What are the properties of polyester?

Let us now discuss the properties of polyester:

Microscopic Properties:
• Longitudinal Section (L.S.): Polyester has a smooth, uniform and rod-like longitudinal section.
• Cross Section (C.S.): The cross-section of polyester fiber is quite circular.

Physical Properties:
• Length and diameter: The length of the polyester fiber depends upon the end-use and can be controlled while the diameter of fiber varies from 12-25 m.
• Colour and lustre: The colour of acrylic fiber is off-white and possess bright lustre as the incident light is reflected evenly when it falls on the smooth surface of the fiber.
• Tenacity: The tenacity of polyester is quite high and varies from 2.5-9.5g/den. It is the large crystalline region present in the polyester fiber that contributes towards strength. There is no loss of strength in wet conditions.
• Elongation and elastic recovery: The polyester fibers have good elastic recovery.
• Density: The density of polyester is 1.39g/ which makes it even heavier than nylon.
• Resiliency: The acrylic fiber when crushed or bent it returns to its original position which imparts good resiliency to fiber.
• Moisture regain: Polyester fiber is hydrophobic due to the presence of a crystalline arrangement that does not allow easy entry of water in the structure.
• Thermal Property: Polyester fiber is thermoplastic in nature and can be easily heat set and thus softened and shaped accordingly.

Chemical Properties:
• Acids: Polyester fibers are resistant to the action of acids.
• Alkalis: The polyester fibers have a fair resistance to alkalis.

Polyester has excellent resistance to sunlight but faces a problem of static charge.