The science of wrinkles ... in clothes, that is
TOKYO We can remove wrinkles in the fabric of our clothes by ironing them. We usually take this process for granted, but why do we get wrinkles in our clothes and why do they disappear?
According to Natsuko Fukuchi, a manager at Kao Corp.’s Lifestyle Research Center in Tokyo, wrinkles occur at the molecular level in the fabric of our clothing. Molecules are connected to one another because of forces of attraction called hydrogen bonds. If hydrogen bonds come into contact with water, they loosen. Once the moisture disappears, they form again.
Wrinkles form when laundry is hung out to dry because hydrogen bonds form again after molecules loosen and become misaligned. Ironing reverses this process, and realigns the molecules.
A steam iron dampens the fabric and loosens the hydrogen bonds. Then pressure is applied to align the molecules. Finally, the heat causes the water to evaporate and the hydrogen bonds to reconnect. Using a steam iron, the above three steps occur almost simultaneously.
The hotter the iron is, the easier it is for the moisture inside the fabric to evaporate, and the faster the hydrogen bonds recover. In short, wrinkles disappear faster when ironing at higher temperatures. However, if your clothes are made from material that is not heat-resistant, they might get damaged, shrink or become shiny. Checking the care instructions on your clothing tags is essential.
Wrinkle remover, which is sprayed onto fabric when ironing, loosens hydrogen bonds. The spray also makes the fabric less prone to wrinkle in the future by leaving a coat of resin on it when dried.
“Wrinkle-free shirts” fix the molecules in place using chemicals or other methods. This makes it harder for the hydrogen bonds to loosen when the shirts are washed and makes them less likely to become wrinkled.
The key to ironing is to loosen the hydrogen bonds effectively. You can add moisture either by using the spray or steam functions. Given the ease of steam irons, many people use them to iron 100 per cent cotton shirts, but the Tokyo Cleaning Association recommends using the spray instead of steam. The water droplets from a sprayer are larger, and adhere well to the cloth. The moisture remains on the fabric, and makes it easier for the hydrogen bonds to loosen.
Since cotton is highly resistant to heat, the temperature of the iron should be used on a high setting, according to the directions on clothing tags. Also, the iron should be used on a dry setting, pressed onto the clothing and smoothed along it in one direction.
On the other hand, the advantage
to using steam is that the droplets are small, so they can penetrate deeper into the fabric. Steam is ideal for giving woollen knit products a soft finish. For such garments, use a medium temperature, hold the iron slightly above the fabric, and apply the steam to the clothing.
Theoretically, wrinkles and pleats in clothes are identical. The hydrogen bonds in woollen slacks will loosen if they get wet in the rain.
“To make a crease in slacks, use your iron’s steam mode, put another piece of cloth in between the iron and the garment and press the iron onto it firmly,” an association official said.