Yan Chen and Ioan Negulescu

Louisiana is the second largest U.S. sugarcane producer, with sugarcane production accounting for 41.5 percent of the nation’s total (Table 1). Sugarcane refining generates a large volume of residue called bagasse. Disposal of bagasse is critical for both agricultural profitability and environmental protection.

The LSU AgCenter is conducting research on converting bagasse into value-added nonwoven materials. This research involves procedures for bagasse fiber extraction, bagasse fiber processing and bagasse fiber formation into nonwoven materials. It also involves methods of evaluating nonwoven bagasse products, including fiber bonding structure, mechanical and physical properties, and biodegradability. Potential applications of bagasse fiber nonwoven materials include horticultural products, animal bedding and aquaculture products.

Sugarcane Production

The sugarcane stalk consists of two parts: an inner pith containing most of the sucrose and an outer rind with lignocellulosic fibers. During refining, the sugarcane stalk is crushed to extract the sucrose. This procedure produces a large volume of residue, bagasse, containing both crushed rind and pith fibers. U.S. sugar mills produced about 13 million tons of dry bagasse in 2001. In Louisiana, approximately 85 percent of waste bagasse is used as in-house fuel for power generation or as raw material for producing low-value products such as mulch and ceiling tiles. The remaining 15 percent is waste that goes to a landfill or is allowed to decay.

Previous research on bagasse has suggested many approaches to converting bagasse into value-added industrial products, such as liquid fuels, feedstocks, enzymes and activated carbon. Use of bagasse fiber for manufacturing material products is another prospective solution. Compared to pure synthetic materials, bagasse fiber-based materials have two advantageous features, light weight and renewability. The LSU Human Ecology Textile Processing Laboratory has developed a method to produce bagasse fiber nonwovens and composites.

These biobased industrial materials have potential for diverse end-uses from automobile interior trim and housing to agricultural and other industrial sectors.

Bagasse Fiber Process

The process for producing bagasse fiber nonwovens and composites includes bagasse fiber extraction, bagasse fiber cleaning, opening and mixing, carding and needle-punching. Waste bagasse is manually sifted and put into an alkaline solution for boiling to remove lignin. After the treatment, bagasse fiber is rinsed with water and dried in an electric oven. The extracted bagasse fiber is cleaned using a cotton cleaning machine. The clean fiber is then blended with carrier fibers or bonding fibers in desired ratios and fed into a universal laboratory carding machine to form a fiber web. During the carding, the fiber blend is further opened and individual fibers are combed to be relatively parallel.

Needle-punching is a mechanical action to entangle fibers in the direction perpendicular to the web surface. After needle-punching, the fiber web is significantly compacted and stronger.

Property Evaluation

End-use quality and performance of the bagasse fiber nonwovens are critical for both the producer and consumer. The bagasse fiber nonwovens are tested for tensile strength, flexibility, compressibility, water absorption and biodegradability. Bonding properties between the cellulose fiber and polymer fiber are also characterized using various instruments.

Agricultural End-uses
End-uses of the bagasse fiber nonwovens in agriculture include:

Horticulture
Bagasse fiber nonwovens can be used to make flowerpots. This type of flowerpot has excellent biodegradability and can be buried in a flowerbed or larger plastic or clay pots. A recent study indicates that the bagasse nonwoven pot buried in a flowerbed is dissolved within only 23 days. When the nonwoven pot is put in a larger plastic pot, it is biodegraded within 50 days. The study also shows that the bagasse nonwoven pot is capable of sustaining weather and watering during seedling and retailing.

Animal Bedding
The bagasse fiber nonwovens can be used as bedding material for poultry farms. Because the nonwoven is easy to lay out and pack, the used nonwoven bedding material (after collecting enough poultry wastes) can be packed and sold as garden mulch directly. This approach not only promotes production of biodegradable and nutritional garden mulches, but also helps ease animal waste management. LSU AgCenter researchers are working on the development and testing of this product.

Aquaculture
Like other geotextiles, the bagasse fiber nonwovens can be applied in aquaculture, such as bank weed control, filtration and pile wraps. Artificial habitats used in fish cultivation can benefit the aquaculture system by providing shelter and separation, additional nutrition and water quality improvement. Thus, availability of inexpensive artificial habitat materials can help fish farmers with profits.

Yan Chen, Associate Professor, and Ioan Negulescu, Professor, School of Human Ecology, LSU AgCenter, Baton Rouge, La.