Sustainable Banana Fiber Extraction and Composting with Replicable Machine Designs

Bananas are the world’s second-most-produced fruit, cultivated across tropical and subtropical regions between 40°N and 40°S. In Nepal, the most common variety used in Sparśa’s production is Musa paradisiaca (AAB group), locally known as Malbhog. A banana plant takes 9–12 months to mature and continuously forms leaves from its core. These overlapping leaf sheaths form the pseudostem, which grows until flowering begins. After fruiting and harvest, the pseudostem is cut at the base because each stem yields bananas only once. Cutting the stem also stimulates growth of the next pseudostem from the same plant. Over its life cycle, a banana plant may generate around 25 pseudostems, each growing at different speeds and harvested at different times.

This agricultural cycle produces large amounts of waste. Every bunch of bananas harvested corresponds to one pseudostem weighing about 30–40 kg. Farmers often burn these stems or leave them to rot in the field. Burning requires kerosene or other accelerants because the stems are highly moist, leading to greenhouse gas emissions and thick smoke. Leaving stems to decay takes months and occupies substantial space on farmland.

Nepal’s major banana-growing districts include Morang, Jhapa, Saptari, Chitwan, Kailali, and Nawalparasi. Nationwide, banana farming covers around 21,413 hectares and produces approximately 1,284,780 tons of agricultural waste annually. Within these areas, Susta municipality in Nawalparasi stands out with nearly 2,200 hectares of cultivation—one of the highest concentrations in Nepal—generating roughly 132,000 tons of waste per year. This is where Sparśa chose to establish its fiber extraction factory.

Susta’s farming communities are community-led and were open and enthusiastic about collaborating with us, making the partnership both practical and impactful. The area was strategically and socially suitable: raw materials are abundant, and transport distances are short, ensuring trunks can be processed within 72 hours to maintain fiber quality. At the same time, Susta faces deeply rooted social challenges. Women have limited opportunities outside the household and often lack equal rights and representation in community decision-making. Menstrual stigma remains strong. Establishing the factory here allowed us to create dignified employment for women, support their financial independence, and run educational campaigns around menstrual health and environmental sustainability.

Sparśa developed a circular economy model that transforms agricultural waste into opportunity. Banana trunks are collected free of charge from farmers after harvest, and in return the factory provides organic compost produced from the residue of fiber extraction. This non-monetary exchange reduces waste, supports soil fertility, and builds long-term trust with farmers.

Banana plant fibers contain 60–65% cellulose, with smaller fractions of hemicellulose (6–19%), lignin (5–10%), pectin (3–5%), ash (1–3%), and extractives (3–6%). Once a pseudostem reaches the factory, its sheaths are separated. Fiber maturity varies depending on the sheath’s position within the stem—outer layers typically produce stiffer fibers, while inner layers yield softer ones. As a result, extraction can be slightly inhomogeneous unless operators grade and separate sheaths properly. On average, 11 usable outer leaves can be extracted per pseudostem.

Sparśa’s fiber extraction facility processes trunks into fibers used for compostable menstrual pads. Trunks must be processed within 72 hours because their moisture content is 90–92%. Delayed processing triggers decomposition and fermentation, causing discoloration, odor, and microbial degradation. Fiber yield remains low: a 20 kg pseudostem yields around 150 grams of dry fiber, leaving behind large amounts of residue converted into compost.

Additional workers are employed seasonally for 3–4 months (August–November) for harvesting, cutting, and transporting trunks from fields to the factory. The main operational costs include labor and tractor transport. Approximately 6,772 m² of farms can supply enough pseudostems annually for consistent fiber production.

After harvesting banana fruits, farmers typically discard the pseudostem—often called the trunk—which actually holds valuable natural fibers within its layered sheaths. However, before fiber extraction can begin, the pseudostem must be split lengthwise to expose the individual sheaths. This step is essential for efficient separation and significantly reduces operator effort during extraction.

Originally, Sparśa used a circular-saw-based pseudostem cutter that allowed workers to split stems into halves. Although functional, this earlier version required operators to continuously lift, balance, and manually push heavy pseudostems through the blade. This made the process physically demanding, time-consuming, and tiring. It also limited throughput, as only one stem could be processed at a time and operator fatigue quickly slowed down the workflow. These constraints made the overall fiber production process less efficient and difficult for long working hours.

To address these limitations, a new and improved trunk cutter was designed. The upgraded model replaces manual pushing with a chain-and-sprocket feed mechanism that automatically grips and advances the pseudostem toward the cutting zone. Instead of relying on a circular saw blade, the machine uses two perpendicular cutting blades positioned to split the stem into two halves in a single pass. This integrated system offers several advantages:

• Reduced physical strain: Operators no longer need to push heavy stems manually.
• Higher throughput: Continuous automated feeding enables faster and more consistent output.
• Improved safety: Guarding and controlled feeding distance keep operators away from moving blades.
• More precise cutting: Automatic feed maintains consistent cutting alignment.

The process works as follows:

1. Placement: The pseudostem is placed on the chain-feed platform.
2. Engagement: Chains and sprockets securely grip the stem and guide it forward.
3. Cutting: The stem passes through two perpendicular blades, which split it cleanly into halves.
4. Output: The cut pieces fall onto the collection side, where they can be peeled manually for fiber extraction.

After splitting, operators peel off each sheath layer by hand. Each sheath contains a fibrous zone along with softer inner tissues. Operators trim non-fibrous edges using a knife to remove sections with little or no fiber, ensuring that only fiber-rich material moves to the extraction machine.

This improved cutter has made material handling far easier, reduced operator fatigue, and supported greater consistency in the extraction workflow. It also makes the process accessible for workers with less physical strength, including women who form a key part of the Sparśa workforce.

Banana fiber extraction offers a sustainable way to transform agricultural waste into a high-value natural material. After the fruit harvest, the banana pseudostem—typically discarded—is rich in long, durable fibers suitable for biodegradable products, textiles, ropes, paper, and sanitary pads.

To extract these fibers efficiently and consistently, Sparśa developed a semi-automatic banana fiber extraction machine that significantly improves output and quality compared to manual scraping.

The machine is a motor-driven system that uses a rotating drum fitted with scraping blades, powered by a 3 HP electric motor. During operation, the operator manually feeds banana sheaths between the rotating roller and a stationary support bar. As the sheath passes through, the blades scrape off the fleshy outer material, separating and releasing clean fibers. An adjustable roller pressure system allows the operator to fine-tune the gap depending on sheath thickness, ensuring smoother operation and higher-quality output.

A simple belt-and-pulley transmission transfers energy from the motor to the drum. The system was intentionally designed to be low-maintenance, easy to repair in rural workshops, and fully compatible with components available in local markets. Its compact welded frame provides stability, even during long operational cycles.

Under typical conditions, the machine produces approximately 5 kilograms of dry fiber per 6–8 hour working day, depending on banana variety, sheath condition, blade sharpness, and operator skill.

Detailed working steps:

1. Preparation:
   Banana pseudostems are collected, split, peeled into sheaths, and trimmed to lengths of about 1–1.5 meters.
2. Feeding:
   One sheath at a time is fed into the machine, with the roller pressure adjusted to match the sheath’s moisture content and thickness.
3. Extraction:
   The rotating drum removes the water-rich tissue and frees the embedded fibers. The process is repeated on both halves of the sheath to maximize yield.
4. Drying and Storage:
   The extracted fibers are sun-dried or placed in a solar dryer for 1–1.5 days depending on weather. Once dried, they are bundled and stored for the next processing stage.

The processing chain begins after the banana pseudostem is collected from nearby plantations. Each pseudostem is made of tightly overlapping leaf sheaths. The outer sheaths and leaves are removed first to expose the usable inner layers. Using the trunk cutter, the pseudostem is halved lengthwise, which makes peeling the sheaths significantly easier and speeds up the extraction process.

The separated sheaths are then fed into Sparśa’s semi-automatic banana fiber extractor. Each sheath contains multiple layers with different proportions of fibrous material and soft inner tissue. During extraction, one end of the sheath is inserted into the machine while the operator holds the other end. The rotating drum and scraping blades break down the inner wall material, releasing the embedded fibers. The softer, water-rich inner layer is scraped away in the process. The operator repeats the extraction on both ends of the sheath to maximize fiber recovery.

For best fiber quality, extraction must occur within 72 hours of harvesting the pseudostem. With a moisture content of 90–92%, the stems decompose quickly. Delayed processing leads to fermentation, discoloration, and unpleasant odor, all of which compromise the resulting fiber.

The Sparśa fiber factory operates three extraction machines, each producing approximately 3 kilograms of dry fiber per day, giving a combined daily output of around 9 kg. Operators typically become proficient within one week of training, and their efficiency improves noticeably with experience, resulting in more consistent fiber output.

The extracted fibers, about four feet in length, are dried immediately after extraction. Drying takes place either in the sun or in the dedicated 251.712 sq. ft solar dryer. Solar drying requires 1–1.5 days in summer and up to 3 days in winter, depending on weather conditions. Once fully dried, the fibers are bundled and stored for the next stage.

Next, the fibers are refined into paper. The long fibers are cut into smaller pieces for easier processing, washed to remove impurities, and fed into a Hollander beater, where they are beaten into a uniform slurry.

Because the final paper is used in sanitary products, hygiene and microbial control are essential. For this reason, we boil the slurry after beating, rather than pre-cooking the raw fibers. Beating takes a long time, and if fibers were boiled beforehand, the extended processing period would increase contamination risk. By boiling the post-beating slurry, we minimize microbial growth and can proceed directly to sheet formation afterward, ensuring hygienic and sanitary-grade paper production.

After cooking, the slurry is diluted with water in a large vat to achieve the correct consistency for sheet formation. A mesh frame is dipped into the vat, allowing a thin, even layer of fibers to settle on its surface and form the initial wet sheet. This sheet is then placed under a pressing machine, which removes excess water and compacts the fibers. Finally, the pressed sheets are transferred to the solar dryer, where they dry into strong, durable banana fiber paper.

Fiber Usage

Banana fiber is a versatile natural material with applications across textiles, ropes, carpets, geotextiles, artisanal crafts, paper products, and eco-friendly packaging. It is valued for its strength, biodegradability, and renewability. Globally, research continues to explore banana biomass as a sustainable alternative to synthetic fibers, supporting circular-economy models and reducing agricultural waste.

At Sparśa, the primary focus is on producing paper-grade banana fiber, used as the absorbent core of Sparśa’s compostable menstrual pads. This aligns with the project’s goals of creating environmentally responsible hygiene products, reducing plastic pollution, and demonstrating how agricultural waste can be transformed into a socially impactful solution.

Banana farming produces large volumes of waste, including pseudostems that are unsuitable for fiber extraction, leaves, and slurry generated during the fiber extraction process. Instead of burning this biomass or leaving it to rot—both of which contribute to greenhouse gas emissions—Sparśa converts it into organic compost. This approach reduces methane emissions, supports soil health, and reinforces the project’s zero-waste mission.

Waste Materials Used

• Banana leaves (40%) — chopped into small pieces (3–50 mm).
• Banana trunks (35%) — unusable parts, chopped while fresh for faster decomposition.
• Slurry (25%) — the fibrous waste remaining after extraction, pressed to remove excess water.
• Biochar (optional) — added to improve aeration, microbial activity, and nutrient retention.

The compost recipe aims to achieve an ideal Carbon-to-Nitrogen (C:N) ratio of 20:1 to 35:1, as this ratio influences microbial activity and the speed of decomposition.

Composting Procedure:

1. Pre-process materials: Chop leaves and trunk pieces to 3–50 mm. Press the slurry to reduce moisture.
2. Weigh or estimate quantities: Use a digital scale at first; later, workers can estimate by volume.
3. Mix thoroughly: Combine ingredients in the ratio of 40:35:25 to form a uniform compost pile.
4. Adjust moisture: Achieve 50–60% moisture content. Add water if dry; add chopped dry leaves/trunks if too wet.
5. Label the pile: Mark each new compost pile with date, batch number, and composition.
6. Monitor conditions: Track temperature, moisture, and pile condition using the factory’s monitoring sheets.

Temperature is measured at two depths: 25 cm and 50 cm. Proper composting requires maintaining temperatures between 55–65°C for sanitization. A steady temperature drop or uneven internal heat distribution indicates the need to turn the pile. Extreme temperatures (>75°C) must be avoided to prevent overheating.

After 4–5 months, the compost becomes stable, crumbly, odorless, and ready for agricultural use. The finished compost enriches soil, reduces dependence on chemical fertilizers, and ensures full utilization of banana plant waste.