plastic injection molding

1. WIOSKA MOLDINGS PRIVATE
LIMITED
Industrial Area, H-132, Lohia Rd, H Block, Sector
63, Noida, Uttar Pradesh 201307
A TRAINING REPORT
SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE
AWARD OF
THE DEGREE OF
BACHELOR OF TECHNOLOGY
(MECHANICAL ENGINEERING)
SUBMITTED BY
NAME: AKHILENDRA SHUKLA
ROLL NO.: 1416140026
(01/06/2017 TO 05/07/2017)

2. Acknowledgement
This report gives the details of the project work done in six weeks summer training at the
end of Fourth semester for partial fulfillment of the requirements for the degree of
Bachelor of Technology (B.Tech), under the Supervision of R.K. Reddy.
I am very grateful to my Project Coordinator/ Supervisor Anurag Saxena for his help and
able guidance for the project. I am very thankful to my company for providing me
resources and facilities to help in the project.

3. Introduction
The Project has tried to highlight the need of Training & Development mechanism which
helps successful organization to build on their success and to generate and meet the desire
of feedback.
The organization is its viability, and hence its efficiency, there is continuous
environmental pressure for efficiency and if the organization does not respond to this
pressure it may find itself rapidly losing whatever share of the market it has. Employee
training, therefore, imparts specific skills and knowledge to employee in order that they
contribute the organization’s efficiency and be able to cope with the pressure of changing
environment.
Employee training tries to improve skills, or add to the existing level of knowledge so
that the employee is letter equipped to his present job, or to prepare him for a higher
position with increased responsibilities.
The effective functioning of any organization requires that employees learn to perform
their jobs at satisfactory level of proficiency, So much that the organizations need to
provide opportunities for the continuous development of employees not only in their
present jobs, but also to develop their capabilities for other jobs for which they later be
considered.
Training is the act of increasing the knowledge and skill of an employee for doing a
particular job. Training will provide for an output in this decision. The positive benefits
of Training are:
· Training helps employees to learn their jobs and attain desired levels of
performance especially thus contributing better utilization of employees,
machines and materials.
· Training helps to reduce the cost of raw materials and products –reducing losses
due to waste, poor quality products and damage to machinery –which would
result if an untrained employee, were to learn on his own.
· Finally, training aids in the development of individual skills, better methods, new
equipment and new work relationship. Such a process would also facilitate
technological change by updating the versatility of employees.

4. TABLE OF CONTENTS
Introduction.....................................................................................................................................................................................
6
1.Revision History.........................................................................................................................................................................
9
2. Approved By........................................................................................................................................................................... 10
Introduction.................................................................................................................................................................................. 11
Overall Description.................................................................................................................................................................... 12
Equipment / Component............................................................................................................................................................ 13
Other Requirements.................................................................................................................................................................... 15
18
1. Revision History...................................................................................................................................................................... 20
2. Approved By........................................................................................................................................................................... 21
3. Introduction ............................................................................................................................................................................ 22
4. Design Considerations.......................................................................................................................................................... 30
5. Design and Calculations........................................................................................................................................................ 32
6. Glossary System Architecture ............................................................................................................................................. 34
7. Bibliography............................................................................................................................................................................ 34
1. Injection Molding Handbook By Tim A. Osswald, Lih-Sheng Turng, Paul J. Gramann .......................................... 34
1 Conclusion................................................................................................................................................................................. 35
I hereby conclude that we have submitted all the documents related to our project in the correct
format as specified....................................................................................................................................................................... 35
We conclude that our project is a simple project for now as it works according to the user. We
have been implementing iterative server, and later on it can be extended to become concurrent
server. It is easier for the programmer to use the code and understand the functionality............................................... 35
2 Bibliography .............................................................................................................................................................................. 36
1. Injection Molding Handbook By Tim A. Osswald, Lih-Sheng Turng, Paul J. Gramann .......................................... 36
3 Checklist..................................................................................................................................................................................... 37

5. 1.0 GENERAL INFORMATION
1.1 Purpose
Plastic has become the 'all-purpose' material. From packaging, plastic plants, domestic items,
containers, pipes to automobile parts, the plastic industry has come a long way from its small
beginnings about a hundred years ago. Some of the processes involved in plastic technology are
compression, moulding, lamination, fabrication etc. Injection moulding and blow moulding are
the commonly used processes.
1.2 Scope
Injection-moulded plastic parts are part and parcel of everyday life. Be they mobile phone
casings, beverage crates, toy figures, gearwheels for adjustment mechanisms, bumpers on cars,
drinking cups, CDs and DVDs, or syringe bodies in medical technology, injection mouldings are
encountered everywhere in all sizes, ranging from a few micrograms to several kilograms.
Uniting several components in a single injection moulding, integrating as many functions as
possible in a single component, and converting production methods comprising several steps into
a single-stage process – these are the chief innovation goals in the injection moulding sector.
1.3 Project References
Engage polyolefin elastomers have a wide processing temperature window. The following
temperatures should be used as a reference point and can vary±5°C. These temperatures should
be usedas a starting point and can be increased by a maximum of +20°C.Note: From starting
point, the hopper feed throat should be cooled below 50°C to avoid polymer bridging, especially
on Engage®8400/Engage® 8407.Successful injection molding of Engage® requires fast
injection velocities to promote shear thinning throughout the material. Typical polyolefin
equipment should be used.

6. 1.4 Acronyms and Abbreviations
GMVC Gentle Molding Vision Center
IMM Injection Molding Machine
IMT Injection Molding Technology
Acronyms with
Definition
MOLDING
AMC Advanced Molding Compound
ASSMC
Aligned Short Fiber
Molding Compound
AMC Alkyd Molding Compound
BMC Bulk Molding Compound
BMCI
Bulk Molding
Incorporated
DMC Dough Molding Compound

7. 1.5 Points of Contact
1.5.1 Information
I’ll take the help from the company.With the help of several machines like
lathe,milling,drilling,shaper etc. or even CNC machine,we used for making the core and cavity
of the sample and these two dies(core and cavity) goes for surface finish.Now,the core and cavity
will fitted together with support plate on their either sides,the complete die will subjected to the
injection moulding machine where the raw granular plastic will suffers through the heater and
the molten plastic will subjected to the middle of the core and cavity through a hole called sprue
bush on a mold core and the clamping opened the die eject the product and finally the product
will thermalised and sintered to form the finalized product.

8. 2.0 MANAGEMENT SUMMARY
2.1 Organizations Involved
Omax Auto Ltd.
2.2 Equipment
Injection molding machines consist of a material hopper, an injection ram or screw-type plunger,
and a heating unit. They are also known as presses, they hold the molds in which the components
are shaped. Presses are rated by tonnage, which expresses the amount of clamping force that the
machine can exert. This force keeps the mold closed during the injection process. Tonnage can
vary from less than 5 tons to 6000 tons, with the higher figures used in comparatively few
manufacturing operations. The total clamp force needed is determined by the projected area of
the part being molded. This projected area is multiplied by a clamp force of from 2 to 8 tons for
each square inch of the projected areas.
Molds are built through two main methods: standard machining and EDM. Standard
machining, in its conventional form, has historically been the method of building injection
molds. With technological development, CNC machining became the predominant means of
making more complex molds with more accurate mold details in less time than traditional
methods.
General Machines which are used in the company
are:lathe,milling,shaper,slotting,drilling and CNC(sanco sdm 2214) and CNC(cosmos cmo
1060).

9. 2.3 Performance Objectives (Efficiency)
If we use cast iron material for a making of any plastic mold,we generally use CNC machines for
making the core and cavity of any component. Other than if we uses different operation in
different machines like lathe,drilling,milling,boring etc.,it takes more time than the CNC
machine, which will reduced in time and processing speed, and increases productivity and staff
.On the other hand the CNC m/c will takes less time and higher processing speed and totally
control over automated decision making. The CNC m/c reduces staff.So,the efficiency of the
CNC m/c is higher than the different operation of machines.
The performance of conventional molding processes are governed by these physics, with
significant trade-offs required in the design of the part geometry, molding process, and
polymeric materials. For instance, a light product may require thin walls. However, the filling of
such a thin-walled product may require very high injection pressures and a lower viscosity resin.

10. 2.4 Assumptions and Constraints
Plastics injection molding is perceived by many as a mature technology. However, many
performance constraints in plastics injection molding still exist that prevent the development and
manufacture of higher performance products at lower cost. A primary issue is not whether these
performance constraints can be overcome, but rather which performance constraints should be
overcome. With respect to control of the melt temperature in plastics injection molding, this
paper
has provided analytical, experimental, and economic proof of feasibility. This analysis provides
convincing argument that control of melt temperature should be overcome and beneficially
utilized
in many commercial applications. Determine the assumptions and constraints, such as
operational
life of the proposed system; period of time for comparison of system alternatives; input, output,
and processing requirements; financial constraints; changing hardware, software, and operating
environment; and availability of information and resources.

11. 2.5 Methodology (Basic Principle involved)
The method used for the making any plastic object by injection molding process are:
First.the plastic matter should filled to the IMM from the top and the matter will heated in the
m/c which is filled to the tool and after the product will ejected through the tool .the cooling
process will be:
Cooling: Once the plastic melt at the gate solidifies, no additional material can be forced into the
cavity and the pressure decays. The amount of energy to be removed, Qcool , required to cool the
polymer melt is related to the change from the melt temperature, Tm, to the ejection temperature,
Te, the heat capacity of the plastic melt, CP, and its mass, m:
Qcool  CP  m  Tm  Te  [J ]
The energy per square meter of surface area, Q, can also be considered as a function of the wall
thickness, h:
Q  CP    h  Tm Te  [J / m2
]
The average cooling power per square meter, Pcool, is:
P 
C
P
h  T
m
T
e

[W / m2 ]
cool
tcooling
The cooling time, tcooling, can be estimated using one-dimensional heat transfer as
h2   Tm Tc 
t  ln

 
2 4 Tcoolin g  T
 
  e c 
where is the thermal diffusivity and Tc is the mold coolant temperature. It should be noted that
for many materials and processing conditions, molders have found the following approximation
o eq. (6) useful where h is measured in mm:
tcooling  4  h2

12. 2.6 Recommendation
- Verify the temperature of the mold cavities using a temperature probe.
- Confirm the melt temperature using a temperature probe moved about in a volume of melt, shot
onto an insulator (a glove, cardboard, etc.)
- Set the initial cooling time
- Set a zero hold time and/or pressure
- Inject incomplete parts by gradually increasing the shot volume using an average to high
injection speed.
- When the mold is almost filled (90 to 95%), set the initial hold pressure and gradually increase
the hold time.
- In this way, the end of the filling is done under constant pressure and part over-packing is
avoided.
- Adjust the hold phase parameters to obtain a constant part weight and the required dimensional
stability.
- The cooling time depends on the part geometry.
- Gradually adjust the cooling time until the optimal cycle time is obtained.
The variety of plugs offered fit a wide spectrum of polymer needs. Vent diameter should be
chosen to correspond to these needs. Examples are listed below.
1. 0.03mm diameter for use with polyethylene and polypropylene
2. 0.05mm diameter used in Nylon, ABS and polycarbonate.
3. 0.10mm diameter vents for highly viscous polymers.

13. 3.0 PROPOSED SYSTEM
3.1 Description of Design / Fabrication of the Proposed System /
Model
The mold consists of two primary components, the injection mold (A plate) and the ejector mold
(B plate). 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
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.
The amount of resin required to fill the sprue, runner and cavities of a mold is a shot. Trapped
air in the mold can escape through air vents that are ground into the parting line of the mold. If
the trapped air is not allowed to escape, it is compressed by the pressure of the incoming
material and is squeezed into the corners of the cavity, where it prevents filling and causes other
defects as well. The air can become so compressed that it ignites and burns the surrounding
plastic material. To allow for removal of the molded part from the mold, the mold features must
not overhang one another in the direction that the mold opens, unless parts of the mold are
designed to move from between such overhangs when the mold opens (utilizing components
called Lifters).
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

14. typically angled slightly with (draft) to ease release of the part from the mold. Insufficient draft
can cause deformation or damage. The draft required for mold release is primarily dependent on
the depth of the cavity: the deeper the cavity, the more draft necessary. Shrinkage must also be
taken into account when determining the draft required. If the skin is too thin, then the molded
part will tend to shrink onto the cores that form them while cooling, and cling to those cores or
part may warp, twist, blister or crack when the cavity is pulled away. The mold is usually
designed so that the molded part reliably remains on the ejector (B) side of the mold when it
opens, and draws the runner and the sprue out of the (A) side along with the parts. The part then
falls freely when ejected from the (B) side. Tunnel gates, also known as submarine or mold
gates, are located below the parting line or mold surface. An opening is machined into the
surface of the mold on
the parting line. The molded part is cut (by the mold) from the runner system on ejection from
the mold.Ejector pins, also known as knockout pins, are circular pins placed in either half of the
mold (usually the ejector half), which push the finished molded product, or runner system out of
a mold.

15. 3.2 Time and Resource Costs
The cost of manufacturing molds depends on a very large set of factors ranging from number of
cavities, size of the parts (and therefore the mold), complexity of the pieces, expected tool
longevity, surface finishes and many others. The initial cost is great, however the piece part cost
is low, so with greater quantities the overall price decreases.
The tooling cost has two main components - the mold base and the machining of the cavities.
The cost of the mold base is primarily controlled by the size of the part's envelope. A larger
part requires a larger, more expensive, mold base. The cost of machining the cavities is
affected by nearly every aspect of the part's geometry. The primary cost driver is the size of
the cavity that must be machined, measured by the projected area of the cavity (equal to the
projected area of the part and projected holes) and its depth. Any other elements that will
require additional machining time will add to the cost, including the feature count, parting
surface, side-cores, lifters, unscrewing devices, tolerance, and surface roughness.

16. 3.3 Rationale for Recommendations
FAULT RECOMMENDATION
1. Short shot, record 1. Adjust feed to minimum consistent cushion
groove effect 2. Increase injection pressure
3. Increase injection speed
4. Increase back pressure
5. Increase barrel temperatures
6. Increase mould temperature, particularly for
very
thin large area parts
7. Check non-return valve
8. Improve venting
9. Enlarge gates, sprue diameters and runners
1. Increase mould temperature
2. Weld line 2. Increase injection speed
3. Increase melt temperature
4. Increase hold on pressure
5. Check venting
6. Relocate gate to change flow pattern

17. 4.0 Alternative Mechanism/ Design
A program begins with a need - either an improvement on something already in
existence, or a unique way of fulfilling a need. The initial idea may start as a sketch or
as a model. The next step is to put the idea into a workable form and to determine how
it will be manufactured and the cost to manufacture it.
With competitive pressures demanding maximum efficiency from every facet of a
company's operations, designers and engineers are faced with the increasingly difficult
task of developing a product which not only meets the functional requirements of the
application, but a product which can be produced in the most cost effective manner. Add
to this challenge the ever-increasing number of government regulations, new materials,
and improved manufacturing processes, and the task of designing even a "simple" pan is
no longer simple. The path becomes more complicated.
4.0 Description of [Alternative Mechanism / Design]
The process cycle for injection molding is very short, typically between 2 seconds and 2
minutes, and consists of the following four stages:
1. Clamping - Prior to the injection of the material into the mold, the two halves of
the mold must first be securely closed by the clamping unit. Each half of the mold is
attached to the injection molding machine and one half is allowed to slide. The
hydraulically powered clamping unit pushes the mold halves together and exerts
sufficient force to keep the mold securely closed while the material is injected. The
time required to close and clamp the mold is dependent upon the machine - larger
machines (those with greaterclamping forces) will require more time. This time can
be estimated from the dry cycle time of the machine.
2. Injection - The raw plastic material, usually in the form of pellets, is fed into the
injection molding machine, and advanced towards the mold by the injection unit.
During this process, the material is melted by heat and pressure. The molten plastic is
then injected into the mold very quickly and the buildup of pressure packs and holds
the material. The amount of material that is injected is referred to as the shot. The
injection time is difficult to calculate accurately due to the complex and changing
flow of the molten plastic into the mold. However, the injection time can be
estimated by the shot volume, injection pressure, and injection power.
3. Cooling - The molten plastic that is inside the mold begins to cool as soon as it
makes contact with the interior mold surfaces. As the plastic cools, it will solidify
into the shape of the desired part. However, during cooling some shrinkage of the
part may

18. occur. The packing of material in the injection stage allows additional material to
flow into the mold and reduce the amount of visible shrinkage. The mold can not be
opened until the required cooling time has elapsed. The cooling time can be estimated
from several thermodynamic properties of the plastic and the maximum wall
thickness of the part.
4. Ejection - After sufficient time has passed, the cooled part may be ejected from the
mold by the ejection system, which is attached to the rear half of the mold. When the
mold is opened, a mechanism is used to push the part out of the mold. Force must be
applied to eject the part because during cooling the part shrinks and adheres to the
mold. In order to facilitate the ejection of the part, a mold release agent can be
sprayed onto the surfaces of the mold cavity prior to injection of the material. The
time that is required to open the mold and eject the part can be estimated from the dry
cycle time of the machine and should include time for the part to fall free of the mold.
Once the part is ejected, the mold can be clamped shut for the next shot to be
injected.
After the injection molding cycle, some post processing is typically required. During
cooling, the material in the channels of the mold will solidify attached to the part. This
excess material, along with any flash that has occurred, must be trimmed from the part,
typically by using cutters. For some types of material, such as thermoplastics, the scrap
material that results from this trimming can be recycled by being placed into a plastic
grinder, also called regrind machines or granulators, which regrinds the scrap material
into pellets. Due to some degradation of the material properties, the regrind must be
mixed with raw material in the proper regrind ratio to be reused in the injection molding
process.

19. Document Outline
1.What is injection molding ?
Injection molding is a method to obtain molded products by injecting plastic materials
molten by heat into a mold, and then cooling and solidifying them.
The method is suitable for the mass production of products with complicated shapes, and
takes a large part in the area of plastic processing.
The process of injection molding is divided into 6 major steps as shown below.
1. Clamping
2. Injection
3. Dwelling
4. Cooling
5. Mold opening
The process is proceeded as shown above and products can be made successively by
repeating the cycle.
2. Injection molding machine
Injection molding machine is divided into 2 units i.e. a clamping unit and an injection unit.
The functions of the clamping unit are opening and closing a die, and the ejection of products.
There are 2 types of clamping methods, namely the toggle type shown in the figure below and
the straight-hydraulic type in which a mold is directly opened and closed with a hydraulic
cylinder.
The functions of the injection unit are to melt plastic by heat and then to inject molten
plastic into a mold.
The screw is rotated to melt plastic introduced from the hopper and to accumulate molten
plastic in front of the screw ( to be called metering ) . After the required amount of molten
plastic is accumulated, injection process is stared.
While molten plastic is flowing in a mold, the machine controls the moving speed of the

20. screw, or injection speed. On the other hand, it controls dwell pressure after molten plastic fills
out cavities.
The position of change from speed control to pressure control is set at the point where
either screw position or injection pressure reaches a certain fixed value.

21. 3. Mold
A mold is a hollow metal block into which molten plastic is injected to from a certain fixed
shape. Although they are not illustrated in the figure shown below, actually there are many holes
drilled in the block for temperature control by means of hot water, oil or heaters.
Molten plastic flows into a mold through a sprue and fills cavities by way of runners and gates.
Then, the mold is opened after cooling process and the ejector rod of the injection molding
machine pushes the ejector plate of the mold to further eject moldings

22. 4. Molding
A molding consists of a sprue to introduce molten resin, a runner to lead it to cavities, and
products. Since obtaining only one product by one shot is very inefficient, a mold is usually
designed to have multiple cavities connected with a runner so that many products can be made
by one shot.
If the length of the runner to each cavity is different in this case, the cavities may not be filled
simultaneously, so that dimensions, appearances or properties of the moldings are often different
cavity by cavity. Therefore the runner is usually designed so as to have the same length from the
sprue to each cavity.

23. System Overview
Injection molding of plastics is one of the most cost effective processes for manufacture of parts
in volume. While mold costs can be significant, amortization over many parts can make the
overall cost of injection molding highly competitive with other manufacturing processes. The
wide range of available polymers multiplied by the huge array of specific blends offer a
tremendous range of physical, thermal, electrical, and chemical properties. Engineering plastics,
classified by mechanical properties such as stiffness, toughness, and low creep, increasingly
replace metals on a cost and performance evaluation.
Designing for injection molded plastics requires planning. Too often parts will be presented to a
molder or tool designer late in the product development process only to be confronted with
feasibility issues. If that happens the developer faces decisions to rework part designs or to face
higher tooling and part costs. Leaving design for manufacturing and assembly (DMFA)
considerations until late in the development program is a common mistake the misses out on
optimization and disrupts the transition to manufacturing.
Design concept modeling is a vital step in preliminary product design. Form and function can be
evaluated in blocked-out quick CAD studies. Drawings produced from 3D CAD model studies
can help evaluate the size, cost, and architecture of a proposed design. Multiple preliminary
model studies are a good use of time because many factors can be evaluated after a few hours of
work. Such studies can include component packaging, part break out, and overall size and
weight. Concept parts can be submitted for preliminary price quotations. DMFA (design for
manufacturing and assembly) has become a hot buzz word in product development the truth is
that consumer products manufacturers have been doing DMFA for decades as a means of
competitive survival.
Injection molding is particularly advantageous for assemblies wherein components can be
mounted using ribs and bosses inside the shell of the parts allowing to easy assembly most
commonly using screws, push nuts, snap latches, or heat staking. Components are commonly
captured between two shells. Consideration for assembly procedure in part design is critical to
reducing cost and boosting assembly line yields. In many industries, cost competitiveness is key
factor in market success. Secondary assembly operations can include sonic insertion of threaded
fasteners and plastic welding operations such as thermal welding, ultra-sonic welding, spin
welding, vibration and laser welding.
Consumer product industries were the first to focus on aesthetics for competitive advantage
wherein one product would out-sell another primarily because of form and function. The field of
Industrial Design sprung up wherein artistic individuals entered into product design realm bring

24. their drawing, rendering, model sculpting skills and aesthetic sensibilities into the product
development process. Early pioneer Raymond Loewy in the 1930s came from the fashion
industry and proved to be a fastidious designer with great attention of detail and construction.
Solid modeling CAD systems offer powerful 3D (three dimension) surface modeling capabilities
that can satisfy high expectations for appearance in the field of Industrial Design. Surface
modeling provides the tools to capture complex surface geometries for seamless data transfer to
machine tooling operations for injection molding. CAD data is captured electronically and
interpreted by CAM (computer-aided-machine) operations. CAM software programs define
specific cutter tool paths for efficient and accurate cutting of mold cores and cavities.
CAD/CAM processes can capture virtually any surface configuration that a designer envisions.
CAM data is used for CNC (computer-numerical-control), EDM (electro-discharge-machining or
spark erosion) and wire EDM cutting methods.

25. Design Considerations
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. [5] Some advantages of
injection molding are high production rates, repeatable high tolerances, the ability to use a wide
range of materials, low labor cost, minimal scrap losses, and little need to finish parts after
molding. Some disadvantages of this process are expensive equipment investment, potentially
high running costs, and the need to design moldable parts.
Assumptions and Dependencies
Injection molding is particularly advantageous for assemblies wherein components can be
mounted using ribs and bosses inside the shell of the parts allowing to easy assembly most
commonly using screws, push nuts, snap latches, or heat staking. Components are commonly
captured between two shells. Consideration for assembly procedure in part design is critical to
reducing cost and boosting assembly line yields. In many industries, cost competitiveness is key
factor in market success. Secondary assembly operations can include sonic insertion of threaded
fasteners and plastic welding operations such as thermal welding, ultra-sonic welding, spin
welding, vibration and laser welding.

26. Conclusion
I hereby conclude that we have submitted all the documents related to our project in the
correct format as specified.
We conclude that our project is a simple project for now as it works according to the user.
We have been implementing iterative server, and later on it can be extended to become
concurrent server. It is easier for the programmer to use the code and understand the
functionality.

27. Bibliography
Injection Molding Handbook By Tim A. Osswald, Lih-Sheng Turng, Paul J.
Gramann
http://www.cadmodels.biz/3d_cad_design_for_injection_molded_plastics.html
http://www.custompartnet.com/wu/InjectionMolding#cost_drivers
http://www.vero-software.com/products.php?page_id=1&sub_id=4
http://www.efunda.com/designstandards/plastic_design/plastic_intro.cfm

28. 9’’’’’’’’