Advance Manu Hadrami Comp.docx

FACULTY OF MECHANICAL ENGINEERING, UNIVERSITI TECHNOLOGI MARA (UITM)

LABORATORY REPORT Program Course Course Code Laboratory Name Lecturer Name Title of Experiment Group

: : : : : : :

Bachelor of Mechanical Engineering (Hons) (EM220) Manufacturing Processes Laboratory MEM564 Advanced Manufacturing MOHAMAD FIRHAD MORNI Advanced Manufacturing (Product Quality) EMD5M15

No Student Name . 1. Muhd hadrami hamdan

2015135647

2.

Muhd faridzwan bin rosli

2014439412

3.

Mohd fadzil bin yaacob

2014246234

4.

Muhd hariz bin rahmat

2015115263

5.

Muhd ammar bin abdul rahman

2015166041

Date of Practical Session

Student ID Number

Signature

Staff Certification (Signature)

12-MAY-2017 Date of Report Submission 19-MAY-2017

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Staff Certification (Signature)

LABORATORY REPORT CONTENTS General Guidelines: LEVEL Lemah (Weak) Scale 1,2

Sederhana (Marginal) 3,4 Page No:

Memuaskan (Satisfactory) 5,6 Marks Allocated

Marks Obtained

Baik (Good) 7,8 CO Achieveme nt

FRONT COVER GRADING FORM CONTENTS

Page 3

1.0 Title

Page 4 Page 4

2.0 Objective(s) 3.0 Introduction (background and theory)

Page 4-7 Page 7-8

4. 0 Apparatus Page 9 4. 1 Industrial Apparatus 5.0 Experimental Procedure

Page 1011

___ x 1 10 ___ x 4 10 ___ x 10 10 ___ x 7 10 ___ x 3 10 ___ x 15 10 ___ x 17 10

6.0 Results & Data Analysis Page 12 7.0 Discussion of Results

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8.0 Conclusion

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9.0 Recommendation

___ x 5 10

10.0 References

___ x 10 10

11.0 Overall Report

___ x 5 10

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CO1 (Total Marks:40)

CO4 (Total Marks:60)

Cemerlang (Excellent) 9,10 Remarks

TABLE OF CONTENT NO

CONTENT

PAGE

1.0

TITLE

4

2.0

OBJECTIVE

4

3.0

INTRODUCTION

4

3.1 INJECTION MOLDING BACKGROUND

4-5 6-7

3.2 INJECTION MOLDING THEORY 4.0

APPARATUS

4.1

INDUSTRIAL APPARATUS

5.0

PROCEDURE

10-11

6.0

DISCUSSION

12-8

8.0

REFERENCES

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7-8 9

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1.0 TITLE ADVANCED MANUFACTURING (injection molding) 2.0 OBJECTIVES 1) To learn processing techniques associated with injection molding. 3.0 INTRODUCTION Injection molding is a process of shaping plastic by melting it and injecting it into a predesigned mold. The process was first designed in the 1930s and was originally based on metal die casting designs. It offers many advantages to alternative manufacturing methods, including minimal losses from scrap (since scrap pieces can be melted and recycled), and minimal finishing requirements. This process differs from metal die casting in that molten metals can simply be poured; plastic resins must be injected with force. The process uses large injection molding machines, which advance the resins through six major processes to produce everything from computer parts to plastic Halloween spiders. Although this machine is a complex piece of equipment, it consists of two basic elements: the injection unit and the clamping unit. Injection molds themselves can be surprisingly expensive,. If the desired part quantity is great enough, however, the mold cost becomes relatively insignificant, and the resulting plastic parts are very reasonably priced. This method of molding can be used with a variety of plastic resins. The most popular resins for this type of molding include polypropylene (PP), polyethylene (PE), and ABS.

3.1 INJECTION MOLDING BACKGROUD Plastic injection molding is the process of heating raw material (plastic resin in pellet form, in our case) to its melting point, forcing the viscous material into a mold, and allowing it to cool into a hardened shape. Injection molding is one of the prime processes for producing plastics. It is a fast process and is used to produce large numbers of identical items from high precision engineering components to disposable consumer goods. Injection molding produce all plastics products from micro parts to large components such as bumpers and wheelie bins. The flexibility in size and shape possible through use of this process have consistently 4 | Page

extended the boundaries of design in plastics and enabled significant replacement of [3] traditional materials thanks to light weighting and design freedom .

The machine works such that the material is introduced into the injection molding machine via a hopper. The injection molding machine consists of a heated barrel equipped with a reciprocating screw which driven by a hydraulic or electric motor and feeds the molten polymer into a temperature controlled split mound via a channel system of gates and runners .

A parting line, sprue, gate marks, and ejector pin marks are usually present on the final part. None of these features are typically desired, but are unavoidable due to the nature of the process. Gate marks occur at the gate which joins the melt-delivery channels (sprue and runner) to the part of forming. In spite of the relatively expensive tooling cost, injection molding remains the most popular manufacturing process for plastic materials in mass production, thanks to its low operational cost, high throughput, and the flexibility to make parts with complex shapes.Polymers commonly used for injection molding include       

Polystyrene (PS) Acrylonitrile Butadiene Styrene (ABS) Polyamide (PA) Polypropylene (PP) Polyethylene (PE) Polyvinylchloride (PVC) Other short fiber reinforced plastics

Figure 3.1 : Injection moulding Parting line and ejector pin marks result from minute misalignments, wear, gaseous vents, clearances for adjacent parts in relative motion, and/or dimensional differences of the mating surfaces contacting the injected polymer. Dimensional differences can be attributed to non-uniform, pressure-induced deformation during injection, machining tolerances, and nonuniform thermal expansion and contraction of mold components, which experience rapid 5 | Page

cycling during the injection, packing, cooling, and ejection phases of the process. Mold components are often designed with materials of various coefficients of thermal expansion

[6 ]

.

These factors cannot be simultaneously accounted for without astronomical increases in the cost of design, fabrication, processing, and quality monitoring. The skillful mold and part designer will position these aesthetic detriments in hidden areas if feasible. Injection molding uses a ram or screw-type plunger to force molten plastic material into mold cavity and it solidifies into a shape that has conformed to the contour of the mold. It is most commonly used to process both thermoplastic and thermosetting polymers, with the former being considerably more prolific in terms of annual material volumes processes 3.2 INJECTION MOLDING THEORY As for the injection molding machine, several types such as plunger type, plunger preplasticating type, screw preplasticating type and in-line screw type, etc. have been developed so far, but presently the in-line screw type injection molding machine as shown in Figure has become the main type.

Figure 3.2 : Theory of the in-line screw type injection molding machine In injection moulding, a plastic is heated to a molten state and then forcefully pushed through a nozzle into a heated mold, typically made of stainless steel (though the ones used in this lab are aluminum). The plastic enters the mold through the sprue, then through runners which distribute the molten plastic evenly to all cavities in the mold. The mold cavity is connected to the runners via a gate .These extra pieces may be later removed, chopped up and recycled back into the machine (called regrind). The mold is used to create the desired resulting part shape and may consist of two or even three pieces.

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The two types of injection molding typically used are screw plunger and plunger. In either case, the plastic, usually in the form of pellets, is fed in through a hopper in the top of the barrel and melted in the barrel. It is next forced into mold through the heated barrel.In the screw plunger method, the faster of the two methods (Figure 4-a), a screw is used to evenly distribute the heat to the plastic pellets, causing them to melt more quickly. The screw can also be used to mix in any additives that could cause the polymer to change color.

4.0 Apparatus 1. 2. 3. 4. 5. 6. 7.

Injection Molding Machine Green Pigment. Machine to recycle the green pigment. Chamber for producing product Hopper. Control Unit Mold.

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.

Figure 4.1: Green Pigment

Figure 4.2: Machine to recycle the green pigment

Figure 4. 3: Chamber for producing product

Figure 4.5: Control Unit

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Figure 4.4: Hopper

Figure 4.6 : Mold

4.1 Industrial Apparatus

Figure 4.1.1: Injection Moulding Machine

Figure 4.1.2 : CW Engineering injection moulding machine Advantage: 

Automated injection molding



Automated, computer aided insert molding



Wide selection of materials such as nylon, polycarbonate, LCP, polyester.



Customized Designs

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5.0- EXPERIMENTAL PROCEDURE 1. The injection moulding machine is set up at the required temperature and pressure by control unit.

Figure 5.1 Control Unit 2. Two cups of white beads were mixed together with the colour pigments. 3. The green pigments are used and weighed by 10% from the amount of high impact polystyrene by using weighing scale. 4. The high impact of polystyrene and the green pigments are mixed and stirred. 5. After the temperature and pressure of the machine have reached at the desirable scale, the excess materials that have been used before is removed. 6. All the mixture of the plastic pallet is poured into hopper. 7. The safety door is closed before starting the process.

Figure 5.2:Safety Door 8. The machine is ran the process of clamping, injection, cooling and ejection.

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Figure 5.3: Molding 9.

The safety door is opened as the final product taken.

Figure 5.4: Final product Injection Molding Product: Gate Runn er

Spru e

Figure 5.5 : final product.

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GROUP 2 A INDIVIDUAL DISCUSSION

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Discussion

Muhd

Hadrami Hamdan

2015135647 1. Based on June 2016 manufacturing question number 4 (C,D). c. With aid of sketches , describe the operation of making drinking plastic bottle? 1. plastic is forced into the mold is by inject injection molding into a parison, 2. blow molding filling the plastic with air then taking shape of mold . shape.

d.Select and state 4 defects and their causes that normally occurred during plastic injection molding?

1. Flow Lines: commonly off-toned in color, caused by the varying speed at which the molten plastic flows as it changes direction through the contours and bends inside the mold tool. 2. Sink Marks: Rapid cooling of plastic into mold therefor plastic solidify rapidly and not filling the mold shape 3. Vacuum Voids: are pockets of air trapped within or close to the surface of an injection molded prototype. 4. Surface Delamination: pockets of air trapped within or close to the surface of an injection molded prototype. Caused by uneven solidification between the surface and the inner sections of the prototype. 5. Weld Lines : a line that appears in a part where molten plastics meet each other as they flow from two different parts of the mold. 6. Short Shots 13 | P a g e

7. Warping

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MUHD HADRAMI HAMDAN TYPE OF DEFECTS Sink Marks Sink marks are small craters or depressions that develop in thicker areas of the injection molded prototype when shrinkage occurs in the inner portions of the finished product. Vacuum Voids

2015135647 CAUSE OF DEFECT when the cooling time or the cooling mechanism is insufficient for the plastic to fully cool and cure while in the mold. They can also be caused by inadequate pressure in the cavity, or by an excessive temperature at the gate.

Vacuum voids are often caused by uneven solidification between the surface and the inner sections of the prototype

1.Locate the gate at the thickest part of the molding. 2.Switch to a less viscous plastic. This will ensure that less gas is trapped as air is able to escape more rapidly. 3.Increase holding pressure as well as holding time.

Foreign materials that find their way into the molten plastic separate from the finished product because the contaminant and the plastic cannot bond. The fact that they cannot bond not only has an affect on the appearance of the prototype, but also on its strength.

1.Pre-dry the plastic properly before molding. 2.Increase the mold temperature. 3.Smooth out the corners and sharp turns in the mold design to avoid sudden changes in melt flow.

Incorrect calibration of the shot or plasticizing capacities can result in the plastic material being inadequate to fill the cavities. If the plastic is too viscous, it may solidify before fully occupying all the cavities and result in a short shot. Inadequate degassing or gas venting techniques can also result in short shots because air is trapped and has no way to escape.

1.Select a less viscous plastic with higher flowability. This plastic will fill the hardest-toreach cavities. 2.Increase mold or melt temperature so as to increase flowability. 3.Account for gas generation by designing the mold so that gas is not trapped within the mold and is properly vented.

Vacuum voids are pockets of air trapped within or close to the surface of an injection molded prototype. Surface Delamination

Surface delamination is a condition where thin surface layers appear on the part due to a contaminant material. Short Shot a molding shot falls short. This means that the molten plastic for some reason does not fully occupy the mold cavity or cavities, resulting in a portion where there is no plastic. The finished product becomes deficient because it is incomplete.

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OVERCOME 1.Mold temperatures should be lowered, holding pressure increased, and holding time prolonged to allow for more adequate cooling and curing. 2.Reducing the thickness of the thickest wall sections will also ensure faster cooling and help reduce the likelihood of sink marks.

2014246234 MOHD FADZIL BIN YAACOB Discussion a) Past Year Question of June 2013 Q: Identify two (2) common defects that would occur during plastic injection moulding process and suggest how to avoid them. A: Firstly, the common defect that would occur is the warping. Warping is the deformation that occurs when there is uneven shrinkage in the different parts of the molded component. The result is a twisted, uneven, or bent shape where one was not intended. Warping is usually caused by non-uniform cooling of the mold material. Different cooling rates in different parts of the mold cause the plastic to cool differently and thus create internal stresses. These stresses, when released, lead to warping. The way how to avoid warping is firstly ensure that the cooling time is sufficiently long and that it is slow enough to avoid the development of residual stresses being locked into the part. Then, design the mold with uniform wall thickness and so that the plastic flows in a single direction.Besides, select plastic materials that are less likely to shrink and deform. Semi-crystalline materials are generally more prone to warping. Secondly, the common defect is flash. Flash is a molding defect that occurs when some molten plastic escapes from the mold cavity. Typical routes for escape are through the parting line or ejector pin locations. This extrusion cools and remains attached to the finished product. Flash can occur when the mold is not clamped together with enough force (a force strong enough to withstand the opposing forces generated by the molten plastic flowing through the mold), which allows the plastic to seep through. The use of molds that have exceeded their lifespan will be worn out and contribute to the possibility of flash. Additionally, excessive injection pressure may force the plastic out through the route of least resistance. The defect can be avoided by increasing the clamp pressure to ensure that the mold parts remain shut during shots. Then, ensure that the mold is properly maintained and cleaned (or replaced when it has reached the end of its useful lifespan). Besides, adopt optimal molding conditions like injection speed, injection pressure, mold temperature, and proper gas venting.

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MOHD FADZIL BIN YAACOB 2014246234 b) The part of injection units (Barrel) The injection unit is much like an extruder. It consists of a barrel that is fed from one end by a hopper containing a supply of plastic pellets. The barrel is the part of the injection molding machine that heats the plastic material into a molten state. This allows the plastic to flow through the barrel, where the screw inside the barrel injects the plastic into molds or cavities in the Clamping Unit. The temperature in the barrel needs to be properly regulated to maintain the appropriate temperature for different types of plastic material. For example, a Nylon base plastic will require a higher temperature than an HDPE plastic. Finally, the process reaches the Clamping Unit. The screw inside the barrel which operation surpasses that of an extruder screw in the following respect; in addition to turning for mixing and heating the polymer, it also acts as a ram which rapidly moves forward to inject molten plastic into the mold. A nonreturn valve mounted near the tip of the screw prevents the melt from flowing backward along the screw threads. Later in the molding cycle the ram retracts to its former position. Because of its dual action, it is called a reciprocating screw, which name also identifies the machine type. Older injection molding machines used a simple ram (without screw flights), but the superiority of the reciprocating screw design has led to its widespread adoption in today’s molding plants.

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DISCUSSION(MUHAMAD AMMAR B. ABDUL RAHMAN)

2015166041

BINDERS

Binder is a materials that hold together other materials to form bonding between other materials or being called cohesive. The cohesive can be form either mechanically or chemically. When bind fibres,filler powder, and other particles added into it,binder will harden by chemical or physical process. Binder can be classified as organic and inorganic.The classification of binder can based on their field use such as nonhydraulic,hydraulic,acid resistant and autoclave according to their chemical resistance.

Physical properties Some binder such as cements has high comprssive strength but low tensile strength and need to reinforced with fibrous materials. Resin is one example of binder that may be tough and possibly elastic but cannot bear compressive and tensile force.

Uses In art usually in painting it be use to hold together pigments and sometimes filling materials to form paint,pastel and other materials. In building construction,cement being use to build concrete. In explosive, wax or polymers are often use as binders for plastic explosives.In cooking various edible thickening agent use as binder(tapioca flour,lactose,sucrose)

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FINAL QUESTION (JANUARY 2012) MUHAMAD AMMAR B. ABDUL RAHMAN

2015166041

QUESTION 7 a) Plastics can be grouped into thermoplastics and thermosetting. Describe and diffrentiate between thermoplastics and thermosetting plastics.

THERMOPLASTICS

THERMOSETTING

 Require heat to form and retain it  Formed into permanent shape and shape when cooled cured by chemical reaction.

 Can be reheat and reform in new  Cannot be remelted and reformed shape a number of times without into another shape but decompose significant change in their property being heated to too high temperature.

 Most thermoplastic consist of very  Cannot be recycled. long main chain of carbon atom covalently bonded together.

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8.0 REFERENCES

1. Jonathan Band; Masanobu Katoh (2011). Interfaces on Trial 2.0. MIT Press. p. 136,.ISBN 978-0-262-29446-1. 2. Todd, Robert H.; Allen, Dell K.; Alting, Leo (1994). Manufacturing Processes Reference Guide. Industrial Press, Inc. 3. Chikofsky, E. J. & Cross, J. H., II (1990). "Reverse Engineering and Design Recovery: A Taxonomy". IEEE Software 7 (1): 13–17. doi:10.1109/52.43044. 4. Vinesh Raja; Kiran J. Fernandes (2007). Reverse Engineering: An Industrial Perspective. Springer Science & Business Media. p. 3. ISBN 978-1-84628-856-2. 5. http://www.bpf.co.uk/plastipedia/processes/injection_moulding.aspx 6. https://www.xcentricmold.com/about-injection-molding.php 7. Serope Kalpakjian; Steven R. Schmid (2014). Manufacturing Engineering and Technology, Seven Edition. 8. https://www.xcentricmold.com/about-injection-molding.php 9. http://www.nikonmetrology.com/en_EU/Products/Coordinate-Measuring-Machines 10. http://www.hexagonmi.com/products/coordinate-measuring-machines

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