Polymaker PolyFlex TPU90: problems, parts and running costs

Checked: 2026-10-26

Summary

PolyFlex TPU90 is a 90A TPU filament whose common troubles are intermittent extrusion loss and buckling on soft feed paths, stringing and slow speeds, and wet-filament surface defects; drying at 70 C for 8 h per the TDS does not fix every problem. Running cost is the filament itself at $39.99 per 0.75 kg spool, with no subscription and an optional one-time PolyDryer at $79.99. At $39.99 for 750 g it is a reasonable buy for direct-drive owners who need 90A softness; Bowden owners or those who cannot dry filament get weaker value.

Common problems and fixes

Intermittent extrusion loss and filament buckling — owners report prints stopping mid-job and resuming after unload/reload, even on machines that handle harder TPU fine; the soft strand deforms between drive gear and melt zone. Fix by shortening the feed path, reducing retraction, and tuning extruder tension; no universal fix is documented. Polymaker’s 60-day return policy covers faulty or nonconforming filament on direct purchases only; opened spools are not returnable for preference. [8][1][11]
Stringing, internal blobs and travel marks — common on models with many travel moves; one owner saw deposits on inside walls while the outside looked fine, and manufacturer profiles warn TPU90 may string heavily. Fix by reducing travel crossings, printing fewer separate objects, drying, and careful retraction; complete elimination is not guaranteed. [1][10][4]
Repeat-print quality drift — an owner saw a good first insole then worsening copies on unchanged G-code despite drying over 12 h at 50 C; the cause was not identified. Re-evaluate moisture, temperature, extrusion and spool drag independently. [9]
Surface defects even after long drying — an owner on a Prusa Core One saw asymmetric defects at 210 C and 30 mm/s after 15 h drying, with better results at 230 C; drying does not fix every problem. [7]
Difficult support removal — strong layer adhesion makes supports hard to remove and can tear detail; reorient parts to avoid internal supports. [4]
Wet filament — moisture causes surface artifacts, bubbling and stringing; Polymaker provides drying instructions, but owner posts show drying does not fix every print problem. [1][2][7][9]

Parts and consumables

PolyFlex TPU90 spool (black 1.75 mm, PD02001) — $39.99 from B&H (in stock at check) or Polymaker direct (backordered at check); replaces whenever 0.75 kg is used, accounting for purge, supports, rafts and failed prints. [5][1]
PolyDryer (PX01002_A) — $79.99 at Polymaker direct, backordered when checked; optional, buy once; no routine annual replacement. [13]
Reusable dry storage box and desiccant — the PolyDryer system uses moisture-indicating desiccant regenerated when it changes color; replace only when regeneration fails or it is contaminated. [13]
Nozzle/extruder — not an abrasive consumable for this filament; replace by diagnosis, with no universal part number or frequency. [2][3]

Yearly running cost

A typical owner spends $39.99 per 0.75 kg spool with no subscription or license. Scenarios: 0.75 kg per year is $39.99, 1.5 kg per year is $79.98, and 3.0 kg per year is $159.96, at the quoted B&H $39.99 retail listing, excluding bulk discounts, returns and shipping. The optional PolyDryer at $79.99 is a one-time purchase, not an annual cost. Electricity for the printer and dryer is not quantified in the sources; annual energy equals metered kWh times the user’s utility rate. Failed prints, nozzle servicing and extra drying can add cost, and no statistically valid annual average was found. [5][13][1][2]

When it is a good buy

Store prices: B&H listed black 1.75 mm / 750 g at $39.99 in stock (Oct 2026); Polymaker direct listed the same at $39.99 backordered; West3D listed $39.99 for 0.75 kg. That is $53.32 per kg by arithmetic. Below $30 for 750 g of genuine TPU90 with valid batch and storage would be a good niche buy; no in-stock US retailer at that price was confirmed. $30 to $40 for 750 g is a fair range when 90A softness and a direct-drive profile are needed; $39.99 at B&H is a defensible benchmark. Above $40 for 750 g is poor value unless a specific color or local availability is indispensable. [5][1][6]

If 95A is sufficient, PolyFlex TPU95 at $29.99 per 0.75 kg and Overture High Speed TPU 95A from $24.99 are economically stronger. PolyFlex TPU95-HF at $49.99 per 1 kg suits throughput at a firmer 95A. Wholesale at $23.99 requires a $1,000 minimum and is final sale, so it is not a normal retail option. [14][15][16][17][12]