How to Wash a 100% Polyester Blanket | Cold Water, Low Heat Only

Wash a 100% polyester blanket in cold or warm water under 120°F on a gentle cycle with mild detergent, then line dry or tumble on low or no heat.

Polyester is plastic-based, so it holds up to washing — it just does not hold up to heat. This method follows what Whirlpool and Berkshire Blanket publish for synthetic and plush bedding, and takes about ten minutes of hands-on work. The care label always wins; if it disagrees, follow the label.

What Water Temperature Should You Use On A Polyester Blanket?

Cold water is the safe default, and warm water is acceptable only when the care label allows it and the temperature stays at or below 120°F.

Push past 120°F and fibers can distort, showing up as shrinkage, a rougher hand-feel, or permanent creases. Berkshire Blanket takes the stricter position for its 100% polyester plush items: cold water only, washed separately on the gentle cycle.

Whirlpool adds the practical layer: separate by color, fasten zippers, buttons, or hooks, turn the item inside out, and don’t overload the drum. A blanket needs room to move so detergent and rinse water circulate through it. Use a mild detergent and skip bleach and chlorine — polyester care sources are consistent on this. The exception is a care label that explicitly permits bleach. For a thick or oversized blanket, use a larger-capacity machine or commercial unit so it tumbles freely instead of balling up against the agitator.

Can You Put A Polyester Blanket In The Dryer?

Yes, if the care label allows machine drying — but only on the lowest heat setting or a no-heat air-fluff cycle, and pull the blanket out while still slightly damp.

Line drying is the safest option and the one Berkshire Blanket recommends for plush polyester. Stop the dryer early, while the blanket is a touch damp, and lay it flat or drape it to finish — this limits static cling and reduces the heat exposure that causes pilling. If the blanket comes out with hard creases, do not iron it;

Common Mistakes That Damage Polyester Blankets

Most polyester blankets are damaged by heat, overloading, or handling while wet — not by the washing itself.

• Washing in hot water. Above 120°F risks fiber distortion. Cold is the default; warm only if the label says so.
• Drying on high heat. Use low heat or no heat. Line drying avoids the risk entirely.
• Using bleach or chlorine. Both degrade synthetic fibers. Skip fabric softener too — it coats the fibers and cuts absorbency without adding softness.
• Wringing or twisting a wet blanket. This distorts fibers and sets creases that are hard to remove later.
• Overloading the washer. A crammed blanket can’t rinse clean. Wash it separately or with one or two similar items.
• Forgetting closures. Unzipped or unfastened hardware snags the fabric surface during the cycle.

Heated blankets are their own case. Detach the controller and cord before the blanket goes near water, and follow the manufacturer’s instructions over any general guidance — their limits are stricter than what a plain polyester blanket tolerates.

The Wash-And-Dry Sequence

1. Read the care label. It states whether machine or hand washing is appropriate and gives a temperature setting whenever hot water could harm the item.
2. Separate and prep. Sort by color, fasten closures, and turn the blanket inside out.
3. Choose the cycle. Gentle cycle, cold water, mild detergent. Warm water only if the label allows it and it stays under 120°F.
4. Wash without crowding. The blanket should move freely through the whole cycle.
5. Dry low or line dry. Low heat, no heat, or a clothesline. Remove while slightly damp and let it finish flat.

If it comes out soft and crease-free with plush fibers, the wash worked. If it shrinks or stiffens, heat was the culprit — adjust the temperature down next time.

If you’re replacing a blanket that heat already ruined, our tested polyester blanket picks cover the options worth buying.

The one authoritative source behind these temperature limits is Whirlpool’s own care guidance: Whirlpool’s how to wash and dry polyester guide.