PETG flame retardant B1S1D0

A flame-retardant PETG grade rated B1/S1/D0 per European standard EN 13501-1. Used where building regulations or safety requirements mandate low flame spread (e.g. interior architecture, public spaces).

Appearance

Pellets: transparent with a clean, extruded-thread-cut appearance (cylindrical, uniform size)
Visually different from V0 grade, which can appear yellowish or have bubble-like pellet forms
The appearance difference is a useful first check when identifying a batch

Print settings (starting point)

These values are for the G1 with a standard 3–5 mm nozzle. Adjust per batch — FR additives vary between suppliers and can shift optimal temperatures.

Zone	Temperature
Feeding Zone (T0)	200–220°C
Melting Zone (T1)	220–240°C
Nozzle Zone (T2)	230–250°C
Bed	75–80°C

SmoothFlow dosage

0.1% (1 g per 1 kg) — same as standard PETG
Required for raw/natural PETG grades: FR grades tend to have higher viscosity than virgin PETG due to the flame retardant additive
SmoothFlow is recommended for all PETG variants, including FR grades, to prevent material sticking to the screw and causing extruder motor skipping

Drying

Required before printing
FR additives are hygroscopic — they absorb more moisture than standard PETG
Dry at 65°C for 4–6 hours before use
Symptoms of wet FR pellets: foaming, bubbles, inconsistent extrusion (same as standard PETG moisture — see PETG foaming and moisture)

Common issues

Pellet bridging / clog at feeding zone

If the Feeding Zone (T0) temperature is too high, pellets can melt prematurely at the top of the extruder barrel, forming a clump that blocks pellet flow from the hopper. Symptoms: material stops feeding, hopper pellets do not drop, extruder motor may skip.

Fix: lower T0 by 5–10°C at a time. Each PETG grade (including FR variants) can have a slightly different melting onset — always verify T0 against the specific batch.

Extruder motor skipping

If the motor is losing steps, the material is likely too cold or too viscous. Add SmoothFlow and increase temperature by 5°C increments.

Supplier notes

Formfutura offers B1S1D0 grade PETG — batch quality can vary; always test a new batch before production
If pellets look yellowish or have irregular shapes, the batch may be degraded → contact the supplier

Key differences vs standard PETG clear

Property	PETG clear	PETG FR B1S1D0
Flame spread	Standard	B1 (low) per EN 13501-1
Smoke	Standard	S1 (low)
Burning droplets	May occur	D0 (none)
Moisture sensitivity	High	Higher (FR additive absorbs moisture)
Color	Clear	Clear (good batches); may be slightly tinted
Print settings	Standard	Same range, verify per batch