Banana-Based Composite - New Hybrid Material
Conventionally glass fibre and carbon fibres are used as reinforcement in thermoplastic and thermosetting matrix. However, this causes environmental problems during disposal. Due to environmental sustainability use of the natural fibres as reinforcement are increased in composites for various applications. In this study Banana, kenaf and hemp fibre are used as a reinforcement to improve mechanical properties of composite materials. Among these fibres banana fibre is gaining more importance because India is largest manufacturer of banana in the world and banana fibre is a waste product of banana cultivation which is obtained from dried stalk of banana trees without any additional cost. Synthetic fibre gives better mechanical strength than natural fibre alone. Therefore, significant improvement in strength of natural fibre composite material is done by hybridization. Therefore, in this study hybridization of banana fibre with some amount of kenaf and hemp fibre is done to improve mechanical strength of composite material. The mechanical property of this composite is investigated using tensile, flexural and impact test. Investigation shows that this composite material shows good mechanical properties as comparable with synthetic fibre reinforced material.
Introduction
Automotive companies are in continuous look for an improved material and production process to lower its costs and improve margin of profit. Lighter materials and recyclable component are mostly utilized by automotive industries due to improved energy efficiency thus continuous efforts are taken to develop new materials like composites using synthetic fibres. Nowadays due to increasing demand for environment friendly materials in field of composite continue to promote researchers into the replacement of synthetic materials with an increasing variety of natural materials. These materials have some interesting features such as low density, high toughness, and comparable specific strength properties, use less energy than manufacture of synthetic materials.There are different types of natural fibres such as kenaf, bamboo, hemp, flax, sisal, banana, and jute are used as reinforcement and the effect of these natural fibres on mechanical properties of composite material is investigated by many researchers. Of this banana and kenaf is gaining more importance. Banana fibre is a waste product of banana cultivation because it is obtained from dried stalk of banana trees without any additional cost attracts industries for engineering application including automotive. It gives good specific strength properties. Hemicellulose and lignin are the main chemical constituent of banana fibre. Lignin is acts as binder for cellulose fibre and behaves as an energy storage system. Kenaffibres belong to family of bast fibres and this fibre shown best co2 absorption rate as well as best nitrogen and phosphorus absorption rate more than other fibre. More over natural fibres can be comparable good to synthetic fibre such as glass in many ecological characteristics but not in respect of mechanical strength therefore the significant improvement in strength of composite can be achieved by hybridization with synthetic fibres or natural fibres because using one type of fibre alone is not enough in tackling all technical and economic present when making fibre reinforced composite. Attempts have been made by other researchers by preparing hybrid composite of natural and synthetic fibre to improved mechanical properties of composite. Banana fibre reinforced polyester composites caused by addition of glass fibre have been studied which shows variation in tensile and impact properties. There has been much research done on different combination of natural fibres however minimum research done on banana-kenaf-hemp combination epoxy composite.In this present study epoxy resin as polymer matrix using banana-kenaf-hemp fibres as reinforcement is used to study its mechanical properties. The composite was prepared with different volume fraction of banana fibre with a fixed proportion of kenaf and hemp fibres by hand layup technique which is comparatively easy for composite manufacturing.
Composite Fabrication
The hybrid of banana, kenaf, and hemp fibre composites were fabricated using hand layup method. The banana, kenaf, and hemp fibre were cut with 2-3mm long. The epoxy resin and hardener are mixed in the ratio of 10:3 (w/w). To avoid air bubbles formation epoxy and hardener are mixed thoroughly in a clean beaker by using a glass rod. Reinforcement is prepared by mixing of banana, kenaf and hemp fibres with epoxy resin and hardener. A glass plate of the dimension 30 cm×30 cm was positioned on a suitable place and a mold with dimension 150 mm×150 mm×3 mm was placed on the glass plate. Precaution are taken for easy removal of composite because when we remove composite material from mold there is a chances of damaging of composite surface so we apply a release agent like polyvinyl alcohol over mold surface to enable easy removal of composite and to get smooth surface of the specimen a thin plastic sheet is applied at the top and bottom of mold plate. Above this layer reinforcement were preciously and uniformly distributed. After this hand roller machine rolled the layers of fibre store move unwanted air bubbles and uniform distribution. After that a dead weight of 25 kg was placed on the arrangement for 24 hours at room temperature. Same process was followed to prepare the other samples.
Conclusion
In this work, the mechanical properties of banana, kenaf and hemp fibre hybrid composite is evaluated and it is concluded that if two or more natural fibres are used as reinforcement instead of using single natural fibre then it exhibits good mechanical properties as compared to composite made of synthetic fibre. The prepared samples were tested for tensile, flexural and impact strength. Overall, different types of natural fibre can be used for fabrication of hybrid composite instead of banana, kenaf and hemp fibre. Moreover, we can also change the fiber’s volume fraction.
