Introduction to nylon PA, PA6, PA66

1. PA:

PA is the general name for polyamide plastics. They all have amide groups in their structures and have similar properties. Its general appearance characteristics are: they are all tough, horny, slightly yellowish transparent to opaque materials. Generally, nylon is a crystalline plastic, and there are also amorphous transparent nylons.

1.1 Combustion characteristics: Slow burning. It can continue to burn or extinguish slowly after leaving the fire. The upper end of the flame is golden yellow and the lower end is blue. When burning, the material melts, drips, bubbles and emits the smell of burnt feathers or nails.

1.2 Advantages:

The commonality of PA mechanically is toughness, with high surface hardness, tensile strength, impact resistance, fatigue resistance, and folding resistance.

PA has high wear resistance, self-lubrication and no noise.

PA is heat and cold resistant and can ensure high mechanical properties even in cold and hot seasons.

PA is resistant to chemicals and oil corrosion. Resistant to stress cracking.

PA is easy to print, easy to dye, and has excellent electrical properties.

1.3 Disadvantages:

The biggest disadvantage of PA is: poor dimensional accuracy, thermal expansion and water absorption have a great impact on its size;

PA has poor acid resistance and cannot be dyed with acid dyes or exposed to excessive acidic substances.

PA has poor light resistance and poor pollution resistance.

1.4 Purpose: production of bearings, gears, wheels, shaft rollers, water pump impellers, fan blades, oil pipes, oil storage pipes, ropes, fishing nets, transformer coils

1.5 Injection molding characteristics: Due to the presence of amide groups, PA absorbs water strongly and firmly. Therefore, it should be fully dried during injection molding, usually at 120°C for 3-4 hours; PA has small viscosity and fast flow speed. In order to prevent the nozzle from flowing out, a self-locking nozzle or a special nylon nozzle should be used. At the same time, pay attention to mold accuracy.

2. PA6:

Introduction PA6 is a yellowish translucent material

Identification: Heating PA6 and hydrochloric acid at 110°C for 4 hours, no small amount of white adipic acid crystals precipitated.

2.1 Combustion characteristics: The same as those of nylon.

2.2 Advantages: PA6 is a type of nylon material with relatively high mechanical strength, but lower than PA66; its tensile strength, surface hardness, and rigidity are higher than other nylon plastics. Impact resistance and flexibility are higher than PA66

3. PA66:

Introduction PA66 is a white translucent material

Identification: Heating PA66 and hydrochloric acid at 110°C for 4 hours, a small amount of white adipic acid crystals precipitated. PA6 does not have it, but PA610B also has it.

3.1 Combustion characteristics: The same as those of nylon.

3.2 Advantages: PA66 is one of the nylon materials with the highest mechanical strength. Its tensile strength, surface hardness and rigidity are higher than other nylon plastics.