DESIGN AND MANUFACTURE OF THERMOPLASTIC HUB NUT

International Journal of Mechanical and Production Engineering Research and Development (IJMPERD) ISSN (P): 2249–6890; ISSN (E): 2249–8001 Vol. 10, Issue 3, Jun 2020, 1751-1760 © TJPRC Pvt. Ltd.

DESIGN AND MANUFACTURE OF THERMOPLASTIC HUB NUT N. SOMESWARA RAO*1, R. NAGARJUNA2, M. BALAJI3 & M. RAJYALAKSHMI4 1,2,3 4

UG Students, Department of Mechanical Engineering, PVP Siddhartha Institute of Technology, Vijayawada, AP, India

Assistant Professor, Department of Mechanical Engineering, PVP Siddhartha Institute of Technology, Vijayawada, AP, India

ABSTRACT Plastic is a polymer having large molecules. Due to their unique diverse properties, polymersare replacing the metallic components in applications such as automobiles, sporting materials, toys etc., Injection moulding is a cyclic process to convert plastic into desired shape by forcing the melted plastic under pressure into the cavity either by hydraulic plunger or by rotating screw of the extruder. It is one of the most common and versatile operations for mass production of complex plastic parts with excellent dimensional tolerance. In the present work hub nut is modelled and manufactured.

This hub nut is widely used to join the parts in many mechanical machines. This hub nut mould is modelled by using NX software. For the die, mild steel is used. For hub nut, thermoplastic materials like Acrylonitrile Butadiene styrene, polypropylene are used. This hub nut is prepared by using hand injection Moulding.

KEYWORDS: Plastic, Injection Moulding, Acrylonitrile Butadiene Styrene, Polypropylene & Hub Nut

1. INTRODUCTION Production industries are the main sector to create job opportunities and enhance the economic development of the country. Nowadays plastic consumption is more than metallic products due to its ease of production and high

Original Article

Received: May 25, 2020; Accepted: Jun 15, 2020; Published: Jun 30, 2020; Paper Id.: IJMPERDJUN2020160

performance. Worldwide plastic consumption in 2014 is estimated at least 125,000 million pounds (by weight).

About 36% is processed by extruding, 32% is processed by injection moulding, 10% by blow moulding and 22% using other processes. There are different types of manufacturing techniques for producing plastic products.

1.1 Types of Plastic Manufacturing Processes 1.1.1 Compression Moulding In this process, a pre-shaped charge of material or a premeasured volume of powder or a viscous mixture of liquid resin and filler material is placed directly into a heated mould cavity. Forming is done under pressure from a plug or from the upper half of the die.

1.1.2 Transfer Moulding It represents a further development of compression moulding. The thermosetting material is placed in a heated transfer pot or chamber. After the material is heated, it is injected into heated closed moulds. A ram, plunger or a rotating screw feeder forces the material to flow through the narrow channels into the mould cavity.

1.1.3 Blow Moulding It is a modified extrusion process. In this process, a tube is first extruded, then clamped into a mould with a cavity much larger than the tube diameter and finally blown outward to fill the mould cavity. Blowing is usually done with an air blast at a pressure from 350KPa to 700KPa.

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1.1.4 Vacuum Forming In this process a sheet of plastic is heated to a forming temperature and then this sheet is stretched onto a single- surface mould and force is applied against mould with the help of vacuum.

1.1.2 Injection Moulding Injection moulding machine offers many advantages including minimal losses from scrap (since scrap pieces can be melted and recycled), mass production is possible, complex parts produced easily and minimal finishing requirements. The thermoplastic materials are used primarily in injection moulding. Many plastic components are manufactured by Injection moulding process. Components produced with this process have good quality. Complex shaped parts can also be produced using this process.

2. LITERATURE REVIEW P.K. Bharti et, al. [1] Reviewed on recent methods for optimization of the plastic injection moulding process. Number of methods have been applied in injection moulding process to enhance the efficiency. In these approaches, number of researchers applied mathematical models, Design of experiments and Evolutionary algorithms to discuss the performance of injection moulding. The pros and cons of each method was also presented in the study. P. Ravinder Reddy et, al. [2]. designed andanalyzed Injectionmoulding of Mineral Water Bottle Cap. In their study, Experimental investigation on thermoplastic (HDPE) was used as a working material. Stress analysis for pressure as well as Temperature variations was also carried out on cap cavity plate.NikMizamzulMehat et, al. [3] Analyzed Injection moulding of plastic gear. Plastic gears fail due to weak strength and mechanical properties. By applying simulation with taguchi method various properties of plastic gears are studiedwith different combination of parameters like location of gates, size of runner, types of gating system etc., Based on the results, polymer flow structure studied by them.Kalpit Jain, et.al., [4]. Applied taguchi method to analyse the influence of parameters on responses in Injection moulding process.Experimental investigation was done by G. Chavhan et, al [5] to study the influence of parameters on injection moulding process and die development. In their study, they developed mathematical relations between the parameters and responses.Two cavity injection mould for fan blade back cover was designed and analysed by Dr. Mohammed Yunuset,al [6] using mould flow analysis.Due to the advantages like durability, light weight, etc., PP was used as back cover for fan blade. Injection moulding process was applied to produce the back cover by conducting various analysis on the process parameters to get better-quality. Gurjeet Singh et,al.

[7] conducted experimental investigations to find the influence of process parameters on quality objectives. N.Divyaet, al [8],designed and analyzeda mould for water bottle caps. To overcome the limitations of cold runner injection moulding and to reduce the wastage of material and improve production rate hot runner injection moulding can be used. With the help of Pro-E software,they modelled and analysed the design for all types of stresses. A die for RAM component of electrical transformer was designed and analysed for manually operated injection moulding machine byKhan Farhan et,al [9]. In their work they followed practical approach to analyse the parameters of the die design with low cost and time.Mould flow softwarewas used to model and study the structural characteristics of a plastic cup by Xuebing liet,al. [10] through simulation of injection moulding process. In their study various forces acting on the flow were also analysed by varying the process parameters to identify the optimum parameters for effective moulding.MaungMyintet,al[11] optimized the mould design for ‘cloths hanger’ to get maximum productivity by following systematic stepsto identify the possible defects. With their analysis, they concluded that with medium carbon steel injection mould highest productivity can be achieved with in minimum cycle time.Kavin Kumar S, et,al. [12]discussed a mould design for injection moulding of various plastic Impact Factor (JCC): 8.8746

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products. By varying various machine parameters and two types of feeding methods they optimized the mould design.

Erdalozturket,al. [13] designed and manufactured plastic injection mould to produce high-density polyethylene injection moulded spur gear. The mould is designed, and the moulding process is simulated by the software Solid works plastics tool with the selection of high-density polyethylene (HDPE) for gear material. The mould itself is constructed from steel 1050.

The mould plates are machined by the CNC operations and the cavity of the desired part (spur gear) is produced by the wire EDM operation with a wire diameter of 0.18mm.The mould cavity including body and the teeth of the gear is usually enlarged by the shrinkage factor of HDPE plastic material to reach the final required size and the geometry after cooling. A preliminary injection process is done with a circular disc (no teeth on the circumference) to reach an experimental shrinkage factor before the actual gear mould is cut. Next, based on the experimentally verified shrinkage factor a 3mm module, 20 number of teeth and 20-degree pressure angle gear cavity is cut by EDM and the injection process is used to produce plastic test gears. After visual inspections of the moulded plastic gears, tip diameter like preliminary measurements were accomplished on the plastic gears.AKhushboo Dadhichet,al [14] Designed &analyzed of ‘Plastic Hanger’ using Mould Flow Software. In the study, they used injection mould for making plastic product. The Injection Moulding process is used to manufacture different kinds of shapes with proper accuracy. Hence, this is the most commonly used for manufacturing plastic products.In tins project, they created a new model of Hanger that is easily movable, easily rotatable and to fulfil current market and human being needs. So, for all these techniques they used mould flow software and make a perfect 3D model of the component. This software is more powerful for simulation and analysis for a component and also locates the defect in a product. So, with the help of this software, the ‘Hanger’ can be easily moved because of its size and weight.Snehal A. Kambleet, al [15]studied design of an automotive switch housing of two-wheeler, To get a quality product, they have optimized various input parameters of moulding.

From the above discussion it is understood that injection moulding is the best suited process for mass production of plastic products. Separate mould is to be designed and analysed to get a good quality product. Injection moulding process can be used for ay type of plastics. In the present work an attempt is made to produce a hub nut by designing and analysing a mould with mild steel material.

3. METHODOLOGY 3.1 Hand Injection Moulding Hand injection moulds are simple in construction and also that have no provision for hating, cooling and ejection.

Whenever hand mould is cycled, universal heating plates are required in order to heat the moulds. In order to remove the mouldings, the moulds must be removed after every cycle. Hand moulds are single cavity moulds, but if the mould is quite small, multi cavity can also be used. For short run, Aluminium or Brass are used for mould material. For Thermo plastic materials, generally steel is used as moulding material.

In hand injection moulding machine, the plastic granuals are pored in the heating chamber to heat up to required temperature. Then the molten plastic is injected into the die by applying manual pressure.

3.2 The Steps Involved in the Manufacturing of Mould 

CAD modelling of a die

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Analysis

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Die manufacturing

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3.2.1 CAD Modelling of a Die Based on practical design parameters, the mould design system is proposed. There are two parts of design- generation and evaluation. With the help of CAD software, one can achieve the modelling of the required product. The components of the mould are modelled with Siemen’s Nx 11.0. asper the specifications required. The component models are shown in figure 1.

Figure1: (a): 3D View of core insert

Figure 1(c): 3D View of Cavity Ring Plate

Figure 1 (b): 3D View of Cavity Plate

Figure1 (d): 3D View of Top Plate

Figure 1: Model of the Components Generated using NX Assembled model of the full mould is shown in the figure 2

Figure 2: Assembly of Full Mould 3.2.2. Strength Analysis The mould design is analyzed with finite element analysis using ANSYS. To analyse the strength, toughness, elasticity etc., Hub nut is manufactured with different materials like ABS, polypropylene. Generally, this hub nut is made with Bakelite material. The strength of the hub nut made with ABS and PP should be known in order to replace the Bakelite material. That’s why Strength of this hub nut made with ABS,PP is analyzed by using ANSYS software. Approximately 10MPA pressure is applied on the threading part, an outer profile of the part is fixed. After that solution was done. Normal stresses, principal stresses and shear stresses obtained are same for both the materials. These stresses are approximately the same as those stresses developed in Bakelite. Figures 3 shows the Normal stresses developed in X, Y, and Z direction.

Principal stresses developed in the hub nut are shown in figure 4. Shear stresses are indicated in figure 5.

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(b) Y- direction

(a) X- direction

(c)Z- direction Figure 3:Normal stress

Figure 4(a): I Principal stress

Figure 4 (b): 2nd principal stress

Figure 4: Principal stresses

Figure 5 (a): XY – Direction

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Figure 5 (b): YZ – direction

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XZ - direction Figure 5: shear stress

3.2.3 Die Manufacturing In order to avoid production problems, occur during production phase, the designer must take care of some important aspects like material usage, shrinkage of material, product outlook design, etc. To prevent back flor over packing, the gate size should be optimal. Usually melted plastic is allowed to pass through a central channel. In the present work, hand mould die for thermoplastic hub nut is manufactured, in which molten plastic material is allowed to pass through the runner and gate to fill the mould cavity. The die is produced using Shaper, CNC Turning and Vertical milling Machines.

The manufactured components are shown in figure 6.

Figure 6 (a): Core Insert

Figure 6 (b): Cavity Plate

Figure 6 (c): Cavity Ring Plate

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Figure 6 (d):Top Plate

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Figure 6 (e): Assemble of the Die Figure 6: Machined Components

4. ASSEMBLY AND PRODUCTION 4.1Working Principle of Hand Injection Moulding In hand moulding machine, first, we place the die carefully in such away that the runner of the die just below the nozzle of the hand moulding machine and then fix the vice. Now pour the plastic granules into the hopper. Now this granules goes into the heating chamber and then heated upto 2200C temperature approximately. Now apply the manual pressure by rotating the wheel. The molten plastic is injected into the die. Now remove the vice and take the die, and separate the plates. Now take the product from die.

Figure 15: Hand Injection Moulding Machine 4.2 Steps Involved in Injection Moulding Various steps followed in the production of plastic product in injection moulding is as shown in figure 7.

Step-1: Select suitable plasticthatsatisfied the required characteristics of the product.

Step-2: Select suitable process parameters after preparing mould, runner and gate.

Step-3: Melt the selected plastic in heated chamber, then inject into the cavity.

Step-4: Allow to solidify.

Step-5: Take out the final product from the mould.

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Figure7: Injection Moulding Process Finished product after solidification is as shown in figure 8 and the final product is shown in figure 9.

Figure 8: The Detailed View of Three Plates with product.

Figure 9: Finished Component.

5. APPLICATIONS 

Hub nut is used in many mechanical machines for joining of several parts.

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Hub nut is used to join the frames of the cylinder.



This is used to join the hollow pipes.

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Hand injection moulding is a cheap process and no need for any skilled labour.

6. CONCLUSIONS In order to meet the rapid market demand, injection moulding is very much preferred. The products with high quality, good dimensional accuracy are manufactured by using this process. Product quality depends on Mould design, material, Impact Factor (JCC): 8.8746

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and other process parameters like injection pressure, solidification time etc. In the present work hub nut with ABS and polypropylene is manufactured. But in practice, this hub nut is made with Bakelite material. Analysis is also doneto check thestrength of r hub nut made with ABS,PP by using ANSYS software. From the results it is observed that normal stresses,principal stresses and shear stresses are same for both the materials. These stresses are approximately the same as those stresses developed in Bakelite material. The cost of Bakelite material is more when compared with ABS and PP. So, it is more economical to use any one of these two materials instead of Bakelite in order to reduce the cost of the product. It is better to perform other teststo find out tensile strength, impact strength of the component.

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P.K. Bharti, M. I. Khan, Harbinder Singh “ 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.

2.

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NikMizamzulMehat, ShahrulKamaruddin,and Abdul Rahim Othman “Modeling and Analysis of Injection Moulding Process Parameters for Plastic Gear Industry Application”,ISRN Industrial Engineering, volume 2013, article id 869736, 10 pages, 2013.

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Kalpit Jain, Deepak Kumar, Sanjay Kumawat “Plastic Injection Molding with Taguchi Approach - A Review”, International journal of scientific research, Volume: 2, Issue: 5, May 2013.

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Parag G. Chavhan, Prof.B.R.Borkar “Review on Injection Moulding Process & its Die Development Using CAD/CAM/CAE”, International Journal of Latest Trends in Engineering and Technology (IJLTET), Vol. 5 Issue 1 January 2015.

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Dr. Mohammed Yunus, Dr. Mohammad S. Alsoufi, Mohammed Salman Mustafa, “Optimizing the Die Design Parameters of a Two Cavity Injection Moulding Tool for a Fan Blade Back Cover using Mold Flow Analysis”, International Journal in IT and Engineering, Vol.03, Issue-06, June 2015.

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Gurjeet Singh, Ajay Verma “A Brief Review on injection moulding manufacturing process”, International Conference of Materials Processing and Characterization (ICMPC 2016).

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N.Divya, Dr.Ch.V.S.Parameswara Rao, Dr.S.S.N.MalleswaraRao, “Design and Analysis of Hot Runner Injection Mould for Water Bottle Caps”, International Journal of Scientific and Research Publications, Volume 7, Issue 3, March 2017.

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KhanFarhan, Rajput, Rushikesh, Mohite Kiran, Sonawane Vishal, S C Pardeshi “Manually operated hand mould die”, International Research Journal of Engineering and Technology (IRJET), Volume: 05 Issue: 03 | Mar-2018.

10. Xuebing li, Design and Checking Analysis of Injection Mold for a Plastic Cup, IOP Conf. Series: Materials Science and Engineering 324, volume -1, 2018.

11. MaungMaungMyint, KhinKhinKhaing, “Design and manufacturing process of plastic injection mould”, International Journal of Scientific and Research Publications, Volume 8, Issue 8, August 2018.

12. Kavin Kumar S, Ravi Kumar “Tool Design for Injection Molding With Basic Parameters”, International Research Journal of Engineering and Technology (IRJET), Volume: 06, Issue: 03, Mar 2019.

13. Erdal öztürka, Mustafa taifora, Bilal qasimb, Nihat Yildirim, mert vardarc, “Design and manufacturing of plastic injection mould to produce high-density polyethylene injection-moulded spur gear”, international conference on mathematics – engineering – natural & medical sciences, March 8-10, 2019.

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14. AKhushboo Dadhich, Avinash Nath Tiwari, Design & Analysis of Plastic Hanger Component using Mold Flow Software International Conference on Advancements in Computing & Management, volume 1,03 April 19.

15. Ms. Snehal A, Kamble A., N. Surde, Swapnil S. Kulkarni “Validation for plastic injection mold design for automotive switch housing through physical experimentation”, International Journal of Advanced Engineering Research and Studies, volume 1,2019.

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