From Fiber to Fashion
Acrylic
| Property | Characteristics |
| Microscopic appearance | Uniform and smooth surface Irregular spaced striations |
| Length | Mainly a staple fibre |
| Colour | White |
| Lustre | Bright or dull |
| Strength | Fair to good strength |
| Elasticity | Good |
| Resilience | Good |
| Moisture absorption | 1 – 3% |
| Heat | Yellowing may occur above 148°C / 300°FSoftening or stocking about 232°C / 450°F |
| Flammability | Burns with yellow flame |
| Electrical conductivity | Fair to good |
Fibre Properties – Comparison
Absorbency
| Fibre | Moisture regain* |
| Cotton | 7 -11 |
| Flax | 12 |
| Silk | 11 |
| Wool | 13 – 18 |
| Acetate | 6.0 |
| Acrylic | 1.3 – 2.5 |
| Aramid | 4.5 |
| Glass | 0 – 0.3 |
| Nylon | 4.0 – 4.5 |
| Polyester | 0.4 – 0.8 |
| Rayon | 15 |
| Rayon HWM | 11.5 – 13 |
| Spandex | 0.75 – 1.3 |
*Moisture regain is expressed as a percentage of the moisture-free weight at 70º Fahrenheit and 65% relative humidity.
Thermal properties
| Fibre | Melting Point | Softening Sticking Point | Safe Ironing Temperature | ||||
| ˚F | ˚C | ˚F | ˚C | ˚F | ˚C | ||
| Cotton | Non melting | 425 | 218 | ||||
| Flax | Non melting | 450 | 232 | ||||
| Silk | Non melting | 300 | 149 | ||||
| Wool | Non melting | 300 | 149 | ||||
| Acetate | 446 | 230 | 364 | 184 | 350 | 177 | |
| Acrylic | 400 – 490 | 204 – 254 | 300 – 350 | 149 – 176 | |||
| Aramid | Does not melt, carbonises above 426°C / 800°F | ||||||
| Glass | 1400 – 3033 | ||||||
| Nylon 6 | 414 | 212 | 340 | 171 | 300 | 149 | |
| Nylon 66 | 482 | 250 | 445 | 229 | 350 | 177 | |
| Polyester PET | 480 | 249 | 460 | 238 | 325 | 163 | |
| Polyester PCDT | 550 | 311 | 490 | 254 | 350 | 177 | |
| Rayon | Non melting | 375 | 191 | ||||
| Spandex | 446 | 230 | 347 | 175 | 300 | 149 | |
Effects of Acids
| Fibre | Behaviour |
| Cotton | Disintegrates in hot dilute and cold concentrated mineral acids |
| Linen | Disintegrates in hot dilute and cold concentrated acids |
| Wool | Destroyed by hot sulphuric, otherwise unaffected by acids |
| Silk | Organic acids do not harm, concentrated mineral acids will dissolve |
| Rayon | Disintegrates in hot dilute and cold concentrated acids |
| Acetate | Soluble in acetic acid, decomposed by strong acids |
| Tri-acetate | Soluble in acetic acid, decomposed by strong acids |
| Nylon | Decomposed by strong mineral acids, resistant to weak acids |
| Polyester | Resistant to most mineral acids; disintegrated by 96% sulphuric acid |
| Spandex | Resistant to most mineral acids, some discolouration can happen |
| Acrylic | Resistant to most acids |
| Glass | Resistant to most acids |
Effects of Alkalis
| Fibre | Behaviour |
| Cotton | Not harmed by alkalis |
| Linen | Highly resistant |
| Wool | Attacked by weak alkalis, destroyed by strong alkalis |
| Silk | Damaged only under high temperature and concentration |
| Rayon | Disintegrates in concentrated solutions |
| Acetate | Not affected, unless high concentration and temperature is applied |
| Tr-acetate | Not affected, unless high concentration and temperature is applied |
| Nylon | Little or no effect |
| Polyester | Resistant to cold alkalis, slowly decomposed at a boil by strong alkalis |
| Spandex | Affected |
| Acrylic | Destroyed by strong alkalis at boil, resists weak alkalis |
| Glass | Attacked by hot weak alkalis and concentrated alkalis |
Effects of Organic Solvents
