中文简体
English
321 clicks1. Choose the Base Resin: PA6 vs PA66 vs High-Temp Nylon
PA6: Good toughness, low cost, easy to process, but low heat resistance (long-term ≤80–100°C) and high water absorption. Only suitable for consumer electronics housings, low-voltage non-precision terminals, and bobbins.
PA66: Melting point ~40°C higher than PA6; superior rigidity, heat resistance, wear resistance, and creep resistance.
The workhorse for E&E. Long-term heat resistance ~120–130°C; HDT exceeds 240°C with GF reinforcement. First choice for connectors, switches, circuit breakers, and relay housings.
High-Temp Nylon (PA46/PA6T/PA9T/PPA/HTN): Long-term use at 130–180°C; withstands SMT reflow (270°C peak).
Used for automotive high-voltage connectors, EV charging gun tips, motor bobbins, and SMT connectors.
Low-Water-Absorption Nylon (PA610/PA612): Dimensional stability in high humidity/outdoor/coolant environments.
Used for outdoor connectors and water pump components.
Rule of thumb: Do not substitute standard flame-retardant PA6 for PA66 in live terminals/switches/sockets—it will likely fail safety compliance.
|
Feature |
Brominated (Halogen) |
Red Phosphorus (HF) |
MCA Nitrogen-based (HF) |
|---|---|---|---|
|
Efficiency |
High (V0 @ 0.8mm) |
Highest (thick sections) |
Moderate (V0 @ 1.6–2.0mm) |
|
CTI |
Low (180–250V) |
Medium |
High (600V+) |
|
Colorability |
Any color |
Black/Dark Grey only |
Any light colors (White/Grey) |
|
Eco-Friendliness |
RoHS OK; restricted by Halogen-Free standards |
HF but contains P |
Halogen-free & Phosphorus-free (Export preferred) |
|
Cost |
Lowest |
Medium |
Medium-High |
General Appliances (Power Strips, Wall Switches): 25%GF Brominated V0 PA66 (Best value).
Industrial/Export/NEV/Charging Piles: 30%GF MCA HF V0 PA66, CTI≥600V, low smoke.
Thick-walled parts needing cost savings + HF: Red Phosphorus grade (accepting black color).
3. Critical Electrical Safety Metrics (Verify Yellow Card)
UL94 V0: Baseline for live parts. Note the thickness (0.8mm/1.6mm/3.2mm). Never trust a "V0" claim without the thickness specified.
CTI (Comparative Tracking Index): ≥400V for low voltage; ≥600V for high voltage/tight pitches/humid environments (select MCA systems).
GWIT/GWFI: Terminals often require GWIT≥775°C, GWFI≥960°C (IEC 60335).
RTI (Relative Thermal Index): Check UL Yellow Card for electrical/mechanical strength retention. Do not rely solely on HDT as an indicator of long-term durability.
Glow Wire: Common requirement for exported appliances/industrial controls (850°C/960°C).
4. Reinforcement & Modification Strategy
Glass Fiber Content: 15%GF (low warpage/aesthetics); 25%GF (mainstream for appliances); 30%GF (Connector/Breaker standard—balance of strength and flow). >35%GF leads to poor flow and severe fiber prominence ("floating fibers").
Impact Modification: Add POE-g or EPDM for snap-fits/frequent assembly, though this slightly reduces strength and heat resistance.
Hydrolysis Resistance: For parts near coils/power modules or in 85°C/85%RH conditions, select hydrolysis-resistant grades (e.g., PA A3HG/A3WG series, PA DPA30SFN).
High Flow: For thin-wall (0.4–0.8mm) connectors, choose High Flow PA66 or neat MCA resins.
Low Floating Fiber: Increase mold temp (80–100°C), use High Flow grades, or switch to mineral-filled/low-GF content resins.
Wall Switch/Power Strip/Low-voltage Terminal: PA66+25%GF, Brominated V0.
Industrial Terminal/EV Charger Socket: PA66+30%GF, MCA HF V0, CTI≥600V.
PCI/DIMM/Auto Connector: PA66+30%GF HF V0 (High Temp Nylon for HV applications).
Miniature Circuit Breaker Housing: PA66+30%GF V0 (Brominated or HF).
Motor Bobbin/Relay Base: PA66+30%GF V0 or HB, High Heat Stabilized.
Outdoor/High Humidity Connector: PA612 or Hydrolysis-resistant PA66 HF V0.
SMT Connector/Charging Gun: PA9T/PA6T/PPA HF V0.
6. Pre-Order Validation Checklist
Check UL Yellow Card: Verify V0 thickness, RTI, CTI, and GWIT.
Aging Test: Measure insulation resistance and CTI decay after 85°C/85%RH testing (1000h).
Mold Trial: Inspect for warpage, floating fibers, and weld lines. Burn-test thin-wall samples (0.8mm strips).
Drying Process: Ensure proper drying (PA66 requires 80–100°C desiccant drying for 4–6h; moisture <0.1%) to prevent silver streaks and bubbles.
* The application cases shown may not fully match your target products. Please inform us of your specific requirements, and we will assist you in material selection.
