Nylon and polyester get treated as the same thing, and they are not. They are different polymers with different weaknesses, and the care that protects one of them damages the other. Knowing which is which explains a lot of otherwise puzzling laundry outcomes.
Two different plastics
Both are synthetic polymers extruded into filaments, which is where the similarity ends.
Polyester is a polyester resin, closely related to the plastic used in drinks bottles. It is stiff, holds its shape, resists stretching, and is almost completely unaffected by water.
Nylon is a polyamide. It is more elastic, stronger against abrasion, and it absorbs a small amount of water, roughly four percent of its weight, which polyester does not do at all.
That small difference in water absorption drives most of what follows, along with one more fact: nylon is significantly more sensitive to ultraviolet light and to chlorine.
Where each one fails
Polyester’s weakness is oil. The fibre is oleophilic, meaning it attracts and holds oily soil, and once body oil is in polyester it is difficult to remove and it is what makes athletic shirts smell even after washing. Water-based stains rinse out of polyester easily. Oil-based ones do not.
Polyester also melts at a fairly low temperature and pills readily on the surface where it rubs.
Nylon’s weaknesses are different. Sunlight degrades it, so nylon items left in the sun weaken and yellow. Chlorine attacks it directly, which is why nylon swimwear fails faster in a chlorinated pool than polyester swimwear does. And heat causes it to lose its elasticity and go limp.
Nylon also picks up dye from other fabrics readily. White nylon washed with anything that bleeds will come out tinted, and it is hard to reverse.
Washing polyester
Warm water rather than cold, which is the counterintuitive part. Cold water leaves oily soil in polyester, and oily soil is polyester’s whole problem. A warm wash removes far more of it.
Use a detergent with enzymes, particularly lipase, which breaks down the fat and oil that a rinse alone will not carry away.
Never fabric softener on performance polyester. It coats the fibres and destroys the wicking that the fabric was engineered for, and it traps the odour-causing oil rather than removing it.
Turn garments inside out to reduce surface pilling.
Low heat in the dryer, or air dry. Polyester dries very fast because it holds almost no water, so a full dryer cycle is wasted energy and unnecessary heat exposure.
Washing nylon
Cool water, and a gentle cycle.
Keep it away from anything that bleeds colour, and wash white nylon separately.
Never chlorine bleach, which attacks the polymer directly and yellows it permanently.
Rinse nylon swimwear in fresh water immediately after a chlorinated pool. Chlorine left in nylon keeps working on the fibre while it sits.
Air dry in shade. Sunlight is the thing that quietly kills nylon, and a nylon item dried repeatedly in full sun weakens noticeably within a season.
Low or no heat, since heat takes the stretch out of nylon and it does not come back.
The smell problem
Synthetic athletic wear that smells even after washing is almost always polyester holding oil.
The fix has three parts. Wash warm rather than cold. Use an enzyme detergent and use less of it, because excess detergent leaves residue that holds odour rather than removing it. And soak in a basin with a cup of white vinegar and cool water for half an hour before washing, which breaks the bond between the oil and the fibre.
Never dry a synthetic garment that still smells faintly wet. Heat sets the odour compounds into the fibre and the next wash starts from further behind.
Do not wash athletic wear with towels or cotton, which shed lint that clings to synthetics and reduces their breathability.
Static, pilling, and snags
Static is a synthetic problem because these fibres do not conduct, and it worsens as the fabric dries. Removing loads from the dryer slightly damp cuts static more effectively than any product does. Wool dryer balls help. Fabric softener also helps and costs you the wicking, so on performance fabric it is a bad trade.
Pilling on polyester is surface fibre balling up under friction. Wash inside out, avoid washing with rough fabrics like denim and towels, and use a fabric shaver rather than picking at pills, which pulls more fibre to the surface.
Nylon snags rather than pills, because the filaments are long and smooth. Wash it in a mesh bag with anything that has hooks or zips.
The Mesa part
Both of these fabrics get worked hard in this climate, and the local conditions hit each one on its specific weakness.
For polyester, the issue is sweat volume. Long stretches above a hundred degrees mean athletic and everyday synthetics absorb far more body oil here than they would in a temperate climate, and body oil in polyester is exactly the failure mode. Cold washing is popular here for good reasons, and it is the wrong choice for polyester specifically. A warm wash with an enzyme detergent, on the synthetics alone, is worth the exception.
For nylon, the issue is the sun. Ultraviolet intensity here is high and the drying is fast, which tempts everyone into hanging things outdoors in direct sun. That is fine for cotton and it steadily destroys nylon. Dry nylon on a shaded patio or indoors, where the dry air still gets it done quickly.
Chlorine is the third local factor, since pool use is high and long. Rinsing nylon swimwear in fresh water on the way home, rather than once you get there, is what separates a swimsuit that lasts two seasons from one that lasts one.
Where the oil actually comes out
Removing oil from polyester needs warm water, working detergent, and enough water volume to carry the loosened oil away rather than redepositing it on the rest of the load.
The machines at our self-service laundry on East Broadway Road run full cycles with real water volume, which is what gets oil out of synthetics rather than moving it around the drum.
Our machines and the store are cleaned daily.
Nou wash-dry-fold service covers the everyday laundry.
The short version
Polyester attracts oil and nylon does not, so polyester wants a warm wash with an enzyme detergent while cold water leaves the oil in. Nylon is damaged by sunlight and by chlorine, so dry it in shade and rinse swimwear in fresh water immediately after a pool. Skip fabric softener on both, since it coats the fibres and kills the wicking. Wash synthetics inside out and away from towels and denim to limit pilling and lint. And never dry a synthetic that still smells, because heat sets the odour into the fibre.
WaveMAX Mesa on Broadway is at 2639 E Broadway Rd, easy to reach from Mesa and the surrounding area. If the synthetics need a warm wash and a real rinse, call us at 513-907-6970.