According to Core Yarn Filament. According to Sheath Yarn Fiber Classification

Classification by core yarn filament

Rigid core-spun yarn: polyester, acrylic, vinylon (including water-soluble vinylon), nylon, etc.

Elastic core-spun yarn: spandex, PTT fiber, PBT fiber, etc. Spandex is the most widely used.

According to sheath fiber classification

Usually cotton, wool, silk, hemp (including ramie, linen, hemp, etc.), colored cotton and other natural fibers;

Viscose, modal, tencel, soybean fiber, milk fiber, bamboo pulp fiber, polyester fiber, acrylic fiber and various colored chemical fibers can be used as the covering fiber of core-spun yarn.