introduction of material & manufacturing process
TRANSCRIPT
Introduction of Material And Manufacturing
IDT 203
Week 1
MANUFACTURING
•According to DeGarmo, (1997) basically, manufacturing is a ‘value adding’ activity, where the conversion of materials into products adds value to the original material.
•According to Magrab, E.B, (1997) manufacturing is interrelated activities involving product and process design, material selection, planning, production and quality assurance
Definition :
Interrelated factors in manufacturing
• Material
• Men
• Methods
• Equipment
They are to be combined properly to achieve low cost,
superior quality and on time delivery.
The Economic Importance Of Manufacturing
Wealth, in this world, springs essentially from one these three sources :
1. What is removed from the ground;
example : minerals, metals and oil
2. What is grown from the ground
example : foods; including grains, fruits and vegetable, nonfood; such as cotton, lumber and natural rubber
3. What is manufactured
Manufacturing costBasically, manufacturing cost consists :
• Material cost
• Indirect cost
• General administration costs in additional to labour cost
Normally manufacturing cost is the largest cost in the selling price. It is estimate that 40% of the selling price of a product.
Parts and material, 50%
Manufacturing costSelling price
Marketing, sales general administrative cost 25%
Profit 20%
Indirect labour 26%
Direct labour 12%
Plant and machinery depreciation, energy 12%
Engineering cost 15%
Manufacturing cost 40%
Designing in relation to manufacturing (competitiveness)
There are various approaches in enhancing the competitiveness
of the product. Example: JIS, DFM (design for manufacturability)
etc.
Design for manufacturability (DFM)
Definitions :
• According to James G. Bralla , (1996) in the broadest sense DFM is
any step, method or system that provides a product design that eases
the task of manufacturing and lower manufacturing cost.
• According to Boothroyd , G (2002) DFMA means the design of product
for ease of manufacturing and assembly .
To add value in the most efficient manner using the LEAST
AMOUNT of:
TIME
MATERIAL MANPOWER
EQUIPMENT&SPACE
Objective Of Manufacturer
The Advantages of Applying DFM during Product Design
Reduced time to market
Cost reduction
Improved quality
Reduced Time To Market
Greater Market Share
Price Premiums
Quick Reaction to Competition
Set Industry Standard
Impact of Speed To Market
Some Benefits of :
Cost reduction
Affordability of the consumer /
user
Increase Market ShareProfit Margin
The Benefits of :
Improve quality
Design SimplificationRedundant
Components
Over Design
Some DFM Guidelines :
1. Standardize.
2. Design parts that can tangle with themselves.
3. Reduce the overall number of components.
4. Reduce the number and types of part.
5. Design with symmetric features
6. Reduce Adjustments
7. Maximize Compliance
8. Eliminate machining Operations
Some DFM Guidelines :• Reduce the Overall number of component
Some DFM Guidelines :• Maximize Compliance
Some DFM Guidelines :• Reduce the number and types of parts
Some DFM Guidelines :• Reduce the number and types of parts
Some DFM Guidelines :• Provide for self-adjustment
Some DFM Guidelines :• Design with symmetric features
Some DFM Guidelines :• Design parts that can’t tangle with
themselves
Conclusion
‘Model T of 1900s’ set out by Henry Ford to cater specifically for a mass-marketSet out to produce it as cheap as possible: mass-production, inter changeable parts, moving assembly lineAn increasing the production volume and decreasing unit costIn 1910, 20,000 Model T manufactured at the cost of US $ 850 eachIn 1916, 600,000 Model T manufactured at the cost of US $ 350 each
TIME LINE OF MATERIAL DEVELOPMENT
SOME IMPORTANT PROPERTIES OF MATERIALS
• HARDNESS
• TOUGHNESS
• MALLEABILITY
• DUCTILITY
• ELECTRIC CONDUCTIVITY
• THERMAL CONDUCTIVITY
• DENSITY
• ELASTICITY
• STRENGTH
Functional requirements
An obvious factor to consider when selecting a material is the
function it should perform. For example, a knife blade must
be hard, a window transparent and an aircraft light.
Some properties of materials:
HARDNESS
A material is hard if it is not easily
worn away or dented. Cutting tools
and some kitchen utensils are made
from hard materials. A simple test to
compare the hardness of different
materials can be carried out using a
centre punch. Drop the punch from the
height of 500 mm onto each sample in
turn and compare the dents. The
smaller the dent, the harder the
material.
TOUGHNESSA tough material is one that can withstand sudden shocks without breaking. (a material that breaks easily with a sudden shock is said to be brittle.) car bumpers and cycle helmets are made from tough materials. A test for comparing the toughness of different materials may be conducted using a hammer and a vice. The samples should have identical dimensions Ø6 mm x 50 mm and contain □5 mm x 3 mm notch. Each sample in turn is clamped in the vice and the raised hammer is released so that it swings under its own weight and hits the sample. The greater the angle of swing needed to break the sample, the tougher it is.
Toughness test using a swinging hammer
MALLEABILITY
A malleable material is one
that can be permanently
deformed without cracking or
tearing when it is
compressed. Malleable
materials can be hammed into
new shapes, an essential
property when making some
jewelers and decorative
products. The malleability of
different materials can be
compared using a doming
block by sinking a dome into
each sample in turn then
examining each for cracks or
tears.
Malleability test using a doming block
DUCTILITYA ductile material is one that can be permanently deformed without cracking or tearing when it is tension. Some rods and wires are made from ductile materials. A test to compare the ductility of materials can be conducted using a draw plate and a pair of tongs. The samples should have identical dimensions and are slowly pulled through the drawplate in turn until they are completely through or broken. By measuring the new length of each sample, the ductility of the materials is determined. The greater the extension of a material, the more ductile it is.
Ductility test using a draw plate and tongs
ELECTRIC CONDUCTIVITYA material is an electric conductor if
an electric current can flow through it
easily. Easily cables and the tracks on
a printed circuit board are made from
materials that are electric conductors.
Materials that do not allow an electric
current to flow through them are
called electric insulators. A sample
electric conductivity test can be
carried out on a range of materials
using a battery, a filament bulb and
two probes ( made from pieces of
wire). The probes, spaced
approximately 500 mm apart, are
placed on each material in turn. The
brighter the bulb shines, the better the
electric conductivity of material.
Electric conductivity test using an electrical circuit
ELECTRIC CONDUCTIVITYA material is a thermal conductor if heat can flow through it easily. Cooking pots and soldering iron tips are made from materials that are thermal conductors. Materials that do not conduct heat are called thermal insulators. A test for thermal conductivity can be carried out using an immersion heater, a set of thermometers and material samples of an equal size that have been predrilled. The immersion heater is inserted into one end of a sample and switched on. The thermometers, inserted in holes along the length of the sample, are examined at regular intervals throughout a five-minutes period and their temperatures are recorded. The greater the increase in temperature along the sample, the better its thermal conductivity.
Thermal conductivity test using a thermal circuit
DENSITYA material is dense if it has a high mass to volume ratio. The density of a material is expressed in kg/m³ and can be calculated using the formula:
Density = mass
volume
Dense materials are used where weight is needed such as to prevent items being blown over by the wind or to hold something underwater. Road rollers, hammer heads, diving belts and multi-gyms are some of the products that make use of dense materials. The density of materials can be compared by weighing each sample in turn and dividing by its volume. The higher the figure, the greater the material’s density.
A material being weighed to check its density
ELASTICITY
An elastic material is one that returns to its original shape after being
deformed. Springs, rubber bands and trampolines and car bumpers are
made from elastic materials. A material that does not return to its original
shape after being deformed is said to be plastic.
A test to compare the elasticity of different materials can be conducted
using a set of 100g masses, a retort stand and samples of the materials in
wire form, each 500 mm long with cross-sectional area of approximately 1
mm².
Each sample is tested in turn by securing one end to the top of the stand,
then suspending a mass from the other end. To begin with, a single 100 g
mass is applied. After 30 seconds the mass is removed and the length of the
wire sample is measured and recorded. This process is then repeated with
an additional 100g mass aded each time to a maximum of 1 kg or until the
sample breaks.
If the length of a sample is
unchanged when the mass is
removed, the material has
behaved in an elastic manner
If the length of a sample has
increased when the mass is
removed, the material has
behaved in a plastic manner.
Nearly all materials have elastic
properties below a certain load.
Beyond it, they behave plastically
then break. This load varies from
one material to another. Elasticity test for materials
STRENGTH
A strong material is one that can resist a force without breaking or permanently distorting. A material will have different strengths against different types of force.
A material has tensile strength if it resists stretching forces
A material has compressive strength if it resists squashing forces
A material has bending strength if it resists bending forces
A material has torsional strength if it resists twisting forces
A material has shear strength if it resists shear forces (forces that attempt to cause one part of the material to ‘slide past’ another part)
DIFFERENT TYPES OF FORCE