How to Select Suitable Nylon Grades for Specific Electrical Insulation Systems？

2026-07-23　

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1. Define Core Operating Conditions of the System
Temperature Classification
Confirm continuous operating temperature and short-term peak temperature.
≤120 ℃: PA6, PA66
Continuous 130~160 ℃: Heat-stabilized PA66
Transient temperature above 180 ℃: PA46
Environmental Conditions
For high humidity, outdoor exposure, oil or coolant exposure, prioritize low-moisture-absorption PA610/PA612.
For general indoor applications, PA6/PA66 are acceptable.
Electrical Safety Requirements
Flame resistance required: Select modified grades with UL94 V-0 flame retardancy.
High voltage and creepage risk: Focus on CTI (Comparative Tracking Index) and arc resistance.
Low-voltage connectors: Conventional insulation grades suffice.
Mechanical Structural Requirements
Housings, supports and latches: Glass fiber reinforced grades (15~35% GF).
For frequent assembly and drop resistance, adopt toughened formulations.

2. Screening Modification Solutions Based on Key Properties
Insulation Stability
Water absorption of nylon reduces insulation resistance. Avoid standard PA6 for high-humidity environments; prefer PA66 or PA612.
Flame Retardant System Selection
Export & environmental compliance: Halogen-free flame-retardant nylon
Cost priority with no halogen-free mandate: Brominated flame-retardant reinforced PA66
Thermal Aging Performance
For components close to coils and heat sources, choose grades with composite thermal stabilizers to prevent embrittlement and insulation degradation under long-term high temperature.
Processing & Surface Quality
Visible parts: Low glass fiber bloom grades. Thin-wall components: High-flow modified nylon.
3. Quick Selection Reference
General chargers, switch bases, power tool insulation parts: Flame-retardant reinforced PA66 GF25/GF30
Economical internal supports for low-voltage electrical appliances: Flame-retardant reinforced PA6-GF
High-humidity/outdoor precision connectors: Modified PA612
Motor bobbins and continuously high-temperature components: Heat-stabilized PA66 / PA46

4. Mandatory Final Verification
Check UL Yellow Card: Flame rating, Relative Thermal Index (RTI) and electrical parameters.
Sample testing: Dielectric strength, CTI, insulation performance after damp-heat aging.
Injection molding trial to verify flowability, warpage and glass fiber bloom for component structures.

Next : Flame-retardant glass fiber reinforced PA66 applied to charging bases