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IJRR0052 - ;ksmckl

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fliud mechanics (2222222)

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See discussions, stats, and author profiles for this publication at: researchgate/publication/ Design and Construction of a Low Cost Plastic Shredding Machine Article · September 2020 CITATIONS 0 READS 6, 2 authors, including: Some of the authors of this publication are also working on these related projects: CFD simulation of a shell and tube heat exchanger View project Power Generation in Nigeria, challenges and prospects. View project Briggs Martins Onyinyechukwu Ogunedo Imo State University 22 PUBLICATIONS 37 CITATIONS SEE PROFILE All content following this page was uploaded by Briggs Martins Onyinyechukwu Ogunedo on 06 October 2020. The user has requested enhancement of the downloaded file.

International Journal of Research and Review

Vol; Issue: 9; September 2020

Website: ijrrjournal

Research Paper E-ISSN: 2349-9788; P-ISSN: 2454-

International Journal of Research and Review (ijrrjournal) 374

Design and Construction of a Low Cost Plastic

Shredding Machine

Briggs M. Ogunedo, Beneth C. Chukwudi

Department of Mechanical Engineering, Imo State University, Owerri

Corresponding Author: Briggs M. Ogunedo

ABSTRACT

The challenge of plastic waste pollution has

made it imperative for a systematic approach to

environmental waste management. Hence,

plastic recycling takes the centre stage due to

the numerous associated benefits it offers.

Therefore, this study focused on designing and

constructing a plastic shredding machine which

will assist small and medium scale

entrepreneurs in plastic recycling industry. The

machine utilizes 3 of mechanical power to

produce a torque of 28 and a shredding

force of 1424. With this force, it is able to

shred 150kg of plastic in 6 with an

efficiency of 97%. Motion simulation analysis

run on the machine shows that during operation,

the maximum values for buckling amplitude,

and deformation of the shaft are 0 Ampres

and 0 respectively. Also the von

Mises stress result showed that all regions of the

shaft are far below the yield strength of the shaft

material, and the FoS corroborated this result

with all regions above 1; having a minimum

value of 157. This shows that the machine will

not breakdown even when running at twice its

loading capacity. Furthermore, at a production

cost of N109,840 the machine is 21%

cheaper than the current market value of

N140,750, hence the aim of producing a cost

effective, durable and efficient plastic shredding

machine was achieved in this study.

Keywords: plastic shredding machine, plastic

waste pollution, environmental waste

management

INTRODUCTION

It is estimated that the earth’s

surface area is 510 million km

2

, and the

oceans account for 70% of this surface

area while the dry land makes up the

remaining 29%

[1]

. Human activities on

land such as the indiscriminate disposal of

solid, liquid and gaseous wastes have been

attributed to be a major culprit and source of

concern in global environmental and

ecosystem changes. These indiscriminate

disposals of solid waste pollute the earth

surface because it causes contamination of

the soil leading to a reduction in the value of

land

[2]

. The most prominent land pollutant is

plastic waste due to its cost friendliness and

wide range of application. Plastics find good

patronage in all industrial sectors, with the

highest application being the packaging

sector where approximately 146 million

tonnes are used per year

[3]

. Plastics being

polymers take a long time to decompose in

landfills as it could last up to 1000 years[4].

Hence, if the rate of cumulative production

of plastics continues as seen in 2015 to be

7 billion tonnes,

[3]

then the challenge

posed by plastics should be taken quite

seriously. It was estimated in 2015 by

Jambeck et. al.

[5]

that Nigeria generates up

to 10 million tonnes of plastic per year. 20%

of this generated plastic is mismanaged due

to inadequate disposal of littering, and is

estimated to exceed 20% by 2025[5]. In the

long run, a large quantity of these wastes

end up in the ocean through waste water

outlets, inland water ways, wind, or by

deliberate disposal by people, leading to

ocean pollution. Hence, proper management

of plastic waste is required to avert the

attendant consequences of plastic pollution.

To achieve this, plastic recycling becomes a

viable option as it promotes plastic waste

International Journal of Research and Review (ijrrjournal) 376 amount of shredding force through a cyclic impact loading on the plastic waste material to be shredded. This induces adequate energy in the plastic material causing its molecules to separate or deform relative to each other. 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. Materials In Table 1, a summary of the components of the machine and materials used is shown. These materials were chosen based on the in-service condition of the components and comparative cost. Table 1: Material selection table S/N Component Material/ Specification Description and Functions

  1. Hopper 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, normalized Produces 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.
  6. Bearing Cast iron Provides support for the shaft while allowing it to rotate freely.
  7. Frame 2½” Angle bar Provides a platform where all the components can be mounted on. Figures 1 – 5 show orthographic and isometric views of major components of the shredding machine.
  • International Journal of Research and Review (ijrrjournal)

International Journal of Research and Review (ijrrjournal) 379 Since loading of the shredding chamber will be steady or gradual, then combined shock and fatigue factors for bending and torsion are taken to be Km = 1 and Kt = 1 respectively. Hence, sizing of the shaft was determined using equation 10. Where σb = maximum tensile stress = 1110Mpa, Me = equivalent bending moment = , M = maximum bending moment. Forces acting on Pulley Total forces acting on pulley is expressed in equation 11 as: Mass of shaft Equation 12 was used to determine the mass of the shredding shaft. Where ρ = density of shaft material = Machine Throughput Capacity This parameter indicates the amount of plastics that can be shredded by the machine in a second. It is expressed in equation 13 as: Where ms = mass of shredded plastic, t = time in secs. Efficiency The machine efficiency is expressed in equation 14 as: Where mi = mass of plastic waste introduced into the machine Motion analysis A motion simulation analysis was carried out on the shaft using the SolidWorks motion simulation tool. The aim of the simulation is to determine the buckling behaviour, deformation, von Mises stress and the Factor of Safety (FOS) of the shaft during in-service conditions. RESULTS AND DISCUSSION The result of the design considerations and parameters used in constructing the machine is shown in Table 2. From Table 2, it is seen that the shaft is expected to be affected more by a bending moment than twisting moment due to torsion. S/n Design Parameter Value 1 Volume of hopper 0 3 2 Plastic waste weight per Batch 1563 3 Number of bottles per batch 150 4 Length of belt 1m 5 Angle of lap 1 radian 6 Mass of belt 160g/m 7 Centrifugal tension 502N 8 Tension of tight side 1498N 9 Tension of slack side 704 10 Maximum tension 2000N 11 Number of belts 2 12 Torque 28 13 Forces acting on pulley 2201 14 Shredding force 1424 15 Equivalent bending moment 269 16 Equivalent twisting moment 23 17 Speed of motor 250 rpm 18 Power of motor 5 hp 19 Mass of shaft 62 kg In figures 6 and 7, the shaft is expected to continually resist a maximum shear force of 2202 exerted by the tight and slack tensions and a maximum bending moment of 335.

International Journal of Research and Review (ijrrjournal) 380 Figures 8 to 11 show the buckling amplitude, deformation, FOS and von Mises stress contour plots of the shredding shaft. In figure 8, the buckling analysis reveal that maximum buckling amplitude expected is 0 Ampres. This occurred at the shredding blade edges because the edge is continually being acted upon by the resisting forces which are equal and opposite in direction to the shredding force. The minimum buckling value is 0 Ampres and it occurred at the ends of the shaft. In figure 9, the deformation plot reveals that the maximum deformation was recorded at the blade edges with a displacement value of 0. this is expected and corroborates the buckling analysis result. The opposition to shredding forces offered by the waste over time is expected to deform the blades of the shredding shaft. However, at a displacement value of 0, the shredding blades would still be efficient. The minimum deformation is at the ends of the shaft with a 0 displacement value.

International Journal of Research and Review (ijrrjournal) 382 effectively withstand induces stresses in the shaft during operation as a result of torsion, bending, tensile or compression. Performance Evaluation Compressed plastic bottles and other plastic waste materials were used to evaluate the performance of the machine after its construction. The MTC of the machine was determined by observing the shredding time using a stop watch for various input masses starting from 15kg to 300kg. Table 3 shows the MTC and efficiency of the machine for various masses tested during the performance evaluation. Table 3: Performance evaluation result Mass input (kg) Mass Shredded (kg) Time(sec) MTC(kg/s) Efficiency 15 14 183 0 0. 30 29 310 0 0. 45 43 437 0 0. 60 58 293 0 0. 75 72 356 0 0. 90 87 332 0 0. 105 102 349 0 0. 120 117 389 0 0. 135 131 399 0 0. 150 146 419 0 0. 165 161 503 0 0. 180 174 729 0 0. 195 189 949 0 0. 210 204 1269 0 0. 225 219 1828 0 0. 240 233 2541 0 0. 255 248 2763 0 0. 270 262 3237 0 0. 285 276 3844 0 0. 300 291 4279 0 0. In figure 12, it is seen that the efficiency of the machine remains relatively constant regardless of the variations in the mass of plastic waste introduced into the machine for shredding. However, the MTC of the machine is affected by the input mass as it is seen to

International Journal of Research and Review (ijrrjournal) 383 increase as volume occupied by the input mass increases, peaking at 150kg. When this mass is increased to 300kg, the MTC is noticed to decline. This is because at a designed shredding force of 1424, increase in mass beyond 150kg will lead to increase in the time needed to shred the plastic waste. From the graph in figure 13, it can be deduced that shredding two batches of 150kg plastic will save more time than a batch of 300kg plastic waste. In Table 4, the Bill of Engineering and Management Evaluation (BEME) is presented. It is seen that the material cost for the production of the shredding machine is 21% lower than the amount previously quoted by similar research works. Figures 14a and b show the 3D model and image of the constructed shredding machine. Table 4: BEME S/N Item Quantity Amount (N)

  1. AC Electric Motors (5 Hp) 1 25,
  2. Pulley 2 8,
  3. Belt 2 6,
  4. Sheet Metal 2mm Thickness 1½ 33,
  5. Shaft 700mm 1 7,
  6. Bearing 2 5,
  7. Paint 4 litres 2,
  8. Bolts and Nuts 30 6,
  9. Sheet Of 4mm Plate ½ 8,
  10. Hinges 4 2,
  11. 3 Length Of 2½ Inch Angle Iron 19ft 1 7, Total 109,840.

International Journal of Research and Review (ijrrjournal) 385 Vol; Issue: 9; September 2020 (2015). Plastic waste input from land into the ocean. Science, 347(6223):768 – 771. 6. Parker, L. (2018). Planet or plastic: a whopping 91% of plastic isn’t recycled. Retrieved on 15/09/2020 from google/amp/s/api.national geographic/distribution/public/amp/ne ws/2017/07/plastic-produced-recycling- waste-ocean-trash-debris-environment 7. Anurag, S., Amit, C., Amritpal, S., and Raghav, S. (2014) Design and Development of a Plastic Bottle Crusher. International Journal of Engineering Research and Technology, 3 (10): 2278 - 2281 8. Senthil, K., Naveen, P., Nirmal, K. and Premvishnu, R. (2016) Design of Mechanical Crushing Machine. Int. Res. J. Engr. and Tech., 3 (1), 2395-0072. 9. Rana, J. Sahil, S. Shah. M., Parjapati, M., and Mehta, H., (2020). Design and Fabrication of plastic bottle shredder. International Research Journal of Engineering and technology (IRJET). 7(4): 1738 – 1745. 10. Ayo A. W., Olukunle O. J., Adelabu D. J., (2017) Development of a waste plastic shredding machine. Int. J Waste Resources. 7(2):1 – 4. Doi:10/2252 – 5211. 11. Atadious D. and Oyejide O. J., (2018). Design and Construction of a Plastic Shredder Machine for Recycling and Management of Plastic Wastes. International Journal of Scientific & Engineering Research 9 (5): 1379 – 1385 12. ARABELT SIG (2020). Conveyor Belting. Aramid straight wrap construction 13. Association of plastic cyclers. plasticrecycling/pet-design-guide retrieved on 15/09/ How to cite this article: Ogunedo BM, Chukwudi BC. Design and construction of a low cost plastic shredding machine. International Journal of Research and Review. 2020; 7(9): 374-385.

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IJRR0052 - ;ksmckl

Course: fliud mechanics (2222222)

16 Documents
Students shared 16 documents in this course

University: جامعة كفر الشيخ

Was this document helpful?
See discussions, stats, and author profiles for this publication at: https://www.researchgate.net/publication/344493844
Design and Construction of a Low Cost Plastic Shredding Machine
Article · September 2020
CITATIONS
0
READS
6,248
2 authors, including:
Some of the authors of this publication are also working on these related projects:
CFD simulation of a shell and tube heat exchanger View project
Power Generation in Nigeria, challenges and prospects. View project
Briggs Martins Onyinyechukwu Ogunedo
Imo State University
22 PUBLICATIONS37 CITATIONS
SEE PROFILE
All content following this page was uploaded by Briggs Martins Onyinyechukwu Ogunedo on 06 October 2020.
The user has requested enhancement of the downloaded file.

Students also viewed

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