Polyamide 66[2]

Updated: 2026-09-14

Overview

Polyamide 66 (PA66) is a semi-crystalline thermoplastic belonging to the nylon family, first commercialized by DuPont in the 1940s. It is synthesized through polycondensation of hexamethylenediamine and adipic acid, resulting in a material with balanced mechanical, thermal, and electrical properties. PA66 is valued in industrial applications for its versatility and cost-performance ratio. Compared to other engineering plastics, PA66 stands out for its high tensile strength, stiffness, and resistance to wear and abrasion. These characteristics, combined with its ease of processing via injection molding or extrusion, make it a preferred choice for demanding technical applications across multiple industries.

Physical and Chemical Properties

PA66 exhibits a melting point of 260-265°C, enabling use in high-temperature environments up to 150°C continuously. Its density of 1.14 g/cm³ makes it lighter than many metals it replaces while maintaining structural integrity. The material's crystalline structure contributes to its excellent dimensional stability. Chemically, PA66 resists hydrocarbons, oils, and many solvents but is susceptible to strong acids and oxidizing agents. Its moisture absorption rate (up to 2.5% at saturation) affects mechanical properties, necessitating pre-drying before processing. Electrical properties include volume resistivity >10^15 Ω·cm and dielectric strength >20 kV/mm, making it an effective insulator.

Main Applications

In automotive manufacturing, PA66 is used for under-hood components (radiator end tanks, intake manifolds), electrical connectors, and fuel system parts due to its heat and chemical resistance. The electronics industry employs it for circuit breakers, coil bobbins, and insulating washers where electrical safety is critical. Industrial applications include gear wheels, bearings, and conveyor components that require durability. Consumer goods range from power tool housings to sports equipment. Glass or mineral-filled grades expand applications to structural components requiring enhanced stiffness and heat deflection temperatures.

Safety and Storage

PA66 pellets or dust may cause respiratory irritation; adequate ventilation and dust masks are recommended during handling. Molten PA66 requires thermal protection gear as it can cause severe burns. The material is generally considered non-toxic but should not contact food unless FDA-compliant grades are specified. Proper storage involves keeping material in original packaging in low-humidity (<50% RH) environments below 40°C. Moisture-sensitive before processing, PA66 typically requires drying at 80-90°C for 4-6 hours to achieve <0.2% moisture content for optimal processing conditions.

B2B Procurement Guide

Industrial buyers should specify required mechanical properties (e.g., tensile strength >80 MPa), thermal stability requirements (e.g., UL temperature index), and any industry certifications (ISO, RoHS). For cost-sensitive applications, consider regrind or off-grade materials where properties permit. Key procurement factors include minimum order quantities (typically 500-1000 kg for standard grades), lead times (2-8 weeks depending on formulation), and regional availability. Establish relationships with suppliers who offer technical support for material selection and troubleshooting processing issues. Price negotiation often depends on annual volume commitments.