What Makes Cotton Shrink? Can You Unshrink It?

Cotton is vulnerable to shrinking in ways that other kinds of synthetic fibers, such as polyester, are not.

So, what exactly makes cotton shrink?

Why Cotton Shrinks

A huge part of cotton's susceptibility to shrinking can be explained by the clothes' individual fibers. According to Jillian Goldfarb, an associate chemical and biomolecular engineering professor from Cornell University, the fabric of cotton is produced by weaving the cotton plant's tiny fibers together. Such fibers mostly consist of cellulose, which is a natural biopolymer.

Cotton clothes also, evidently, absorb moisture well. Other synthetic fabrics have higher resistance to shrinkage and sweat because their fibers do not swell when wet.

The material is vulnerable to shrinking because of how the fibers contract when dry and swell when wet.

Chemist Erika Milczek, who is the CEO of CurieCo, a biotechnology firm, says that chemically speaking, weaving of such cotton fibers leads to tension that produces a network of hydrogen bonds.

When certain variables, such as water and heat, are introduced, the network could see the transformation, leading to the relaxation or contraction of the fabric. This is also the science that explains clothing wrinkling.

Milczek also noted that the extent of shrinking could depend on other factors. For instance, whether the clothes are washed with just water or with added detergent could contribute to shrinking. This is due to how detergents could disrupt hydrogen bonds further.

Moreover, whether clothing drying is done at high heat, low heat, or through hanging could also affect the extent of shrinking.

Goldfarb noted that line drying temperatures are quite lower, which makes evaporation happen more slowly. Such a case does not make the fibers stressed by the shrinking heat.

Line-dried clothes also experience humidity that is more consistent between the closet and outdoor setups. This could lead to lesser shrinking.

A study also discovered that drying could shrink clothes twice as much as washing does. Moreover, tumble-drying could shrink clothes to double that of air-drying.

Goldfarb also said that some cotton fabrics are more susceptible to shrinking. This may depend on the assembling of their fibers.

For instance, though woven cotton undeniably shrinks, their shrinkage would be less compared to knit cotton.

ALSO READ: Cooler Than Cotton: Research Team Develops Modified Silk Cloth That Keeps Temperature Cool Even Under Direct Sunlight

Can You Unshrink Cotton Clothes?

As for unshrinking clothes, there could be a scientifically supported way to deal with it. Goldfarb explained that, though this may depend on the yarn and weave quality, if fibers are swelled and allowed to dry in tension, it could be possible to unshrink some fabrics temporarily.

The use of a steam iron is one way to do this. The device could reintroduce moisture in order to stretch the fibers while applying force to stretch them out.

However, it is also easy to overstretch the cotton using such a method. It could also end up warping the fabric if it is unevenly done.

Milczek also noted that an obvious solution for handling the shrinking of cotton would be to opt for more shrink-resistant clothes. Such options cover preshrunk cotton clothes or cotton clothes that have synthetic blends.