International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395-0056

Volume: 05 Issue: 09 | Sep 2018 www.irjet.net p-ISSN: 2395-0072

Review on Plastic Moulding

Golait Sagar1, Patil Shubham2, Gaikwad Shubham3 , Bachhav Nandu4

1,2,3,4BE, 5Prof. H.B. Jagtap
5Department Of Mechanical Engineering
1,2,3,4,5S.N.D. College Of Engineering & Research Centre, Yeola, India
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Abstract—For making of plastic parts the injection and the part is ejected from the machine. Therefore the
moulding is mostly used. And is versatile for mass main phases in an injection moulding process involve
production of plastic parts. For determining the cycle time filling, cooling and ejection. The cost-effectiveness of the
the cooling system is much important. A good cooling process is mainly dependent on the time spent on the
system design can reduce cycle time and achieve moulding cycle in which the cooling phase is the most
dimensional stability of the part. This paper describes a significant step. Time spent on cooling cycle determines
cooling channel system for injection moulding dies. Both the rate at which parts are produced. Since, in most
simulation, optimization and experimental verification have modern industries, time and costs are strongly linked, the
been done with these new cooling channels system. An longer is the time to produce parts the more are the costs.
industrial part, a plastic bowel, with conventional cooling A reduction in the time spent on cooling the part would
channels using the Moldflow simulation software for drastically increase the production rate as well as reduce
comparative parts. Experimental verification has been done costs. So it is important to understand and optimize the
for a test plastic part with mini injection moulding machine. heat transfer process within a typical moulding process.
Comparative results are based on temperature distribution The rate of the heat exchange between the injected plastic
on mould surface and cooling time or freezing time of the and the mould is a decisive factor in the economical
plastic part. The results provide a uniform temperature performance of an injection mould.
distribution with reduced freezing time and hence reduction
Heat has to be taken away from the plastic material until a
in cycle time for the plastic part.
stable state has been reached, which permits demolding.
Keywords—Conformal cooling channel, Cycle time The time needed to accomplish this is called cooling time
Mouldflow, Square shape. or freezing time of the part. Proper design of cooling
system is necessary for optimum heat transfer process
1.INTRODUCTION
between the melted plastic material and the mould.

Injection moulding is a widely used manufacturing process Traditionally, this has been achieved by creating several

in the production of plastic parts [1]. The basic principle of straight holes inside the mould core and cavity and then

injection moulding is that a solid polymer is molten and forcing a cooling fluid (i.e. water) to circulate and conduct

injected into a cavity inside a mould which is then cooled the excess heat away from the molten plastic. The methods

© 2018, IRJET | Impact Factor value: 7.211 | ISO 9001:2008 Certified Journal | Page 1299
 International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395-0056
Volume: 05 Issue: 09 | Sep 2018 www.irjet.net p-ISSN: 2395-0072

used for producing these holes rely on the conventional that can be applied to build mathematical models of
machining process such as straight drilling, which is injection molding process with consideration of the most
incapable of producing complicated contour-like channels important parameters.
or anything vaguely in 3D space.

2.INJECTION MOULDING PROCESS VARIABLES

AND ARTIFICIAL INTELLIGENCE METHODS

According to Karbasi and Reiser, the injection molding

process includes three nested process loops as shown in
fig 1 . The first loop called machine control includes Fig. 2. Classification of optimization methods1

control of machine parameters, such as speed, pressure

3. APPLICATION OF AI METHODS FOR
and temperature. The middle one (process control)
THERMOPLASTICS INJECTION MOLDING
includes such variables as in-mold temperature and
pressure. The last loop, which is called set point control,
3.1. Heating And Cooling Systems
takes care of part quality feedback.

Machine Part
There are several techniques that can be applied to reduce
Inputs Machine Injection Attributes
Actuators Process time of the cooling stage of injection molding process and
Machine
Feedback
increase quality of a produced part. Conformal
Machine
Control

Process cooling/heating channels are one of them. They are

Variables
Process
Control
Feedback
“conforming” to the shape of the cavity in the mold making
Quality
Feedback
it possible to reduce part’s temperature faster and more
Set Point
Control
evenly. They allow coolant to access all part locations
Fig. 1 Injection molding control loops1 uniformly, making the process more efficient and
consistent. However, they can also be used to increase
2.1. Artificial Intelligence Methods temperature in the cavity, for example, during injection
stage not to allow injected earlier plastics to cool down
According to Dang , there are two main groups of
and solidify too early. This is important for increase of
simulation-based optimization methods, which are direct
quality of injection molding of parts with very thick and
discrete optimization and metamodel-based optimization
very thin walls. Molds with such channels can be produced
methods. The methods and their short description , where
using direct metal sintering (additive manufacturing
GA stands for genetic algorithm, RSM for response surface
technique), as well as through vacuum diffusion bonding
methodology, RBF for radial basis function and ANN for
and liquid interface diffusion .
artificial neural network. Of course, these are not all the
simulation-based optimization methods used. Among Kitayama et al. propose a framework for numerical and
others, in the metamodel-based methods group ANN is experimental examination of conformal cooling channels.
mentioned. This is one of the artificial intelligence methods
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 International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395-0056
Volume: 05 Issue: 09 | Sep 2018 www.irjet.net p-ISSN: 2395-0072

To asses cooling performance cycle time and warpage are Showcase & Third Annual Workshop, Canada;
considered. Melt temperature, injection time, packing 2006
pressure, packing time, cooling time, and cooling
[3] Wang Guilong, Zhao Guoqun, Li Huiping, Guan
temperature are taken as the design variables. At first, a
Yanjin,“ Analysis of thermal cycling efficiency and
multi-objective optimization of the process parameters is
optimal design of heating/cooling systems for
performed, then the process parameters of the cooling
rapid heat cycle injection molding process”,
channel are optimized. A sequential approximate
Materials and Design 31 (2010) 3426–3441
optimization using a radial basis function network is used
to identify a pareto-frontier. According to the model with [4] A B M Saifullah and S. H. Masood, Optimum

optimized parameters, the conformal cooling channel is cooling channels design and Thermal

produced using additive manufacturing and the analysis of an Injection moulded plastic part

experiment is carried out to validate performance of the mould, Materials Science Forum, Vols. 561-

channel. 565, pp. 1999-2002, (2007).

[5] A B Saifullah, S. H. Masood and Igor Sbarski,

4. Conclusion
cycle time optimization and part quality
Quality issues are a common problem for injection molding improvement using novel cooling channels in
process due to non-uniform temperature variation in the plastic injection moulding. ANTEC@NPE 2009,
mold. During design of the molds for injection molding USA.
process, it is very difficult to achieve efficient cooling with
uniform thermal distribution. It is attempted to be
achieved through application of variotherm technology, as
well as conformal cooling/heating channels. However,
most of rapid heating and cooling systems are still difficult
to apply in the mass production of plastic parts in injection
molding industry due to extra complex heating setups,
weak mechanical strength of the mold and lack of a
standardized control option.

REFERENCES

[1]Olga Ogorodnyk, Kristian Martinsen,

“Monitoring and control for thermoplastics
injection molding A review”,2018

[2] Karbasi H, Reiser H, Smart Mold: Real-Time

in-Cavity Data Acquisition. First Annual Technical

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