Mechanical Summer Training Report

Plastic Injection Moulding Dies

Summer Training Project Report

Submitted in partial fulfillment of the requirements for the degree of

Bachelor of Technology (B.Tech)

By

Saurav Jaitly

ME/10/743

August 2012

Plastic Injection Moulding Dies

Summer Training Project Report

Submitted in partial fulfillment of the requirements for the degree of

Bachelor of Technology/Engineering (B.Tech/ B.E.)

By

Saurav Jaitly

ME/10/743

August 2012

under the Supervision of <Manager’s Name>

CERTIFICATE

This is to certify that the Project titled _ Plastic Injection Moduling Dies and submitted by Saurav Jaitly having Roll No ME/10/743 for the partial fulfillment of the requirements for the degree of Bachelor of Technology (B.Tech), embodies the bonafide work done by him/her under my supervision.

__________________________

Signature of the Manager

Place: ____________________

Date: ____________________

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 <Mana.

I am very grateful to my Project Coordinator/ Supervisor <Manager’s Name> for his/her

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.

____________________ Signature of the Student

Name: Saurav Jaitly

Date: 9th August,2012

Table of Contents

1 Introduction..................................................................................................................6

2 Feasibility Report.........................................................................................................7

3 Requirement Specification.........................................................................................22

4 Design Specification..................................................................................................33

5 Conclusion.................................................................................................................51

6 Checklist....................................................................................................................53

1 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.

Feasibility Report / ME

FEASIBILITY Report

Plastic Injection Moduling Dies

9th August,2012Saurav JaitlyME/10/743

Page 1 of 54


TABLE OF CONTENTS

1.1 Purpose 9

1.2 Scope 9

1.3 Project References 9

1.4 Acronyms and Abbreviations 9

1.5 Points of Contact 10

1.5.1 Information 11

2.1 Organizations Involved 12

2.2 Equipments 12

2.3 Performance Objectives 13

2.4 Assumptions and Constraints 14

2.5 Methodology (Basic Principle Involved) 14

2.6 Recommendation 15

3.1 Description of Design / Fabrication of Proposed System / Model 16

3.2 Time and Resource Costs 17

3.3 Rationale for Recommendations 18

4.0 Description of [Alternative Mechanism / Design of System / Model] 19

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1.0 GENERAL INFORMATION

1.1PurposePlastic 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.

1.2ScopeInjection-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.

Bryce, Douglas M. Plastic Injection Molding: Manufacturing Process Fundamentals.

SME, 1996.

Brydson, J, Plastics Materials, Butterworths 9th Ed (1999).

Callister, William D, Materials Science and Engineering: An Introduction, John Wiley

and Sons

HI *Whelan, Tony. Polymer Technology Dictionary Springer, 1994.

1.4 Acronyms and Abbreviations

Acronyms with MOLDING

Definition Language Category

AMC Advanced Molding CompoundAcronym in English

Science, Unit Measure, Chemistry, Biology, Acronym

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ASSMCAligned Short Fiber Sheet Molding Compound

Acronym in English

General, Common Abbreviation, Slang, Acronym

AMC Alkyd Molding CompoundAcronym in English

Science, Unit Measure, Chemistry, Biology, Acronym

BMC Bulk Molding CompoundAcronym in English


BMCIBulk Molding Compounds Incorporated

Acronym in English


DMC Dough Molding CompoundAcronym in English


GMVC Gentle Molding Vision CenterAcronym in English


IMM Injection Molding MachineAcronym in English


IMT Injection Molding TechnologyAcronym in English


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.

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2.0 MANAGEMENT SUMMARY

2.1Organizations Involved

Omax Auto Ltd.

2.2Equipment

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).

2.3 Performance Objectives (Efficiency)

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http://en.wikipedia.org/wiki/Machining

http://en.wikipedia.org/wiki/CNC


http://en.wikipedia.org/wiki/Electrical_discharge_machining


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.

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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.

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:

][JTTmCQ emPcool

The energy per square meter of surface area, Q, can also be considered as a function of the wall thickness, h:

]/[ 2mJTThCQ emP

The average cooling power per square meter, Pcool, is:

]/[ 2mW

t

TThCP

cooling

emPcool

The cooling time, tcooling, can be estimated using one-dimensional heat transfer as [5]:

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ce

cmcooling TT

TTht

4ln

2

2

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 of eq. (6) useful where h is measured in mm:

24 htcooling

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 polypropylene2. 0.05mm diameter used in Nylon, ABS and polycarbonate.

3. 0.10mm diameter vents for highly viscous polymers.

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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

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http://en.wiktionary.org/wiki/cavity

http://en.wikipedia.org/wiki/Sprue


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.

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

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http://en.wikipedia.org/wiki/Parting_line


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.

3.3 Rationale for Recommendations

FAULT RECOMMENDATION

1. Short shot, record

groove effect

1. Adjust feed to minimum consistent cushion

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

2. Weld line

1. Increase mould temperature

2. Increase injection speed

3. Increase melt temperature

4. Increase hold on pressure

5. Check venting

6. Relocate gate to change flow pattern

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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

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may 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.

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Requirements Specification Plastic Injection Moduling Dies

9th August,2012Saurav JaitlyME/10/743

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Table of Contents1. Revision History 24

1. 2. Approved By 25

2. Introduction 26

2.1 Purpose 26

2.2 Document Conventions 26

2.3 Reading Suggestions 26

2.4 Project Scope 26

2.5 References 27

3. Overall Description 27

3.1 Product Perspective 27

3.2 Assumptions 28

4. Equipment / Component 28

4.1 Give the of names of each Component 28

4.2 Specification of each Component 28

4.3 Material of the Component used 29

4.4 Basic Principle of Working of Component 30

4.5 Material of the Component used 30

5. Other Requirements 30

Appendix A: Glossary31

Appendix B: Analysis Models 32

Appendix C: Issues List (Optional) 32

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1.Revision History

Version Name Reason For Changes Date

1.0 Initial Revision

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2. Approved By

Approvals should be obtained from faculty/ HOD

Faculty comments : _____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

Faculty name: faculty signature

_______________________________________________________

Project coordinator project coordinator signature

_______________________________________________________

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Introduction

Purpose

Injection molding is the most commonly used manufacturing process for the fabrication of plastic parts. A wide variety of products are manufactured using injection molding, which vary greatly in their size, complexity, and application. The injection molding process requires the use of an injection molding machine, raw plastic material, and a mold.

Document Conventions

In this process, the plastic granules or pellets are poured into a machine hopper and fed into the chamber of the heating cylinder. A plunger then compresses the material, forcing it through progressively hotter zones of the heating cylinder in order to accelerate the heating of the center of the plastic mass. The torpedo may also be heated so that the plastic is heated from the inside as well as from the outside.

The material flows from the heating cylinder through a nozzle into the mold. The nozzle is the seal between the cylinder and the mold. It is used to prevent leaking of the material caused by the pressure used. The mold is held shut by the clamp end of the machine. For polystyrene, two to three tons of pressure on the clamp end of the machine is generally used for each inch of projected area of the part and runner system. The conventional plunger machine is the only type of machine that can produce a mottle-colored part.

Reading Suggestions

KPa x 0.145 = psi

MPa x 145 = psi

°C x 1.8 + 32 = °F

Liters/min x 0.2642 = Gal/min

Inches x 25.4 = mm

Flow rate = ((# of cavities) x (volume per cavity))/(injection time)

Project Scope

Injection molding is the most commonly used manufacturing process for the fabrication of plastic parts. A wide variety of products are manufactured using injection molding, which vary greatly in their size, complexity, and application. The injection molding process requires the use of an injection molding machine, raw plastic material, and a mold. The plastic is melted in the injection molding machine and then injected into the

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mold, where it cools and solidifies into the final part.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.

References

Bryce, Douglas M. Plastic Injection Molding: Manufacturing Process Fundamentals. SME, 1996.

Brydson, J, Plastics Materials, Butterworths 9th Ed (1999).

http://www.mold-mould.com/conventional-injection-molding-machine-289.html

Overall Description

Product Perspective

Plastic injection molding is a manufacturing process for producing parts from

both thermoplastic and thermosetting plastic materials. 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.[1] After a product is designed, usually by

an industrial designer or an engineer, molds are made by a moldmaker (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 .It utilizes

a ram or screw-type plunger to force molten plastic material into a mold cavity .It

produces a solid or open-ended shape that has conformed to the contour of the

moldUses thermoplastic or thermoset materials. It produces a parting line, sprue, and

gate marks. Ejector pin marks are usually present Injection molding is used to

produce thin-walled plastic parts for a wide variety of applications, one of the most

common being plastic housings. Plastic housing is a thin-walled enclosure, often

requiring many ribs andbosses on the interior. These housings are used in a variety of

products including household appliances, consumer electronics, power tools, and as

automotive dashboards. Other common thin-walled products include different types

of open containers, such as buckets. Injection molding is also used to produce several

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http://en.wikipedia.org/wiki/Sprue_(manufacturing)


http://en.wikipedia.org/wiki/Automobile

http://en.wikipedia.org/wiki/Body_panel

http://en.wikipedia.org/wiki/Aluminum

http://en.wikipedia.org/wiki/Steel

http://en.wikipedia.org/wiki/Moldmaker

http://en.wikipedia.org/wiki/Engineer

http://en.wikipedia.org/wiki/Industrial_design

http://en.wikipedia.org/wiki/Injection_molding#cite_note-0

http://en.wikipedia.org/wiki/Plastic

http://en.wikipedia.org/wiki/Thermosetting

http://en.wikipedia.org/wiki/Thermoplastic

http://en.wikipedia.org/wiki/Manufacturing



http://en.wikipedia.org/wiki/Packaging


everyday items such as toothbrushes or small plastic toys. Many medical devices,

including valves and syringes, are manufactured using injection molding as well.

Assumptions

Optimal process settings are critical to influencing the cost, quality, and productivity of

plastic injection molding. The main trouble in injection molding is to have a box of good

plastics parts contaminated with scrap. For that reason process optimization studies have

to be done and process monitoring has to take place. First article inspection of internal

and external geometry including imperfections such as porosity can be completed

using Industrial CT Scanning, a 3D x-ray technology. For external geometry verification

only a Coordinate-measuring machineor white light scanner can be used.

To have a constant filling rate in the cavity, the switch over from injection phase to the

holding phase can be made based on cavity pressure level.

Having a stable production window, the following issues are worth investigating:

Equipment / Component

Give the of names of each Component

1.Support Plate

2.Ejector Box

3.Ejector Plate

4.Ejector Retaining plate

5.Mold Core

6.Mold Cavity

7.Sprue Bush

8.Locating ring

Specification of each Component

Injection molding machines are typically characterized by the tonnage of the clamp force they provide. The required clamp force is determined by the projected area of the parts in the mold and the pressure with which the material is injected. Therefore, a larger part will require a larger clamping force. Also, certain materials that require high

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http://en.wikipedia.org/wiki/White_light_scanner

http://en.wikipedia.org/wiki/Coordinate-measuring_machine

http://en.wikipedia.org/wiki/Industrial_CT_Scanning

http://en.wikipedia.org/wiki/Porosity


injection pressures may require higher tonnage machines. The size of the part must also comply with other machine specifications, such as shot capacity, clamp stroke, minimum mold thickness,and platen size.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.

Babyplast Powerline Maxima

Clamp force (ton) 6.6 330 4400

Shot capacity (oz.) 0.13 - 0.50 8 - 34 413 – 1054

Clamp stroke (in.) 4.33 23.6 133.8

Min. mold thickness (in.) 1.18 7.9 31.5

Platen size (in.) 2.95 x 2.95 40.55 x 40.55 122.0 x 106.3

Material of the Component used

There are many types of materials that may be used in the injection molding process. Most polymers may be used, including all thermoplastics, some thermosets, and some elastomers. When these materials are used in the injection molding process, their raw form is usually small pellets or a fine powder. Also, colorants may be added in the process to control the color of the final part. The selection of a material for creating injection molded parts is not solely based upon the desired characteristics of the final part. While each material has different properties that will affect the strength and function of the final part, these properties also dictate the parameters used in processing these materials. Each material requires a different set of processing parameters in the injection molding process, including the injection temperature, injection pressure, mold temperature, ejection temperature, and cycle time.

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Basic Principle of Working of Component

The working principle of injection molding machine is similar to injection syringe, it using screw thrust injection the plasticized plastic into die cavity, after formalization take out products.

Injection molding is a cyclical process, every cycle mainly include: rated material feeding-- melt and plastication—pressure injection—mold filling and cooling --startup mould. Closed modules after remove mold parts then go ahead next cycle.

The injection molding are basic requirements of the plasticizing, injection and molding. Plasticizing is achieve and guarantee the quality of molding products, in order to meet requirements of molding, injection must have enough pressure and speed. At the same time, injection pressure high, consequently produce high pressure in die cavity, so must have enough clamping force. Thus it can be seen, injection equipment and clamping equipment key parts in injection molding machine.

Material of the Component used

The main tool of injection molding is made up cast iron or copper or HSS.

Other Requirements

Other Requirement for injection molding process is the making the mold of tool of the machine by general operation like lathe,milling,drilling,shaper or it can be done in the CNC machine.

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Appendix A: Glossary

Acceptable runner/cavity ratio: runner systems designed for high pressure drops to minimize material usage and increase frictional heating in the runner.

Additive: A substance compounded into a resin to enhance or improve certain characteristics.

Adhesive Assembly: The process of joining two or more plastic parts by means of an adhesive.

Aging: The process of, or the results of, exposure of plastics to natural or artificial environmental conditions for a prolonged period of time.

Backing Plate: A plate used as a support for the mold cavity block, guide pins, bushings, etc.

Balanced Runner: A runner system designed to place all cavities at the same distance from the sprue.

Barrel: The section of a molding machine that contains the feed screw, also the section where resin heating and mixing occurs.

Binder: A resin or other material used to hold particles together. The binder is the continuous phase in a reinforced plastic, which provides mechanical strength or ensures uniform consistency, solidification, or adhesion to a surface coating. Typical binder materials include resin, glue, gum and casein.

Clamping Plate: A plate fitted to a mold and used to fasten the mold to a platen.

Clamping Pressure: The pressure applied to the mold to keep it closed during the molding cycle.

Core: A protrusion, or set of matching protrusions, in a plastics forming mold which forms the inner surfaces of the molded articles.

Cavity: A depression, or a set of matching depressions, in a plastics-forming mold which forms the outer surfaces of the molded articles.

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Appendix B: Analysis Models

Appendix C: Issues List (Optional)

In this list the following pending decisions, information that is needed, conflicts awaiting resolution are lefted:1.making of core and cavity2.process in the CNC machine3.parts of Injection molding machine4.concept of the resins of the making component

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Plastic Injection Moduling Dies

Design Specification

Date of Submission : 9th August,2012

Submitted by: Saurav Jaitly

Roll No: ME/10/743

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Table of Contents

1. Revision History 35

2. Approved By 36

3. Introduction 37

3.1 Document Outline 38

3.2 Document Description 41

3.2.1 Introduction.......................................................................................................41

3.2.2 System Overview..............................................................................................42

4. Design Considerations 45

4.1 Assumptions and Dependencies 45

4.2 General Constraints 45

4.3 Goals and Guidelines 45

5. Design and Calculations 47

5.1 Drawing of the each Component being used 47

5.2 Design and Calculation of the Component being used 48

6. Glossary System Architecture 49

7. Bibliography 49

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1. Revision History

Version Name Reason For Changes Date

1.0 Initial Revision

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2. Approved ByApprovals should be obtained from faculty/ HODFaculty comments : _____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

Faculty name: faculty signature

_______________________________________________________

Project coordinator project coordinator signature

_______________________________________________________

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3. Introduction

Tool design & manufacturing capabilities of the group are a key to its ability to provide full system solutions. The group has collaborations with Sumitomo Wiring Systems, Japan and Center Tooling, Australia for tool design & manufacturing.

The tool rooms specialize in high precision, multi cavity, small, medium and large size tools capable of running on injection molding machines upto 3200 tonnes.

Tool manufacturing is done on state-of-the-art CNC machines. In-house proving & tryout facilities on injection molding machines are in tandem with tool manufacturing facilities.

The complete range of services from tool design to tool manufacturing and injection molding under one roof make the group a Total Tooling Solutions provider.

A successful application of an engineering thermoplastic requires more than identifying a specific product or grade. Three areas – design, product, process – are all interrelated and the appropriate rules in each area must be followed to ensure a successful application. In most cases, the process must be determined before a specific resin grade can be selected. During this review, designers also need to consider whether the process is capable of meeting the design requirements such as size, shape, detail and tolerance.

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.

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.

The electrical discharge machining (EDM) or spark erosion process has become widely

used in mold making. As well as allowing the formation of shapes that are difficult to

machine, the process allows pre-hardened molds to be shaped so that no heat treatment is

required. Changes to a hardened mold by conventional drilling and milling normally

require annealing to soften the mold, followed by heat treatment to harden it again. EDM

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http://en.wikipedia.org/wiki/Spark_erosion



http://en.wikipedia.org/wiki/CNC



http://en.wiktionary.org/wiki/cavity

http://en.wikipedia.org/wiki/Sprue


is a simple process in which a shaped electrode, usually made of copper or graphite, is

very slowly lowered onto the mold surface (over a period of many hours), which is

immersed in paraffin oil (kerosene).

3.1 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. Clamping2. Injection3. Dwelling4. Cooling5. Mold opening6. Removal of

products

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

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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 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.

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.

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http://www.polyplastics.com/en/support/mold/outline/index.html#inj3


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.

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3.2 Document Description

Utilizes a ram or screw-type plunger to force molten plastic material into a mold

cavity

Produces a solid or open-ended shape that has conformed to the contour of the

mold

Uses thermoplastic or thermoset materials

Produces a parting line, sprue, and gate marks

Ejector pin marks are usually present

3.2.1 Introduction

Purpose:

The purpose of the injection molding is used to produce thin-walled plastic parts for a wide variety of applications, one of the most common being plastic housings. Plastic housing is a thin-walled enclosure, often requiring many ribs and bosses on the interior. These housings are used in a variety of products including household appliances, consumer electronics, power tools, and as automotive dashboards. Other common thin-walled products include different types of open containers, such as buckets. Injection molding is also used to produce several everyday items such as toothbrushes or small plastic toys. Many medical devices, including valves and syringes, are manufactured using injection molding as well.

Scope:

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.

Summary:

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http://en.wikipedia.org/wiki/Sprue_(manufacturing)



There is no mystery in injection moulding of plastics. Each and every phenomenon has its scientific reasons. Since injection moulding involves Polymers, Mould and Machinery, it is necessary to understand all of them; their role and their limitations. We explore in this book –Cavity pressure profile, pvT diagram, Shear thinning of plastics, Flow mechanism- simultaneous flow and freeze of melt with skin formation and fountain flow.

We also appreciated the root cause of most of the quality problems lie with three balancing tricks in the process.

Flow balance in part, Heat balance in mould,

Uniform freezing in mould.

Moulding process in this book is not discussed in lay man's point of view but it is discussed in terms of physics of plastic melt, which is best described by pvT characteristic, shear thinning characteristic and orientation characteristic of melt.

This book provides technical perspective to the process that is relevant to understand CAE technologies. You can develop skills to visualise the happenings inside the Screw-Barrel and inside the Mould. This knowledge can help you to understand the root causes of all the quality related problems.

Very vital information are provided with figures and tables about Screw Design, Machines, Support Equipment, Service lines, Injection Moulding Process, Quality related Problems, Mould, Hot Runners, Mechanical failures in Moulds, Energy efficiency, Testing of Machines, Robot, Multi-component Moulding, Gas assisted Moulding, Thermoset Moulding, CAE, CAD, CAM Technology. A chapter on Myths and Truth clarifies the most misunderstood aspects in the industry..

3.2.2 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.

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Planning begins in preliminary design. Some will argue that consideration for manufacturing early in the program will inhibit creativity; the reality is that it does not if perspectives are kept in balance. In fact design committee often err in committing to a design that later reveals feasibility and cost issues. While designers and engineers need to be free to brainstorm potential solutions, taking time to evaluate for manufacturing options is vital to assume a successful program.

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 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.

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4. 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.

4.1 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.

4.2 General Constraints

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:

1)Correct Part Design

2)Accurate Selection of Material

3) Processing Plastic Processing

4.3 Goals and Guidelines

1 Use uniform wall thicknesses throughout the part. This will minimize sinking, warping, residual stresses, and improve mold fill and cycle times.

Wall Section Considerations Voids and Shrinkage

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http://www.efunda.com/designstandards/plastic_design/shrinkage.cfm

http://www.efunda.com/designstandards/plastic_design/wall.cfm




Warpage

2 Use generous radius at all corners. The inside corner radius should be a minimum of one material thickness.

Radius Limitations

3 Use the least thickness compliant with the process, material, or product design requirements. Using the least wall thickness for the process ensures rapid cooling, short cycle times, and minimum shot weight. All these result in the least possible part cost.

4 Design parts to facilitate easy withdrawal from the mold by providing draft (taper) in the direction of mold opening or closing.

Draft and Texture

5 Use ribs or gussets to improve part stiffness in bending. This avoids the use of thick section to achieve the same, thereby saving on part weight, material costs, and cycle time costs.

Rib Design

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http://www.efunda.com/designstandards/plastic_design/ribs.cfm

http://www.efunda.com/designstandards/plastic_design/draft.cfm

http://www.efunda.com/designstandards/plastic_design/radius.cfm

http://www.efunda.com/designstandards/plastic_design/warpage.cfm


5. Design and Calculations

5.1 Drawing of the each Component being used

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5.2 Design and Calculation of the Component being used

Injection molding machines are typically characterized by the tonnage of the clamp force they provide. The required clamp force is determined by the projected area of the parts in the mold and the pressure with which the material is injected. Therefore, a larger part will require a larger clamping force. Also, certain materials that require high injection pressures may require higher tonnage machines. The size of the part must also comply with other machine specifications, such as shot capacity, clamp stroke, minimum mold thickness, and platen size.

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.

Babyplast Powerline Maxima

Clamp force (ton) 6.6 330 4400

Shot capacity (oz.) 0.13 - 0.50 8 - 34 413 - 1054

Clamp stroke (in.) 4.33 23.6 133.8

Min. mold thickness (in.)

1.18 7.9 31.5

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Platen size (in.) 2.95 x 2.95 40.55 x 40.55 122.0 x 106.3

6. Glossary System Architecture

1. Granules of plastic powder (note the plastics listed above) are poured or fed into a hopper which stores it until it is needed.

2. A heater heats up the tube and when it reaches a high temperature a screw thread starts turning. 3. A motor turns a thread which pushes the granules along the heater section which melts then into a liquid. The liquid is forced into a mould where it cools into the shape (in this case a DVD storage unit). 4. The mould then opens and the unit is removed.

7. Bibliography

1. Injection Molding Handbook By Tim A. Osswald, Lih-Sheng Turng, Paul J. Gramann

2. http://www.cadmodels.biz/3d_cad_design_for_injection_molded_plastics.html

3. http://www.custompartnet.com/wu/InjectionMolding#cost_drivers

4. http://www.vero-software.com/products.php?page_id=1&sub_id=4

5. http://www.efunda.com/designstandards/plastic_design/plastic_intro.cfm

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http://www.efunda.com/designstandards/plastic_design/plastic_intro.cfm

http://www.vero-software.com/products.php?page_id=1&sub_id=4

http://www.custompartnet.com/wu/InjectionMolding#cost_drivers

http://www.cadmodels.biz/3d_cad_design_for_injection_molded_plastics.html


2 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.

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3 Bibliography

1. Injection Molding Handbook By Tim A. Osswald, Lih-Sheng Turng, Paul J. Gramann

6. http://www.cadmodels.biz/3d_cad_design_for_injection_molded_plastics.html

7. http://www.custompartnet.com/wu/InjectionMolding#cost_drivers

8. http://www.vero-software.com/products.php?page_id=1&sub_id=4

9. http://www.efunda.com/designstandards/plastic_design/plastic_intro.cfm

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http://www.efunda.com/designstandards/plastic_design/plastic_intro.cfm

http://www.vero-software.com/products.php?page_id=1&sub_id=4

http://www.custompartnet.com/wu/InjectionMolding#cost_drivers

http://www.cadmodels.biz/3d_cad_design_for_injection_molded_plastics.html


4 Checklist

1. Is the report properly hard/ spiral bound? Yes / No

2. Is the Cover page in proper format? Yes / No

3. Is the Title page (Inner cover page) in proper format? Yes / No

4. (a) Is the Certificate from the Company in proper format?

(b) Has it been signed by the Manager?

Yes / No

Yes / No

5. (a) Is the Acknowledgement from the Student in proper format?

(b) Has it been signed by the Student?

Yes / No

7. Does the Table of Contents include page numbers?

(i). Are the Pages numbered properly?

(ii). Are the Figures numbered properly?

(iii). Are the Tables numbered properly?

(iv). Are the Captions for the Figures and Tables proper?

(v). Are the Appendices numbered properly?

Yes / No

Yes / No

Yes / No

Yes / No

Yes / No

Yes / No

8. Is the conclusion of the Report based on discussion of the work? Yes / No

9. Are References or Bibliography given in the Report?

Have the References been cited inside the text of the Report?

Is the citation of References in proper format?

Yes / No

Yes / No

Yes / No

10. A Compact Disk (CD) containing the softcopy of the Final Report (preferably in PDF format) and a Final Project Presentation in MS power point only has been placed in a protective jacket securely fastened to the inner back cover of the

Yes / No

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Final Report. Write the name and Roll No on the CD.

Declaration by Student

I certify that I have properly verified all the items in the checklist and ensure that the report is in proper format as specified in the course handout.

Name: Saurav Jaitly

Place: Sonepat, Pallari

Date: 9th August,2012

Signature of the Student:

Verification by Faculty Project Coordinator

I have duly verified all the items in the checklist and ensured that the report is in proper format.

Name:

Place:

Date:

Signature of the Project Coordinator:

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Documents

Mechanical Summer Training Report