1. Animal fiber In order to survive and develop, the organisms in nature have created a series of optimal compositions and structures under the impetus of the external environment, so that the organisms have special structures and functions to adapt to the environmental changes of nature. For example, the diameter of the silk spit out by spiders under normal circumstances is 0.5-1.0 μm, with good toughness (elongation at break up to 14%), and a strong ability to withstand heavy objects or strong external shocks. It can be used to prepare body armor and The protective cover of military machinery can also be used in the fields of aerospace, construction, medicine and health care, and has great potential application value.
Silk is another important natural protein fiber. It consists of silk fibroin and sericin wrapped around the periphery of silk fibroin. Each silk is made up of two single fibers juxtaposed. Silk has high strength, elongation at break can reach 15%~25%, and wear resistance is also better than other natural fibers. It also has important applications in medicine, textile and military fields. In addition, animal fur (the diameter of microfibrils of wool fibers is 10-15nm) and the linear density of fibrils in cortex are both less than 1.1dtex, which are the main reasons for the excellent performance of natural leather, and become the first choice for bionic research and artificial leather manufacturing.
2. In addition to animal fiber, plant fiber is another natural fiber with excellent performance. It is mainly distributed in the sclerenchyma of seed plants. thing.
As an outstanding representative of ultra-fine natural plant fibers, cotton fibers have a diameter of 10-17 μm, and the smallest unit of cotton fibers - microfibrils, with a diameter of about 6 nm, are widely distributed on the surface of plant seeds. important raw material for application. In addition, among the plant stems, some hemp herb stems. For example, ramie, jute, flax, etc., have relatively developed fiber bundles, and the fiber diameter is between 10 and 40 μm, which is an important source of raw materials for industrial textiles.