PA66 (Nylon 66): Applications, Advantages & Injection Molding Guide

PA66, or Nylon 66, is a semi-crystalline engineering thermoplastic known for its excellent strength, stiffness, and wear resistance. It is widely used in demanding structural and mechanical applications across automotive, electrical, and consumer goods industries.

What Is PA66?
PA66 is a type of polyamide synthesized from hexamethylenediamine and adipic acid. It has a high melting point (around 260 °C), making it suitable for high-temperature applications. Nylon 66 exhibits strong abrasion resistance, excellent dimensional stability, and low permeability to gases.

PA66 Applications
PA66 is used in products where long-term mechanical performance and thermal resistance are required.

Automotive
– Gears, bearings, bushings
– Radiator end tanks, fasteners, air intake manifolds

Electrical & Electronics
– Cable insulation, connectors, switches
– Circuit breaker components

Industrial
– Machinery housings, conveyor belts, power tool parts

Consumer Products
– Sports equipment, furniture components, zippers

Advantages of PA66 Plastic
– High tensile strength and stiffness
– Excellent fatigue and abrasion resistance
– High melting temperature (~260 °C)
– Good chemical resistance (especially to oils and greases)
– Low creep and good dimensional stability
– Compatible with glass fiber reinforcement for enhanced strength

PA66 Injection Molding Guidelines
Injection molding Nylon 66 requires moisture control and elevated processing temperatures to ensure performance and part quality.

1. Drying Requirements
PA66 is highly hygroscopic and must be dried thoroughly before molding.
– Target moisture: below 0.2%
– Drying temp/time: 80–90 °C for 4–6 hours (or vacuum dried at 105 °C for 8+ hours)

2. Injection Temperature
– Melt temperature: 260–290 °C
– For reinforced grades: 275–280 °C
– Avoid degradation by limiting max melt temperature to below 300 °C

3. Mold Temperature
Mold temperature significantly affects crystallinity and mechanical properties.
– Recommended: 80–90 °C
– Thin-walled or complex parts may require mold temps above 90 °C
– For thick parts: 20–40 °C is acceptable

4. Injection Pressure & Speed
– Pressure: 750–1250 bar
– Speed: High speed recommended (lower for filled materials)

5. Runner and Gate Design
– Use large runners and short paths
– Gate size: >0.5 × part thickness
– Submarine gate min. diameter: 0.75 mm

Final Thoughts
PA66 is ideal for structural applications that demand strength, thermal resistance, and dimensional stability. With proper drying and temperature control, it provides long-lasting performance even under harsh conditions. Reinforced grades offer even higher strength for automotive, industrial, and high-load uses.
Need help selecting the right PA66 grade or optimizing your molding process? Contact our materials team for expert support and tailored recommendations.