Soybean Fibers - A Review

Introduction

Soy Protein Fiber (SPF) is the only protein fiber made from soybean cake. Its physical properties are similar to that of synthetic fiber. When mixed with other fibers, it produces significant changes in properties such as smoothness, luster, comfort, absorbency, strength, and shrinkage. For instance, when soybean fibers are blended with cashmere, it enhances the smooth quality and easy-care properties. When combined with wool or silk, it reduces shrinkage and improves ease of care.

SPF is considered the only renewable botanic protein fiber. With its 16 amino acids, it offers health benefits and nutritional value to the skin. Derived from soybeans, a plentiful and nutritionally rich plant source, this active fiber showcases superior qualities of both natural and synthetic fibers.

Processability/Pretreatment: SPF possesses different physical and chemical characteristics from natural protein fibers. During production, appropriate equipment and settings are crucial:

a) Desizing: All textile materials require desizing, which can involve enzymatic, alkali, or oxidative desizing. However, SPF is unable to withstand strong caustic soda, making mercerization generally not recommended.

b) Scouring & Bleaching: Scouring and bleaching are necessary to remove oil, lubricants, and pigments. Methods like hydrogen peroxide bleaching or reduction bleaching might be employed based on color requirements. The natural color of SPF, curcuma, is challenging to remove, often requiring the use of bleaching agents, especially for lighter colors.

Synthesis: SPF is an advanced textile fiber derived from Soybean cake following an oiling process and new bioengineering techniques.

First, protein is extracted from soybean cake and refined.
Next, auxiliary agents and biological enzymes alter the space structure of the spherical protein. This results in the creation of a protein spinning liquid by adding high polymers.
Finally, the liquid undergoes wet spinning to produce 0.9-3 dtex fiber, stabilized through acetalizing, and then cut into short staples after curing and thermoforming.
Features: Fabrics made from SPF exhibit several notable characteristics:

Luster: Similar to silk, SPF fabrics possess excellent drape and luster.
Comfort: Soft, smooth, and lightweight, offering exceptional comfort.
Absorbency: Comparable moisture absorption to cotton and superior moisture transmission.
Easy Dyeing: Good dye penetration and colorfastness properties.
Strength: Higher breaking strength than wool, cotton, and silk but lower than polyester.
Shrinkage: Does not shrink under the influence of boiling water.
Easy Care: Anti-crease, easy to wash, and fast-drying properties.