RESULTS AND DISCUSSION
The different ratio of length over diameter were successfully obtain by using florescence microscope. The result showed in fig. 1, the value of L/D ratio. For kenaf fiber sieve under 250 to 425 micron, showed that the value is 4.46. for kenaf sieve under 500micron, the value show increasing up to 6.73. But, for the kenaf sieve under 425 microns, the value of L/D ratio increase until 7.35. the increasing value show that there were not so different L/D ratio for all this size of sieve. While, the smallest value of L/D ratio show for the 250 to 425 micron.
Fig 1: Graph of L/D ratio vs size of sieve.
To determine the amount of moisture content in kenaf stem, the sample have taken in day one until day seven. The result showed in fig. 2.The amount of moisture in kenaf stem were calculate in percentage of weight lost. All the process to dry the kenaf stem done under sun light. When the weight of kenaf stem were consistent, the process was finish. The percentage of moisture in kenaf stem calculated was 91.85%. the moisture content were very important to determine because kenaf fiber very light in weight and have a special ability in its structure to absorb water.
Fig 2: Graph of Moisture content of kenaf fiber per day.
To determine the density of kenaf fiber after pulverizes, we calculated the bulk density of kenaf by measure the bulk density of kenaf fiber. There were two companies done the pulverized process for kenaf fiber and each showed different value of bulk density. For kenaf fiber pulverized at Kenaf Fiber Industri Sdn. Bhd., the value is 0.08262g/cm3, and value for kenaf fiber pulverized at Polyregion Sdn. Bhd. is 0.1854 g/cm3. The different is quite low. The differences occur maybe cause by absorption of moisture during shipping from factory to laboratory. This also cause by type of pulverizette use by company.
Fig 3: Graph of bulk density kenaf fiber pulverizer at Kenaf Fiber Industri sdn. Bhd. And Polyregion Sdn. Bhd.
To study about morphological properties of kenaf fiber in different size, we have done confocal scanning electron microscopy (SEM) kenaf fiber interaction with plastic in biocomposite sheet. Fig 4 showed that confocal SEM picture. In this composite sheet show that two different size of kenaf fiber bonded together with plastic.
Fig 4: Confocal SEM
Chemical properties of kenaf fiber are very important in composite research; this is because it needs to determine the degradation temperature, chemical contain in kenaf fiber, also the volatile organic compound in kenaf. To determine that properties, several method have done, include Thermogravimetric Analysis(TGA), and Fourier transform spectroscopy( FT-IR). In fig 5 showed that DTG from TGA thermogram of kenaf fiber whole stem.
Fig 5: DTG for whole stem kenaf
