PA66: PA66 (聚酰胺66)
Polyamide 66, a nylon with higher melting point, stiffness and strength than PA6. It is used for monofilament, engineering parts and some moulded components that need heat resistance. PA66 absorbs moisture, which changes dimensions and flexibility, so conditioning and drying are controlled before processing. Good tensile strength and fatigue resistance make it suitable for teeth that flex repeatedly, and grade selection considers colour and UV stability.