10. Pineapple Fibers

Pineapple (Ananas comosus) belongs to the Bromeliaceae family and is a short tropical plant that grows to 1–2 m in height and width. About 21.9 million tons of pineapples were produced in the world in 2011 [14FAO]. As seen from Fig. 10.1, pineapple plants consist of a rosette of 20–30 leaves that are generally 6 cm wide and up to 1 m long. About 96–100 tons of fresh leaves are generated per hectare. Fresh pineapple leaves yield about 2.5–3.5 % fibers that are white, creamy, and silk like with a soft texture and also absorb high amounts of moisture [12Nad]. Fibers obtained from pineapple leaves are composed of relatively higher amounts of cellulose (74 %), lignin (10.4 %), and ash (4.7 %) [12Nad]. Pineapple leaf fibers (PALF) fibers are reported to have a microfibrillar angle of 14° that results in lower elongation. Traditionally, fibers are manually extracted from pineapple leaves by scrapping the outer layers. During the last decade, decorticating machines have been developed that can process about 35 kg of fibers per 8 h shift.