Polyester melting temperature

Should you be using a polypropylene or polyester sewing thread? We compare these two different materials to help you decide.

Polypropylene - Advantages:

• Lower specific gravity/density (0.91 g/cm³) – More fibers/unit weight (~25% more).
• More hydrophobic – absorbs less water and therefore dries faster.
• Lower heat transfer – Retains more heat.
• Inert to most chemicals.

Polypropylene – Disadvantages:

• Lower Melting Point 165 degrees C.
• 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 and higher elongation.
• Poor abrasion resistance.
• Not suitable for high speed sewing applications.

Polyester Advantages:

• Higher strength, tenacity and creep resistance – distinct advantage in Geotextiles and especially when load is on a fabric.
• Greater yield per pound.
• Higher melting point (260°C vs 165°C).
• Withstands high temperature washing and drying.
• More UV resistant - Retains strength and color better.
• Resistant to most chemicals.
• Has good flame resistance and flame retardant properties.
• Has good abrasion resistance.
• Polyester is used more for sewing – Higher strength and can withstand high temperatures generated during the sewing process (up to 350°C).
• Polyester produces a better all-around fabric and sewing thread.

Polyester Disadvantages:

• Higher specific gravity.
• Less hydrophobic, requires additives or coating to prevent wicking.
• Susceptible to damage if exposed to highly alkaline chemicals.