eBook PSP | Natural Cellulosic Fiber 43 3.9 Fiber Production Bast fibers require extensive processing to remove the fibers from the woody stem in which they are held, a factor that adds considerably to the cost. The procedure is similar for all bast fibers. The deseeded flax straw has to be partially rotted to dissolve the substances that hold the fiber in the stem. This first step in preparing the fiber is called retting. Retting is accomplished through the breakdown of the materials that bind the fibers into the plant stems. Highly specific enzymes that attack only the binding materials and not the fibers are secreted by fungi and bacteria. Retting processes are of three types: a. Dew retting takes place in the field. The flax is laid out in swaths in the fields where the action of rain and dew together with soil-borne microorganisms causes the bark of the stems to become loosened. This may take from 3 to 6 weeks, depending on weather conditions. After retting, the bark is removed, and retted straw bundles are set up in the fields to dry. Figure 3.11: Flax harvesting process (Image source: eng.belta.by)
44 eBook PSP | Natural Cellulosic Fiber b. Water retting takes place when flax is submerged in water for 6 to 20 days. When the water temperature is cooler, the process takes a longer amount of time. Water retting may be done in ponds, in vats, or sluggish streams. As in dew retting, the bacterial action causes the bark to be loosened. Water retting produces finer fiber but is costlier; therefore, the less expensive and more easily mechanized dew retting process is generally preferred except for certain qualities of fiber needed for fine, wet-spun yarns. Figure 3.12: Flax Dew Retting process (Image source: exhibitions.psu.edu) Figure 3.13: Flax water retting process (Image source: slideshare.net)
eBook PSP | Natural Cellulosic Fiber 45 c. Chemical retting processes of several types have been developed. In one, flax is sprayed with a systemic herbicide that kills the flax as it grows. If weather conditions are right, retting takes place in the standing plant, and the dry, retted flax can be pulled. This approach, however, is too dependent on weather. Acceptable fibers have also been obtained from harvested flax by chemical or enzyme treatments to act on binding materials. Retting only loosens the bark from the stem. Following retting, breaking and scutching finish the job of separating the fiber from the stem. In breaking, the flax straw is passed over fluted rollers or crushed between slatted frames. This breaks up the brittle, woody parts of the stem but does not harm the fiber. In scutching, the broken straw is passed through beaters that knock off the broken pieces of stem. The fibers are baled and shipped to spinning mills. At the mill, the fibers go through yet another process before they are ready for spinning. The fibers are hackled, or combed, to separate shorter fibers (called tow) from longer fibers (called line fibers) and to align fibers parallel preparatory to spinning. Even with all this processing, individual fibers do not separate, and bundles of fibers continue to cling together. Flax fibers are long; therefore, they must be processed on specialized machinery. Figure 3.14: Retting can be carried out chemically by treating the flax straw with the solutions of caustic soda, sodium carbonate, acid and soap (Source: slideshare.net)
46 eBook PSP | Natural Cellulosic Fiber 3.10 Properties of Flax Fiber Physical Properties a. Color. Unbleached flax varies in color from a light cream to a dark tan. Different types of retting may produce differences in fiber color. b. Shape. Fiber bundle length may be anywhere from 5 to 30 inches, but most line (longer) fiber averages from 20 to 30 inches, whereas tow (shorter fiber) is less than 15 inches. Single fiber diameter averages 15 to 18 microns. In microscopic cross section, flax has a somewhat irregular, many-sided shape. Like cotton, it has a central canal, but its lumen is smaller and less distinguishable than that of cotton. Looking at the lengthwise direction of fiber under the microscope is rather like looking at a stalk of bamboo. Flax has crosswise markings spaced along its length that are called nodes or joints. c. Luster. Because it is a straight, smooth fiber, flax is more lustrous than cotton, but it does not have the smooth surface that most manufactured fibers display. A special finishing technique called beetling can be employed to increase the luster of linen fabrics. The specific gravity of flax is the same as that of cotton. Linen fabrics are, therefore comparable in weight to cotton fabrics but feel heavier than silk, polyester, nylon, and even cloth similar weaves. Microscopic Properties (Cross-sectional and longitudinal view): The cross-sectional properties of flax refer to the characteristics observed when looking at a cut or transverse section of the flax stem under a microscope. This provides insights into the internal structure of the plant and is important in understanding the properties of flax fibers. Here are some key cross-sectional properties of flax: a) Cell Arrangement: • Epidermis: The outermost layer of the flax stem, consisting of closely packed cells that serve as a protective barrier.
eBook PSP | Natural Cellulosic Fiber 47 • Cortex: Below the epidermis, the cortex is a region with parenchyma cells that provide structural support to the stem. • Bast: The bast region contains the flax fibers. It is situated between the cortex and the central pith and is the primary source of fibers. c) Pith: • Central Pith: The central pith is the innermost part of the stem, composed of loosely arranged parenchyma cells. It provides additional support to the stem. d) Cell Types: • Fiber Cells: Elongated and thick-walled cells in the bast region that make up the flax fibers. These cells contribute to the strength and durability of the fibers. • Parenchyma Cells: Found in the cortex and pith, parenchyma cells are generally softer and have diverse functions, including storage of nutrients and water. e) Vascular Tissues: Xylem and Phloem: Vascular bundles contain xylem for water transport and phloem for nutrient transport. These tissues contribute to the overall structural integrity of the stem. Figure 3.15: Cross-Sectional View of flax fiber. Image source: textileengineering.net)
48 eBook PSP | Natural Cellulosic Fiber Understanding the cross-sectional and longitudinal view properties of flax is essential for various industries, particularly in processing flax for fiber extraction. It helps in optimizing the extraction process, assessing fiber quality, and understanding how the plant's internal structure influences the characteristics of the final products, such as textiles made from flax fibers. Mechanical Properties a. Strength. Flax is stronger than cotton, being one of the strongest of the natural fibers. It is more crystalline and more oriented than cotton. It is as much as 20 percent stronger wet than dry. b. Modulus. Flax fibers have a high modulus. In former days sails were made of linen because it resisted the wind forces without deforming greatly. c. Elasticity and Resilience. The elongation, elasticity, and resilience of flax are lower than those of cotton because linen lacks the fibril structure that gives some resilience to cotton. Linens crease and wrinkle badly unless given special finishes. d. Flexibility. Just as flax fibers resemble bamboo stalks, they also display the brittleness one associates with bamboo. Although fairly soft fabrics can be made from very fine yarns, generally linen fabrics feel stiff because the fibers have high resistance to bending. Figure 3.16: Photographs of flax fiber taken through an electron scanning microscope. (Left) cross section and (right) longitudinal view. Image source: Understanding textile, Sixth Edition)
eBook PSP | Natural Cellulosic Fiber 49 Chemical Properties a. Absorbency and Moisture Regain. Moisture regain of linens is higher than that of cotton (11 to 12 percent). Unlike cotton, linen has very good wicking ability; that is, moisture travels readily along the fiber as well as being absorbed into the fiber. Both absorbency and good wicking ability make linen useful for towels and warm weather garments. b. Heat and Electrical Conductivity. Linen conducts heat more readily than cotton and is even more comfortable for summer wear. The conductivity of electricity prevents static electricity build up. c. Effect of Heat; Combustibility. Higher temperatures are required to scorch linen than to scorch cotton. Linen is slightly more resistant to damage from heat than cotton. The burning characteristics of linen are similar to those of cotton; it is combustible, continues to burn when the flame is removed, and burns with an odor like that of burning paper. d. Chemical Reactivity. The chemical reactions of linen closely parallel those of cotton because both are composed of cellulose. Like cotton, linen is destroyed by concentrated mineral acids, not harmed by bases or decomposed by oxidizing agents, and not harmed by organic solvents used in dry cleaning. Linen could be mercerized, but because the flax is naturally stronger and more lustrous, mercerization offers few advantages. Environmental Properties a. Resistance to Microorganisms and Insects. If linen is stored damp and in a warm place, mildew will attack and harm the fabric. Dry linen is not susceptible to attack. It generally resists rot and bacterial deterioration unless it is stored in wet, dirty areas. Moths, carpet beetles, and silverfish do not usually harm unstarched linen fabrics. b. Resistance to Environmental Conditions. Linen has better resistance to sunlight than cotton. There is a loss of strength over a period of time, but it is gradual and not severe. Linen drapery and curtain fabrics are quite serviceable. The resistance of linen to deterioration from age is good, especially if fabrics are stored properly. Linen, however, has poor flex abrasion resistance. To avoid abrasion and cracking at folded edges, a linen fabric should not be repeatedly folded in the same place.
50 eBook PSP | Natural Cellulosic Fiber Other Properties a. Dimensional Stability. Like cotton, linen has poor dimensional stability because the fibers swell when exposed to water. Tension from manufacturing therefore results in relaxation shrinkage of fabrics. Preshrink age treatments can be applied to linen fabrics to prevent relaxation shrinkage. b. Abrasion Resistance. Linen fabrics have fairly low abrasion resistance. Because of their high bending stiffness, their flex abrasion is also low. 3.11 End use of flax fiber Flax fiber finds various end uses across different industries due to its unique characteristics. Some common end uses of flax fiber include: a. Textiles: Linen Fabric: Flax fibers are extensively used in the textile industry to produce linen fabric. Linen is valued for its natural luster, breathability, and comfort, making it suitable for a range of clothing such as shirts, dresses, and bed linens. b. Home Furnishings: Bedding and Towels: Linen's absorbent and moisture-wicking properties make it ideal for bedding and towels. Linen sheets, pillowcases, and towels are known for their durability and luxurious feel. Figure 3.17: Linen fabric (Image source: ebay.com)
eBook PSP | Natural Cellulosic Fiber 51 c. Industrial Applications: Technical Textiles: Flax fibers are increasingly used in technical textiles for applications such as composite materials, reinforcement in plastics, and automotive components. The combination of strength and low weight makes flax composites an eco-friendly alternative. d. Paper Industry: Specialty Papers: Some specialty papers, such as currency paper and high-quality writing paper, may contain flax fibers. Flax contributes to the strength and texture of these papers. e. Art and Craft Materials: Canvas: Flax fibers are used in the production of artist canvases, providing a sturdy and durable surface for paintings. f. Bio-Composites: Automotive Parts: Flax fibers are used in the manufacturing of bio composite materials for automotive components, reducing the environmental impact of vehicle production. g. Personal Care Products: Cosmetics and Hygiene Products: Flaxseed oil, derived from the flax plant, is used in cosmetic products and skincare formulations due to its moisturizing properties. h. Animal Bedding: Pet Bedding: Flax straw, a by-product of flax cultivation, is sometimes used as bedding material for animals due to its absorbency and cushioning properties. i. Nutritional and Health Products: Flaxseed Products: While not directly related to fiber, flaxseeds are rich in omega3 fatty acids and are used in various nutritional products, including supplements, oils, and food additives.
52 eBook PSP | Natural Cellulosic Fiber j. Erosion Control: Geotextiles: Flax fibers can be used in geotextiles for erosion control and slope stabilization due to their ability to provide natural reinforcement. The versatility of flax fibers, along with their eco-friendly and sustainable characteristics, makes them appealing for a wide range of applications. As technology and research advance, new and innovative uses for flax fibers may continue to emerge in various industries. . Figure 3.18: Bedding set made of linen fiber (Image source: www.secretlinenstore.com)
eBook PSP | Natural Cellulosic Fiber 53 Figure 3.19: Natural waffle linen bath towel (Image source: houseofbalticlinen.com)
54 eBook PSP | Natural Cellulosic Fiber Figure 4.1: Pineapple field (Image source: istock.com)
eBook PSP | Natural Cellulosic Fiber 55 04 LEAF FIBER Chapter four description This topic covers the introduction of leaf fiber, cultivation of pineapple and abaca plants, production methods of pineapple leaf and abaca fiber, the properties of pineapple leaf and abaca fiber and also the end uses of both fibers.
56 eBook PSP | Natural Cellulosic Fiber 4.1 Introduction to Leaf Fiber Leaf fibers are derived from the leaves of plants. Typically, these fibers are lengthy and possess a degree of rigidity. Many leaf fibers exhibit a restricted affinity for dyes, often making them suitable for use in their original, natural color. Leaf fibers are a valuable natural resource that has been used for centuries in various textile applications. These fibers have been utilized in various cultures for centuries, demonstrating their historical and cultural significance. Leaf fibers, commonly known as "hard fibers," are typically less commercially valuable due to their inherently stiffer and coarser texture when compared to bast fibers. Among the notable fibers in this category, we find pineapple, henequen, and abaca to be of paramount importance. 4.2 Cultivation of Pineapple Pineapple (Ananas comosus) as in Figure 4.1, is a member of the Bromeliaceae family. Figure 4.2: Pineapple (Ananas comosus) (Image By vecstock, https://www.freepik.com) Researchers believe that pineapple originated in Southern Brazil and Paraguay. Pineapple is a tropical fruit known for its juicy, sweet, and tangy flavour. It is a rich source of vitamins A and B and is rich in vitamin C. Some minerals are also associated with pineapple such
eBook PSP | Natural Cellulosic Fiber 57 as calcium, magnesium, potassium and iron. It is also a source of bromelain, a digestive enzyme. The cultivation of pineapple involves some important factors such as climate, soil, temperature, fertilization and knowing the best time to harvest the fruits. Pineapples are best suited to tropical and subtropical climates. They require temperatures between 60°F to 85°F (15°C to 30°C) for optimal growth. They can tolerate short periods of lower temperatures but are sensitive to frost. Pineapples need at least six hours of direct sunlight daily. Well-draining, sandy loam or loamy soils are ideal for planting pineapples. Pineapples prefer slightly acidic to neutral soil, with a pH range of 4.5 to 6.5. Before planting, prepare the soil by removing weeds and rocks. Incorporate organic matter to improve soil fertility and structure. Pineapples go through several stages: ▪ Vegetative Growth: This stage lasts for about 12-16 months. During this time, the plant grows leaves and establishes its root system. ▪ Flowering Stage: Typically occurs in the second year. The plant produces a tall stalk with purple or red flowers. ▪ Fruit Development: After flowering, the fruit starts to form and mature. This process can take around 4-6 months. Pineapples are ready for harvest when they have turned golden yellow. The fruit should have a sweet aroma and give slightly when squeezed. Harvesting usually takes place 16- 24 months after planting. 4.3 Pineapple Leaf Fiber (PALF) Production Methods Pineapple leaf fiber (PALF), also known as Piña fiber. Pineapple leaves are a by-product of the pineapple fruit harvest, and this waste is creating an additional income stream for some farming communities. The strength, lightness, and shiny appearance of pineapple leaf fiber make it valuable. It is often blended with other fibers, such as silk or cotton, to enhance its qualities and create unique textile fabrics. Pineapple fiber textiles have become famous for their elegance and can be processed into a material that can be used in various textile applications.
58 eBook PSP | Natural Cellulosic Fiber Harvesting the fruit of pineapple left behind the leaves as waste. Instead of burning the leaves, farmers can convert the excess leaves to make other downstream products. Pineapple leaves can be further processed to obtain the fiber. Figure 4.2 shows the fiber obtained from the pineapple leaf while Figure 4.3, the fiber after the drying process. Figure 4.3: Pineapple leaf fiber. (Image source: https://textileengineering.net)
eBook PSP | Natural Cellulosic Fiber 59 Figure 4.4: Extracted PALF after drying (Image source: NextEvo/Sourcing Journal) Pineapple leaf fiber, PALF has a ribbon-like structure, consists of a vascular buddle system and is present in the form of bunches of fibrous cells. In producing pineapple leaf fiber, there are several processes involved such as: Producing pineapple leaf fiber involves extracting fibers from the leaves of the pineapple plant. Two primary methods are commonly used: manual (traditional) methods and mechanical methods. The illustration of the manual production methods can be found in Figure 4.4. Here's an overview of both: ▪ Manual Method: a. Harvesting: Select mature pineapple leaves for harvesting. These are typically the outermost leaves of the plant. b. Stripping: Use a knife or machete to strip away the outer skin of the leaves. This process exposes the long fibers underneath. c. Scraping: After stripping, the leaves are typically scraped to remove any remaining fleshy parts. This can be done manually using a simple tool.
60 eBook PSP | Natural Cellulosic Fiber d. Retting: The stripped and scraped leaves are subjected to a process called retting, which involves soaking the leaves in water. This helps to break down the non-fibrous material and separates the fibers. e. Drying: The fibers are then laid out to dry in the sun. This step is crucial for removing excess moisture and achieving the desired quality of the fibers. f. Manual Extraction: Once dry, the fibers are manually extracted from the leaves. This is often done by hand, separating the individual fibers from the bulk of the leaf. ▪ Mechanical Method: a. Harvesting: Similar to the manual method, mature pineapple leaves are selected for harvesting. b. Decorticating Machine: The leaves are fed into a decorticating machine. This mechanical equipment is designed to strip away the outer layers of the leaves and separate the fibers efficiently. c. Scraping and Cleaning: The machine may include mechanisms for scraping and cleaning the fibers, removing any remaining impurities. d. Retting: In some cases, a mechanical retting process may be employed, where machines facilitate the soaking and separation of fibers. e. Drying: Mechanical drying methods, such as hot air drying or industrial dryers, may be used to accelerate the drying process. f. Mechanical Extraction: The final step involves the mechanical extraction of fibers from the processed leaves. Machines may be employed to separate individual fibers and prepare them for further processing. Additional Processing Steps: Regardless of the method used, the extracted pineapple leaf fibers may undergo additional processing steps such as combing, spinning, and weaving to produce the final products, including textiles or other fiber-based materials. It's important to note that the specific methods employed can vary based on the scale of production, available technology, and the desired end products. Additionally, sustainable and eco-friendly practices are increasingly being incorporated into pineapple leaf fiber production processes.
eBook PSP | Natural Cellulosic Fiber 61 Figure 4.5: The production steps of Pineapple leaf fiber (Image source: https://textilelearner.net) 4.4 Properties of Pineapple Leaf Fiber (PALF) Pineapple fiber is white in color, soft, smooth, and feels like silk. The chemical properties of pineapple leaf fiber are as follows: a. Cellulose Content: The primary chemical component of pineapple leaf fiber is cellulose, a complex carbohydrate composed of glucose units linked together. Cellulose gives the fiber its strength and rigidity. b. Hemicellulose: Another important component is hemicellulose, which is a branched polymer of various sugar molecules. It contributes to the fiber's flexibility and helps hold the cellulose fibers together. c. Lignin Content: Pineapple leaf fibers contain lignin, a complex polymer that provides rigidity and resistance to degradation.
62 eBook PSP | Natural Cellulosic Fiber d. Pectin: Pineapple leaf fibers may also contain small amounts of pectin, a complex carbohydrate found in plant cell walls. Pectin contributes to the fiber's water absorption properties. e. Proteins and Enzymes: Depending on the processing methods, pineapple leaf fiber may contain residual proteins and enzymes. These can have implications for the fiber's stability and behavior in certain environments. Some key characteristics of pineapple leaf fiber, PALF: a. Strength and durability: PALF are strong and durable material, which means that it can withstand wear and tear over time. It is stronger than cotton and has a similar tensile strength to silk. b. Lustrous appearance: PALF has a shiny, silky texture that gives it a lustrous appearance. This makes it an ideal material for creating garments and accessories with a luxurious look and feel. c. Softness: Despite its strength, PALF is also soft and comfortable to wear. It is not itchy or scratchy like some other natural fibers, making it a great choice for people with sensitive skin. d. Eco-friendly: PALF is a sustainable and eco-friendly material, as it is made from the leaves of the pineapple plant, which are a by-product of the fruit industry. This means that no additional resources are required to produce the fiber, and it helps to reduce waste. e. Breathable: It is naturally breathable, which means that it allows air to circulate through the fabric. This makes it a great choice for warm weather clothing, as it helps to keep the wearer cool and comfortable. f. Absorbent: Pineapple fiber is also absorbent, which means that it can wick moisture away from the skin. This makes it a great choice for activewear and other garments that need to be moisture-wicking.
eBook PSP | Natural Cellulosic Fiber 63 g. Lightweight: PALF is lightweight compared to some other natural fibers like jute or hemp, making it suitable for a wider range of applications. h. Dyeability: PALF is 10 times coarser than cotton and because of its higher moisture regain characteristic, it has a higher dye absorption ability. i. 4.5 End Uses of Pineapple Leaf Fiber (PALF) PALF has a range of end uses and unique properties compared to other natural fibers. Here are some of the end uses that suit most with it. a. Textiles and Apparel: PALF can be processed into fabrics and used in various forms of clothing, including shirts, dresses, and accessories like handbags and hats. b. Furniture and Upholstery: The fiber can be used in the production of eco-friendly furniture and upholstery materials. It's valued for its strength and durability. c. Automotive Interiors: PALF is being explored as a sustainable alternative to synthetic fibers in automotive interiors for components like seat covers, door panels, and carpets. d. Packaging Materials: PALF can be used in packaging applications, including bags, boxes, and other types of eco-friendly packaging. e. Paper and Cardboard: The fiber can be used in the production of paper and cardboard, providing a sustainable alternative to wood pulp. f. Construction Materials: PALF can be incorporated into composites for various construction applications, including roofing, wall panels, and reinforcement in concrete. g. Aerospace industry: Parts for airplanes and spacecraft that are robust and lightweight can be made using PALF. The weight of the aircraft or spacecraft can be decreased by combining the fiber with a resin matrix to form strong, lightweight composite materials.
64 eBook PSP | Natural Cellulosic Fiber Figure 4.6: Men's clothing made from pineapple fiber. (Image source: weddingsinthephilippines.com)
eBook PSP | Natural Cellulosic Fiber 65 4.6 Abaca Fiber Abaca as in Figure 4.5 scientifically known as Musa textilis, is a fibrous plant native to the Philippines. The abaca fiber is extracted from the leaf stalks of the plant. In Ecuador, Costa Rica, Russia and the Philippines, abaca is farmed for commercial purposes. Abaca is also known as Manila hemp. Its appearance is similar to the banana plant, but it is completely different in its properties and uses. It's primarily grown for its strong, durable fiber. Figure 4.7: Abaca plant (Image source: https://pinterest.com)
66 eBook PSP | Natural Cellulosic Fiber 4.7 Cultivation of Abaca Fiber Cultivating abaca necessitates specific environmental conditions. It flourishes in tropical climates characterized by temperatures ranging between 20-34°C (68-93°F) and requires well-draining soil enriched with ample organic matter. Propagation is typically achieved through suckers or offsets from mature plants. These shoots, originating at the base of the parent plant, serve as the primary means of propagation. Proper spacing, typically around 1.5 to 2 meters apart, facilitates healthy growth. Regular weeding and potential fertilizer application are essential for optimal development, while consistent irrigation, especially during dry spells, is crucial to maintain moisture levels. Pest and disease management strategies, such as natural predators or targeted insecticides, are employed to mitigate threats from mites, aphids, nematodes, and diseases like leaf spot and bacterial wilt. Crop rotation is recommended to preserve soil fertility and prevent pest build-up. Finally, postharvest, processed abaca fibers are bundled and stored in well-ventilated, dry environments to prevent mold and deterioration. 4.8 Abaca Fiber Production Methods The harvesting process of the abaca plant is a critical step in obtaining its prized fibers. Typically conducted when the plant reaches a maturity of 18 to 24 months, the procedure involves cutting down the entire plant close to the ground. This timing is crucial, as it ensures that the fibers are at their strongest and most durable state. Harvesting generally includes several operations involving the leaf sheaths: ▪ Tuxying (separation of primary and secondary sheath). A tuxy is the term for the split outer sheath layer. ▪ Figure 4.8: Tuxy (Image source: www.cropshub.com)
eBook PSP | Natural Cellulosic Fiber 67 ▪ Stripping (getting the fibers) The fiber extraction process of the abaca plant involves several methods, including both manual and mechanical processes. Hand Stripping: This is a manual method that involves using a tool called a sinamay stripper. The tool is designed with serrated edges that allow workers to strip the outer leaf sheaths of the abaca plant to access the fibers. While labor-intensive, this method is effective for small-scale operations or in areas where mechanized equipment is not readily available. Decorticators: Decorticators are mechanical machines used for fiber extraction. They work by mechanically stripping the outer layers of the abaca plant to expose the fibers. Decorticators are equipped with rotating drums or serrated rollers that effectively separate the fibers from the plant material. This method is more efficient and suitable for larger-scale operations. Figure 4.9: Hand Stripping (Image source: ecokaila.files.wordpress.com) Figure 4.10: Decorticator machine (Image source: www.youtube.com/WellbonEnterprise)
68 eBook PSP | Natural Cellulosic Fiber Stripping Machines: Stripping machines are specialized equipment designed specifically for abaca fiber extraction. They use a combination of rollers and blades to strip the fibers from the plant stems. This mechanized process is highly efficient and widely used in commercial abaca production. The choice between manual and mechanical methods depends on various factors, including the scale of the operation, available resources, and local preferences. Smallscale or traditional operations may opt for manual methods due to their accessibility and lower initial investment. However, for larger commercial operations, mechanized processes like decortication and stripping machines offer increased efficiency and productivity. Producers should consider their specific needs and resources when determining which extraction method to employ. ▪ Drying (usually following the tradition of sun-drying). The duration of the drying process varies, ranging from a few hours to several days, contingent upon prevailing weather conditions. Simultaneously, during this drying phase, an initial classification is performed based on the fiber's color. After the drying process, the fibers are stacked in dry locations, preferably covered and well-ventilated. This precaution is crucial because, despite the drying phase, the fibers retain a certain level of moisture, and without proper ventilation, there is a risk of discoloration and a potential decrease in quality. Figure 4.11: Stripping Machines (Image source: https://ecokaila.files.wordpress.com)
eBook PSP | Natural Cellulosic Fiber 69 Figure 4.12: Drying process of abaca (Image source: https://www.cropshub.com) ▪ Grading and Baling After the drying process, the fibers undergo grading, considering factors such as color, texture, length, strength, and cleanliness. The superior grades of Abaca exhibit fine, lustrous qualities, a light beige hue, and exceptional strength. Subsequently, these graded fibers are meticulously bundled and compressed into bales weighing 125 kilograms each. These bales serve the purposes of storage, export, and transportation to diverse industries. Figure 4.13: Baling of abaca (Image source: ASM.pdf)
70 eBook PSP | Natural Cellulosic Fiber 4.9 Properties of Abaca Fiber Figure 4.14: Abaca fiber (Image source: https://textilelearner.net) a. Strength and Durability: Abaca fiber is known for its exceptional strength and durability. It is one of the strongest natural fibers available, making it highly desirable for applications where tensile strength is crucial. b. Flexibility and Elasticity: Abaca fibers are flexible and possess a degree of elasticity, allowing them to bend without breaking. This property makes them suitable for applications requiring flexibility, such as cordage and ropes. c. Lightweight: Despite its strength, abaca fiber is relatively lightweight. This property contributes to its versatility in various industries. d. Moisture Resistance: Abaca fibers have a natural resistance to moisture, making them suitable for applications in humid or wet environments. e. Resistance to Insects and Pests: Abaca fiber contains natural compounds that render it resistant to pests, insects, and fungi, enhancing its longevity.
eBook PSP | Natural Cellulosic Fiber 71 f. Bio-Degradability: Abaca fiber is biodegradable, making it an eco-friendly alternative in industries seeking sustainable materials. g. Low Thermal Conductivity: Abaca fibers have low thermal conductivity, which means they are not excellent conductors of heat. This property can be advantageous in certain applications. h. Reaction of Abaca Fiber towards Acid: Abaca fiber is generally resistant to mild acids. However, exposure to strong acids can lead to degradation and a reduction in its tensile strength. i. Reaction of Abaca Fiber towards Alkali: In contrast, abaca fiber is more resistant to alkalis, making it suitable for applications in alkaline environments. It retains its strength and integrity better when exposed to alkali solutions compared to strong acids. Microscopic properties of abaca fiber: a. Cross-sectional view: 1. Shape: Abaca fibers typically have a polygonal cross-section with rounded corners. The shape may resemble an irregular polygon, and the corners can be slightly curved. 2. Central Lumen: The cross-section will reveal a central hollow core known as the lumen. The size and shape of the lumen can vary, and it contributes to the overall geometry of the fiber. b. Longitudinal view: 1. Length: Abaca fibers are relatively long, ranging from several millimeters to several centimeters. The length contributes to the strength and durability of the fibers. 2. Fibrils: When viewed longitudinally, abaca fibers consist of bundles of smaller fibrils. These fibrils contribute to the overall strength and flexibility of the fiber. Both the cross-sectional and longitudinal views play a crucial role in understanding the microscopic structure of abaca fibers. The polygonal cross-section with a central lumen
72 eBook PSP | Natural Cellulosic Fiber contributes to the fiber's overall characteristics, while the longitudinal view highlights the arrangement of fibrils and provides insights into the fiber's strength and flexibility. 4.10 End Uses of Abaca Fiber In practical applications, the properties of abaca fiber make it a valuable material in various industries, including papermaking, textiles, cordage, and specialty papers where strength, durability, and flexibility are key considerations. Here are some common applications: a. Textiles and Apparel: Abaca fiber is often used in the production of textiles and fabrics. It is known for its strength and durability, making it suitable for products such as ropes, twines, and coarse textiles. b. Handicrafts and Artisanal Products: Abaca is popular in the creation of handicrafts and artisanal products. It can be woven to make baskets, bags, hats, and other decorative items. Figure 4.15: Cross-sectional view of abaca fiber (Image source: www.sciencedirect.com) Figure 4.13: Longitudinal view of abaca fiber (Image source: www.sciencedirect.com)
eBook PSP | Natural Cellulosic Fiber 73 c. Paper Production: Abaca is a key raw material in the production of specialty papers. Its long and fine fibers contribute to the strength and quality of paper used for tea bags, currency notes, filter papers, and other high-quality paper products. d. Furniture and Home Decor: Abaca fibers are used in the manufacturing of furniture and home decor items. Woven abaca fibers are often employed in the production of chairs, tables, lampshades, and other decorative pieces. e. Geotextiles: Due to its strength and resistance to deterioration, abaca fiber is used in geotextiles for erosion control, slope stabilization, and other geotechnical applications. f. Fisheries and Agriculture: Abaca fibers are used in the production of fishing nets and other fishing gear due to their strength and resistance to saltwater. Additionally, abaca twines are used in agriculture for tying and supporting plants. g. Automotive Industry: Abaca fibers can be incorporated into composite materials for automotive components, providing a lightweight and strong alternative. h. Construction Industry: Abaca fibers are sometimes used in construction materials, such as reinforcement in concrete, to enhance strength and durability. i. Textile Reinforcement: Abaca fibers are used as reinforcement in composite materials, providing added strength to products such as rubber goods and plastic items. j. Medical and Cosmetic Products: In some cases, abaca fibers are used in the production of medical and cosmetic products, such as wound dressings and natural fiber-based cosmetics. These diverse applications highlight the versatility and strength of abaca fiber, making it a valuable resource in various industries.
74 eBook PSP | Natural Cellulosic Fiber Questions 1. Explain the properties that are common to all cellulosic fibers. 2. Define the following terms in cotton growing and processing: a. Ginning b. Linters c. Convolution 3. Cotton is the widely used fiber in the textile industry. State why it is sometimes blended with other fibers in producing the end uses. 4. List the steps in processing flax. What is the purpose of each step? 5. Compare the structural differences of cotton and flax. How do these differences affect fiber properties? 6. Explain the properties of pineapple leaf fiber. 7. Identify the properties of abaca that could make it a substitute for man-made fiber in pursuing sustainable resources in industry. State the substituted related industry. 8. Some fibers undergo a process of retting. What is the retting process? 9. Identify a cellulosic fiber that would be an appropriate choice for each of the following end uses. a. Tablecloth for an expensive ethnic restaurant b. Socks for active 4-years old child c. Sheets for a durable bed for the master bedroom
eBook PSP | Natural Cellulosic Fiber 75 References Phyllis G.T. Billie J.C. (1997) Understanding Textiles, Fifth Edition. Prentice Hall, USA Kadolph, Sara J. Langford, Anna L. (2002) Textiles, Ninth Edition. Prentice Hall, USA Jabay P, Radek M, et al. (2016) Abaca Sustainability Manual. Philippine Fiber Industry Development Authority, Philippine Billie J. Collier, Phyllis G. Tortora (2001) Understanding Textiles, Sixth Edition, Prentice Hall, USA ` Marjory L. Joseph, (1981) Introductory Textile Science, Fourth Edition. Holt, Rinehart, and Winston, USA