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International Journal of Science, Technology & Management
Volume No.04, Issue No. 05, May 2015
www.ijstm.com
ISSN (online): 2394-1537
PARAMETRIC EFFECT DURING PLASTIC
INJECTION MOLDING PROCESS ON
POLYPROPYLENE MATERIAL
Himanshu Arora1, Dhirendra Pratap Singh2, Sunil Kumar3,
1
M.Tech Student, 2HOD Mechanical Department, Subharti Institute of Technology & Engineering,
Swami Vivekanand Subharti University, Meerut, (India)
3
Assistant Professor, Faculty of Engineering and Technology,
Gurukula Kangri Vishwavidyalaya, Haridwar, (India)
ABSTRACT
Today’s Plastic Injection molding process as one of the most widely used processes for producing plastics
products. As in other forming processes, the characteristics of plastic injection molding procedures are
significantly affected by the quality of the plastic products by the different levels for its process parameters. To
find the effect of various level for the process parameters is becoming a research issue and is now known as
finding the efficient frontier of the parameters. The effect of parameters in plastic injection molding process and
its influence on product quality and costs. The main aim of this paper is to study the effect of different
parameters on polypropylene work material for a plastic injection molding process during manufacturing of
bottle cover. In this paper study of parameter like injection molding temperature, injection molding pressure
and cooling time used to find the effect on polypropylene work material in plastic injection molding process with
a number of experiments have been conducted in pre-planned way on injection molding machine to understand
the effect of various parameters on weight of product.
Keywords: Plastic Injection Molding Process, Polypropylene, Parameter Effect
I. INTRODUCTION
With the continuous progress of manufacturing techniques for latest products, better and better quality of
products is required for the survival in the present market. The plastic injection Molding is the most important
process for plastic parts mass production. Among the all plastic products about one fourth are made by injection
molding. Selecting the proper plastic injection molding process settings is necessary because during production
the behavior of the plastic material is highly affected by the process parameters. Consequently, the process
parameters govern the quality of the part produced. A sufficient amount of research has been directed towards
determining the process parameters settings for the plastic injection molding process. There are number of
parameters that affect the properties of plastic product. There are different processing parameters for all
different materials. Melting temperature, injection pressure and cooling time are the main processing
parameters. Therefore, the setting of process parameters for plastic products has a noticeable influence on their
quality and cost.
As a raw material plastic is used in plastic injection molding process such as low density
polyethylene, nylon, polypropylene, flexible PVC, polystyrene and machine used for the injection process is the
injection molding machine. [1]
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International Journal of Science, Technology & Management
Volume No.04, Issue No. 05, May 2015
www.ijstm.com
ISSN (online): 2394-1537
In plastic injection molding process raw material is melted in the injection molding machine and then forwarded
into the mould with the help of reciprocating screw where it cools and solidifies into the final product part. The
reciprocating screw is mounted on gear box in the barrel; barrel contains heaters for heating the raw material. In
the injection process raw material is melted by heat and pressure. While forwarding material the material enters
the grooves of reciprocating screw. After cooling and solidification final product is obtained. [2]
The work material used in this research is Polypropylene. Polypropylene is a thermoplastic polymer having
chemical formula (C3H6)n and chemical name of poly(1-methylethylene). It is a very versatile material; it offers
very great combinations of properties such as light weight, strong, high heat resistance as well as stiffness and
flexural retention. By these properties polypropylene is easily fabricated. The polypropylene has many variants
but the material used is homopolymer polypropylene. [3]
II. EXPERIMENTAL PLANNING
Fig.1 show the plastic injection molding machine set up used for conducting the number of experiment. The
plastic injection molding machine is of three types hydraulic, mechanical and electric, these types are classified
by their driving systems. The machine mainly consists of two main parts injection unit and clamping unit. Many
types of injection machine are available in the market but the most widely used machine is horizontal plastic
injection molding machine. In plastic injection molding process the plastic material usually in the form of
powder or pallet are fed from hopper which directs the raw material to the injection chamber. The material
moves forward from hopper to injection chamber by piston and cylinder arrangement. In injection chamber raw
material first enters into the barrel and raw material melts in the injection unit due to external heaters of the
barrel. The molten plastic material is then injected into the mould cavity through the nozzle and allows it to cool
and solidifies into the mould, after that it will remove from the mould cavity.
Polypropylene raw material used for production of final product i.e. bottle cover. Polypropylene (PP) is a linear
hydrocarbon polymer, expressed as (C3H6)n.
The polypropylene has many variants but the material used in the manufacturing of the bottle cover is
homopolymer polypropylene of H110MA grade. The electronic weighing machine is used for Weight
measurement after plastic injection molding process. The weighing machine used for the experiment is
electronic type having the weight limit 0.01 gm to 200gm.
III. RESULTS AND DISCUSSION
Two major parameters e.g. melting temperature and injection pressure are studied in current work mostly
affected the weight of final product.
Fig. 3 shows the S/N ratio response curve for melting temperature of final Product. It clears from the figure that
during experiment S/N ratio behaves differently at four level of temperature. For weight of the product lower the
best value calculated. So the effective value of melting temperature is 2150C.
Fig. 4 shows the S/N ratio response curve for injection pressure of final Product. It clears from the figure that
during experiment S/N ratio first increases up to 55mpa injection pressure and then decreases. For weight of the
product lower the best value calculated. So the effective value of injection pressure is 65MPa.
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International Journal of Science, Technology & Management
Volume No.04, Issue No. 05, May 2015
www.ijstm.com
ISSN (online): 2394-1537
IV. FIGURES
Fig.1 Plastic Injection Molding Machine
Fig. 2 Final Product Used for Experiments
Fig. 3 S/N Ratio Curve of Melting Temperature for Weight (Gram)
Fig. 4 S/N Ratio Curve of Injection Pressure for Weight (Gram)
V. CONCLUSION
The effect of various factors has been identified and believed can be a key factor in helping to produce best
quality and less cost in plastic injection molding process parameters. In plastic injection molding process of
Polypropylene, for weight melt temperature and injection pressure are found to be the most significant factor
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International Journal of Science, Technology & Management
Volume No.04, Issue No. 05, May 2015
www.ijstm.com
ISSN (online): 2394-1537
which contributes. The results show that, for polypropylene the best combination of processing parameters in
terms of weight are 2150C melting temperature, 65MPa injection pressure. This paper shows that by optimizing
the melting temperature & injection pressure we can reduce weight of material used in production. This research
will improve the performance of injection molding machine as well as reducing the cost also. By carrying out
experimental tests the best combination of process parameters was found that would provide the lowest weight
of specimens made of polypropylene homopolymer material. On this basis, it was found that melting
temperature and injection pressure are the two most influential process parameters affecting the process. Other
parameter of this process is still under research and need more involvement of multidisciplinary science and
technology to achieve improvement.
REFERENCES
[1]. R. A. Lindberg; “Processes and materials of manufacture”; Prentice-Hall of USA, Inc., New Jersey, 247250; 1990.
[2]. P.K. Bharti, “Recent Methods for Optimization of Plastic Injection Moulding Process –A Retrospective and
Literature Review”, International Journal of Engineering Science and Technology Vol. 2(9), 2010.
[3]. Y. P. Tidke , A.V.Dhote, Dr.C.R.Patil; “Study and Optimization of Process Parameters in Plastic Injection
Moulding- A Review”, international journal for research in applied science and engineering technology
Vol. 2 Issue IV, April 2014.
[4]. S. Kamaruddin, Zahid A. Khan, K. S. Wan; “The Use Of The Taguchi Method In Determining The
Optimum Plastic Injection Moulding Parameters For The Production Of A Consumer Product”; Jurnal
Mekanikal; Bil.18 , 98 – 110; December 2004.
[5]. Mr. A.J. Yadav, Mrs. S.V. Dravid, Mr. V.D. Rajput, “taguchi technique in optimization of injection
molding process parameters for manufacturing plastic parts”, Proceedings of the NCNTE- 2012, Third
Biennial National Conference on Nascent Technologies Fr. C. Rodrigues Institute of Technology, Vashi,
Navi Mumbai, Feb 24-25, 2012 Department of Mechanical Engineering.
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