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Plastic bottle shredder; Rana j; designed and fabricated a compact sized plastic bottle shredder, in the design, pairs of cutting disc with four cutting points were mounted on a pair of shaft. Both shafts where mounted on bearings with an electric motor, as the prime mover. The power source (motor), was coupled to one of the shafts were Power transmission was achieved from the driving shaft to the driven shaft by an arrangement of meshing gears. Structural analysis was carried out to determine the total deformation, maximum shear stress and strain of both shaft and cutter. Results showed that the design is safe since the maximum stress values exerted on the shaft and cutters did not exceed the yield stress values of the material of both shaft and cutter. The limitation of this design is in the usage, as it cannot function optimally for commercial production of shredded plastic chips. In addition, the overall objective was to fabricate a machine that is affordable with a low cost of production but on average putting into consideration the materials used the money summed up to $360.87, which can be quite expensive for an average Zambian to replicate. Plastic Shredder machine is composed of two-shaft shredder with rotary blades and spacer combs. The high cutting torque and the different conformation of the cutters group make it possible to shred pieces made of different materials. The Plastic Shredder machine is composed of two-shaft shredder with rotary blades and spacer combs. Once the material is taken into the hopper, the shredder catches the material and begins to cut it grossly. The high cutting torque and the different conformation of the cutters group it’s possible to shred pieces made of different materials. (Rana, 2020) Low cost plastic shredder machine; The plastic bottles have more volume compared to its weight. Therefore, in the environment they tend to be more noticeable because they take more space than other scraps causing unattractive sight these empty bottles becomes bleeding site for mosquitoes. The cutting of these plastics make it easy to transport and easy to store them in large quantities. Therefore, in this design a decision was taken in making a motor operated plastic shredder machine inexpensive. The bottle crusher cut parts from the bottles with moving cutting blade with a particular depth and speed, then two parts separately or it will be shorten. The machine is powered by motor. (Et-al, 2020) The principle of operation is a follows: • Feed the plastic bottle into the hopper. • Blades will rotate by the shaft is rotated after starting of motor. • Bottle will cut on contact with the cutting blades. • The scroll will fall in the collector. This type of machine is made up of five main parts namely: prime mover, hopper, shredding chamber, shredding shaft, and the collector bin. The prime mover is an electric motor, which generates the torque needed to rotate the shredding shaft. The hopper is the part of the machine that empties the plastic waste into the shredding chamber. A chute located by the side of the hopper guides the plastic waste into the hopper. The top of the hopper is covered in order to prevent popping/flying plastic waste from escaping during operation. The shredding chamber is made up of a pair of static blades attached by the length of the inner wall and a mesh screen at the base. The mesh screen ensures that only shredded plastic particles smaller than the mesh size are allowed to pass through to the collecting bin. The shredding shaft is housed, in the shredding chamber; as it turns, it shreds plastic waste caught between the blades on the shaft and the static blades by the sides of the wall. This action is carried out repeatedly until the plastic waste in the shredding chamber has considerably reduced in size and are no longer been trapped between the shredding blades. The materials used. S/N 1. Component Hopper Material/ Description and Specification Functions Mild steel A hoper is a funnel-shaped container from which plastic waste can be emptied in to the shredding chamber. 2. Shredding chamber Mild steel Houses the shredding shaft and mesh, also provides the space for shredding of the plastic to take place. 3. Shredding shaft AISI 4340 Steel, Produces normalized the shredding force needed to shred the plastic waste. 4. Prime mover AC motor (5 Hp) Converts electrical energy to rotary mechanical energy needed to cause rotation of the shaft. 5. Belt Aramid Transmits mechanical power to the shaft. 7. Bearing Cast iron Provides support for the shaft while allowing it to rotate freely. 8. Frame 2½” Angle bar Provides a platform where all the components can be mounted on. Figure 1 autographic view (Briggs M. Ogunedo) Figure 2 shredding shaft (Briggs M. Ogunedo) Figure 3. 3D model of a shredding machine Shredder Waste plastic; the waste plastic shredder has four main components; the feeding unit, the shredding unit, the power unit and the machine frame. The feeding unit is made of 16 – gauge galvanized mild steel sheet of 2mm thick plate and a dimension of 200 mm × 550 mm through which the waste plastic are fed into the shredding unit. The shredding unit is where the waste plastic are been cut into smaller sizes. The unit consists of a shaft, 50 mm length made up of 30 mm mild steel rod and a cylinder of 55 mm length and 200 mm diameter. Attached to the shaft are cutters made of 12 mm mild steel having nine serrated teeth welded 2 mm apart. The cylinder equally has same cutters with sharp edges to shred the waste plastic. Underneath the shredding unit is the outlet made of 16-gauge galvanized mild steel of 43 mm × 27mm dimension. The shredded waste plastic discharge freely from the shredding unit through the outlet. The machine is powered by 10 Hp electric motor with the aid of belt and pulley arrangement which has 110 mm diameter driven pulley and 60 mm driver pulley as shown in Figures below shows. Design considerations Some of the factors considered in the design of the recycled plastic waste shredding machine are safety, power requirement, and compactness, ease of operations and overall cost of production. Material selection based on availability, durability, cost and ease of fabrication were also considered. Figure 4 side view(Akinfiresoye Waleola Ayo) The advantage to this design is that the design was Material selection based on availability, durability, cost and ease of fabrication were also considered. Mini plastic shredder machine: with increase of plastic use in the day to day activities ,which results in serious environmental issues, which growth rates causing damage to the environment an eco-friendly recycling possible waste plastic is hence necessary. the main objective to this project to design and fabrication a cost effective plastic shredder machine, the use of power supply and single shaft mechanism which can be useful for Micro, Small & Medium Enterprise (R, 2018). The concept of the plastic shredder machine consists mechanical & electrical components like Frame, hopper, electric motor, V-belt drive System, shredder setup. It is used for cutting the plastic in to small pieces, which are in irregular shaped flakes which can be processed further. The benefit to this design is that the cost and time is effective when compared to the existing available model. The machine is user friendly hence offers safety towards the user , in other words its user friendly has the rotating elements like belt and pulley and gears are covered, so it is fully safety to operator The overall performance of shredder machine was satisfactory by considering the quantity of powder produced with respect to time (R, 2018). The set back to this model is the it uses two shaft shredders hence future study could be based on the development of a single shaft shredder. Figure 5 isometric view() Figure 6 3D model (Sudhakara Reddy and Thunga Raju 2018) 5. Design Specification and Figure 7 fixed & unfixed cutting blades(Sudhakara Reddy and Thunga Raju 2018) Electric Motor A 1-phase electric motor with 1.1 kW (1.5 hp), 1400 rpm (rotational speed) and 50 Hz was used. Transmission Drive The power transmission drive used for the machine is belt and pulley drive Figure 8pulley(Sudhakara Reddy and Thunga Raju 2018) References Et-al, B. (2020). Desidgn and construction of a low cost plastic shredding machine. R, s. R. (2018). Material science enginering. design and developement of a mini plastic shredder. Rana, j. e.-a. (2020). design and fabrication of a platic bottle shredder. internatinal reseach journal of engeering and technology .