Static electricity in clothes

Short answer: Static builds up when dry fabric rubs against dry fabric. Fibres that absorb moisture carry the charge away, which is why they crackle less than synthetic fibres that hold on to it.

Dry air is the main cause

In winter the air indoors is dry, because cold outdoor air loses its relative humidity when it is heated. With little moisture in the air, the charge created by movement stays in the fabric instead of fading away. That is why most people notice crackling from November to March and much less in summer, see bamboo boxers.

What happens when fabric rubs

When two fabrics rub together, small charges move from one to the other. It happens all day, when you walk, sit down or pull a jumper over your head. Normally the charge disappears quickly through moisture in the air and in the fabric. Only when it has nowhere to go do you feel a small shock or hear a crackle.

Moisture in the fibre carries the charge away

Bamboo viscose is a cellulose fibre, and it always holds a little moisture, even when the garment feels dry. That moisture works as a path for the charge, so it spreads out and fades instead of collecting in one spot. It is the same reason cotton crackles less than polyester. The fibre works with the air around it, see bamboo sweat for men.

Synthetic fibres hold on to the charge

Polyester, acrylic and nylon absorb almost no moisture. The charge has no way out, so it stays on the surface until you touch something. That is why a fleece or a polyester lining often crackles clearly when you take it off. The drier the air, the more noticeable it becomes over the course of the day.

It happens between the layers

Static is felt most between an outer layer and an inner layer that rub against each other. If both layers are synthetic, the charge grows, because neither can carry it away. If the inner layer is a fibre that absorbs moisture, most of it is dampened. So it makes sense to think about what sits closest to your skin, see bamboo sweat for men and women.

The tumble dryer makes it worse

In a tumble dryer, clothes rub against each other for a long time while all the moisture is drawn out. Those are close to perfect conditions for static. If you take the laundry out bone dry, it is fully charged. Stop the programme a little early, or let the clothes finish on a drying rack so the fibres can take up some moisture again.

Wash and rinse properly

Detergent residue can make the surface of a fabric rougher, and a rough surface creates more friction. Use no more detergent than needed and let the machine rinse properly. Fabric softener can reduce crackling in the short term, but it leaves a film on the fibres and can make an absorbent fabric less absorbent over time.

Small everyday habits

A little more moisture in the air helps, for example a bowl of water on the radiator or a humidifier in the bedroom. Choose an inner layer made from a fibre that absorbs moisture, and avoid stacking several synthetic layers on top of each other. Take a jumper off calmly rather than in one quick pull. Small changes remove most of the problem.

Frequently asked questions

Why do clothes crackle in winter

Because the indoor air is dry, and the charge from friction between layers cannot be carried away through moisture. In summer there is more moisture in the air, and the charge fades by itself.

Which fabrics crackle the most

Synthetic fibres such as polyester and acrylic. They absorb no moisture and therefore hold on to the charge, especially when layered in dry air.

What can you do about it

Choose an inner layer that absorbs moisture, and avoid drying clothes completely in a tumble dryer. A little more moisture in the indoor air helps as well.