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ABSTRACT
In recent years natural fibers are the outstanding materials for the expensive and non-renewable synthetic fiber. Natural fibers like sisal, banana, jute, oil palm and coir has been used as reinforcement in thermo set composite for applications in consumer goods, furniture, low cost housing and civil structures, Pineapple leaf fiber is one among them. Pineapple is a significant fruit of India. Pineapple leaf contains only 2.5-3.5% fiber, covered by a waxy layer. Extraction of millions of tons of pineapple leaf fiber can be done after the harvesting of the fruit. Usually those leaves are kept as agricultural waste. So here the pineapple leaf fiber was extracted and to make a composite material with PALF. The objective of the work is to explore the potential of using PALF as reinforcement and investigate the mechanical effect of PALF reinforced Epoxy composite under various compositions of PALF
INTRODUCTION
Overview of composites: Composites are materials made from two or more constituent materials with significantly different physical or chemical properties, that when combined, produce a material with characteristics different from the individual components. The individual components remain separate and distinct within the finished structure
Composites are generally very unique materials of light weight and high corrosion resistance. They also display properties of high fatigue resistance and low coefficient of thermal expansion.
Constituents: Composites are made up of individual materials referred to as constituent materials. There are two main categories of constituent materials
Matrix phase: It is the part of the composite material in which the fiber materials are embedded. It surrounds and supports the reinforcement materials by maintaining their relative positions.
Reinforcement phase: It is the part of the composite material which carries the majority of loads. There inforcements impart their special mechanical and physical properties to enhance the matrix properties.
Types of fibers:
• Synthetic fiber
• Natural fiber
Synthetic fibers: Synthetic fibers are those fibers which are man-made. They are often non-biodegradable. Natural fibers: Natural fibers are those fibers which are taken from naturally occurring plants, animals etc. Major constituents and methodology:
Reinforcement: The part of the composite that provides strength, stiffness, and the ability to carry a load make-up the reinforcement. Among various natural fibers, we have chosen Pineapple Leaf Fiber (PALF).
Pineapple Leaf Fiber (PALF) serving as reinforcement fiber in most of the plastic matrix has shown its significant role as it is cheap, exhibiting superior properties when compared to other natural fiber as well as encouraging agriculture based economy. The fiber extracted from pineapple leaf was the natural fiber used in the present work. It is one such fiber source known from a long time obtained from the leaves of pineapple plant from the family of Bromeliaceous. Pineapples may be cultivated from a crown cutting of the fruit, possibly flowering in 20–24 months and fruiting in the following six months. Pineapple does not ripen significantly post-harvest. Pineapple is the third most important tropical fruit in the world after banana and citrus. The information provided by Indian Horticulture Database suggest that Pineapple is cultivated in an area of 85.4 thousand ha and total production is 1,353.1 thousand tons in India, and also that it is the 6th largest country in the production
MATERIALS AND METHODOLOGY
Fiber extraction: PALF is contained in the spiky leaves of pineapples. The pineapple leaves are very fibrous and have high contents of hemi cellulose, pectin and lignin. The wax content available in the leaves must be retained in order to retrieve high strength and hence the method of fiber extraction must be adopted with utmost care. The leaves are pressed using two-roll mill to remove circa and 90 % of the water content. Pineapple leaf fiber is nothing but the fiber extracted from the leaf of the pineapple plant. The extracted fiber was altered and modified by some chemical process and later used to make a good composite material.
For the purpose of getting a valuable outcome result the fiber should be treated by alkali method. It will increase the strength of the pineapple leaf fiber.
Fiber surface treatment: For reasons of ease and availability the alkali method of fiber treatment was adopted. It is the most commonly used treatment for bleaching, cleaning and removing the impurities from the surface of natural fibers to produce high-quality fibers. Hence it is also known as surface embellishment. The fiber surface treatment has an effect on the following:
• Fiber-matrix bond strength
• Interfacial and mechanical properties
• Flexural properties
• Fiber surface area
Procedure of treatment: The following steps are carried out during chemical treatment of PALF:
• The methods for the making of the work were discussed as follows; first of all the pineapple leaf from the pineapple plant was collected from a field near parassala. After that the collected the pineapple leaf from the field was allowed to be dry in room temperature for 15 to 30 days up to the condition the leaf.
• After that the dried pineapple leaf fiber was allowed for the cleaning process by alkali method. For that process the NaOH pellets and distilled water were mixed in a beaker, and then the dry pineapple leaf fiber was dipped in the solution for 30 – 60 minutes.
• Then they were allowed to keep in sunlight for drying purpose for minimum of one day up to the condition.
• Then the pineapple leaf fiber was chopped into small particles, they have to be cutted into very small pieces around 1 – 2mm thick.
• The pineapple leaf fiber mixed with resin was to be made into a composite by the hand layup method, for that purpose the pattern was to be made and then the resin with various compositions like 10%, 20% and 30% of the pineapple leaf fiber among the whole weight of the specimen was to be applied on the reinforcement glass fiber by sandwich process. Here in this the pattern was to be made by three layers among them the middle layer having a rectangular hole, on that hole only the materials were applied were the top and bottom layers of the pattern were connected by a bolt and nut joint so as it can make the composite more stiff by the force applied on the bolt and nut of the pattern and it is allowed to kept for some hours to make the composite to settle.
• Then the composites were taken from the pattern and they have to be cuts into the sizes and dimensions needed for the various mechanical testing’s. Among the three specimens obtained after manufacturing the composites, they all should be made up to the dimensions needed for the mechanical testing and the various testing are like impact, flexural and tensile tests were made on them.
Fiber testing: The fiber testing is very important as it determines the effect of chemical treatment on the fiber as
well as its properties and performance parameters. For this reason the fibers were initially segregated into 3 parts. This is done so that the concentration at which the optimum performance parameters are obtained can be determined. Each sample was treated with 3%, 5% and 10% concentration of NaOH individually. The samples were then washed with distilled water. After this the fibers were dried in an oven for 3 hours at 70 ̊C. The treated fibers were sent to the South India Textile Research Association (SITRA) for testing.
CONCLUSION
The present work proved that PALF has good potential as a reinforcement in bio-composites. It was
observed that fibers with 10% conc. NaOH displays higher strength with lower elongation when compared to fibers treated with other concentrations.
SCOPE FOR IMPROVEMENT
For extracting PALF we carried out manual extraction process. This resulted in fibers of comparatively lower strength because of reduced wax content. Hence different methods of extraction like microbial extraction and water retting can be adopted in order to rectify problem. For improving the strength of the fiber, other methods of surface treatment like bacterial treatment, silane coupling can be used. Fibers can also be oriented in different direction to determine their effect on the physical properties of the composite.