above	0.2 mm and above
Abrasiveness (nozzle wear)	none	none
Warping tendency	none	none
Stringing tendency	high	low
Layer bonding	very good	good
Support removal	difficult	easy
Temperature resistance	70 °C	80–100 °C
Impact resistance	very high	high
Flexibility	high	high
Moisture resistance	medium	low
Surface finish	matt, flexible	smooth, flexible
Opacity	opaque	opaque
Colour saturation	medium	high
Odour	none	none
Post-processing	very difficult	easy
Chemical solubility	very poorly soluble	poorly soluble
Spool material	recycled plastic	recycled plastic
Recycled content in filament	no	no
Recyclability	no	no
Diameter tolerance	±0.03 mm	±0.03 mm

Source: the official Porima FDM technical data table (FDM Technical Data). The descriptive ratings (none / low / medium / high) are the manufacturer's own labels, not the result of testing to any standard. Temperature resistance is the manufacturer's own declared figure — it is not HDT, nor any other normed test. The ±0.03 mm diameter tolerance comes from the manufacturer's data, not from the FDM table. See also the print temperature table and the filament drying guide.

How to print TPU

Direct drive and slow speed

In the printer-compatibility field for TPU 98A the manufacturer says it outright: direct drive extruder recommended. It rates the print speed as slow — the only such entry in the whole table. The longer the filament's path from the drive gear to the nozzle, the more a flexible material behaves like a spring and the harder the flow is to control. You can print it on a Bowden setup, but more slowly and with minimal retraction.

The feeder: too much grip destroys the filament

A flexible material squeezes into the gap beside the drive gear instead of moving forward. The symptoms are filament grinding and jamming. Reduce the grip and shorten the retraction — with TPU usually to the minimum that still stops oozing.

Cooling: 40–70% for TPU 98A, 100% for Easy Flex

This is one of the larger differences between the two entries. TPU 98A prints with partial cooling, Easy Flex with full. Nozzle temperature: 230–260 °C for TPU 98A and 240–260 °C for Easy Flex.

Bed: 40–60 °C for TPU 98A, 0–60 °C for Easy Flex

TPU 98A needs a heated bed, Easy Flex does not. The warping tendency for both is none, so the problem is more likely to be sticking too well than letting go.

Drying: 2–4 h at 40–60 °C (TPU 98A) and 30–40 °C (Easy Flex)

Moisture resistance is rated medium for TPU 98A and low for Easy Flex. Damp TPU strings in a way that no settings will eliminate — and the stringing tendency for the 98A is marked as high in any case.

Bambu AMS: Not recommended — for both

The manufacturer advises against feeding either flexible material through the AMS. It gives no justification; in practice it comes down to guiding soft filament through the feeder path. Use an external holder placed as close to the extruder as possible.

The most common problems with TPU

• Filament grinding — soft filament buckles under the drive gear instead of advancing — the most common failure with flexible materials
• Filament jam — TPU squeezes into every gap in the feeder path, especially on a Bowden extruder
• Stringing — the tendency is rated high, and aggressive retraction makes matters worse rather than better
• Under-extrusion — with a slow print speed and a soft material, too much flow jams in the heat break
• The printer stops extruding halfway through — the typical end result of too much feeder grip on a long print
• Tangled filament on the spool — flexible filament pulls a loop tighter than rigid filament does and stops the print without warning

Filament from this page: TPU 98A Porima 1 kg. Category: flexible filaments. For TPU 95A the manufacturer did not include a row in the FDM table — no manufacturer data, so we do not quote parameters for it. Easy Flex is available to order, see the full Porima range.