Polymaker PC-PBT Filament — 1.75mm, 1kg, Tg 140°C, Tough from -30°C to 107°C HDT, Chemical Resistant PC/PBT Blend for Automotive & Industrial Parts

Standard polycarbonate is exceptional at handling heat. What it's not known for is staying tough when temperatures drop below zero. Polymaker PC-PBT is the answer to that gap — a precision blend of polycarbonate (PC) and polybutylene terephthalate (PBT) engineered specifically for parts that need to survive both ends of the thermal spectrum: heat deflection at 107°C on the hot end and maintained toughness down to -30°C on the cold end, combined with robust chemical resistance to fuels, oils, lubricants, and detergents. This is the material behind automotive exterior components, outdoor electronics housings, and industrial parts that live in environments where temperature swings and chemical exposure are daily realities — not edge cases.

⚠️ Heated chamber required: 100–115°C. PC-PBT is a true industrial PC blend — it cannot be printed successfully on an open-frame printer without a heated enclosure. Verify your printer can maintain chamber temperature before ordering.
⚠️ No part cooling fan. Zero fan at all times — forced airflow causes delamination and warping in PC-based blends.
⚠️ All-metal hotend required — 260–280°C exceeds the safe range of PTFE-lined hotends.
⚠️ Bed adhesive required. PVA glue stick or Magigoo PC on any bed surface — adhesive is not optional with this material.
✅ Dry only if moisture-absorbed: 75°C for 6h. Unlike some hygroscopic engineering materials, PC-PBT only needs drying if it has been exposed to humidity — not as a routine pre-print step on fresh sealed spools.
✅ Anneal after printing for best results: 90°C for 2h releases residual internal stress and maximizes dimensional stability and toughness.

Why PC-PBT — The Specific Problem This Blend Solves

The PC/PBT combination is not a marketing blend — it's a materials engineering decision made by automotive OEMs decades before desktop 3D printing existed. Pure PC is rigid and heat resistant but becomes brittle in cold environments, particularly under impact. Pure PBT is chemically resistant and tough at low temperatures but has a lower heat deflection point. Blending the two at the right ratio produces a material that inherits the thermal ceiling of PC and the cold-weather toughness and chemical resistance of PBT — without sacrificing either property significantly. The result is a filament that holds its geometry at automotive operating temperatures, doesn't crack when a door panel is slammed at -20°C in a Canadian winter, and resists the fuel splashes, lubricants, and cleaning agents that industrial and automotive parts see throughout their service life.

Chemical Resistance — What PC-PBT Can Handle

The PBT component of the blend gives PC-PBT meaningful chemical resistance that standard PC and most engineering-grade filaments cannot match. Parts printed in PC-PBT maintain structural integrity with sustained exposure to:

Chemical category	Examples	PC-PBT behavior
Automotive fuels	Gasoline, diesel	Good resistance — no significant degradation
Oils and lubricants	Engine oil, hydraulic fluid, cutting oil	Good resistance — no swelling or weakening
Cleaning and detergent agents	Industrial degreasers, detergent solutions	Good resistance — maintains surface integrity
Aqueous solutions	Coolants, saltwater, weak acids	Good resistance at standard concentrations

Thermal Performance — The Full Spectrum

Property	Value	What it means in practice
Glass Transition Temp (Tg)	140°C	Part remains structurally stable above boiling water temperature
Vicat Softening Temp	139°C	Consistent with Tg — predictable thermal behavior
Heat Deflection Temp (HDT)	107°C	Survives sustained thermal load well above automotive interior temps
Low-temp toughness	Down to -20°C / -30°C	Maintains impact resistance in freezing conditions where standard PC embrittles

Mechanical Properties

Young's Modulus	1986 ± 85 MPa
Tensile Strength	41.8 ± 0.9 MPa
Bending Strength	64.4 ± 0.3 MPa
Charpy Impact Strength	21.4 ± 3 kJ/m²

Print Settings

Filament diameter	1.75mm
Hotend temperature	260–280°C (all-metal hotend required)
Bed temperature	100–115°C
Chamber temperature	100–115°C ⚠️ required
Print speed	30–50 mm/s
Part cooling fan	OFF — zero fan at all times
Bed preparation	PVA glue stick or Magigoo PC — required on any surface
Direct drive retraction	1mm / 20mm/s
Bowden retraction	3mm / 40mm/s
Drying (if needed)	75°C for 6h — only if moisture-absorbed
Annealing (recommended)	90°C for 2h after printing
Recommended support	PolyDissolve S2 (dual extrusion)
Spool weight	1kg
Spool type	Recycled cardboard — eco-friendly packaging
Spool inner hole diameter	55 ± 1mm
Spool outer diameter	200 ± 1mm
Spool width	65.6 ± 2mm

Who Is This For?

Polymaker PC-PBT is the correct material for three situations that no other commodity filament handles simultaneously: parts that face heat and cold in the same service life (automotive exterior — from a desert highway to a winter parking lot), parts that need chemical resistance alongside structural integrity (industrial housings near lubricants, fuels, or cleaning agents), and parts where dimensional stability under thermal cycling is a functional requirement rather than a preference. Specific applications where PC-PBT is the default choice in injection molding — and now in 3D printing: automotive bumpers, roof rail brackets, door handles, outdoor enclosures for electronics, VR/AR headset housings, battery cases, and any industrial part that alternates between cold storage and hot operating environments. If your printer can hold a 100–115°C chamber, PC-PBT opens a performance envelope that no filament below it in the material stack can reach.