Aramids are resistant to most ketones, alcohols, dry cleaning solvents and many other organic solvents.
Its acid resistance is superior to that of nylon but is not as good as that of polyester. Aramids show good resistance
to alkalis at room temperature, but is degraded by strong alkalis at higher temperatures.
Aramids are compatible with fluorine-containing elastomers, resins, and refrigerants at high temperatures, and is
resistant to fluorine compounds in concentrations usually encountered in stack gases from metallurgical and
rock-processing operations.
The resistance of aramids to oxides of sulphur at temperatures above the acid dew point is superior to that of polyester.
Below the dew point, concentrated sulphuric acid may condense on the fiber and cause a progressive loss in strength.
In moderate to strong acid or alkali environments, evaluation of aramids should be made to ensure that the yarn will
perform acceptably before use.
In moderate to strong acid or alkali environments, evaluation of aramids should be made to ensure that the yarn will
perform acceptably before use.
Polyester and nylon are not significantly affected by most compounds of the following classes: Alcohols, Dry
Cleaning Solvents, Halogenated Hydrocarbons, Ketones, Soaps and Synthetic Detergents, and Water (Including Sea Water).
Polyester also shows good to excellent resistance to:
- Aqueous solutions of most weak acids at the boil, and to most strong acids at room temperature, but is disintegrated
by concentrated (95%) sulphuric acid at room temperature.
- Aqueous solutions of strong alkalis at room temperature, but is degraded at the boil.
- Oxidizing agents, and is not degraded by bleaching treatments ordinarily used for textiles.
Nylon is not significantly affected by most aldehydes, alkalis, ethers, or hydrocarbons, but is deteriorated by dilute
acids (e.g., hydrochloric acid and sulphuric acid in 10% concentrations at room temperature cause a noticeable loss in
breaking strength in 10 hours).
Solvents for nylon includes: Concentrated formic acid, Phenolic compounds at room temperature, Calcium chloride in
methanol at room temperature.
Hot solutions of calcium chloride in: Glacial Acetic Acid, Ethylene Chlorohydrin, Ethylene Glycol.
Hot solutions of zinc chloride in methanol Benzyl alcohol at the boil.
Aramids are resistant to most weak acids and alkalis, ketones, alcohols, hydrocarbons, oils and dry cleaning solvents.
Strong acids and bases and sodium hypo-chlorite bleach attack aramids, particularly at high temperatures of high
concentrations.
K-Spec® core yarn strength retention is based on test results of components at 65°C/150°F (or less)
for 6 months. K-Spec® has a 100% strength retention when exposed to: Age, 10% detergent solution, rot and mildew,
sunlight and Toluene; 99% strength retention when exposed to: acetic acid, gasoline, hydrochloric acid 1m, hydraulic
fluid, kerosene, and sea water; 98% retention when exposed to: 25% ammonium hydroxide, 10% hypophosphite solution, and
40% phosphoric acid; 97% retention when exposed to 5m sodium hydroxide; 95% retention when exposed to Portland cement
and sulfuric acid; and 88% retention when exposed to Clorox®, and nitric acid.
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