plastic Injection Molding, Thermosets, Thermoplastics, Polymers

This video will explain you that how the plastic injection molding works.

Plastic injection molding is the method which is mainly used to manufacture parts of thermosetting also thermoplastic materials. In this molding work, the scrap material is put into a box. temperature is given to that box  so as to get a plastic design.

Plastic injection molding is generally used to manufacture car parts, and can be utilized so as to get large car parts as well as small parts. 

The essential difference is that thermoplastics remain permanently fusible so that they will soften and eventually melt when heat is applied, whereas cured thermoset polymers do not soften, and will only char and break down at high temperatures. This allows thermoplastic materials to be reclaimed and recycled.

The reason for this is that thermoplastics have relatively weak forces of attraction between the chains, which are overcome when the material is heated, unlike thermosets, where the cross-linking of the molecules is by strong chemical bonds. Effectively the thermoset is one large molecule, with no crystalline structure.

Compared with thermoplastics, thermosets are generally harder, more rigid and more brittle, and their mechanical properties are not heat sensitive. They are also less soluble in organic solvents.

A Detail Guide From Final year Project Selection To its Completion

Every project needs good management so that your project should be best and end with some achievements. Be it a mechanical engineering project or some other project, it is necessary and important to strictly follow certain steps for higher efficiency and success rate. If you are a mechanical engineer then your project preparation is the key to success. Here I will discuss some things about the final year project. How to select it and how to manage it.

You project must Value Addition:

Always select such kind of project that is actually the addition of value. Don’t ever pick just any project because your advisor or supervisor handed over it to you or your friend suggested it to you. This means that you must choose a kind of a project which has some substance. As a mechanical engineer you must select a project which is either beneficial to a lot of people or improve your skill technical and managerial both. You project must play its role towards a positive growth in that particular field. Consider how will it affect your growth in terms of learning as an engineer and how will it affect other propel? So for this purpose, do a “need assessment” of your project which will let you know the need and value of the project.

Concentrate on Your Area of Interest:

Being a student of mechanical engineering, I have experienced it many times. I have seen many of my fellows selecting projects out of the scope of their interest. Many engineers select their project without looking at their interest and select it randomly. Which is totally wrong? During the selection of our final year project, my team also did the same. First of all gather the team ideas about the final year project and then select one of them which you will feel better for you.

Get to know the objective and scope of your project:

This is very important; the scope of your project. Before finalizing selection of your project, you need to know the scope of your project. You must know whether the scope of your project is within your resources? Can you do it within available resources in your college, university and labs?

Take the project and execution seriously:

Now that you have finally picked up a project, make sure that you execute and complete it seriously and put your heart into it. Show your responsibility as a team player. Being irresponsible in the field of mechanical engineering is non-tolerable and a mechanical engineer can never survive without being responsible. Remember that as a mechanical engineer whatever you do or build, it’s going to effect a lot of people, so do it accurately and precisely with maximum efficiency.

Make a schedule (Gantt Chart) and stick to it:

Doing mechanical engineering projects preparation entails a lot of thought and careful planning. Make a list of everything that needs to be done, and make a schedule for each. This chart or schedule that you will make is called “Gantt Chart”. Of course, in order to be successful in your undertaking, you have to make sure that you follow the plan to the letter. Doing so will allow you to complete the project within your allotted time frame.

Consult your advisor and guide at all stages:

This is a very common mistake that many of the mechanical engineering students make. They don’t consult their advisors on regular basis. Always keep I mind that there is always a set of guidelines that will determine how you should go about doing things in every project. Every time you are about to do something major or important, make it a point to consult your guide to see if you are on the right track. This will greatly reduce the chance that you will fail with the project or else commit mistakes.

Always there are problems so be prepared:

No matter what kind of project you have chosen to do, problems are inevitable. Do not get frustrated whenever a problem strikes. Have enough courage and determination to complete the project no matter the gravity of the issues you encounter. Have faith that whatever hindrance you may face while doing the project, you still have a chance to succeed and finish your endeavor. Believe that you have the potential to finish the work in within the allotted time.

As said, in mechanical engineering projects, preparation is the key to success. No matter what kind of project you choose, make sure that you take time to consider all the pertinent factors. Doing so will prepare you for whatever obstacles you might encounter as you try to finish your project. With ample preparation, too, you will be able to arm yourself with sufficient knowledge about the things that are important to the project's completion.

AutoCad Tutorial 07

Today i am going to discuss here the 7th tutorial of the Autocad. The main features which i will discuss in this class are listed below.

OBJECT SNAPPING

An object snap mode specifies a snap point at an exact location on an object. OSNAP specifies running object snap modes, which remain active until you turn them off.

• Running object snap in AutoCad
• Case by Case (temporary mode)
• How to do OSNAP setting in AutoCad

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AutoCad Tutorial 06

Here is the new tutorial of Autocad after a long time... actually i was busy in my final year project of engineering....

The main things which i will discuss in this tutorial are listed here.

The basic topic of this tutorial is     DRAWING AIDS

And the things included in drawing aids are

1. How to use snap command in Autocad
2. Snap angle
3. Grid command activation
4. Uses of Grid command

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AutoCad Tutorial 05

Today i am going to upload here the 5th tutorial of Autocad... you will enjoy it a lot like the previous Tutorials... the main theme of this tutorial is to introduce and explain the basic display commands to you which are very important in Autocad.

Here is the list of commands which are explained in this tutorial.

• how to use Zoom command in Autocad
• how to use Pan command in Autocad
• how to use Redraw and Regen command in Autocad
• how to use Blipmode command in Autocad

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If you need any help regarding any thing then you can contact me in the chat box. which is located on your right side....



AutoCad Tutorial 04

Today i am going to upload here the Tutorial#04. The main features which are discussed in this tutorial are listed below.

• How to Erase any thing in Autocad
• Selection Set options
• Window
• Crossing
• How to remove object from selection set in Autocad
• How to use OPPS command in Autocad
• Selection Preview

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if you need any other information related to this topic or any other topic related to mechanical engineering you can contact me here on the chat box which is on your right side.

Aerosols Introduction and Detail

It is a system consisting of finely divided fluid or solid particles of dispersed in and which are surrounded by gas. In recent years aerosols have become well known products discharged from spray dispensers, and the term aerosol has, in popular speech also come to means the dispenser itself i.e. a pressurized container made of metal or glass and provided with a discharge valve, which may be a spray valve or a foam valve. It is filled with the product to be sprayed and the propellant gas under pressure.

The aerosol can was invented in 1926 by Erik Rotheim. He invented the first aerosol can and valve that could hold and dispense products and propellant systems. This was the forerunner of the modern aerosol can and valve. The patent was sold to a US company for 100,000 Norwegian kroners, but it wasn't until 1941 that it was first put to good use by Americans Lyle Goodhue and William Sullivan. They turned it into an instrument for the US military to fight the malaria mosquito in the Pacific during World War II. Aerosol spray products have three major parts; the can, the valve and the actuator or button.

The term aerosol derives from the fact that matter floating in air is a suspension i.e. a mixture in which solid or liquid or combined solid-liquid particles are suspended in a fluid. To differentiate suspensions from true solutions, the term sol evolved originally meant to cover dispersions of tiny particles in a liquid. With studies of dispersions in air, the term aerosol evolved and now embraces liquid droplets, solid particles, and combinations of these. An aerosol may come from sources as various as a volcano or an aerosol can.

The product to be dispersed as an aerosol may have the liquefied propellant mixed with it in the form of a solution (Fig.1). Alternatively, the propellant may be present as a separate gaseous phase in the dispenser, in which it does not mingle with the product (two-phase system: Fig.2).

An example of the first type is afforded by hair spray. The spray or lacquer, usually dissolved in alcohol, is completely miscible with the liquefied propellant. When the valve button on the dispenser is pressed, the propellant vaporizes immediately, and its pressure forces the liquid out of the nozzle. The liquid i.e., the lacquer solution is discharged as a fine mist. The most commonly employed propellants are chlorinated hydrocarbons, butane, propane, isobutane, vinyl chloride and nitrogen. Nitrogen is used particularly for products that on no account be contaminated in flavor or smell e.g., toothpaste packaged in aerosol dispensers.

Aerosol toothpaste is an example of the second category of aerosol systems particularly, the two-phase system in which the propellant gas forms a separate layer over the product to be discharged. The dispenser is half milled with nitrogen or some other suitable gas and half with the product. The pressure in the dispenser is about 6 to 8 atm. (90 to 120 lb. /in2). Nitrogen can also be used as the propellant for foods packaged in aerosol form e.g., cheese spreads, malt extracts, vitamin preparations, syrups, pudding sauces, whipped cream.

 Filling an aerosol dispenser at the factory is a simple operation (Fig.3: stages 1 to 5). First the product is introduced into the dispenser. This is done by a pneumatic filling machine. Then the aerosol valve is placed on the dispenser. In the next stage the valve is force-fitted under high pressure into the neck of the dispenser, so that a strong gastight seal is formed between the latter and the valve unit. The propellant gas is now forced into the dispenser. Finally, the dispenser is immersed in water to test it for possible leakage, which is manifested by escaping bubbles of gas.

Aerosols are coming into increasingly widespread use in industry. They are used for the disinfection of milk tanks. For this purpose a spraying device is used which draws the disinfectant solution by suction from a container and disperses it as an aerosol by means of two atomizing discs. These discs rotate, and their centrifugal action sets up a suction which draws the disinfectant forward through the hollow shaft of the motor.

To make the aerosol mist flow in the desired direction, a second air stream is needed. A turbine is installed behind the motor sucks in air, which flows along the motor and emerges from the annular aperture around the atomizing discs. This stream of air carries along the aerosol particles of disinfectant (Fig.5).

Airfoil Introduction, Air flow Over Airfoil, Properties of Airfoil

The properties of airflow mainly depends upon

1)       The profile of the airfoil section and on

2)       The occurrences occurring at the boundary layer, it is basically a thin layer of air attached to a solid surface e.g.  We have an airfoil and the air is flowing over it, and which is distinguished from the main airflow by distinctive flow characteristics of its own set up by friction. The flow in the boundary layer where the thickness of the layer is shown greatly exaggerated may be laminar or turbulent. In laminar flow the velocity distribution in the layer shows a steady increase from zero at the surface of the airfoil: more particularly, the wing of an aircraft: to a maximum corresponding to the velocity of the main airflow.

An airfoil is a instrument which gets a necessary reaction from air moving over its surface. When an airfoil moved in air or the air passed through over airfoil, it is capable of producing lift. Lift is the vertical force which the air exerts on the airfoil for e.g.: Wings, horizontal tail surfaces, vertical tails surfaces, and propellers. The flow is smooth and it always move in parallel layers; hence the term laminar. In turbulent flow, the fairly regular motion of the laminar boundary layer is destroyed. The boundary layer undergoes transition; it becomes thicker and is characterized by large random

Types of Mechanical Power Tranmission Devices

Mechanical transmission devices are the basic devices which are used in every machine to transfer power from one part of machine to another part of the machine. By using different kind of mechanisms and motions we can use these devices effectively. These mechanisms are used parallel and the motion is transferred. There are several combinations and or modifications possible but there are six basic types of mechanism.

Crank mechanism The main element is the crank which is rotated and mounted on the frame and is so designed that it can perform complete revolutions/rotation, and its motion is transmitted through the coupler rod to the lever arm, like wide rotatable mounted, but not performing complete revolutions. Other alternative is, instead of being connected to a lever, the coupler may be attached to a sliding element like a piston, in a steam engine or internal combustion engine.

Gear Mechanism This type of mechanism transmits circular motion from one shaft to another, usually in conjunction with a change in rotational speed and torque. Usually in a gear mechanism, the transmission is effected by the meshing of gear teeth, but in the friction-gear mechanism this positive drive is replaced by frictional contact of wheels or rollers.

pulley mechanism Connection between the pulleys on the respective shafts is effected by flexible elements like belts, rope, etc..

Cam mechanism A cam plate mounted on a frame is driven and thus moves a lever or slider which thus performs a desired predetermined motion depending on the shape of the cam, for example like valve control mechanism in an internal combustion engine.

Ratchet mechanism this serves to arrest a motion or to produce an intermittent circular rotation in the driven element. The pawl allows the ratchet wheel to rotate in one direction only preventing rotation in the opposite direction by engaging with the specially shaped teeth on the wheel.

Screw mechanism when the screw spindle is rotated, the element attached to the nut will move in longitudinal direction of the screw. If the nut is rotatable mounted in the frame of the mechanism and driven, the screw spindle will move longitudinally.

The Feller Buncher, the Tree-Ripping Mega Claw

Obviously, this is a robot brontosaurus with a saw on its head. Left to fend for itself, it satisfies its bloodlust by bursting into two-bedroom houses, holding the occupants down with its mighty claw and shearing their faces off. An army of these could conquer the world using nothing but fear, because anybody who looks at one would assume that conventional weapons are useless against it. And trying to hide from one in the forest is clearly ridiculous, so really, the mountains or a desert would be humanity's best hope for survival.

What It Is:

The feller buncher, like the Timberjack, is a logging harvester. It cuts through trees like grass -- and we're not exaggerating. It takes less than a second to bite through a tree trunk, and it can cut through them in bunches, grabbing one after another in its massive claw. It really does need to be seen in action.

At 20 seconds, the feller buncher starts cutting down its first tree. Before 21 seconds, the tree has been cut through and is securely in the grip of the machine. At 25 seconds, the machine starts on the second tree, and by 26 seconds that tree has been lopped down and secured. Two trees in six goddamn seconds. Somewhere, Captain Planet just shit his pants.

The Walking Harvester, the Tree-Eating Robo-Spider

This thing will poach your nightmares with its horrible claw and fling them screaming back into your face. We expect that at any second, Ewoks will emerge and start throwing rocks at it. It looks like it should be guarding Dick Jones at OCP headquarters, ready to throw a goddamn tree at RoboCop's head. Really, it looks like anything but a lumberjack.

What It Is:
A lumberjack, more or less. Existing logging machinery can't get into every place that trees grow. The idea behind the Plustech/Timberjack walking harvester is that it can cross terrain that a machine with wheels or treads wouldn't be able to and clear out trees like a giant green Jean-Claude Van Damme in a head-kicking contest.
Also, the harvester won't tear up the ground around it like a track or wheel, making it about as environmentally conscious as a machine designed for eating a forest can be. Currently it's only a prototype, and there aren't any others in existence, but the benefits of walking technology almost guarantee it a place in future machinery, not just in forestry but in other applications, such as construction and the military.

world heaviest machines (The Rock Wheel, Circular Saw)

This seems like something The Shredder built which is used for robery, or a vehicle from a future world where the only currency is violence.

What It Is:
A rock wheel. It's basically a giant circular saw on treads, and it's used to cut trenches through concrete, asphalt and, you guessed it, solid rock. So really, robbing a bank still seems like a practical application.




Seriously, this has never been written into a movie before? Villain uses one of these to saw into Fort Knox and take all the gold? Hell, we're surprised nobody has done that in real life.
We're not saying the rock wheel will give you a better shot at taking over the world, we're just saying we don't understand the point of taking over the world if it doesn't give you the opportunity to own things like this.

MACHINE "LEVER"

A machine is a device that helps make work easier to perform. (Remember, Work = Force X Distance). A machine makes work easier to perform by accomplishing one or more of the following functions:

1. transferring a force from one place to another,
2. changing the direction of a force,
3. increasing the magnitude of a force, or
4. increasing the distance or speed of a force.

MECHANICAL ADVANTAGE

TOOLS

Their are different types of tools which we can use in a workshop.
Single point tool
Multi point tool

Mechanical Energy Background and Industrial Revolution

Background

• before the industrial revolution which began 200 years ago, people were torally dependent on human/animal labor

• life was simple, unsophisticated and the environment was relitively clean. as such energy requirement were met through food in-take.

Industrial Revolution

• invention of steam engine by james ex scotland brought industrial revolution in 1785. a first step toward industrialiazation revolution or beginning of mechanical age or age of machines.

• the advent of IC engine in 19th century gave further momontum to this trend.

• gradually, industrial revolution spread the whole world.

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Working of Sensitive Inclined Manometer

The inclined manometer, it’s for measuring the actual airflow and is simply a more sensitive way of using a manometer, what is of interest is still the height the fluid moves up vertically.

By inclining, the fluid will travel a further distance for any change in height making it much easier to read small changes.

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Comparison Of Hybrid and Simple Gasoline Technology

Parts Of the Hybrid and Normal Car


Hybrid Car:

Gasoline Engine:

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Working Of Differential Gear

Working of Differential Gear:

The differential has three jobs:  


•To aim the engine power at the wheels


•To act as the final gear reduction in the vehicle, slowing the rotational speed of the transmission one final time before it hits the wheels


•To transmit the power to the wheels while allowing them to rotate at different speeds.

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Car Engine Components

Study of the engine (petrol engine, diesel engine, rotary engine, stirling engine) is very important in Mechanical Engineering. It has a complete cource named as "IC ENGINES" which the student normally study in BSc Mechanical engineering in 6th or 7th semester.


These are the some pictures which explains you the Working of Engine and Its Different Parts


1.    working

2.       Components

 3.           Model

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Working Of A Car Engine

How a Car Engine Works
A gasoline engine operates on the principle of combustion. A fuel/air mixture is pulled into a cylinder, the cylinder is then closed off and the piston is thrust upward to create compression. A spark is introduced to ignite the mixture to create combustion to thrust the piston downward in the engine block.

 

more detail here 

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