The effect of sisal fiber content in the biocomposite product from injection molding process on its mechanical properties

Many products made of composite have been found in human everyday life. Products such as vehicle component, electrical appliances, household appliances to medical equipment are made from composite. Composites are composed more than one basic constituent material. Polymer Matrix Composite (PMC) is kind of composite that polymer (plastic) as the based component. Most of PMC use synthetic fiber-materials as filler, but several kinds of synthetic fiber - materials can cause damage of the environment and the price is expensive. Because of this undesirable properties, environmental friendly and cheap filler materials are searched to replace the materials that have been used. Currently, many researchers are doing research using natural fibers as an alternative reinforcement (filler) to form a new composite called biocomposite. One of the natural fibers that can be utilized is sisal fiber. Sisal fibers are derived from sisal plants that are widely found in Indonesia. Sisal fiber is an effective polymer filler and can alter the physical and mechanical properties of a polymer. This research was conducted by experimental study to make the product from biocomposite material by using injection molding machine, consisting of several composition of polypropylene (PP) as a matrix, sisal fiber (SS) as reinforcement (filler) and maleic anhydride polypropylene (MAPP) as adhesive. The mixed material is printed in the form of a tensile and impact test specimen by injection molding machine. Injection molded specimens will be tested for tensile strength and strength of shock or impact load. In addition, it will also check the temperature of the specimen melting through the DSC and its permeability configuration via SEM. From these test and examination, it is expected to know the mechanical properties, such as tensile strength and impact strength, of biocomposite material, melting temperature and its surface configuration. Sisal fiber bio-composite can be used as product material in injection molding process. The product results still indicate a slight shrinkage so it is necessary to adjust the value of the appropriate parameter process. The value of tensile strength increases with the addition of sisal fiber percentage to the biocomposite mixture, while the impact test decrease. The highest tensile strength and impact test are 32.14 Mpa and 1.54 kj/mm² respectively. The addition of sisal fiber makes the material becomes brittle. The visible void increases with the addition of sisal fibers.