ISSN: 2319-8753
International Journal of Innovative Research in Science,
Engineering and Technology
(An ISO 3297: 2007 Certified Organization)
Vol. 3, Issue 2, February 2014
Copyright to IJIRSET www.ijirset.com 9695
Injection Mould Tool Design of Power Box
Side Panel
B.Iftekhar Hussain
1
, Mir Safiulla
2
, Mohamed Ali
3
, G.Suresh
4
Assistant Professor, Mechanical Engg. Dept., Bapatla Engg. College, Bapatla, Guntur Dt., A.P, India.
1
Professor & Head (R&D), Mech. Engg. Dept., Ghousia College of Engg., Ramanagaram, Karnataka, India
2
Lecturer, Mechanical Engg. Dept., Bapatla Polytechnic College, Bapatla, Guntur Dt., A.P, India
3
Assistant Professor, Mechanical Engg. Dept., Vignan University,Vadlamudi, Guntur Dt., A.P, India
,4
Abstract: Injection moulding is a manufacturing process for producing plastic parts from both thermoplastic and
thermosetting plastic materials. The aim of this paper is to model, extract core–cavity and develop injection moulding
tool for manufacturing an object. The part modelling, Core–Cavity design is done using PLM software
Pro/ENGINEER 4.0. Mould base design is done according to HASCO standards. The plastic flow analysis is
performed. NC code for fabricating the mould is generated using Vericut software. The unit cost to make a component
is estimated including all the costs like material cost, tooling cost, machining cost etc.
Keywords: Injection Moulding, plastic, core-cavity, cost, tooling, machining
I. INTRODUCTION
Injection molding is a manufacturing process where material is fed into a heated barrel, mixed, and forced into a mold
cavity where it cools and hardens to the configuration of the mold cavity. After a product is designed, usually by an
industrial designer or an engineer, molds are made by a mould maker (or toolmaker) from metal, usually either steel or
aluminum, and precision-machined to form the features of the desired part. Injection molding is widely used for
manufacturing a variety of parts, from the smallest component to entire body panels of cars.
The object for study taken is power box panel which is used in earth movers to control the power circuit. It has top
cover, front cover, back cover and side panel. The paper provides insight on power box side panel, its modeling, mould
flow analysis, fabrication and cost estimation.
II. LITERATURE SURVEY
Injection moulding is an area where continuous work is being carried out for a long period of time. An attempt has been
made to develop a prototype intelligent design system for injection moulds based on usage of internet based
technologies as in [3]. Studies have been made for understanding the effect of thermal residual stress and warpage [4].
Studies revealed the optimum parameters that minimize the warpage in injection mould using Taguchi approach [5].
Researchers had studied cooling channels in the mould and its affect on final product temperature to know the
shrinkage rate distribution [6]. Efforts have been made to build a methodology for process selection and
manufacturability evaluation of computer based rapid tooling for producing injection moulds [7]. Attempts were made
to develop a model so as to have the lowest life cycle cost in the manufacture of injection moulds [8]. Previous results
show that cavity pressure and mold temperature are the dominant factors determining the quality of the final product in
plastic injection molding [9].
The present studies aims at designing an injection mould tool for fabricating power box side panel and study the
parameters by performing the flow analysis on the part. It provides an insight into manufacturability of the mould. It
also depicts the methodology for arriving at the unit cost of the product including the tooling costs.
III. MATERIALS AND METHODS
A. Material
Power boxes are metal or plastic enclosures used as housings for wiring connections. The material proposed for the
manufacturing of power box panel is Acrylonitrile Butadiene Styrene (ABS) plastic to have,
ISSN: 2319-8753
International Journal of Innovative Research in Science,
Engineering and Technology
(An ISO 3297: 2007 Certified Organization)
Vol. 3, Issue 2, February 2014
Copyright to IJIRSET www.ijirset.com 9696
resistant to corrosion
protection against dust, fire and moisture for the interior of power box
low contact resistance
durability
flame retardant
high heat resistance
high impact resistance
manufacturability
dimensional stability
B. Methodology
The 3D CAD model of the power box panel modeled using Pro/ENGINEER 4.0 is shown in figure 1. It is designed as
per HASCO standards by providing shrinkage allowance of 1.25%, draft angle of 1
0
along core side and 1 mm radius in
all sharp corners [11].
Fig 1. Model of power box side panel
Mould flow analysis is carried out to reap the following benefits.
Optimize the part wall thickness to achieve uniform filling patterns, minimum cycle time and lowest part cost.
Identify and eliminate cosmetic issues such as sink marks, weld lines and air traps.
Determine the best injection locations for the part design.
Pro/ENGINEER Plastic Advisor is used to simulate mould filling for injection moulded plastic parts. Advanced
features are also used to provide valuable manufacturability insight that can significantly reduce late-cycle design
changes and mould reengineering costs. Vericut 6.2.1 is used to study the manufacturing of mould and its allied
difficulties therein.
IV. RESULTS AND DISCUSSION
The following results are embodied after conducting the study. The fill time result is shown in figure 2 which depicts
the flow path of the plastic through the part by plotting contours which join regions filling at the same time. The
maximum fill time is found to be 2.99 sec. The confidence of fill result is displayed in figure 3 which depicts the
probability of a region within the cavity filling with plastic at conventional injection moulding conditions. It is found
that the material will definitely fill in the entire cavity based on the temperature and pressure. The Pressure Drop result
shown in figure 4 is a contour plot showing the pressure required to flow the material to each point in the cavity. The
pressure drop is found to be 27.42 MPa. The Injection Pressure result shown in figure 5 is a contour plot of the pressure
distribution throughout the cavity at the end of filling. The maximum value is at the Injection Location and the
minimum is at the last point of the cavity to fill. The flow front temperature result shown in figure 6 indicates the
region of lowest temperature (blue colour) through to the region of highest temperature (red colour). The result shows
the changes in the temperature of the flow-front during filling and is found to be 225.41
0
C. The quality prediction
results are shown in figure 7. In these results, red colour represents unacceptable quality, yellow colour represents
acceptable quality and green colour represents preferred quality. The results shown clearly indicate that the preferred
quality can be obtained with little chance of acceptable quality at few regions. The non-representation of red colour
clearly depicts that the design is safe with respect to quality. The exploded view of the entire mould assembly is
ISSN: 2319-8753
International Journal of Innovative Research in Science,
Engineering and Technology
(An ISO 3297: 2007 Certified Organization)
Vol. 3, Issue 2, February 2014
Copyright to IJIRSET www.ijirset.com 9697
depicted in figure 8. The different status of machining the mould is simulated and is depicted in Fig. 9 & Fig. 10 for
core and cavity respectively.
Fig. 2 Fill time results showing the flow path of the plastic through the part
Fig. 3 Confidence of fill results showing the probability of a region
within the cavity, filling with plastic (above & below)
A: will definitely fill.
B: may be difficult to fill or may have quality problems
C: may be difficult to fill or may have quality problems.
D: will not fill (short shot).
Fig. 4 Pressure Drop results showing the
pressure required to flow the material to each
point in the cavity
Fig. 5 The Injection Pressure result showing
the pressure distribution throughout the
cavity at the end of filling
ISSN: 2319-8753
International Journal of Innovative Research in Science,
Engineering and Technology
(An ISO 3297: 2007 Certified Organization)
Vol. 3, Issue 2, February 2014
Copyright to IJIRSET www.ijirset.com 9698
Fig. 6 The flow front temperature result
indicating the region of lowest temperature
(blue) through to the region of highest
temperature (red)
Fig. 7 The quality prediction results
Fig. 8 Exploded view of the entire mould assembly
Fig. 9 The work piece, play path of cutting tool, roughing view, and finishing view for core (L to R)
ISSN: 2319-8753
International Journal of Innovative Research in Science,
Engineering and Technology
(An ISO 3297: 2007 Certified Organization)
Vol. 3, Issue 2, February 2014
Copyright to IJIRSET www.ijirset.com 9699
V. ESTIMATION OF COST
The bill of materials required to fabricate a mould with its associated cost is furnished in Table 1. The processing cost
required to make an entire mould assembly is shown in Table 2.
TABLE 1
INDIVIDUAL COMPONENT COST
S. No.
PART DESIGNATION
MATERIAL WITH SPECIFICATIONS
(All the dimensions are in millimetres)
PRICE (INR)
1
Core plate
535x535x180=413kg
Material used is EN38R
Rs. 97,055
2
Cavity plate
535x535x225=502kg
Material used is EN38R
Rs. 1,17,970
3
Core back plate
500x500x30=63kg
Material used is mild steel
Rs. 4200
4
Cavity back plate
500x500x30=63kg
Material used is mild steel
Rs. 4200
5
Ejector plate & retainer
plate
500x360x30=46kg
Material used is mild steel
Rs. 4876
6
Ejector pins
Qty-7
Material used is OHNS
Rs. 2800
7
Retainer pins
Qty-4
Material used is EN8
Rs. 1200
8
Guide pillar and guide
sleeves
Qty-4
Material used is carbon steel
Rs. 4000
9
Grids
500x180x70 length, Qty-2
Material- EN8
Rs. 5670
10
Sprue bush
Material- EN8
Rs. 600
11
Allen keys
Ø18x16 pins, Ø8x12 pins
Rs. 500
MATERIAL COST
(+) 20% Allowance
TOTAL
Rs. 2,43,071
Rs. 48,614
Rs. 291685
Fig. 10 The cavity, play path of cutting tool, roughing view, and finishing view for cavity