Key differences between nylon and polyester fabric:
Nylon is about twice as expensive as polyester.
Nylon feels smoother and softer compared to polyester.
Both fabrics have similar abrasion resistance.
Nylon has a slight stretch, while polyester has no elasticity.
Dyeing nylon is more difficult than dyeing polyester.
Polyester:
Mechanical properties: Polyester has a higher elongation at break and a large extension; it has a high initial elastic modulus, good extension response, and the fabric is stiff. It's wear-resistant with reliable specifications.
Moisture absorption and dyeing: Polyester has poor moisture absorption (W = %), and it can't be dyed at room temperature. It tends to build static and is not very resistant to dirt.
Thermal properties: Polyester has a high melting point (255-265°C), good heat resistance, and temperature tolerance.
Optical properties: Good light resistance, second only to nylon.
Acid resistance: Not resistant to strong acids but is resistant to mold and rot.
Relative density: g/cm³
Nylon (Polyamide):
Mechanical properties: Nylon has a higher elongation at break and greater bending resistance, with a low initial elastic modulus and high rupture strength. It has good extension and wear resistance but is less stiff and less rigid than polyester.
Moisture absorption and dyeing: Nylon absorbs moisture better than polyester and is easier to dye.
Thermal properties: Nylon has poor temperature resistance. The safe working temperature is below 93°C (Nylon 6) or below 130°C (Nylon 66). Melting points are 215°C (Nylon 6) and 250°C (Nylon 66).
Light resistance: Nylon's light resistance is weaker than polyester's.
Alkali resistance: Nylon does not resist alkali well but is more resistant to acid.
Relative density: Lower than polyester (g/cm³)
General properties of Nylon: Nylon typically has good stretch. It can be dyed at temperatures as low as 100°C using neutral or acid dyes. While it doesn't handle high temperatures as well as polyester, it has superior strength and better resistance to pilling. When exposed to flame, it produces a white ash color, while polyester burns with black smoke and produces dark gray ash. Dyeing polyester requires temperatures around 130°C (high-pressure, high-temperature), and hot-melt processes usually occur below 200°C.
Polyester in clothing: Adding small amounts of polyester to clothes can help prevent wrinkles. The downside is it tends to generate static electricity and is prone to pilling.