Download New literature

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 .