FR-PA6
Lower processing temperature, generally lower cost. General E&E housings, cable ties and clips where PA66’s extra heat resistance is not required.
- Halogen-free or brominated on request
- UL94 V-0 in unfilled and glass-filled grades
Flame Retardant Nylon (PA6 / PA66)
Nylon holds connectors, relays and structural parts together under heat and load — but neat PA6/PA66 burns and drips. We supply halogen-free and brominated flame retardant systems built for both resins, as additive powder and masterbatch, reaching UL94 V-0 down to 0.8 mm with the CTI and glow-wire performance connector specs demand.
GradesFR-PA6 · FR-PA66
FormsAdditive powder · masterbatch
SystemsHalogen-free · brominated
TargetsUL94 V-0 · GWIT · CTI
Fig. N01 — molded FR-PA66 connector partsConnector-grade parts molded from flame retardant nylon compound.
FR-PA series
Form — additive / masterbatch
Goal — V-0, high CTI
Use — connectors, relays, E&E
Form — additive / masterbatch
Goal — V-0, high CTI
Use — connectors, relays, E&E
01 / 07Why Nylon Needs Help
Nylon Is Tough. It Is Not Fire-Safe.
PA6 and PA66 are the connector world’s default resin — strong, heat-resistant, dimensionally stable. Neither burns safely on its own. Unfilled nylon can scrape a marginal V-2 because it drips away from the flame; glass-filled nylon loses even that, because the fibers wick the flame instead of letting it drop. Any real UL94 or glow-wire rating needs a formulated package.
Grades: FR-PA6 · FR-PA66
Forms: additive powder · masterbatch
Fit: connectors, relays, E&E, automotive
FR-PA66
Higher heat deflection and dimensional stability — the connector and relay standard, including automotive and EV applications.
- Glow-wire and CTI-oriented packages available
- Survives 280–300 °C processing
Additive or Masterbatch
Powder packages for compounders running their own twin-screw line; pre-dispersed masterbatch on a PA carrier for molders dosing at the press.
- Loading and carrier matched to your line
- See additives vs masterbatch for the trade-off
02 / 07Systems
Three Flame Retardant Routes for Nylon
Same three chemistries as any engineering plastic — color, electrical spec and halogen policy decide which one fits your part.
| System | Typical loading | Strengths | Related page |
|---|---|---|---|
| Halogen-free phosphinate | 15–20% + N-synergist | High CTI (400–600V), light colors, V-0 at 0.8mm | DEPAL page |
| Red phosphorus | 6–10% | Lowest loading, best mechanical retention, dark colors only | Phosphorus family |
| Brominated + antimony trioxide | 12–20% | Lowest cost, any color, halogen-tolerant markets only | DBDPE page |
In unfilled nylon parts (cable ties, clips), melamine cyanurate alone often reaches V-0 at just 8–12% — the cheapest halogen-free route, but it only works before glass fiber enters the resin. For the full resin-by-resin selection logic, including PA66 vs PA6 processing differences, see our flame retardant nylon 66 selection guide.
03 / 07Applications
Where Flame Retardant Nylon Is Used
Nearly all of it is E&E and automotive — parts where a fire fault has to stop at the part, not spread through it.
Connectors & Terminal Blocks
CTI and glow-wire performance often matter as much as UL94 — the phosphinate route’s home turf.
Relays & Circuit Breakers
Thin-wall housings around live current; V-0 at 0.8mm is now the common ask, not the exception.
Automotive & EV Hardware
Under-hood brackets, battery hardware, charging connectors — heat resistance plus fire rating together.
General E&E Housings
Cable ties, clips, sensor housings — where unfilled PA and a lean melamine cyanurate package keep cost down.
04 / 07Standards
What Connector Specs Actually Ask For
UL94 is rarely the whole exam anymore. Confirm all three before formulating.
01UL94 class at actual wall (0.8–1.6mm)
02Glow wire GWIT / GWFI (IEC 60695)
03CTI / arc tracking resistance
04Halogen-free declaration or RoHS-only
05Color (natural / black / HV orange)
06Glass fiber content
07Moisture / hydrolysis exposure
08Processing temperature window
09Cost per rated part
05 / 07Manufacturing
FR Nylon Supply from Rectivas
FR-PA6 and FR-PA66 are standing grades — halogen-free by default, brominated on request — compounded on our partner factory’s twin-screw line and burn-verified at our partner factory before shipment.
Forms: additive powder · masterbatch
Testing: UL94 screening we arrange · LOI ladders
Documents: TDS · SDS · COA · an accredited third-party laboratory reports
- C-01System selection: phosphinate, red phosphorus or brominated
- C-02Glow-wire and CTI-oriented formulation
- C-03Twin-screw loading ladders and burn verification
- C-04Moisture / hydrolysis-aware drying and stabilization guidance
- C-05Pre-dispersed masterbatch on PA carrier
- C-06Batch QC with TDS / SDS / COA per shipment
- C-07Export packaging and worldwide delivery
Fig. N02 — burn verification in our partner factory’s labEvery system burn-tested at your actual wall thickness.
Fig. N03 — export packagingBags, big bags and palletized supply for overseas buyers.Reinforced or Not? That Decides Your Chemistry
Almost every wrong recommendation in flame retardant polyamide comes from skipping one question. Answer it first and the options narrow to one or two.
| Your Grade | What Works, and What Will Waste Your Trial |
|---|---|
| Unfilled PA6 / PA66 | Melamine cyanurate is efficient and inexpensive here. It works by promoting dripping that carries heat away. |
| Glass-filled (GF15–GF50) | MCA loses most of its effect — glass fibre stops the part dripping. Switch chemistry to phosphinate with MPP. Do not raise MCA dosage — the mechanism is gone, not weak. |
| Glass-filled + CTI 600 V | Phosphinate, halogen-free by necessity. Brominated systems with antimony typically track at PLC 2–3 and will not reach PLC 0. |
| Any reinforced grade, thin wall | Expect higher loading than the unfilled datasheet implies. Fibres wick molten polymer to the flame, and thin sections have less material to form char. |
The mistake that costs a trial batch: assuming a flame retardant that worked in your unfilled grade will scale into the reinforced version. It is not a dosage problem — melamine cyanurate depends on dripping, and reinforcement is precisely what prevents it. Tell us your glass content with the wall thickness and CTI target, and we will propose a starting loading rather than a product list.
06 / 07FAQ
Buyer Questions About Flame Retardant Nylon
The four that open most nylon FR inquiries.
What is flame retardant nylon used for?
Connectors, relays, circuit breakers, terminal blocks, sensor housings and structural automotive parts — anywhere PA6 or PA66 needs a UL94 rating alongside its natural toughness and heat resistance.
Is PA6 or PA66 better for flame retardant parts?
Both take the same flame retardant systems. PA66 offers higher heat resistance and dimensional stability — common in automotive and high-temperature connectors. PA6 processes cooler and often costs less, suiting general E&E parts. The resin choice, not the flame retardant, usually decides between them.
What flame retardant is used in nylon 6 and nylon 66?
Three main routes: halogen-free phosphinate (aluminum diethylphosphinate with a nitrogen synergist) for high-CTI connectors, red phosphorus for the lowest loading in dark parts, and brominated systems with antimony trioxide for cost-driven, halogen-tolerant parts.
Can flame retardant nylon be supplied as masterbatch?
Yes — powder additive packages for compounders, or pre-dispersed masterbatch on a PA carrier for molders without in-house compounding, matched to your resin grade and target rating.
Request a Flame Retardant Nylon Recommendation
Send your resin (PA6 or PA66), glass content, wall thickness and the full spec line — UL94 class, glow wire, CTI. We will recommend the system and prove it in our partner factory’s burn lab before you commit a trial.
Include in your inquiryPA-RFQ
- ResinPA6 or PA66; glass fiber content
- Target ratingUL94 class at actual wall; GWIT/CTI if specified
- ColorNatural, black, or HV orange
- ComplianceHalogen-free declaration, RoHS, REACH
- Trial volumeSample quantity and expected annual demand