2.2 Industrial And Commecial Practice Flashcards
Scales of production
Batch
Batch production refers to products whose exact quantity is decided before production begins.
Once that number is reached production stops and the equipment will then be adjusted or modified and used to make another similar item.
Examples include: newspapers, books, pre-recorded DVDs, football shirts and food products.
Scale of production
Continuous
Continuous production refers to products whose exact quantity is not decided before production begins.
The equipment will be very specialized and will continually make the same product.
Examples include: paper, kitchen roll, blank CDs, nuts and bolts, batteries and tyres.
Manufacturing methods and scales of production
As the scale of production increases the tools and equipment required to manufacture the product change.
One-off production requires incredibly flexible tools and equipment that can be used for multiple functions with multiple materials.
Batch production is likely to be mechanised with tools and equipment that do a specific job, but have the flexibility to vary the outcome.
Continuous production is likely to be highly automated with machines built to complete one specific task.
Talk about just in time
Companies that exist, purely, to make money for share holders.
Management is constantly under pressure to make as much profit as possible.
To do this sales must be maximised and expenses must be cut.
A very large expense for most companies is their inventory- this includes building, equipment and the amount of unsold items it owns.
In the case of manufacturing companies this includes the stock of materials that will be manufactured into products.
Talk about the history of just in time
Just-in-time was developed in Japan in the 1970s.
The theory is simple. If a company can reduce its inventory to as close to zero as possible then none of its available finances will be tied up.
This means that available money can be banked and earn interest rather than be tied up in materials or components.
To be successful at just in time, companies need to predict their sales figures accurately so they can manufacture only what is required.
This will allow them to have materials and components delivered the day that they are needed for manufacture.
Drawings
Isometric
An isometric drawing is a quick and easy way to produce a 3D sketch.
With an isometric drawing the vertical line remains vertical and the horizontal lines are turned through 30 degrees.
(There are two very quick methods for producing high quality isometric drawings.)
The first is isometric paper, the horizontal lines have already been turned through 30 degrees.
The other is to use a 30 degrees set square.
What is perspective?
Perspective is very simple: the further away things are, the smaller they appear to be.
Drawings
One-point perspective
When studying perspective drawings people usually start out with one-point perspective.
All lines appear to head towards a single point in the distance.
As a result objects in the distance appear smaller.
One-point perspective works relatively well for street scenes or buildings.
It is not very effective for drawing products as they appear skewed and poorly proportioned.
Drawings
Two-point perspective
Two-point perspective produces more realistic results.
Instead of a single vanishing point, two are placed at opposite ends of the horizon line.
(You should always try and place the vanishing points as far away as possible from your sketch.
Poorly positioned will lead to distortion and an unrealistic appearance for your designs.)
Drawings
Traditional
Presentational drawings must be as realistic as possible.
Traditionally these have been known as artists impressions.
They give the best possible indication of what the product will look like, including colour and surface texture
Scales of production
One-off
One-off production refers to any products that are uniquely manufactured in quantities of one.
These tend to be specialized items and include: a wedding dress, rings and cakes, oil rigs, houses, product prototypes and the majority of products you have built in Design and Technology.
Computer graphics
There are a vast array of computer graphic programs but they app fall into two categories: vector and pixel.
Computer graphics
Vector graphics
The best way to think of this graphic as a map with grid references.
For a line, the computer simply needs to know where it starts, where it finishes, how thick it is and what colour it should be.
For a circle, the computer simply needs to know where the centre is, what the diameter is, whether it has an outline and what colour it should be.
The big disadvantages are:
•The image can be printed at any size without losing quality or resolution.
•The computer needs to hold very little information to produce a high quality image.
Computer graphics
Pixel graphics
The best way to think of this graphic is a sheet of graph paper. Each square can only be one colour.
The smaller the squares, the more detail can be included. But the file size will increase.
The larger the squares, the less detail can be included. This will make the file size smaller.
Pixel sizes are measured in dpi (dots per inch).
Pixel graphic software can be used for two purposes; to repair images or to manipulate them.
The next few slides show some examples of the effects you can achieve with a pixel graphic programme.
Black and white
Colour can be removed from an image or part of an image.
Morphing
Morphing allows selected pixels to be stretched, squashed and moved whilst still attached to those around them.
Flipped and rotated
Images or parts of images can be flipped or rotated.
Tensol cement
Tensol cement is a solvent and is ideal for joining thermoplastics but cannot be used for thermosetting plastic or other materials.
The bonds produced are very strong, non-porous and are resistant to weathering, which makes them ideal for outdoor signage.
The cement is applied to both surfaces, which must then be clamped together to allow the process to work.
The solvent melts the upper layer of the plastics, which mix together and reharden, effectively becoming one piece.
Tensol cement fumes can be harmful and it must only be used in a well ventilated environment.
Tensol cement
The good stuff
Tensol cement is: Permanent Equivalent to welding metals Extremely strong Able to produce invisible finishes Weatherproof Non-porous
Tensol cement
The bad stuff
Tensol cement:
Can only be used for thermoplastics
Can be messy if not used carefully
Must be used in a well ventilated environment
Hot melt glue
Hot melt glue is a thermo or thermosoftening plastic.
When the hot melt glue is heated it softens and its viscosity increases and becomes molten.
Upon cooking it returns to a solid state and is ideal as an expensive, quick to apply and versatile, quick to apply and versatile temporary adhesive for certain materials.
Hot melt glue has a major safety issue that must be taken into consideration.
The hot melt gun becomes molten at around 250F/120C.
If the glue or the heating element come into contact with skin they can create serious burns.
Please note that in thickly applied areas the core of the glue may remain molten and dangerously hot for a considerable time.
Hot melt glue
The good stuff
Hot melt glue is: Asily applied Joins a variety of materials Requires limited preparation Joins uneven surfaces Available in a range of colours Relatively inexpensive
Hot melt glue
The bad stuff
Hot melt glue:
Can only be used for lightweight materials
Can be messy if not used carefully
Is not permanent
Can cause injury of misused
Must be used in a well ventilated environment
Spray glue
Spray glue, also known
