Can you distinguish between polyester, nylon, and polyamide?
1、Polyester — Polyethylene terephthalate fiber
Also known as polyester, its characteristics include excellent breathability and moisture-wicking properties. It also has strong resistance to acids and alkalis, as well as UV resistance. Generally, fabrics with a denier of 75D and above are considered polyester, such as 75D, 150D, 300D, 600D, 1200D, and 1800D. The surface of these fabrics is darker and rougher compared to nylon.
2、Nylon — Polyamide
Also known as nylon, it is a polyamide fiber. Its advantages include high strength, high abrasion resistance, excellent chemical resistance, and good shape retention and aging resistance. The drawback is that it has a relatively stiff hand feel. Notable brands include PERTEX and CORDURA. Generally, fabrics with a denier of 70D and above are considered nylon, such as 70D, 210D, 420D, 840D, and 1680D. These fabrics have a shiny appearance and a smoother feel.
In general, oxford fabric for bags is typically made from nylon. The simplest way to distinguish between nylon and polyester is through the burning test! Polyester produces a strong black smoke, while nylon emits white smoke. Additionally, the residue left after burning can help: polyester crumbles when pinched, while nylon remains plastic. In terms of price, nylon is about twice that of polyester.
Nylon: In the flame — shrinks, melts, burns slowly, produces small bubbles, has a small blue flame. Away from the flame — stops burning and self-extinguishes. Burning smell — has an amine or celery-like odor. Residue characteristics — forms a hard, black, round ball of ash that is difficult to crush with fingers.
Polyester: Near the flame — softens, melts, shrinks; in the flame — melts, burns slowly with a yellow flame, blue at the edge, and produces black smoke at the top. Away from the flame — continues to burn, sometimes self-extinguishes. Burning smell — has a slight sweet or aromatic odor. Residue characteristics — forms a hard, black, round ball of ash that is difficult to crush with fingers.
The hand feel is also different. Polyester feels relatively rough, while nylon has a smoother and softer touch. You can also scratch them with a fingernail; if there are clear marks left, it's polyester, while less noticeable marks indicate nylon. However, this method is not as intuitive as the burning test.
In terms of performance differences, nylon generally outperforms polyester but comes at a higher cost. Nylon products excel in abrasion resistance, tensile strength, color fastness, and glossiness compared to polyester products, and they are less prone to permanent wrinkles. In terms of hand feel, nylon is soft while polyester is harder!
The main differences between polyester and nylon fabrics are:
Price: Nylon is about twice as expensive as polyester.
Hand Feel: Nylon is smoother and softer compared to polyester.
Abrasion Resistance: Both have similar abrasion resistance.
Elasticity: Nylon has slight elasticity, while polyester has none.
Dyeing: Dyeing nylon is generally more challenging than dyeing polyester.
01 Polyester
Mechanical Properties:
High tensile strength and large elongation.
High initial modulus.
Good elasticity and recovery.
The fabric is stiff with good abrasion resistance and dimensional stability.
Moisture Absorption and Dyeing:
W = %; cannot use normal temperature dyeing.
Prone to static electricity and has poor stain resistance.
Thermal Properties:
High melting point of 255-265°C.
Good heat resistance and thermal stability.
Optical Properties:
Good light resistance, second only to acrylic.
Chemical Resistance:
Resistant to acids but not strong alkalis; does not mold or rot.
Density:
g/cm³
02 Nylon (Polyamide)
Mechanical Properties:
High tensile and bending strength with significant elongation.
Lower initial modulus and high breaking work.
Good elasticity and abrasion resistance, but poor shape retention and stiffness of the fabric.
Generally better elasticity than polyester. Dyeing temperature can be at 100°C using neutral or acidic dyes.
Nylon’s resistance to high temperatures is inferior to that of polyester, but its strength and resistance to pilling are better. When burned, nylon produces a whitish smoke, whereas polyester releases thick black smoke accompanied by black ash. The dyeing temperature for nylon is typically 130°C (high pressure), while heat melting methods are generally below 200°C.
Characteristics of Polyester
Polyester is known for its stability. Adding a small amount of polyester to garments can help improve wrinkle resistance and shape retention. However, it is prone to static electricity and pilling, though these issues have been improved in modern polyester fabrics.
How to Differentiate:
Polyester: Has a strong silk-like feel, bright luster, but is not very soft. It has a shiny finish and smooth texture, with good elasticity. When pinched, it does not leave obvious creases. After getting wet, the yarns do not easily break.
Nylon: Has a duller sheen and feels somewhat waxy. Its colors are not as vibrant. The fabric feels stiffer, and pinching it leaves noticeable creases, though it can slowly return to its original state.
Durability: Nylon excels in strength and abrasion resistance, being ten times more durable than cotton fibers and dry viscose fibers, and 140 times more durable than wet fibers, making it highly durable. However, nylon fabrics can easily wrinkle under small external forces and have poor ventilation.
Nylon has a good moisture absorption rate compared to other synthetic fibers, making clothing made from nylon generally more comfortable than that made from polyester. Additionally, nylon offers good resistance to pests and corrosion but has poor heat and light resistance, with ironing temperatures should be controlled below 140°C.
Polyester Performance
Strength: High; short fiber strength is around ~dtex, and high-strength fiber is around ~dtex.
Moisture Absorption: Lower moisture absorption means that its wet strength is similar to its dry strength.
Impact Resistance: Four times higher than nylon and twenty times higher than viscose fibers.
Elasticity: Good, comparable to wool, recovering almost completely after stretching by 5%–6%.
Wrinkle Resistance: Exceeds other fibers, with excellent dimensional stability.
Density and Abrasion Resistance: Good, second only to nylon.
Chemical Resistance: Resistant to bleach, oxidizers, hydrocarbons, ketones, petroleum products, and inorganic acids; resistant to mild bases, not prone to mildew, but hot alkalis can decompose it.
