Down jackets can’t be machine washed, and they can’t be dry cleaned either?

Audit expert: Zhu Guangsi

Member of Beijing Science Writers Association With the arrival of winter, down jackets, sweaters, wool or cashmere coats and other clothes with strong thermal insulation performance have once again become essential cold-proof equipment for going out, but the temperature is guaranteed, and once these heavy clothes get dirty, cleaning becomes a problem.

Sending it to a dry cleaner for cleaning is expensive and there is also the worry of chemical residue; if you just throw it into the washing machine for cleaning, your down jacket may become fluffy, your sweater may shrink into the size of children's clothing, and even your down jacket may explode if you are not careful!

Source: Weibo/CCTV News

In fact, news of down jackets exploding when put into washing machines is not new and happens occasionally in various places every year.

So how should these winter clothes be washed correctly?

Before giving the method, it is better to briefly understand the principles behind it to ensure that you can cope with every winter with ease.

How can a down jacket explode when washed?

When a down jacket is placed in a washing machine for washing, the fluffy down is fully absorbed by water and is constantly stirred as the washing machine rotates. The wet down gathers together and forms a ball, leaving large gaps in the remaining part.

When spinning, the down begins to expand again after being dehydrated, and gradually returns to its previous fluffy state. During the expansion process, due to the poor air permeability of the outer fabric of the down jacket and the thicker coating of some fabrics, the air inside the down jacket is difficult to discharge. At this time, it is like a "balloon" that is constantly being inflated. When the gas gathers to a certain extent, it may burst the washing machine and explode.

Source: Photographed by the author

In addition, when spinning, the down jacket and the inner wall of the machine are constantly rubbing against each other, generating static electricity. Heat accumulates in a short period of time, which may cause accidents and pose a major safety hazard.

The spin drum of a twin-tub washing machine or a pulsator washing machine generally has a smaller capacity and is more likely to explode.

Source: A certain picture material website. This picture does not support reprinting.

Of course, there are many machine-washed down jackets that have not exploded. From the above principle, we can know that this mainly depends on two factors: the breathability of the surface fabric of the down jacket and the mode of the washing machine.

So if neither your down jacket nor your washing machine poses a safety hazard, is machine washing the best way to clean your down jacket?

How should you wash a down jacket?

In fact, the best way to clean a down jacket is by hand!

Machine washing saves time and effort, but in addition to the possibility of explosion, the stirring of the washing machine can also cause irreversible damage to the down jacket: friction between the fabric, wear of the coating, wrinkles and down penetration, and reduced service life of the down jacket.

Dry cleaning is not only expensive, but also very damaging to down jackets. Dry cleaning agents containing tetrachloroethylene can effectively dissolve most oil stains, but they will also dissolve a layer of cell membrane on the surface of down protein fibers, causing the down to break, reduce fluffiness, and make the down jacket thinner. Even if the down jacket is restored to its fluffy state through drying, its warmth retention will still be greatly reduced because the internal down structure has essentially changed.

In addition, dry cleaning agents will also dissolve the coating of some fabrics, resulting in down penetration, and the windproof and dustproof functions are reduced. The poor air permeability of down jacket fabrics will also cause more dry cleaning agent residues, which is harmful to human health.

Source: Photographed by the author

Key points for hand washing down jackets:

1. Choose a neutral laundry detergent (you can check whether the laundry detergent notes indicate that it can wash down jackets), and avoid using soap, washing powder and other highly alkaline detergents for washing, because laundry detergents with strong alkalinity or added oxidants will oxidize and degrade the keratin that makes up the down, causing the originally soft and resilient down to turn yellow, brittle, dull, rough to the touch, and less fluffy.

2. The soaking time should not be too long and the water temperature should not be too high. For reference: 10 minutes and 30 degrees Celsius.

3. Use a soft-bristled brush to gently scrub areas with more stains, and avoid rubbing vigorously, which will cause down accumulation, fabric wrinkles, larger pinholes, and down drilling.

4. Gently squeeze out the water, avoid wringing out to avoid damaging the fabric and down.

How sweaters shrink: directional friction effect

After talking about down jackets, let’s take a look at the principle of sweater shrinkage.

The scale structure on the surface of wool can be clearly observed through a microscope. When the wool fibers slide along the direction of the scales, the friction is small and they can move easily. However, if the direction is reversed and the wool slides against the scales, the scales will generate greater friction and hinder the movement. Therefore, each wool fiber tends to move in one direction and it is more difficult to move in the opposite direction. This is the "directional friction effect."

Source: pixabay

When washing sweaters in a washing machine, the scale tissue on the surface of the wool will expand and open. The rubbing or stirring of the washing machine causes the wool to be affected by the directional friction effect, continuously moving in the direction of less friction, and then continuously tightening and entangled together, filling the original gaps between the fibers little by little, causing the fabric to shrink in length and become thicker. The textile term is called "shrinkage" or "felting."

In addition to external friction, factors such as water temperature and detergent will also affect the shrinkage of wool. Generally speaking, hot water and alkaline detergents will increase the degree of shrinkage of sweaters, so you should try to choose special laundry detergents for wool and cashmere.

How to wash a sweater? It depends on the material

If it is a sweater or coat with a high cotton content and low wool and cashmere content, or mercerized wool (the wool fiber is treated to make the surface smooth to avoid the "directional friction effect"), put it in a laundry bag to reduce friction, and choose the gentle wash mode or sweater wash mode of the machine wash. Machine washing is undoubtedly the most practical way.

Source: Lu Kai. Research on microscopic visual feature expression and recognition algorithm of cashmere and wool fibers

Compared to sheep wool, cashmere is taken from the fine and dense hair closest to the goat's skin. The fiber scales of goat cashmere are arranged more loosely, in a ring shape, and close to the hair shaft. The "directional friction effect" is weaker and less likely to shrink. Therefore, cashmere sweaters made of cashmere are softer and less irritating to wear, and they are also warmer. It is no problem to wash them in a washing machine marked with cashmere cleaning function.

Of course, for sweaters with good materials and high prices, it is most recommended to wash them gently by hand and lay them flat to dry to avoid stretching and deformation.

Down, wool and cashmere all contain natural protein fibers with unique properties. As long as they are properly maintained, we can enjoy the high-quality wearing experience brought by natural fabrics.