Polyester fibre: Characteristics
Denier, tenacity and why dyeing shows every flaw
What this tab covers The physical and chemical properties that set its grade, price and uses, with the commercial grades and the standards that define them.Spinners and weavers buy polyester on denier (fineness), tenacity, elongation, lustre and dye uptake consistency. Staple fibre is also specified by cut length and crimp. Small batch-to-batch differences show up as dyeing streaks, so consistency is the main quality measure.
Properties that matter commercially
| Property | Value / specification | Why it matters | Source |
|---|---|---|---|
| Fineness | staple 1.2-1.5 denier for cotton blends; filament 50-300 denier yarn (indicative) | Matches cotton or viscose in blends; sets fabric weight | indicative |
| Tenacity | about 4-6 g/denier textile; 7-9 g/denier industrial (indicative) | Strength in weaving and in tyre cord | indicative |
| Lustre | bright, semi-dull (about 0.3% TiO2), full-dull (about 2%) | Appearance of fabric | indicative |
| Moisture regain | about 0.4% (indicative) | Low comfort versus cotton (about 8%) but fast drying | indicative |
Commercial grades
- POY, FDY and DTY filament
- PSF for cotton and viscose blends (1.2-1.5 d, 38-51 mm)
- Hollow conjugate fibrefill
- High-tenacity industrial yarn
- Recycled PSF and rPET filament
- Dope-dyed fibre