Manufacture

toc = 3.3 Manufacturing processes = Students should identify the processes involved in the manufacture of products, including: It is always necessary when choosing materials for a product to consider how that product might be made and the scale of production ( how many of these you would expect to be manufactured and sold). Some materials are easier to work with than others. Materials can be shaped and formed in many different ways, for example applying heat to plastic in order to bend, soften or melt to shape using a mould. Other materials can be joined easily using adhesiveness or fasteners.
 * the stages of the manufacturing process
 * the advantages/disadvantages of the manufacturing process
 * justification of the choice of manufacturing process

Some materials are suitable for a number of manufacturing processes and it is the scale of production and cost which determine which methods are used. For example, many plastics that can be joined successfully using adhesive, can also be moulded through injection moulding or casting processes. However these processes can have expensive tooling costs and are therefore only appropriate when considering large-scale (mass) production.

It is important to understand the term **manufacturing processing:** Some products in their finished state contain just one process for example a metal paper clip, others contain just a few processes for example a simple pen, and others are made up of many hundred or even thousand of components for example an iPhone. = 2.1 Scale of production = Characteristics, application and advantages/disadvantages of the following scales of production in the manufacture of electronic products: = Tasks = Watch the following presentations and **complete** the student tasks on the first two presentations in your journals, or on to your website, you could even embed the presentations into your website: The manufacture of a single item usually produced to a specific customers' need and specification. This type of production has the highest cost per unit. Examples of electronic products such as a customised computer, a house security system, or an electric guitar. Specialist and experts are required to produce these products. = Batch Production = A batch can be any number of items from 50 to a few thousand, what is important to remember is that the batch run can be repeated many time to suit the clients/customers needs, and that the work force machines and material supply are flexible, in order to be able to change quickly from the manufacture of one batch of products to another. The time taken to change the set up is known as **down time** and is expensive as no products are being produced. Examples of batch production in electronics are the manufacture of the PCBs for the school projects per year group, medical specialist equipment, MRI scanner. = = Here are images of the range of tools and equipment available in the workshops at STC. You can download and use the photos (click on the photos and you will be taken to the original site hosting the photos) in you coursework and project portfolio. media type="custom" key="8263610" = Mass Production = High volume production of products including personal computers, cars, televisions and mobile phones, and the production of components and sub-assemblies for these electronic products such as integrated circuits, and silicon chips. Mass production requires specialist equipment, but often a large unskilled workforce is used especially in the assembly area. Mass production processes are broken down into many small simple repetitive tasks, which enables a flexible unskilled workforce to be used and trained. Click on the picture just to get an idea how many people are employed in the production of you iPods, iPhones and Android phones etc. Some processes such as the manufacture of steel are only economical if they are kept running. Usually this involves primary processes such as the refining of oil in the petrochemical industry. These require high investments in capital equipment. = Task 1 = Check out this great resource:
 * the method of taking a material, component, ingredient, and improving it in some way so that it can be used as a finished product or as part of a larger product.
 * processing may involve the casting, forming and shaping, cutting, machining, joining, printing, heating or moulding of a product
 * [[image:EP_paper_clip.jpg width="173" height="124" align="center"]] || [[image:EP_Biro.jpg width="239" height="148"]] || [[image:EP_iphone_exploded.jpg width="208" height="176"]] ||
 * [[image:EP_PaperclipMan.jpg width="235" height="124"]] || [[image:EP_Pen.jpg width="210" height="209"]] || [[image:EP_pcb_03.jpg width="217" height="205"]] ||
 * one-off
 * batch
 * mass
 * media type="custom" key="8337146" || media type="custom" key="8337160" ||
 * media type="custom" key="8337164" ||  ||
 * One-off Production**
 * One-off and Batch Production Tools**
 * Continuous Production **
 * **How things are manufactured**

= 2.2 Forming techniques = Characteristics, preparation, processes, application and advantages/disadvantages of the following methods for the batch and mass production of electronic products: Below is an excellent website which demonstrates the preparation, processes, applications and advantages/disadvantages of each of the moulding and forming processes listed above - these are the ones you need to know for your GCSE exam. (More are included in the website - it also includes links to videos well worth taking a look at). It is important to learn the stages involved in each of these forming processes and be able to sketch and annotate them so below the website I have included a brief description and an easy to follow sketch - draw them out in your journal. media type="custom" key="8345482" = = = Injection moulding = Plastic pellets are loaded into the hopper and stored until the correct amount of plastic material needed to make the component is heated to a liquid and forced into the mould under pressure. Both thermoplastic and thermosetting polymers can be formed using injection moulding. Once the plastic has cooled and solidified into the desired shape, the mould comes apart, releasing the plastic component. the mould closes and the whole process is repeated, producing plastic products and part every 10 seconds. //**Advantages:**// //**Disadvantages:**//
 * injection moulding
 * vacuum forming
 * line bending
 * blow moulding (dome blowing).
 * Complex shapes can be formed
 * Low labour costs, can be automated
 * High production rate
 * Little or no finishing of parts is required
 * Able to process a wide variety of materials
 * Minimum scrap losses
 * Mould cost is high, so low part volumes are not recommended
 * Large undercuts cannot be formed (such as bottles)

= Vacuum forming = Vacuum forming works heating ( 200 - 400°C) a thin sheet of High Density Polystyrene (HDP), then by removing the air - creating a partial vacuum - from underneath this soft and flexible thermoplastic sheet allowing atmospheric pressure to to push the plastic down onto the mould. The mould should be made with care, it should have no undercuts, corners should be rounded and it should have tapered sides to allow the mould to be removed from the formed plastic once it has cooled.
 * // Advantages: //**
 * Very low tooling costs (compared to injection or blow molding)
 * Short lead time (able to move from concept to production rapidly)
 * // Disadvantages: //**
 * Webs form around the mould, which is due to overheating the plastic and so must be carefully monitored.
 * Webbing can also occur when a mould is too large or parts of the mould are too close together.

= Line bending = Line bending is a thermoforming process, i.e. it is a method of forming a thermoplastic after it has been heated until it has become soft and pliable. Line bending involves heating a thermoplastic sheet material over a strip heater until it becomes soft and pliable, then bending it, usually over a former. Thermoplastics may be bent to any angle, using a jig or a former, or if the angle is not critical, simply by bending the thermoplastic sheet by hand and then holding it until it has cooled. //**Disadvantages**//:
 * // Advantages: //**
 * straight bends are produced very efficiently
 * set up costs are low
 * no tooling is involved
 * Overheating
 * Stresses from the heated and non-heated areas

= Blow moulding = This method is used to make hollow plastic part such as bottles or food containers. First the plastic material is heated and formed into a tube. The tube whilst hot is placed into a mould, the final component is formed by blowing air or steam into the mould, which forces the plastic tube out, taking the shape of the mould cavity. The mould then comes apart, freeing the finished part. //**Advantages:**// //**Disadvantages:**//
 * Low tool and die costs (compared to other molds)
 * Rapid production rates
 * Able to mold complex shapes in one piece
 * Limited to the forming of hollow or tubular shapes

= 2.3 Health and safety = You must be able to show that you know: You must ensure that you work safely and that you are not endangering yourself or others, this includes other students, teachers and technicians in the workshop. When working in the workshop, you need to be responsible and mature, because there are many dangers that you need to be aware of: Workshops can often be noisy and full of moving machinery, this can make you feel uncomfortable, tired or lose concentration - particularly if you are already feeling a little under the weather. Stop working, go into some fresh air and take a rest, in order to avoid any serious injuries and accidents. When you are working in the workshop you could create a log of basic workshop safe working practices.
 * How to understand/describe safe working practices.
 * How to identify workshop hazards and precautions.
 * Sharp tools and objects
 * Moving machinery such as lathes, milling machines, jigsaws, disc / belt sanders, and drills
 * Slippery floors from oil, water, and coolants
 * Heated materials or ingredients
 * Irritant and toxic materials

Behave in a sensible manner, and report anybody who is behaving in a way that may be dangerous for them or for others. Always **WALK** around the workshop, **NEVER RUN.** These are found in all the workshops in several places. Make sure you know what they look like (usually a large red button) and where they are. If you see someone in danger, you should hit the emergency stop button and tell your teacher immediately.
 * Behaviour**
 * Emergency stop buttons**

Know where the fire extinguishers are and note there are different types for different fires. As a student you should not attempt to put a fire out, but inform your teacher or technician immediately if you spot a fire however small. Know where the fire alarm is and how to use it. Know where the emergency exits are, and the emergency assembly points. When the alarm sounds, leave the building silently, walking. **DO NOT RUN.** Leave your books and bags in the room. Assemble at the assembly point in the way you have been instructed, wait to be accounted for and for further instructions.
 * Fire Safety & Fire Drills**

This is a method of looking at a particular area or machine or procedure to determine what risks are involved, so that a risk assessment form can be produced as guidance for safe practise. For example: You are required to wear goggles when soldering, this is because the solder itself spits and this has been assessed as a risk and to reduce the risk of somebody having their eyes burnt with hot solder, the operator has to wear eye protection. //**Five steps to risk assessment:**//
 * Risk** **Assessment**
 * 1) Look for hazards.
 * 2) Decide who might be harmed and how.
 * 3) Evaluate the risks and decide whether existing precautions are adequate, or whether more should be done.
 * 4) Record your findings.
 * 5) Review your assessment and revise it if necessary.


 * Personal Protective Equipment**
 * Eye protection
 * Aprons / protective clothing
 * Face masks
 * Ear defenders
 * Gloves
 * Closed toe shoes / protective shoes

Keep your tables and work areas, and machine areas clean and tidy. Check the condition of tools and machines, report any damage or breakages. Keep gangways and emergency exits clear at all times. Report any accident, however small, your teacher has to record them. Read and follow all safety instructions on chemical-based substances such as adhesives and solvents, pay particular attention to skin contact and ventelation. Always tidy up and wash your hand thoroughly after you have finished your work.
 * Working Practices**

For more detailed information about Health and Safety in D&T workshops look at this website: @http://www.data.org.uk/index.php?option=com_content&view=article&id=877&Itemid=696 = Task 2 = Identify workshop hazards from a workshop picture below: Download and print the PDF below: = Task 3 = Download and complete the following A3 worksheet, adding details to the manufacturing methods and adding your own photographs.

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= 5.3 CAD / CAM = Computer-aided design/computer-aided manufacturing technology. Characteristics, processes, application and advantages/disadvantages of CAD/CAM in the design, development and manufacture of electronic products:
 * virtual modelling and testing of circuit and case designs
 * PCB track patterns/design layout
 * automated component placement (pick and place)
 * computer integrated manufacture (CIM)
 * computerised testing systems for quality control

= **CAD /** CAM =
 * **The advantages of using CAD:**


 * 1) Easy to modify and edit designs.
 * 2) Virtual prototypes can be produced, (these can be visual and functional).
 * 3) Prototypes can be tested virtually.
 * 4) Designs can be communicated worldwide
 * 5) Allows for easy collaboration between designers, clients and manufacturers. || **The advantages of using CAM:**


 * 1) Consistent quality of production
 * 2) Machines can run 24 hours a day.
 * 3) Machines require minimum human input and down time minimised.
 * 4) Rapid prototypes can be manufactured and tested very quickly. ||
 * **The disadvantages of using CAD:**


 * 1) Cost of some very advanced software.
 * 2) Cost of hardware powerful enough to run software.
 * 3) <span style="margin-bottom: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0.5em; padding-bottom: 0px; padding-left: 3em; padding-right: 0px; padding-top: 0px;">Constant training requirements as software is constantly updated. || **The disadvantages of using CAM:**
 * 4) <span style="font-weight: normal; margin-bottom: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0.5em; padding-bottom: 0px; padding-left: 3em; padding-right: 0px; padding-top: 0px;">Cost of machines.
 * 5) <span style="font-weight: normal; margin-bottom: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0.5em; padding-bottom: 0px; padding-left: 3em; padding-right: 0px; padding-top: 0px;">Cost of running the machines.
 * 6) <span style="font-weight: normal; margin-bottom: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0.5em; padding-bottom: 0px; padding-left: 3em; padding-right: 0px; padding-top: 0px;">Human input required is minimal.
 * 7) <span style="font-weight: normal; margin-bottom: 0px; margin-left: 0px; margin-right: 0px; margin-top: 0.5em; padding-bottom: 0px; padding-left: 3em; padding-right: 0px; padding-top: 0px;">Cost of training (Software and Hardware). ||

= CIM = media type="custom" key="3456674" All aspects of a company's operations are integrated so that different computers can share the same information and communicate with one another. Computers are used to link production systems and business information and manufacturing operations in order to create cooperative and smooth running production lines. The task performed within **CIM** include the following:
 * Computer - integrated manufacture** is an interlink network of computers controlling machinery and the flow of information during the manufacturing process. The system is totally automated and involves the control of subsystems such as **CAD/CAM** and **CNC** machines.
 * The design of components
 * Planning the most effective production stages and workflows
 * Controlling the operations of machines
 * Performing business functions - e.g. ordering stock and materials, invoicing customers.

This relies on the use of project management software which allows a manufacturer to create different workflows for different jobs and to organize production //cells// in an overall production schedule.
 * Controlling workflow**

For example, Electronics design automation (EDA), within a single company a **CAD** file might be sent automatically from the designer to a production engineers for comment, then onto a purchasing department for components and materials. At each stage in this workflow, one individual or group is responsible for a specific task, for example making sure that the right components are in the right place when they are needed. Once the task is complete, the whole workflow software makes sure that all the individuals responsible for the next task are notified in advance and recieve all the information they need to complete their stage of the process. Schematic Capture Program (KICAD Eeschema). || Gschem and gerbv showing a simple connector design under creation using components from the [|gEDA] Suite || PCB layout Program (KICAD PCBnew). || 3D View. PCB layout Program (KICAD PCBnew). || There are many subsystems within the **CIM** including design cells, ordering cells and manufacturing cells.
 * [[image:EP_CIM1.jpg width="210" height="155"]]
 * Manufacturing cells**

Think of IKEA if you jhave ever bought a piece of furniture, or Argos in the UK Ina fully automated production line, the main computer will control the transportation of materials and components to the required points on the assembly lines. This is acheived by using two main methods: A coordinate measurement machine (CMM) is a fully automated instrument, controlled by the main computer, for checking the measurements of manufactured components. It is a method of quality control, because it measures the length, hieght, width, weight inside and outside diameters, thickness and even flatness any features which are important for the use of these components.
 * Automated storage and retrieval systems (ASRS)**
 * **Conveyor -** All stocks of components and materials are stored in pallets on large storage shelves. The **ASRS** system will select the correct components from the shelves using cranes, retrieve it and place it on the **AGV** to deliver to the manufacturing or assembly cell
 * **Automated guided vehicle** **(AGV) -** This is an unmanned vehicle that carries components automatically along a pre-programmed path. The simplest way of doing this is by using reflective tape fixed along the route of the vehicle. the **AGV** will 'read' this route using an on-board photo-sensor.
 * Quality Control**

= References = [] [] [] [] http://wiki.yacapaca.com @http://www.schenectady.k12.ny.us/users/pattersont/IBDT%20Website/Page_Generators/Shaping%20Processes.html