IRJET- Simulation for Optimum Gate Location in Plastic Injection Moulding for Spanner

International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395-0056
Volume: 06 Issue: 04 | Apr 2019 www.irjet.net p-ISSN: 2395-0072
© 2019, IRJET | Impact Factor value: 7.211 | ISO 9001:2008 Certified Journal | Page 1228
Simulation for Optimum Gate Location In Plastic Injection
Moulding for Spanner
Atul B. Munankar1, Niranjan A. Sitap2, Alok A. Tembhurkar3, Mahesh B. Thakur4,
Sandip S. Kanse5
1,2,3,4Student, Mechanical Engineering, BVCOE NaviMumbai, India
5Associate Professor, Mechanical Engineering, BVCOE, Navi Mumbai, India
---------------------------------------------------------------------***----------------------------------------------------------------------
Abstract - As there is tremendous demand of various
plastic products, plastic producing industries are increasing
in a fastest rate. Injection moulding is the most commonly
used manufacturing process for the fabrication of plastic
parts. A wide style of product area unit factory-made
exploitation injection moulding, that vary greatly in their
size, complexity, and application. The optimum gate
location is one of the most important criterions in mould
design. Moldflow analysis is effective simulation tool to
optimize the gate location at lowest possible cost with least
defects and it requires less time to achieve a quality result
with material waste as compared with typical trial error
methodology on production floor. In this project an analysis
has been performed by taking varying gate locations for a
spanner as a component . Autodesk Moldflow Advisor
simulation software from Autodesk was used for the
analysis and optimum gate location was found with least
defects.
Key Words: Injection moulding; Autodesk Moldflow
Advisor; Simulation; Gate Location; moulding defects
1. INTRODUCTION
One of the most common methods of converting plastics
from the raw material form to an article of use is known as
injection molding. This method is most –usually used for
thermoplastic materials which can be in turn dissolved,
reshaped and cooled. Injection mould components are a
feature of almost every functional manufactured article in
the modern world, from automotive products through to
food packaging. This versatile method permits United
States to provide top quality, simple or complex
components on a fully automated basis at high speed with
materials that have changed the face of manufacturing
technology over the last fifty years close to.
To understand the engineering and operation of
modern day injection molding machines, it is useful to first
look at the not too distant origins of the process. The first
injection molding machines were primarily based around
pressure die casting technology used for metals process,
with patents registered in the USA in the 1870's
specifically for celluloid processing. Further major
industrial developments failed to occur till the 1920's once
a series of hand operated machines were created in
Federal Republic of Germany to method thermoplastic
materials. A simple lever arrangement was wont to clamp
a two piece mould along. Molten plastic was then injected
into the mould to produce the
mould component. Being an inherently low method, it was
limited in use. Pneumatic cylinders were accessorial to the
machine style to shut the mould, although little
improvement was made. Hydraulic systems were first
applied to injection molding machinery in the late 1930's
as a wider range of materials became available, although
the machine design was still largely related to die casting
technology.
Large-scale development of injection molding machinery
design towards the machines we know today did not occur
until the 1950's in Germany. Earlier machines were
supported a straight forward plunger arrangement to
force the fabric into the mould, although these machines
soon became inadequate as materials became more
advanced and processing requirements became more
complex. The main drawback with a simple plunger
arrangement was that no soften mix or blend can be
without delay imparted to the thermoplastic material. This
was exacerbated by the poor heat transfer properties of a
chemical compound material. One of the foremost
necessary developments in machine style to beat this
drawback, which still applies to modern processing
equipment today, was the introduction to the injection
barrel of a plunging helical screw arrangement. The
machine subsequently became known as a 'Reciprocating
Screw' injection molding machine.
2. LITERATURE REVIEW
Plastic injection moulding, the polymer analogue of die
casting for metals, is the most widely used technique for
fabricating thermoplastic materials. It is a high rate
production process, with good dimensional control.
Moreover, this is a net-shape process, so highly complex
components can be produced in the finished state. Plastic
injection moulding (PIM) has many advantages such as
short product cycles, high quality part surfaces, good
mechanical properties, low cost, and light weight, so it is
becoming increasingly more significant in today’s plastic
production industries. Costs can be reduced further by the

integration of components, while there is the potential for
weight savings over metal counterparts. A finely pelletized
or granulized plastic is forced, at an elevated temperature
and by pressure, to flow into, fill and absorb the shape of a
mould cavity. Ming Zhai& Ying Xieexplained [6]that gate
location optimization can be done by changing the gate
location. He concluded that the gate location optimization
can be done to achieve a balanced flow for injection
molding. Yung-Kang. Napsiah Ismail & A.M.S. Hamouda.
This paper presents the design of plastic injection mould
for producing a product. The
plastic half was designed in numerous sorts of product,
but in the same usage S.R. Pattnaik [1]studied gate
location optimization by selecting two gate locations for L-
shaped plastic part, Moldflow plastic adviser software is
used for simulation. A comparative analysis for locating
the optimum gate location is also performed with the
assistance of mould flow software and selected the
optimum gate location. Jagannatha Rao M B, Dr. Ramni [4]
analyzed plastic flow of two plate multi cavity injection
mould for plastic component pump seal, CAD/CAE
technology facilitates the design of mould. He allover
simulation reduces range and complexness of manual
setup operations.
R.A. Tatara [5]studied the injection molding processing
for dispensing closure having an integral hinge with
minimal input; and concluded that Moldflow is able to
perform a relatively sophisticated analysis of an injection
molding function. One half is victimization clip perform
and another half is victimization stick perform. In the
laptop power assisted design (CAD), two plastic parts
were drawn in 3dimension(3D)view by using Pro-
Engineer(Pro/E) parametric software .In the computer-
aided manufacturing(CAM), Pro Manufacturing from
Pro/E parametric software was used to develop the
machining program. For mould style, the product was
designed into two changeable inserts to produce two
different types of plastic production one mould base.
Before continuing to injection machine and mould style,
this part was analyzed and simulated by using Part
Advisor software. From the analysis and simulation we are
able to outline the foremost appropriate injection location,
material temperature and pressure for injection. The
predicted weld lines and air trap were also found and
analyze .OYETUNJI .A development of small injection
molding machine for forming small plastic articles in
small-scale industries was studied. This work which
entailed design, construction and test small injection
molding machine that was capable of forming small plastic
articles by injecting molten resins into a closed, cooled
mould, where it solidifies to administer to specified
merchandize was developed. The machine was designed
and created to figure as a model for manufacturing terribly
tiny plastic parts.
3. METHODOLOGY
3.1. Definition of Optimization Problem
To define the problem, we must first identify all the
inputs and outputs of the system in PIM. Optimization of
gate location is the main criterion in the mould tool design.
The production of injection moulded parts is a complex
process where, without the right combination of material,
part and mould design and processing parameters, a
multitude of manufacturing defects can occur, thus
incurring high costs. The injection moulding process itself
is a complex mix of time, temperature and pressure
variables with a multitude of manufacturing defects that
can occur without the right combination of processing
parameters and design components. Determining best
initial process method parameter settings critically
influences productivity, quality, and prises of production
within plastic injection molding (PIM) business.
3. Study of Component (Spanner)
The component for which mould gate location is to be
selected is “Spanner”. This spanner is of material
Glassfibre 66 Nylon which is most commonly used in
Autodesk Moldflow Advisor 2016. A spanner is used for
turning a nut, bolt or similar fixing that is done to tighten.
The spanner is used to grip the given fixing (whether it is
nut, bolt, concrete screws etc.)and turrn it, allowing you to
apply torque and tighten the nut onto the bolt. During the
study of component following points were found
important to be considered to find the gate location in
mould design of spanner as shown in fig.3.1.
1. The component is thick and chunky and is
appropriate for 3D modelling analysis
2. The component is design in such a manner so that
it can turn or fix the nut or bolt on required
operation.
3. The spanner is of size of bolt diameter on one side
ϕ17 and ϕ13 on other respectively..
Fig 3.1 model of spanner designed in CATIA V5

3.3 Parameters for Finding Gate Location
Proper gate location of a component depends on
different parameters such as melt temperature type of
material and its properties, type of gate, number of gate
locations etc
Material Type: Glassfibre Reinforcements: Fibreglass
Reinforced Plastics, FRP, is an excellent choice of material
for the construction of chemical storage tanks, piping
systems, apparatus and other types of industrial process
equipments. The FRP material properties may beat many
conventional materials, such as steel when it comes to
chemical and corrosion resistance. Little maintenance and
long product life time, that is what well engineered FRP
equipment promise. Plastic material used for spanner is
glassibre 66 nylon, so parameters are as follows.
Grade : Nylon 66 (RTP 0207)
Melt temperature : 290°c.
Number of Gate Locations:
Gate location for a component can be selected more than
one at a time, as per the requirement/ But for our
component we will use only one gate location because our
component is small. If the number of gate locations are
increased then it will give more weld lines. So it is good to
avoid extra gate locations in the component. For finding
optimum gate location, the component is checked with
two different gate locations. These locations are as follows.
1. Gate 1:- At the centre of the spanner handle
2. Gate 2:- At the centre of curved surface of spanner
on the side of ϕ13
Fig3.2. gate locations selected in spanner
Now with these two gate location, as shown in fig.3.2,
simulation is carried out of the component, and from
results the best gate location is obtained.
4. Flow simulation of spanner component
The benefits of using CAE software to design and
engineering components and feed system include.
1. Innovative, reliable and high quality products and
processes.
2. Fewer ROI, due to fewer physical prototypes and
test setups.
3. A more flexibl0e and responsive information
based development process enabling modification
of designs at later stages.
4. A seamless exchange working of data , regardless
of location, industry, CAD environment etc.
5. Lower manufacturing cycle times..
6. Improved and consistent component quality.
The simulation of selected component is carried out
by using “Autodesk Mouldflow Advisor”. The
resolution of component is carried out in high analysis
resolution form. The simulation gives the following
results for fill time, Quality predictions, injection---
pressure, Air traps and Weld lines.
4.1. Fill Time
One of the important process parameters to establish
and record for any injection moulded part is its
injection or filled time. The fill time result shows the
position of the flow front at regular intervals as the
cavity of the component fills. All the regions which
have same colour are filled simultaneously. The result
we get at the start of the injection is dark blue and the
last remaining areas are to be filled with red colour. If
the part which is short shot, the section which is not
filled has no colour. The fill time can be used to
estimate possible areas of short-shot, over packing,
weld lines and air traps.
The fill time for the first gate location is 0.3054 sec.
and for the second gate location is 0.5098 sec. The
results as shown in the fig.4.1 and 4.2 gate location 1
requires less time to fill the cavity then the gate
location 2.
Fig4.1: Fill time of gate location 1
Gate 2
Gate 1

Fig.4.2:Fill time of gate location 2
4.2. Quality prediction
The Quality prediction result’s won’t to estimate the
standards of the mechanical properties and look the half.
This result is derived from pressure, temperature and
other results. The colours displayed in the Quality
prediction result indicate the following.
1. Green- Will have high quality.
2. Yellow- May have quality problems.
3. Red- Will definitely have quality problems.
The result as shown in fig.4.3 and 4.4 shows maximum
percentage of high quality part of a component, less
percentage of medium quality part of a component and no
gate shows low quality part of a component. The quality
predictions of both the gate location are given below.
Fig 4.3 Quality prediction result of gate 1
Fig 4.4 Quality prediction result of gate 2
4.3 Time to reach ejection temperature
The time to reach ejection temperature results show
the amount of time required to reach the ejection
temperature, which is measured from start to fill.
If the half has not frozen by the tip of the cycle time
provided, a projected time to freeze is displayed within
result.
Ideally, the part should freeze uniformly. Areas of the half
that take longer to freeze could indicate thicker areas of
the half or areas of shear heat throughout filling and/or
packing.
If along period of time to reach the ejection temperature is
caused by thick areas in the part, consider redesigning the
part. Long periods of time that time that are due to shear
may be difficult to solve. Reducing the shear may cause the
time to reach ejection temperature to adversely effect
volumetric shrinkage and warpage.
If the resulting values of the part as whole appear high,
action to reduce the cycle time may need to be taken, Such
as reducing the mould and melt temperature.
The results as shown in fig. 4.5 and 4.6 shows that gate
location one takes 22.79 sec. and gate location two takes
22.97 sec. which is more in gate location two .So, gate
location one is more optimum for time to reach ejection
temperature.
Fig.4.5 time to reach ejection temperature at gate 1

Fig.4.6 time to reach ejection temperature at gate 2
4.4 Air traps
An air traps is the air that is caught inside the mould
cavity. It becomes cornered by convergence compound
soften fronts or as a result of it didn’t shaped the mould
vents, or mould inserts, which also acts as
vents. Air traps locations are usually areas that fill last.
Lack of vents or undersized vents in these last-to-fill areas
are a common cause of air traps and the resulting defects.
Problem caused by air traps:
1. Racetrack effect: The racetrack effect occurs when
molten plastic flows into thicker regions more
easily than thin regions. The flow divides then fills
thicker sections before combining again to fill the
diluents sections. The recombined flow will
reverse to satisfy the oncoming flow within the
diluent section.
1. Hesitation: In a part with multiple flow paths, the
flow can slow down or hesitate in thin regions.
2. Unbalanced flow paths: Flow paths do not needs
to exhibit the racetrack effects or hesitations to
have unbalanced flow. In a give up uniform
thickness, the physical length of flow paths may
vary, and again, air traps may occur.
3. Inadequate venting: Lack of vents or undersized
vents in these last-to-fill areas are common cause
of air traps.
Remedies:
1. Balance flow paths.
2. Avoid hesitation and racetrack effects.
3. Balance runners. Changing the runner system can
alter the filling patterns in such a way that last-to-
fill areas are located at the proper venting
locations.
4. Vent appropriately. If air traps do exist, they
should be positioned in regions that can be easily
vented or ejection and / or vent pins added so
that air can be removed.
4.4 Injection Pressure
The injection pressure result, which is produce by Fill
analysis, shows the maximum injection pressure value
obtained before the velocity / pressure switch-over occurs
during the filling phase. The pressure at specific location
starts to increasing only after the melt front reaches that
location. The pressure continues to increase as the melt
front moves past, due to increase in flow length between
these specific location and the melt front. The magnitude
of the pressure or pressure gradient depend on the
resistance of the polymer of the mould. This is a result of
compound with high viscousness needs a lot of pressure to
fill the cavity.
The pressure result as shown in fig. 4.7 and 4.8 shows
that the first gate location require minimum injection
pressure as compared to second gate location. The
pressure result shows that the first gate location require
the pressure of 8.744 MPa and for second gate location is
10.17 MPa. Higher injection pressure indicates the
occurrence of higher shear rate and shear stress level.
Fig 4.7 Injection pressure at gate location 1
.
Fig 4.8 Injection pressure at gate location 2
5. Simulation results summary
The component is simulated on the Autodesk
Moldflow Advisor 2016 Software. The result obtained
from the stimulation helps to identify the correct gate
location and helps to identify the possible defects in the
design phase itself, which may arise due to actual
production. Stimulation result obtained are summerised
in the table below.
Table 1: Results summary table
Results 1st location 2nd location
1. Fill time 0.3054 sec 0.5098 sec
2.Quality Predictions High,
Medium
High, Medium

3.Time to reach
ejection Temperature
22.79 sec 22.97 sec
4.Air Traps Present at
top
Present at top
5.Injection Pressure
(MPa)
8.744 10.17
Table 2: Reference of colour
From the above simulation results of the component it can
be seen that the 1st gate location suggests itself “most
adaptable values”. The 2nd gate location shows the values
that are adaptable at some extent. Therefore the 1st gate
location can be selected as final gate location for further
process of mould design. So gate can placed “At centre of
the handle” of the component (gate location).
6. Conclusions
In this study, the spanner component is flow
simulated for two gate locations to find the better location.
The following conclusions can be derived from the above
stimulation.
 The fill time required for gate location 2 is more
than gate location 1, so fill time of gate location is
considered as most adoptable value.
 The minimum pressure is required for first gate
location that is 8.744 MPa, which gives the
occurrence of minimum shear rate and shear
stress level.
 The time to reach ejection temperatures is
maximum in gate location two, which gives
thicker areas of the part of shear hitting during
 filling.. Therefore gate location one is most
preferable.
 All cases may form small amount of air traps,
which can be avoided by providing proper air
venting.
So finally by combining all results of the gate
locations of component, first gate location is best for
further mould design process.
REFERENCES
1. S.R. Pattnaik, D.B.Karunakar, P.K. Jha. “Application
of computer simulation for finding optimum gate
location in plastic injection Moulding process”,
journal IJIR, vol-3, issue-5 2017
2. Y. P. Tidke, A.V. Dhote, Dr. R. C. Patil. “Study of
optimization in PIM using Taguchi method.” ,
journal IJRASET, vol-5, issue-4, April 2017
3. Sanjay k. Nayak, Pratap Chandra Padhi, Y.
Hidayathullah. “Fundamentals of Plastics Mould
Design”, Tata McGraw Hill Education Private
Limited, 2012.
4. Jagannatha Rao M B, Dr. Ramni, “Analysis of
Plastic Flow in Two Plate Multi Cavity Injection
Mould for Plastic element for Pump Seal”,
International Journal of Scientific and Research
Publications, Volume 3, Issue 8,ISSN 2250-3153
August 2013
5. R.A. Tatara, R. M. Sievers, Valentin Hierzer,
“Modeling the injection moulding processing of a
polypropylene closure having an integral hinge”,
Journal of Materials Processing Technology
6. Ming Zhai& Ying Xie, “A study of gate location
optimization of plastic injection MOULDING using
sequential linear programming”, Int J
AdvManufTechnol (2010) 49:97–103.
7. Zhou Chun-ying, Wang Li-tao,” InjectionMold
Design based on Plastic Injection mould cooling
system layout design,” IEEE 2010 [205-208]
BIOGRAPHIES
Atul B Munankar
“Student, Bharati Vidyapeeth
college of engineering, Navi
Mumbai”
Niranjan A. sitap
Mumbai”
Alok A. Tembhurkar
Mumbai”
Most adoptable values. (compared to other
values)
Values that can be adoptable at some
extent.(compared to other values)
Values which are not preferable to adopt.
(compared to other values)
Values which are not adoptable at any cost.
(compared to other values)

Mahesh B. Thakur
Mumbai”
Prof. Sandip S. Kanase
“Associate Professor, Bharati
Vidyapeeth college of
engineering, Navi Mumbai”

IRJET- Simulation for Optimum Gate Location in Plastic Injection Moulding for Spanner

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