Polypropylene and Polyester are the two major fibres used in traditional spinning and weaving, non-wovens, Industrial yarns and composites. Polyester is made from Dimethyl terephthalate (DMT) and Mono Ethylene Glycol. Modern processes use pure Terephthalic acid (PTA) in place of DMT. Polypropylene is a polyolefin made from a polypropylene monomer obtained from naphtha. Both fibres are available as virgin and bottle grade (from regenerated material).
The main difference between polyester and polypropylene is that polypropylene is more water-resistant than polyester.
Polyester lacks the quick-drying properties of polypropylene, but it is washable and wrinkle-resistant, qualities that make it easy to care for.
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- About 25% less dense than most fabric, Polypropylene is more hydrophobic, which means it absorbs less water and therefore dries faster.
- Polypropylene in fabric retains more heat;
- It is inert to most chemicals.
- Lower melting point;
- Lower UV resistance – needs additives like Carbon Black to prevent rapid deterioration with UV exposure.
- Lower Strength – requires larger thread or yarn to meet strength targets.
- Lower creep resistance inflicts higher elongation;
- Polypropylene has poor abrasion resistance and is unsuitable for high-speed sewing applications.
- Higher strength, tenacity, and creep resistance.
- Higher melting point (260°C vs 165°C).
- Withstands high-temperature washing and drying.
- More UV resistant.
- Resistant to most chemicals.
- Has good flame resistance and flame retardant properties.
- Has good abrasion resistance.
- Higher specific gravity.
- Less hydrophobic, and requires additives or coating to prevent wicking.
- Susceptible to damage if exposed to highly alkaline chemicals.
11 differences between polyester and polypropylene
- Polyester is available in higher tenacity grades compared to polypropylene.
- Polyester for producing sewing threads of super tenacity. Polypropylene is not normally used for sewing threads because of its low melting point.
- Elongation is much higher in polypropylene.
- The density of polypropylene (0.91g/cc) is much lower than polyester’s (1.38 g/cc). As a result, thicker, bulkier yarns, loftier fabrics, and more comfortable carpets are made with the former for a given count of yarn and the area density of the fabric.
- Polypropylene is dope dyed and is available in an extensive range of colours and shades. Dope-dyed polyester is available only in a limited number of colours and shades.
- The melting point of polypropylene (165oC) is much lower than that of polyester (260oC).
- Resistance to UV light is inferior to PP compared to PES.
- Polypropylene tends to form beads during carding. Because of card loading, achievable production rates are lower with polypropylene than with polyester.
- Polypropylene is highly inert to chemicals and is suitable as fishing nets and geotextiles in alkaline and acidic soils. polyester hand loses its strength in alkaline soils and should not be used.
- Polyester has higher creep resistance (retention of tensile properties over a long duration of time) than PP.
- Polyester/ cotton and Polyester/viscose blends are very popular as apparel materials. Polypropylene is on the other hand not usually blended with cotton or viscose.
Works Cited: Polyester vs Polypropylene