Fiber reinforced polymer composites are being used in almost every type of applications in our daily life and its usage continues to grow at an impressive rate. The manufacture, use and removal of traditional composite structures usually made of synthetic fibers are considered critically because of the growing environmental pollution. It creates interest in the use of biofibers as reinforcing components for thermoplastics and thermo sets. Sisal fiber (SF), a member of the Agavaceae family is a biodegradable and environmental friendly plant. Sisal fiber is a strong, durable, stable and versatile material and it has been recognized as an important source of fiber for composites.
It is generally accepted that the mechanical properties of fiber reinforced polymer composites are controlled by factors such as nature of matrix, fiber-matrix interface, fiber volume or weight fraction, fiber aspect ratio, fiber orientation etc . The combination results in superior properties not exhibited by the individual materials. Many composite materials are composed of just two phases one is termed as matrix phase, which is continuous and surrounds the other phase often called the dispersed phase. Composites reinforced with natural fibers received increasing interest from industries in a wide field of application such as automobile, construction, aerospace and packing (Ku H et al. 2011; Pickering KL et al. 2007). The main drawback of using natural fiber is their high level of moisture absorption, insufficient adhesion between untreated fibers and the polymer matrix which can lead to deboning with age (Gassan J 2002). Many of the plant fibers such as coir, sisal, jute, banana, palmyra, pineapple, talipot, hemp, etc. find applications as a resource for industrial materials (Satyanarayana et al., 1990b; Thomas & Udo, 1997; Rowell et al., 1997) Proper design of a composite system subjected to high loading rates can be accomplished only if the strain rate sensitivity of the material has been measured and the modes of failure and energy absorption are well characterized .
For instance, sisal is a hard leaf fiber but jute and hemp are both bast fibres and are generally referred to as ‘soft’ fibers to distinguish them from Journal of Applied Science and Engineering, Vol. 18, No. 3, pp. 289294 (2015) DOI: 10.6180/jase.2015.18.3.09 *Corresponding author. E-mail: [email protected] the hard leaf fibers. Both leaf and bast fibres are multicellular with very small individual cells bonded together (Preston, 1963; Hearle, 1963 and Hegbom, 1990). Composites filled with micro particles in epoxy system gained significant importance in the development of thermosetting composites. Epoxy resins the most important matrix polymer preferred when it comes to high performance. Its combination with glass fibers gives an advanced composite with properties like low weight, good mechanical and tribological properties. The study deals with the effects of natural fibers on some mechanical properties of the Epoxy composite. Jayamol George  made experimental studies on Short Pineapple-Leaf-Fiber-Reinforced Low-Density Polyethylene Composites.
The influence of fiber length, fiber loading, and orientation on the mechanical properties has also been evaluated. Measurement of fiber length is often performed on photographs of short fibers obtained from burning off or dissolving the matrix. Correction of the measurement of fiber length was carried out and the real value of mean fiber length and the real fiber length distribution were obtained .
Materials and Methods
Sisal is a natural fiber (Scientific name is Agave sisalana) of Agavaceae (Agave) family yields a stiff fiber traditionally used in making twine and rope. Sisal is fully biodegradable and highly renewable resource of energy. Sisal fiber is exceptionally durable and a low maintenance with minimal wear and tear strength. Sisal fiber is produced by the way known as decortications, where leaves are compressed by a rotating wheel set with blunt knives, so that only fibers will remain.
Physical Property Sisal Fiber
- Density (g/cm3) upto1.5
- Specific modulus (Gpa)
- Cellulose content (%)
- Young’s modulus (Gpa)
- Diameter of ultimates
Matrix and Hardener
Epoxy is a thermosetting polymer that cures when mixed with a hardener. Epoxy resin of the grade LY556 was used in this study. The hardener of the grade HY951. The reinforced matrix material was prepared with a mixture of epoxy and hardener at a ratio of 10:1.