Kamble et al., International Journal of Advanced Engineering Research and Studies
E-ISSN2249–8974
Research Paper
VALIDATION FOR PLASTIC INJECTION MOLD DESIGN FOR
AUTOMOTIVE SWITCH HOUSING THROUGH PHYSICAL
EXPERIMENTATION
1
Ms. Snehal A. Kamble, 2A. N. Surde, 3Swapnil S. Kulkarni
Address for Correspondence
1
ME- Mechanical – pursuing, 2Mechanical Department- Walchand Institute of Technology, Solapur
3
Director-Able Technologies India Pvt. Ltd., Pune
ABSTRACT:
The paper discusses about the design of automotive switch housing of two wheeler, its trial on machine of 40 tons and mold
design. To insure a quality final product, it is necessary to start out with quality components. Injection molded parts can be
molded to a high quality standard by focusing on these areas of plastic technology: Correct part design, Accurate selection
material, processing plastic. Only by drawing on expertise from these three areas of plastic technology can a product
designer create quality molded parts that maximize performance and are cost effective. The purpose of this design deals with
the first of these three issues part design. The problems which may occur in the development phase of the product are solved
in the design phase itself. So the rework and modification of mold is avoided by minimizing the wastages and scrap.
KEYWORDS:- Plastic Injection Mold, Injection Process, Mold Design.
I) INTRODUCTION:
Since 1949, Plastics has specialized in the custom
design, tooling, and injection insert molding of
products used in the medical, telecommunications,
aerospace and consumer products industries, most
plastic materials have greater chemical resistance
than most metals. Plastics do not rust or oxidize as
metals do and most are not affected, as are metals, by
acids or base compounds. The molding may cause
defects and its processing offers a challenge during
its development phase. The cost of the mold is high
and any process that is not optimized renders heavy
overheads during its development cycle and
production. So designing the mold which ensures
best suitability for the features on the component
with smooth flow of molten plastic is very important
part of development process. The Plastic adviser
Software is one of software used to ensure the best
choice location of feeding system and size of gate,
runner and sprue. With the aid of mould flow
analysis, engineers can obtain statistical data of the
moulding process before the mould is actually
constructed. The object is to optimize the fill process
of a mould and the integrity of the moulded part. The
data provided during the analysis helps the engineer
select the optimum location for gate, sprue and
runner. Temperature variations and all the suitable
parameter are clearly defined in the simulation. The
end result is accurate, economical and reliable plastic
parts. The successful launch of any plastic product
depends knowing the true costs and profitability
before the job is started.
Injection molding typically involves large volumes of
parts. Small cost overheads per part can be
compounded to large cost differences over the life
span of the part. Major cost components considered
here are material, re-grind and machine costs. Scrap,
rejections and regrind costs are also accounted in the
cost. Injection molding is used to create many things
such as wire spools, packaging, bottle caps,
automotive dashboards, pocket combs, some musical
instruments (and parts of them), one-piece chairs and
small tables, storage containers, mechanical parts
(including gears), and most other plastic products
available today. Injection molding is the most
common method of part manufacturing. It is ideal for
producing high volumes of the same object.
II) A photograph of the sample produced:1)Material:-Nylon-30%Glass Filled
Int. J. Adv. Engg. Res. Studies/III/I/Oct.-Dec.,2013/77-79
Fig1a. Physical Component (as molded)
Fig1b. 3D Solid Model images
2)Part Name:-Switch Housing
3)Function:-Enclosure for wires and parts of switch
buttons
Some specifications are given below:Overall Dimension of product:• Length-70mm
• Width-55mm
• Height-45mm
• Thickness-outer Rib-3mm
Inner Rib-2mm
• Color-Black
• Shrinkage: 1.5 %
• Component weight: 10.5 grams
• Moulding type: Multi Cavity injection
mould tool
III) 3D MODEL FOR MOLD DESIGN:a) Basic mould consisting of cavity and core :-
Fig3a:-3D View of a MOLD Cavity
a) Mould Cavity:The mold consists of two primary components, the
injection mold (A plate) and the ejector mold (B
plate). The cavity is the female portion of a mould
Kamble et al., International Journal of Advanced Engineering Research and Studies
which gives to the moulding its external forms
.Plastic resin enters the mold through a sprue in the
injection mold; the sprue bushing is to seal tightly
against the nozzle of the injection barrel of the
molding machine and to allow molten plastic to flow
from the barrel into the mold, also known as the
cavity. The sprue bushing directs the molten plastic
to the cavity images through channels that are
machined into the faces of the A and B plates. These
channels allow plastic to run along them, so they are
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referred to as runners. The molten plastic flows
through the runner and enters one or more
specialized gates and into the cavity geometry to
form the desired part. Sides of the part that appear
parallel with the direction of draw (The axis of the
cored position (hole) or insert is parallel to the up and
down movement of the mold as it opens and closes)
are typically angled slightly (with draft) to ease
release of the part from the mold.
b) Mould Core:
Fig3b:- View of the Mold Core
Figure 4.shows the two-plate mold which are
A core is the male portion of a mould which forms
separated by one line called parting line into two
the internal shape of the moulding. Core plate is a
side, core side and cavity side.
plate or block of steel which incorporates the core .A
core shaft is the rear portion. Core pin is a circular
hardened steel pin which forms the internal shape of
the mould. A side core is a local core of mould which
is normally mounted at right angles to the mould axis
for forming a hole or recess in the side face of a
moulding. This side core prevents the in-line removal
of the moulding and some means must be provided
for withdrawing the side core prior to ejection. The
fig.3.shows the side core in the forward and the
withdrawn positions respectively
Fig4a:--A Two-Plate mold
Tooling design review encompasses things such asCore
side
content
ejector pin, core insert which is
• Heater design
moving after plastic inject into the mold and the
• Cavity & Core layout
ejection bar will push the ejector pin and the ejector
• Venting
pin then push the part out from the mold.
• Balancing of runners & Gates
Cavity side is a fixed side, not moving and content
• Parting line locking system
feed system (sprue, runner and gate). Plastic material
• Proper sizing and balancing of the Manifold
will injected from the machine nozzle into a sprue
• Gating system locations
bush and through the runner to the cavity
• Materials for Cavity/Core
For this work, the two-plate mold design was found
• Slide design
suitable.
• Mold sized for proper machine pressure.
IV) INFO OVER THE `MACHINE' FOR
• Material for mold and cavity
TRIALS (L&T DEMAG - 40TON)
Injection
molding
machines
are
typically
• Water lines
characterized by the tonnage of the clamp force they
Mold components are often designed with materials
provide. The required clamp force is determined by
of various coefficients of thermal expansion. These
the
projected area of the parts in the mold and the
factors cannot be simultaneously accounted for
pressure with which the material is injected.
without astronomical increases in the cost for design,
Therefore, a larger part will require a larger clamping
fabrication, processing, and quality monitoring. The
force. Also, certain materials that require high
skillful mold and part designer will position these
injection pressures may require higher tonnage
aesthetic detriments in hidden areas if feasible.
machines. The size of the part must also comply with
IV. TYPE OF MOLD:
other machine specifications, such as shot capacity,
a) TWO PLATE MOLD:
clamp stroke, minimum mold thickness, and platen
This kind is used for parts that are typically gated on
size. Present day moulding machines range from
or around their edge, with the runner in the same
around 15 to 4,000 metric tonnes available clamping
mold plate as the cavity.
force (150 to 4000 kN).
Two-plate mold can be divided into three category
that is cold runner, hot runner and conventional.
Int. J. Adv. Engg. Res. Studies/III/I/Oct.-Dec.,2013/77-79
Kamble et al., International Journal of Advanced Engineering Research and Studies
Injection molded parts can vary greatly in size and
therefore require these measures to cover a very large
range. As a result, injection molding machines are
designed to each accommodate a small range of this
larger spectrum of values.
Sample specifications are shown below for three
different models (Babyplast, Powerline, and Maxima)
of injection molding machine that are manufactured
by Cincinnati Milacron.
V) CONCLUSION
The trials out of the injection mold tool revealed that
the components produced are defect free. The
component is made of nylon66 (PA66) polyamide
materials have high mechanical strength and superior
resistance to wear and organic chemicals. NYLON
66 GF30 has more than doubles the strength and
stiffness of unreinforced nylons and a heat deflection
temperature which approaches its melting point.
NYLON 66 is 30% glass-fiber-reinforced nylon 66
materials whose important properties include high
tensile and flexural strength, stiffness, excellent heat
deflection temperature, and superior abrasion and
wear resistance. The Injection Molding is
advantageous in high production rates repeatable
high tolerances, low labor cost minimal scrap losses
etc.
It also has some limitations expensive equipment
investment, Potentially high running cost etc..Welldesigned part which minimizes part volume by
avoiding
thick
sections
and
maintaining
homogeneous wall thickness reduce not only the cost
of materials but also important parameter which is
machine time. By using auto-ejection, optimized
cooling control system, optimized wall thickness of
Int. J. Adv. Engg. Res. Studies/III/I/Oct.-Dec.,2013/77-79
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component and cycle time can also be reduced so that
idle time of machine can be minimized thus
improving the efficiency of production.
REFERENCES
1.
SharifahImihezri Syed Shaharuddin, Mohd.Sapuan Salit,
Edi SyamsZainudin, “A Review of the effect of Moulding
Parameters on the Performance of Polymeric Composite
Injection Moulding”, Turkish J. Eng. Env. Sci. 30, (2006)
2. Design
Solutions
Guide,
http://www.honeywell
plastics.com/
3. Technical Directory on design and tooling for plastics,
CIPET, Guindy, Chennai.
4. A Design Guide, Part and mold design, thermoplastic,
Bayer Material Science, (2000).
5. Dr.J. FazlurRahman, Mohammed Yunus, Mohammed
Irfan, T.M. TajuddinYezdani, “Optimizing the Die Design
Parameters for FRP Components Produced in Injection
Molding using Mold Flow Analysis”, Dr.J. FazlurRahman,
Mohammed
Yunus,
Mohammed
Irfan,
T.M.
TajuddinYezdani International Journal of Engineering
Research and Applications (IJERA), (2012).
6. Book on Injection mould design by R.G.W.PYE
7. http://www.bayer.com/polymers-usa
8. http://www.academia.edu/1206855/A_CADCAE_Integrated_Injection_Molding_Design_System
9. http://www.compasstech.com/visi-flow/
10. http://en.wikipedia.org/wiki/Injection_molding