Sock Fiber Overview
Socks come in a variety of fibers and fiber combinations. Commonly used fibers include cotton, wool, nylon, acrylic, polyester, olefin, and spandex. Occasionally, luxury fibers such as silk, linen, cashmere, or mohair will be blended for softness, but this adds to the cost.
Synthetic fibers, particularly nylon, are strong and make an excellent choice for socks which commonly receive hard wear. Besides durability, synthetic fibers add shrink resistance. Socks may be 100% nylon or reinforced at the toe and heel with this durable fiber.
Acrylic fibers are long wearing but also add a cushiony softness and bulk to socks made from them. Acrylic fibers are commonly found in socks for casual wear. Olefin fiber has become important for outdoor sport socks. Olefin fibers do not absorb moisture; however, both olefin and acrylic have wicking ability. This means that moisture travels along the fiber away from the skin. Some blends of socks are made so the fibers with wicking ability are next to the skin and the absorbent fiber forms an outer layer. This accomplishes the same result as wearing two socks, but is less bulky.
Stretch fibers, including spandex, elastic or rubber, are present in many socks. They help socks stay up and hug the leg and foot. Spandex is used extensively to provide support in the ankle, calf, and arch areas, especially in sport socks. These socks stay in place. While elastic or rubber yarns sometimes are used, they deteriorate from body oils and do not last as long as spandex stretch yarns. Also, elastic in sock tops binds more than spandex.
Fiber Finishes
Few finishes are applied to socks. However, those that are perform important functions. Anti-static finishes are desirable on socks made from synthetic fibers. They help prevent trousers from clinging to the socks and lint from collecting on them during wear and laundering.
A more common finish for socks is one that resists the buildup of odor and bacteria. The feet are among the three areas of the body that contain large sweat glands (the other two are the armpits and the palms of the hands). Feet wrapped in a layer of socks and shoes for long periods become warm and perspire. Although perspiration is odorless and 99% water, it provides a perfect medium for bacteria to grow. The bacteria cause foot odor. Anti-bacterial agents in the fiber reduce bacteria growth and resulting odor. Most anti-bacterial finishes used today are durable and remain after repeated launderings.
Characteristics of Specific Sock Fibers
CoolMax®
DuPont manufactures this fiber with a unique four-channel cross section that produces a soft, cotton-like yarn with such superior moisture transport qualities that skin temperatures prove perceptibly cooler in comparison yarn testing. CoolMax® provides excellent blister protection while keeping you comfortably cool.
Wool
There are two types of yarns generated in the spinning of a wool fiber. The first is worsted ( pronounced "wuu-sted"), the other woolen. Worsted yarns are stronger, smoother, lighter weight, quicker drying, pill less and are more durable due to the fact that the fibers are longer and more uniform. Conversely the woolen yarns are weaker, fuzzier, heavier, slower drying and tend to pill more often, and contain the shorter wool fibers - as it has not been combed and carded. Both types have distinct usages; however worsted yarns are used to create some of the finest in apparel and accessories, including luxury hosiery.
All wool is not created equal. Today, it is widely recognized that the Merino species of sheep produces a far superior fleece. Originally from Spain, this species is now primarily raised in Australia and its fleece yields the finest fiber of all sheep. The end result of this extra fine fiber is a yarn with incomparably soft hand and higher thread count per square inch. These fibers create incredibly luxurious superior hosiery both as the sole component as well as when blended with other fine fibers such as silk and cashmere, alpaca, vicuna, and angora.
Merino wool is a special, fine grade wool that originally came from Merino sheep. It has all the characteristics classic to wool such as wrinkle resistance, shape recovery and insulation, but what makes Merino wool different is the luxurious softness and comfort provided by the fine diameter Merino fibers. Unlike traditional wools, Merino wool does not itch and is shrink treated to hold its size and shape even after repeated washings.
“New wool” is the first spin of the wool, which guarantees softness and quality. It avoids the uncomfortable itch created by recycled wool. It offers excellent insulation and is highly breathable.
Acrylic
A man-made fiber that provides softness and warmth with little weight and high durability.
Nylon
Introduced by DuPont in the 1940s as a 'miracle' fiber. It enables multiple size ranges, good fit and shape retention, along with durability.
Spandex
A synthetic fiber with elastic properties that is often used in place of rubber. Used with other fibers, it provides elasticity, recovery and close fit.
Source: A portion of this information appeared in Ohio State University Extension fact sheet: “Textiles and Clothing - Selecting Socks” by Joyce Smith, Ph.D., and Norma Pitts.
