The study aims to examine the relationship of the effect of the type of adhesive
and the rotational speed of the granulator on the physical properties of urea
granules (slow release fertilizer). In this study the results showed that the type of
adhesive (tapioca, sticky rice, rice, sago, cornstarch) on the granulation process
affected the bulk density value, the percentage of carved granules 2-5 mm, and
durability to get the best value is in the type of tapioca adhesive. The best type of
adhesive is tapioca and based on observations to the end to get the longest
dispersion results. Whereas the percentage of tapioca DSA (water absorption) has
the lowest percentage, it means that the absorbed level is small. In the variable
rotation speed of the granulator (5, 10, 15, 20 and 25 RPM) the higher causes the
value of bulk density, water absorption (DSA), the percentage of granules size 2-5
mm has increased. while the durability and faster dispersion time. So it can be
concluded that the granulator putran velocity affects the physical properties of
SRF urea granules. In SEM tests veriable adhesive types that have high
amylopectin with high viscosity (ie tapioca 92%) can increase the uniform
distribution of urea and small granule pores. In the type of tapioca adhesive there
are a few pores with an average diameter of 2.57 μm, whereas in the type of
adhesive maize (amylopectin 70%) has a pore diameter of 11.5 μm. At the
granulator variable speed of 5 RPM the surface of the granule has a pore diameter
of 4.6 μm. with the uneven distribution of urea, there are slightly large white
particles on the granules.