How to Wash a Weighted Blanket
Most weighted blankets need a laundromat machine. Blankets over 3 kg dry weight require a drum of 10+ kg capacity.
Identify the fill type first. Plastic pellets: cold wash only. Glass beads: any temperature safe for the outer fabric.
Fill Types and Why They Matter
Weighted blankets are fundamentally different from regular duvets or blankets because of the fill material sewn into their internal pocket grid. Understanding the fill type determines how the blanket can be safely cleaned. The two most common fills are glass micro-beads and plastic poly pellets. Glass micro-beads are tiny balls of borosilicate or soda-lime glass, approximately 1–2 mm in diameter. They are chemically inert, do not absorb water, and have no temperature sensitivity — they can be washed and dried at any temperature safe for the outer fabric. The challenge with glass beads is weight: a 7 kg (15 lb) glass-bead weighted blanket holds approximately 4–5 kg of beads, and when the outer fabric absorbs water, the total wet weight reaches 18–22 kg. A standard domestic washing machine with a 7–8 kg drum rating cannot safely handle this weight — the drum bearings are not designed for it, and the garment does not have enough room to agitate properly. Plastic poly pellets (typically ABS or polypropylene) are lighter than glass beads but have a critical temperature sensitivity: most plastic pellets begin to deform or fuse together above 50–60°C. Hot water or high-heat drying can permanently fuse pockets of pellets into a solid lump, creating hard irregular patches in the blanket. This is why plastic-filled blankets must always be washed in cold water and dried on low or air heat only. The sewn pocket grid in a weighted blanket serves to distribute the fill evenly. Improper washing (overloaded machine, aggressive cycle) can stress the pocket seams — once a seam tears, the fill migrates and redistributes unevenly, creating permanent heavy patches.
By Fill Type
Glass micro-beads
Inert, no temperature restriction on the fill itself. Temperature limit is the outer fabric (usually cotton: 40°C, or polyester: 30°C). Heavier than plastic pellets. Laundromat machine required for blankets over 3 kg.
Plastic poly pellets (ABS/polypropylene)
Plastic pellets deform and fuse above 50–60°C. Cold wash only. Air dry or tumble dry on the lowest heat setting. Check individual pockets to feel for any fused lumps after drying.
Steel shot beads
Extremely heavy — requires large commercial machine. Must dry completely — moisture trapped with steel beads causes rust spots on the fabric. Air dry in sections.
Natural fills (rice, sand) — older blankets
Natural fills absorb water, can rot or grow mould, and lose their shape when wet. Spot clean the outer fabric only with a damp cloth and mild detergent. These fills are not designed for machine washing.
Washing Steps
Check the care label and identify the fill type
Look for weight, fill material, and temperature instructions on the care label. Most modern weighted blankets state the fill type. If it says 'glass beads', any cool or warm wash temperature safe for the fabric is fine. If it says 'poly pellets' or 'plastic beads', cold wash only (max 30°C). If the label is missing or unclear, treat as plastic pellets (most conservative approach).
Assess whether your machine can handle the weight
Weigh the blanket when dry. A blanket weighing more than 3 kg (6 lbs) needs a laundromat front-loading machine with at least 10–12 kg capacity. The general rule is: a blanket should be no more than half the machine's rated capacity by dry weight. This allows the blanket to move freely and ensures the drum bearing is not strained by the wet weight.
Pre-treat any spots or stains before washing
Apply a small amount of dish soap or enzyme detergent to any stained areas and work it in gently. Allow to sit for 15–20 minutes before loading the machine. Stains treated before washing are much easier to remove than stains that have been through a full wash cycle without pre-treatment.
Wash on a gentle cycle at cold or warm (not hot)
For glass beads: use the temperature appropriate for the outer fabric (cotton: 40°C maximum; polyester outer: 30°C maximum). For plastic pellets: cold water only (max 30°C). Use a gentle detergent — half the normal dose is sufficient, as the fill does not need cleaning, only the outer fabric. Do not use fabric softener — it leaves residue in the fill pockets that is difficult to rinse out.
Inspect pocket seams after washing while still wet
Before moving to drying, lay the blanket flat and run your hands over every section to check for intact pocket seams. If any pocket has a tear, the fill will migrate to one side during drying, creating permanent heavy patches. A torn pocket seam can often be sewn back up before the fill shifts further.
Tumble dry on LOW heat — 2–3 hours with breaks
Plastic pellets: low heat only or air dry. Glass beads: low to medium heat. Drying time is 2–3 hours for a typical weighted blanket because the inner pockets retain moisture much longer than the outer fabric feels dry. Every 30–45 minutes, remove the blanket and press each section firmly — feel for damp pockets inside. Any section that feels cool or damp needs further drying. Store only when every pocket feels fully dry to the touch.
FAQ
Can you wash a weighted blanket in a home washing machine?
Only if it is light enough. For blankets weighing 3 kg (7 lbs) or less when dry, a domestic machine with adequate drum size may work. For heavier blankets — most adult-sized weighted blankets are 5–10 kg — you need a laundromat machine with 10–12 kg capacity. The wet weight of a heavy blanket (the dry weight plus 3× the fabric weight in absorbed water) can exceed the drum bearing rating of a domestic machine, causing damage to the machine and inadequate agitation for the blanket.
How do you dry a weighted blanket?
Tumble dry on low heat for 2–3 hours for plastic pellet fills, or low to medium heat for glass bead fills. Every 30–45 minutes, remove the blanket and press firmly on each section to feel for remaining damp pockets — the outer fabric will feel dry long before the fill pockets are fully dry. For plastic pellet blankets, air drying flat on a clean surface is the safest option if you want to avoid any risk of pellet deformation.
How often should you wash a weighted blanket?
Every 2–4 weeks if it is used nightly without a cover. If used with a removable cover (a duvet cover or the outer shell of the blanket removes and washes separately), the inner weighted layer only needs washing every 2–3 months. Spot cleaning between full washes is effective for minor marks and extends the time between machine washes.
What happens if you wash a weighted blanket on hot?
For plastic pellet-filled blankets: the pellets can deform and fuse together, creating hard lumps inside the pockets that permanently change the feel and weight distribution of the blanket. This cannot be repaired. For glass bead-filled blankets: if the outer fabric can tolerate the temperature, the glass beads themselves will be unaffected. Cotton outer fabrics may shrink at high temperatures even if the beads are fine.
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