Manufacturing Practices & Materials Components And Fabrication Flashcards
What are the different types of scales of production?
-One-off/Jobbing production
-Batch Production
-Mass production
-Continuous production
What is one off/jobbing production?
Making a single product to the specific requirements of the consumer. So every item will be made differently
What are the disadvantages of one off/jobbing production?
-Requires a highly skilled workforce
-Very labour intensive
What are some examples of one-off productions?
-Bridges
-Statues
-Personalised jewellery
What is batch production?
Where a specific quantity of products are made, between 2 and 100 units.
How does batch production work?
A production line is set up where each worker completes a task and passes it along the production line to the next worker.
What are the advantages of batch production?
-Workers are only semi-skilled or unskilled
-Flexible workforce
Why does the production line need to be easily and quickly changed in batch production?
So different products can be made
What are examples of batch production?
-Sport shoes
-Clothes
-Books
What is mass production?
High volume production of products, usually over 100 units made
What is the main disadvantage and advantage of mass production?
D: Initial set up cost is high for machinery
A: Since high costs are spread across large number of units the cost per unit is reduced greatly allowing more profit
What are the examples of mass production?
-Electrical goods
-Cars
What is continuous production?
Uninterrupted 24/7 mass production of tens of thousands of identical products.
How does continuous production work?
A semi-automated production line is set up using computer control and a combination of skilled and unskilled workers.
What are the advantages of continuous production?
-Has unskilled workers
-Workers less flexible than batch manufacturers
What are the disadvantages of continuous production?
-Training needed for new equipment or new staff
-Quality control occurs at every stage if production.
-High level of investment in machinery needed
What are examples of continuous production?
-Petrol & oil products
-Cars
-Bricks
What is in-line assembly?
Used for mass production, most of production line is automated.
What is the used of unskilled labour and semi skilled workers in In-line assembly
-Unskilled labour used for assembly
-Semi-skilled workers make sure there is continuous flow along production line
What are the advantages of in-line assembly?
-Human error reduced due to machinery
-Company produced larger quantity of one product
-Labour costs reduced and production increases
What are the disadvantages to in-line assembly?
-System is inflexible as production process cannot be changed
-Lack of variety in system as all products are all produced on one production line
What are flexible manufacturing systems?
Where semi-skilled workers are able to do a variety of jobs
What is the approach to the idea of flexible manufacturing systems?
A flexible workforce and flexible machinery is key to successful manufacturing
What are the advantages of flexible manufacturing systems?
-Useful for batch manufacturing where change and flexibility needed
-Manufacturing time reduced per product
-Cost per unit reduced
What is the disadvantage to flexible manufacturing systems?
Requires alot of pre planning and organisation prior to starting production
What does just-in-time manufacture require?
Requires high level of forward planning as materials and components only bought when needed
What are the advantages to just in time assembly?
-Resources not stockpiled which saves warehouse space and money
-Reduces chance of stock going out of date
-Avoids build up of unfinished products as demand changes
What are the disadvantages to just-in-time assembly?
-Little room for mistakes as minimal stock kept
-Very reliant on suppliers
-No excess finished products to meet unexpected orders
What are the two types of industrial practices?
- Standardised components, assemblies and bought in components
- Sub-contracting
What are standardised components, assemblies and bought in components?
Building of blocks of much more complex products
What are the advantages of standardised components, assemblies and bought in components?
-Speed up manufacturing and reduces maintenance and manufacturing costs
-Means manufacturers do not have to create everything from scratch
What is the disadvantage of standardised components, assemblies and bought in components?
-Manufacturer depends on other manufacturers to supply them
What is subcontracting?
When a part of a job or manufacturing process is contracted out to another source or company to compete.
When does sub-contracting occur?
When machines and operators are working to full capacity and production is at its full efficiency but orders are still being placed
What are the advantages of sub-contracting?
-Provides relief to manufacturer
-Prevents manufacturing plant from becoming overburdened
-Improves efficiency
-Helps manufacturers meet delivery dates
What are the disadvantages to sub-contracting?
-Time consuming
-Difficult to ensure quality
-Tracking parts can be an issue
What should improved quality and improved reputation of company return in?
-Greater demand for products
-Increase in production volumes
-Unit costs being reduced
-Higher selling prices
-Customer satisfaction
What is quality assurance?
Setting standards and meeting them.
What is quality control?
How you check standards of product.
What does quality control ensure?
-Does job it was designed to do
-Conforms to design specifications
-Gives customer satisfaction
What are the 3 types of sample testing?
- Measuring
- Non-destructive testing
- Destructive testing
What happens in measuring in sample testing?
Where measuring can be completed using a limiting gauge, micrometer, vernier gauge. Very time consuming and costly
What is non-destructive testing in sample testing?
Testing where the sample isn’t damaged, as testing is visual it used x-rays or dyes to find defects.
What is destructive testing in sample testing?
Testing that is physical and destroys product to see how product would collapse or how fractures develop
What is tolerance in testing a sample?
The amount of error allowed.
What is manufacturing cost?
The sum of all costs of resources needed in process of making a product
What are the 3 categories of manufacturing cost?
•Direct costs
•Overhead costs
•Manufacturing overheads
What are the 2 types of direct costs?
- Human
- Material costs
What are the 4 types of overhead costs?
- Management
- Administration
- Research and development
- Marketing and sales
What are the 3 types of manufacturing overheads?
- Manufacturing equipment
- Manufacturing plant
- General overhead costs
What are the direct labours cost?
The cost of paying employees directly involved in production process.
How to calculate direct labour costs?
Multiply production time period by hourly cost of paying each worker
What are the direct materials cost?
The raw materials that become a part of the finished product
What are the manufacturing overhead costs?
Any costs which are not the direct labour or direct materials, e.g equipment
What is the total cost of manufacturing a product?
The direct costs + the indirect costs
What is reforming?
When plastics or metals are liquefied with heat pressure, then shaped with a mould
What is deforming?
When the shape of a material is changed
What are methods of reforming
-Extrusion
-Die casting
-Injection moulding
What are methods of deforming?
-Blow moulding
-laminating
-press/compression moulding
What materials and what is extrusion used for?
Used on Thermoplastics and some metals.
Used to make sheets of plastic for fabrication, pipes, tubes etc… And to mould copper for pipes, wires etc…
What are the advantages of extrusion?
•High production rates are achievable
•Many materials can be extruded
•Products have very good surface finish
What are the disadvantages of extrusion?
•Complex parts can’t be produced
•Only shapes with uniform cross sections can be produced
What is injection moulding used for?
To produce bottles, sand buckets, electrical components etc
How does injection moulding work?
By forcing the molten material into a closed mould
What are the advantages of injection moulding?
•High production rates are achievable
•Products have good surface finish
What is the disadvantageof injection moulding?
Very expensive
What is die casting used for?
Kitchen equipment and castings for car industry
How does die casting work?
Material is melted and poured into a mould that is the required shape of product
What are the advantages of die casting
•Fast
•Produces durable parts
•Parts have good surface finish
What are the disadvantages of die casting?
•Initial cost setups are high
•Large production volume is required
•Only non-ferrous metals can be used
What is made with blow moulding?
drink bottles, cosmetics, plastic pipes
What are the advantages of blow moulding?
•Less expensive
•Fast production
•Need for adhesives is reduced
What is the disadvantage of blow moulding?
Can only be used to manufacture hollow products
What is laminating?
Process of constructing a material with two or more layers together
What is made with laminating?
Table, chair legs, roof beams
What is press moulding and how does it work?
A mould is made in two halves and sheet plastic is placed between them, they’re heated and pressurised forcing plastics to form the shape
What are circular saws used for?
Cutting woods into size
What are band saws used for?
To cut wood and other materials for straight or curved cuts
What are jigsaws?
A power tool with a thin blade that reciprocates
What are jigsaws used for?
Cutting curves and custom shapes into wood and other materials
What is a planer used for?
To remove shavings of wood. Used to reduce material to its required size
What is a sander used for?
To sand or smooth wood
What are the tools used in manufacturing processes?
-Circular saw
-Band saw
-Jigsaw
-Sander
-Planer
What is computerised production?
When manufacturing process becomes automated by using computer aided design
What are the advantages of CAD systems?
•Produces high quality and consistent drawings
•Changes to drawings are easily made
•Drawings can be emailed
What are the disadvantages of using CAD systems?
•Not a substitute to freehand sketching
•Initial set up cost is high
What is computer aided manufacture?
The process that converts drawings produced by CAD into actual products
What are the advantages to using CAM?
•High production speed
•Flexible as they can be reprogrammed
•Ensures products are produced accurately
What are the disadvantages to using CAM?
•Initial setup costs are high
•Training required for the operation
What materials are laser cutters used for?
-Plastic
-Wood
-Card
What materials are lathes used for?
-Wood
-Metal
-Nylon
What materials are routers used for?
-Foam
-Wood
-Metal
What materials are milling machines used for?
-Wood
-Metal
-Plastic
What materials are milling machines used for?
-Wood
-Metal
-Plastic
What is computer integrated manufacture? (CIM)
Central computer system used to link together all stages of design and manufacturing process
What are the advantages to using CIM?
•Lower costs
•Human error is reduced
What are the disadvantages to using CIM?
•Initial setup cost are high for machinery and training
•Fast special purpose machines cheaper to run for large scale production
What is the intended uses for selection of materials?
-What will it be used for?
-Where will the product be used?
-How long will it last?
What are the properties for the selection of materials?
-Strength
-Hardness
-Durability
-Malleability
-Heat, electrical conductivity
What are the functions of its finish for selection of materials?
-Does product need aesthetically pleasing finish?
-Does it need a protection finish?
What are the shape and cross sections of materials?
Sheet, bar, tube, angled, u-shapes channel, i-shaped section
What shapes and cross sections can metals be?
-Flat sheet
-Solid bar
-Tubes
-Angled u-shaped channel
-I-Shaped sections
What shapes and cross sections can plastics be?
-Rods
-Sheets
-Extruded mouldings
What shapes are metals in stock form available in?
-Sheet
-Bar
-Rod
-Tube
What shapes are plastics in stock form available as?
-Sheet
-Rod
-Bar
-Granules
What is different groups of woods?
-Hardwoods
-Softwoods
-Manufactured boards
What is the appropriate use of hardwoods?
-For furniture as very aesthetically pleasing.
-Building beams and flooring as very strong
What is the appropriate use of softwoods?
-Furniture, ceilings, doors as it is aesthetically pleasing and easily cut
-Staircases as it also cheaper
What can be done to improve the aesthetic of manufactured boards?
They can have a thin layer of wood covering them to improve appearance.
What are the different types of manufacturing boards?
-MDF
-Chipboard
-Plywood
-Blockboard
What is the issues with using wood?
Shrinkage
Expansion
What is the difference between ferrous and non-ferrous metals?
Ferrous contains metal
Non-ferrous don’t contain metal
What is an alloy?
A mixture of two or more metals
What are the appropriate uses for metals such as brass?
-Malleable and machines well
-Doesn’t tarnish and resist corrosion
-Has good acoustic properties which makes it ideal for musical instruments
What is the difference between thermosetting plastics and thermoplastics?
Thermosetting can’t be reheated and reshaped.
Thermoplastics can be reheated to be shaped and moulded
What is an advantage and a disadvantage of thermosetting plastics?
A: Resists heat and fire well
D: Cannot be recycled
What is an advantage and a disadvantage to thermoplastics?
A: Can be recycled
D: Doesn’t resist heat well
Where can butt joints be used?
-Basic boxes or cabinets,
-Building frames
Where can dowel joints be used?
-Chair and table legs
-Table tops
-Cabinets
Where can comb or finger joints be used?
-Tables and chairs
-Floor boards
-Roof and door construction
Where can dovetail joints be used?
-Drawers
-Jewellery boxes
-Cabinets
Where can half-lap joints be used?
Framing
Where can mitre joints be used?
-Picture frames
-Pipes
-Moulding
Where can housing joints be used?
-Bookcases
-Cabinets
Where can mortise and tenon joints be used?
-Table and chair legs
Where can bridle joints be used?
-Legs or stiles to rails
-Frames
Where can corner halving joints be used?
Frames
Where can cross-halving joints be used?
-Strengthening rails for tables and chairs
-Trellis
Where can biscuit joints be used?
Table tops
What are the smart materials?
Shape memory alloy (nithinol) and polymorph
What are shape memory alloys?
Alloys that change to their original shape when heated
What are shape memory alloys used for?
Glasses frames
What is nithinol?
An alloy that when cool is easily shaped but if heated to certain temperature it will return to remembered shape
What is nithinol used for?
Glasses frames, wires of teeth braces, equipment for medical industry
What is polymorph?
A new type of plastic smart material ideal for model making
What is polymorph used for?
One off moulds, orthopaedic splints and specialised prototyping
What are the types of composites?
-Fibre based
-Particle based
-Sheet based
What are fibre based composites?
Composites reinforced with fibres
What is glass reinforced plastic (GRP) made from?
Glass fibres and resin
What is carbon reinforced plastic made from?
Carbon fibre and resin
