Properties of Nylon 6,6

Properties of Nylon 6,6

Strength

The most outstanding property of nylon is its strength and elasticity. The tenacity varies from 8.8-4.3 gpd while corresponding elongation at break varies from 18-45%. The wet strength of nylon is 80-90% of its dry strength and the elongation at break increases by 5-30% on wetting.

Density: 1.14 g/cc

Elastic Recovery

When nylon yarn is stretched 1,2 and 4% with a load of 0.25 gpd for 30 seconds and then released the recovery after 60 seconds is 38, 63 and 73% respectively.

Moisture Regain

Nylon has a moisture regain of about 4% at 65% RH and 70 deg F.

Action of Light

Like other fibres, nylon undergoes degradation and weakens when exposed to lights.

Appearance

Nylon is dull and semi opaque before cold drawing, but on orientation its lustre is greatly incresed. Delustering is done by adding TiO2 in the polymerisation mixture.

Action of Heat

Nylon melts at 262 deg C in an atmosphere of Nitrogen and at 250 deg C in air. When a very hot iron is used for ironing nylon garments, sticking or even fusion may take place. Therefore ironing should not be done above 180 deg C. Permanent set may be applied to Nylon by heat setting with 25 psi pressure with saturated steam. The pleats thus set remian on wearing and washing even in hot water.

Chemical Properties

Nylon is extremely stable chemically. For example dry cleaning solvents, alcohols, aldehydes, ketones, ethers, hydrocarbons, chlorinated hydrocarbons, soaps and synthetic detergents and water including sea water do not affect Nylon.

Also it has got a remarkable stability towards alkali.

Biological Properties

Nylon is not a nutrient for Mildew or bacteria and is not eaten up by moth larvae. But they bite their way up when imprisoned in nylon cloth. It is harmless to human skin.

Effect of Fabric Structure on Fabric Properties

Effect of Woven Fabric Structure on Fabric Properties

1. Tensile Strength: The more the crimp the less the strength. Other things being equal, plain weave fabrics which have the highest crimp have the lowest strength.

2. Extensibility: The more crimp there is in the yarn the more extensible is the fabric, therefor longer the floats, the less extensible is the fabric.

3. Surface Friction: Whether surface is smooth or rough. Long floats produce smooth fabrics with low crimp levels.

4. Tear Strength: In case of tensile loading, all the yarns in the direction of the loading share the load. In tear loading only one, two or at most few yarns share the load. In tight constructions, the movement of the yarn is restricted during loading and yarn will be presented to the load one by one; this results in a low tearing strength. Loose open constructions allow more freedom for the yarns to move and group together, thus presenting bundles of yarns to the tearing load, in consequence the tear strength is high. Designs which have group of yarns woven together such as rib or basket will have hight tear strength.

5. Abrasion Resistance: The most important factors are the crimp levels and the height of the crowns caused by the crimp. The greater the number of crowns/area or the greater the area of each crown, the less will be the stress concentration on the crowns and this leads to a high abrasion resistance. The longer the floats the larger the area of contact between the yarn and the abraidant and the higher the abrasion resistance.

6. Drape: Heavy fabrics from coarse yarns and dense constructions have poor drape characteristics. Fabrics with long floats in the weave permit the yarns to move freely; this reduces the bending and shear resistance of the fabric, leading to a better drape behaviour.

7. Crease Resistance: A plain woven fabric with a high fabric count puts a heavy strain on the fibres and limits the recovery of the fabric. The longer the floats, the higher will be the crease resistance of the fabric.