Sisal fiber started being used many decades ago. However, all possible applications of the raw material have not yet been explored, and some of the applications that are known today have not yet passed the laboratory phase, especially with regards to sub-products, which the economic examination is still difficult to be done as per the current technological methods in use.
The use of sisal was limited, all through its history, to fiber, which its transformation into finished products can be divided basically into three distinct stages as follows:
This sector is the major field of sisal application. The expression 'Ropes Industry' used means here many sorts of products made of sisal such as threads, strings, yarns, twines and all types of ropes used of agriculture and cattle-raising, both on industry and commerce. Type 3 is the main sisal type used for the manufacturing of these products.
As the sisal fiber is rich in cellulose, it is widely used for the manufacturing of cellulose paste of superior quality, for the production of high quality paper. The types bucha and refugo are mostly used for this since the length of the fiber is not important on its industrial process.
Bucha is used in this sector for the polishing of ceramic coverings, and in the composition of ‘pastes’ for the production of linings and plasters. In the field of construction, sisal can also have other applications such as on residential houses, offering more resistance to composites, as well as replacing asbestos in the composition of roofing tiles for the covering of industrial and residential properties. The reason for the use of sisal in the construction industry is that the adding of the fiber to the base of cement (paste, mortar, concrete) significantly increases the tenacity and pos-cracking behavior of the cement. Besides bucha, sisal type 1 has also been used when there is a need for better quality results.
Article that has considerable demand, especially after the green politics developed in Europe, Australia and in the United States, sisal carpets and rugs are no longer used only on rustic architecture; nowadays, it decorates big offices and modern companies worldwide. A significant quantity of fiber is needed for the manufacturing of sisal carpets (from 800 to 1,000 m/kg) and quality is also a must, as the production depends on the length of the fiber (approximately 1,10 m) and on its cleanliness. Despite being a growing sector, the quantity of sisal used in the carpet industry is small when compared to the quantity normally used in the agricultural twine industry (baler twine). Sisal type 1 is the main sisal type used as it is the best quality sisal fiber produced in Brazil.
Some countries use sisal fiber for the manufacturing of bags. Type 3 is the main sisal fiber type used.
Vegetal fibers have been largely used in the past as a composite of latex - natural rubber - reinforced with coconut fibers, for example, for the production of automobile padding.
From the 1960's, it started to be gradually replaced by polyurethane foam. This replacement was done simply due to the high productivity at less cost, not taking into consideration its poor performance nor its environmental and social issues.
Vegetal fibers have high capacity to absorb humidity which offers more comfort indispensable to professional taxi, bus and truck drivers, who spend a long time sited at their vehicles. The creation of rural and industrial jobs is another important aspect of the use of vegetal fibers. A car sit composed of vegetal fiber uses at least four times more labor than the one composed of foam. Still today, first-class vehicles from companies such as Mercedes-Benz use vegetal fibers for padding. Another advantage of the use of vegetal fiber is that it is not toxic. The polyurethane made of isocyanate releases during combustion a gas called cianidric gas, which is highly toxic.
In this sense, when preparing a project, it is known today of the tremendous importance of considering both the performance of product in all its levels as well as the socio-environmental implications that may from derive its use.
It is in this context that the sisal has been occupying more space in this industrial segment. Nowadays, the car and plastic industries are reviving their interest for vegetal fiber due to its advantages in the replacement of inorganic fibers, such as the glass fiber.
Another important aspect is the fact that the decorticated / brushed residues of the fibers, such as bucha, may also be used in the composition of plastic. It is important to clarify that in this application short-length fibers may be used (in dimensions that can go down to a few millimeters)
Sisal fiber, threads, strings, yarns, twines, etc, may be used for the production of various types of handcrafts such as bags, rocking chairs, brushes, general decoration and so forth.
The Sisal Tow can be used in packing segment, generally protecting many types of products inside boxes and bags. Its discard, unlike plastic, polysterene or other used synthetic materials, is totally harmless to the environment.
Cotesi provides sisal tow in packages of 100 g and 250 g to retail market and in special packages to the industry.
The sisal pad is a product of multiple applicability. Its consistency is firm, but at the same time is extremely softness, allowing good air ventilation on its inside. It is quite tough, has a strong texture and abrasive properties. It’s a natural filter product, hygroscopic, thermal and acoustic.
Its main usage purpose is in the manufacture of mattresses, upholstered and padded in general. Its application in the manufacture of upholstered and composite in the automotive industry is already a reality among key brands on the market (not forgetting the policies for conservation of the environment), and increasingly becoming a market tendence. Great opportunities arise for new applications, especially for being a 100% biodegradable.
Sectors such as packaging, special filters, cleaning of ceramics in construction, lining thermo-acoustic and special floors, barriers against spill of many products in ecological disasters are examples of potential consumers of the product.
The pads can be provided:
The cut fiber may be used to manufacture composites, I.E., molded materials which require mechanical strength, such as plaster, fiber-cement, thermoplastic resins and other products. Cotesi do Brasil is working together with universities and technology centers to develop projects for application of the cut sisal fiber.
The Sisal Wick is how the fiber is presented – continuously and brushed, with many thicknesses and levels of brushing. Its applications are still in research level, but the sisal wick is a strong ally in the installation of slab for lowering ceilings in the gypsum industry.