Cotton and polyester are two of the most used fibres in many industrial applications. Everyone knows the basic difference between cotton yarn and polyester yarn. Cotton is a natural fabric. Polyester is a synthetic fabric made using chemicals. However, there are other key differences between these fabrics. Both fabrics have unique properties. These properties depend on the material and how it is processed.

Cotton Yarn

Cotton plant is the source of cotton fibre. The fibre contains pure cellulose. The fibre is hollow in the middle. This hollow opening running the length of the fibre is known as the lumen. The lumen collapses when the fibre is exposed to the sun. This makes the fibre twist and results in the formation of convolutions. The fibre comes with a natural wax coating that protects it from elements that can cause some sort of damage. This coating is the reason why cotton yarn is hydrophobic i.e. it repels water. This natural fibre is known for its absorbency. The purification process removes its natural oils and waxes. If it does not go through this process, it remains hydrophobic. Cotton gets its absorbency when these waxes and oils are removed. 

Cotton Properties

Cotton is the most preferred fibre for baby and children’s apparel. It’s because cotton is natural, soft, hypoallergenic, comfortable and breathable. It is also the best fabric for non-woven hygiene products. There are many other attributes that make cotton ideal for many non-woven applications. Its strength ranges from moderate to above average. When dry, it has a strength of 3.0-5.0 grams/denier. It becomes stronger when it is wet. Its strength is increased to 3.3-6.0 grams/denier. When cotton yarn is under normal humidity conditions and temperature, the natural moisture regain of the fabric is 8.5%. As it is a sustainable and biodegradable fabric, it is still relevant and popular in the era of environmental concerns.   

Polyester Yarn 

Polyester is polyethylene terephthalate. This synthetic fabric is the end product of a chemical reaction. The reactants in this chemical reaction are petroleum, water and air. Polyester yarn is comprised of monotheluene glycol (MEG) and purified encephalitic acid (PTA). As it is thermoplastic, polyester is easy to melt and reform. Polyester is made by forcing polyester pellets in a molten state through small holes/spinnerets. As it exits spinnerets, the result is polyester fibres. The diameter and shape of the fibre depend on the shape and size of the hole. These polyester fibres are in solid form. The fabric does not void space inside. These are continuous filaments known as “tow”. They can be cut to produce stable fibres for textiles and nonevents use. However, they can be continuous monofilament as well.

Polyester Properties 

As the polyester fabric is hydrophobic, it does not absorb perspiration. It is not good at wicking sweat. Polyester is stronger than cotton. It has a strength ranging from .5 grams/denier to 9.5 grams/denier. Polyester is also more stretchable than cotton. There are some environmental concerns linked with polyester yarn. It is not sustainable and biodegradable. 

Polyester Yarn vs. Cotton Yarn 

Cotton yarn is natural, absorbent, breathable, sustainable and biodegradable. Polyester is not breathable and sustainable. However, many industrial applications use blends of cotton and polyester to get the properties of both. One can choose cotton yarn, polyester yarn or different blends of both for the application.