Plant Fibers as Reinforcement for Green Composites

Fiber crops have accompanied human society since the start of our time. In early history, humans collected the raw materials for ropes and textiles from the wild. Later societies learned to cultivate such crops. Plant fiber crops are among the earliest known cultivated plants and humans continued the domestication of these crops over millennia.1 Fiber crop varieties have been extensively developed through breeding and selection, according to the societies’ needs and values. For instance, hemp and linen fragments were found in Neolithic sites in Syria, Turkey, Mesopotamia (present-day Iraq), and Persia (present-day Iran), and have been carbon dated back to 8000-6000 B.C.2-4 The ancient Egyptians wrapped their corpses in linen cloth for thousands of years. Tomb paintings and hieroglyphs show and describe the production of flax, retting, spinning, and weaving as well as the treatment and dyeing of linen cloths. In Central Europe, the Swiss lake dwellers started flax cultivation and the production of linen more than 4000 years ago. Fiber crops have been bred focusing on fiber quality, climatic adaptability, and yield factors. Ingenious fiber crops, such as flax, hemp, and nettle, possessed great agricultural importance for the production of textile fibers until the late 19th century. However, the mechanization of cotton harvest, processing, and development, and the growing demand for and production of cheap synthetic textile fibers destroyed the production of traditional fiber crops. Gradually, they became less significant and almost vanished in Western Europe and North America.