Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

DT Section B Metals > Section A > Flashcards

Section A Flashcards

1
Q

Thermoforming/ Thermoplastics

A
  • thermoplastics
  • when heated the plastic becomes soft and flexible
  • they can be remoulded without affecting the material’s physical properties
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Thermosetting

A
  • thermosets
  • this plastic can’t be reformed once set into a shape
  • they have strong chemical bonds between molecules which can’t be broken by heat
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Molecular structure in thermosets

A

individual monomers join to form a larger polymer.
these long chains of molecules are cross- linked resulting in a rigid molecule

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Thermoplastic pros and cons

A

PROS- can be repeatedly heated and remoulded, good surface finish gives it good superior aesthetics, can be recycled.
Because it can be remoulded the plastic is reusable, and creates less landfill waste.

CONS- not suitable to use under heat or UV sensitivity. Every time it is heated the plastic tries to return to its original shape- plastic memory.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Thermosets pros and cons

A

PROS- hard and durable with good structural rigidity, can withstand high temps, waterproof so great to use as adhesives, good electric insulator

CONS- can’t be remoulded or recycled

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Uses of Plastic- Moulding and Forming

A
  1. Blow moulding- forming hollow plastic items
  2. Extrusion- creating objects with a cross section profile
  3. Vacuum forming- sheet of softened plastic is forced onto a mould
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Thermoplastic- Polyethylene (PETE/ HDPE/ LDPE)

A
  • rigid with good strength to weight ratio
  • good ductility (easily extruded into sheets) and impact strength
  • used for plastic packaging
  • lightweight
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Examples of ALL thermoplastics

A
  • PETE: bottle
  • HDPE: plastic bag
  • PVC: sports equip - rigid, flexible
  • LDPE: juice bottles
  • PP: food container- lightweight, ductile, chemically resistant and easily cleaned
  • HIPS: food container- flexible, shatterproof
  • Oher e.g. Acrylic- versatile and hardwearing
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Examples of ALL thermosets

A
  • epoxy resin: reactive polymers, and is supplied as a resin and a hardener which acts as a catalyst to set the resin. Used as adhesives, good strength to weight ratio.
  • melamine formaldehyde: hard thermoset, good resistance to heat, chemicals and moisture. Often used in tile flooring and kitchenware products.
  • urea formaldehyde: good electrical insulator, used for manufacturing electrical fittings. Used in clothing to prevent anti-wrinkling, used in papers to improve tear strength
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Synthetic Fibres

A
  • made from different types of polymer, derived from petrochemicals
  • during manufacture, dye is added for wide range of colors
  • Polyester and Polyamide:
    1. Hardwearing
    2. Non- Absorbent and wash well
    3. Can blend with other fibres
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Examples of Synthetic Fibre

A
  1. Polycotton: polyester and cotton
    Lightweight, can absorb moisture, durable fabric for bed sheets, pillow cases
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Properties of Wood

A
  • aesthetically pleasing
  • good insulator
  • durable and tough
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Felling

A

traditional way: saws and axes
modern way: chainsaws which can fell, debranch and log tree in one go

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Softwood

A
  • coniferous trees
    PROS: grow faster than hardwood
    cheaper and more readily available
    CONS: grain is wider so they are absorbent and low density making them weaker.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Hardwood

A
  • deciduous trees
    CONS: slower to grow and therefore more expensive
    PROS: variety of colors and grains, good aesthetic and physical properties
    very dense and hardwearing
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Examples of Softwood

A

pine- window frames; lightweight
larch- timber external cladding; durable and water resistant
cedar- wooden roof tiles; naturally water resistance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Examples of Hardwood

A

oak- front door; tough, hard
beech- cooking utensils
ash- shock resistant
mahogany- used in guitars, interiors, boats
has a pretty warm reddish hue, however the desire for it has increased leading to illegal logging trade.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Ferrous Metals

A
  • contains iron so may rust
  • rust is iron oxide layer formed when iron and oxygen in the presence of moisture
  • some are magnetic
  • e.g. stainless steel
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Ductility and Malleability

A

Ductile- will stretch without being damaged, can be drawn into long wires
Malleable- can be hammered without breaking, can be pressed into sheets

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Hard Vs Tough

A

Hard- likely to crack or shatter but will be able to withstand abrasion
Toughness- won’t shatter upon impact but likely to be prone to scratches

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Tensile Strength

A

amount of tensile stress (stretching) a material can withstand before breaking or failing.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Different Ferrous Metals

A

LOW CARBON STEEL: tough, ductile- construction like bridges as bolts
HIGH CARBON STEEL: hardwearing, less ductile and malleable- saw blades
CAST IRON: hard and easily cast into shapes-
frying pains

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Mild Steel is Low carbon steel

A

It is used in the construction and automotive industries, and for fencing, signs, and innumerable other applications. It is valued for its weldability, machinability, and ductility.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Properties and uses Alloys

A

Alloys are mixture if two or more elements that are metals.
- improves working quality and appearance
- brass and steel for e.g.
- alloys are stronger, harder, more durable, and sometimes more corrosion-resistant than their pure metal counterparts.

25
Q

Aluminium- Non Ferrous Metals

A
  • don’t contain iron
  • more expensive than ferrous metals
  • lightweight
  • ductile and malleable
  • good conductivity
  • resistant to corrosion
26
Q

Properties and Uses of Cardboard

A
  • comes in range of thickness and strengths
  • made of recycled paper
  • can be laminated to other materials to increase strength or provide and alternative surface
  • used for cereal box, milk cartons, packaging
27
Q

Properties and Uses of Corrugated Cardboard

A

made up of one or two outer flat layers and a corrugated layer
- used for delivery packaging
- lightweight but strong
- can be printed on

28
Q

Properties and uses of Duplex Board

A

Duplex paperboard is an eco-friendly material made from 100% recycled paper.
- great for offset printing
- ideal for folding and cutting
- used for food packaging

29
Q

Properties and uses of Foam Board

A

consists of sheet of polystyrene foam sandwiched between outer layers of paper
- rigid, lightweight
- cuts clean with blade making it ideal for architectural models and prototypes
- 100% recyclable and reusable

30
Q

Smart materials

A

Smart materials have properties that react to changes in their environment. This means that one of their properties can be changed by an external condition, such as temperature, light, pressure, electricity, voltage, pH, or chemical compounds. This change is reversible and can be repeated many times.

31
Q

Example of Smart Material

A

Shape-memory alloys (SMA) are metal alloys that can remember their shape when heated. These alloys have been utilised on spectacle frames that spring back to shape if they are squashed.

32
Q

Different types of Forces

A

Tension
Compression
Torsion
Bending
Shear

33
Q

Motion

A

-action of something being moved
- motionless: at rest

34
Q

4x types of Motion

A

LINEAR- one direction in straight line e.g. car
ROTARY- back and forth or up and down motion in a straight line e.g. sewing machine needle
RECIPROCATING- circular motion around an axis e.g. fan
OSCILLIATING- back and forth motion in a curved path e.g. pendulum

35
Q

Types of Mechanisms- Lever

A
  • has a mechanical adv
  • they have bar, pivot and fulcrum (like the pivot)
  • MA = LOAD/ EFFORT
36
Q

First order LEVER

A
  • act in seesaw or scissors action
  • load and effort are on opposite ends with fulcrum in between
37
Q

Second order LEVER

A
  • act in a wheelbarrow action or a nutcracker
  • effort and fulcrum are on opposite sides with load in between
38
Q

Third order LEVER

A
  • action like tongs and tweezers
  • load and fulcrum are on opposite ends
  • effort is in between
39
Q

Reverse Motion Linkage

A
  • changes direction of input motion
  • if input is pulled, output is pushed
  • it has a central fixed pivot
40
Q

Parallel Motion Linkage

A
  • also known as push/pull linkage
  • direction of output is same as input
41
Q

Bell Crank Linkage

A
  • input direction is converted through 90deg
  • horizontal turns vertical and vice versa
42
Q

Crank and Slider Linkage

A

converts rotary motion to reciprocating motion and vice versa

43
Q

Treadle Linkage

A

converts rotary motion to oscillating motion

44
Q

Types of cams

A

Eccentric cam
Pear cam
Snail cam
Heart-shaped cam

45
Q

Types of followers

A

Flat Follower
Knife-edged follower
Roller Follower

46
Q

Idler Gear

A

Ensures that direction of drive gear is the same as driven gear. Idler sits between these two gears and directly transfers drive.

47
Q

1.Before designing it is important to do research

A
  1. Primary research- new data collected by designer e.g. interviews, questionnaires, case studies
  2. Secondary research- part of research from articles, books and magazines
    Questions to ask:
    - What are clients requirements?
    - who will use the product?
    - suitable materials and their cost
48
Q
  1. Market Research and 3. Product Analysis
A

Research helps designer analyse and identify the market need for a product, the competition…
Product Analysis- consider product functionality, observe the aesthetics and appeal, note materials and finishes, evaluate strengths and weakness of design.

49
Q
  1. Functional Performance
A

Product analysis helps with:
- production method
- types of finishes and materials needed
- functionality of design
FOCUS ON ACCESSFM

50
Q
  1. Response to Product + Focus Group
A

Focus group is made of diverse people who have a trial of early version of design
This is useful to gather their reaction and attitude towards product.
It is a good way for business to engage with their customers

51
Q

Ergonomics

A

Science of how people interact with objects- design for efficiency and comfort

52
Q

Anthropometrics

A

Measurements of physical properties of human body.
- height, weight, viewing distance and angle

53
Q

Ergonomic design

A
  • design should be functional and comfortable
  • touch, feel and smell are all considered
54
Q
  1. Percentiles Graph and Charts
A

anthropometric data is presented in bell graph
- top and bottom (5th and 95th percentile) 5% of people will be excluded as products can’t fit 100% of the audience
- the 50th percentile is the avg person measurement

55
Q
  1. Design Brief
A

this the conclusion of all your research to summarise your design plan,it should be clear and precise

56
Q
  1. Design specification
A

used to describe all client and technical requirements gathered in research process. It has function, material and anthropometric data. It is used to create final design

57
Q
  1. Manufacturing Specification
A
  • includes drawings, CAD or 3d designs
  • should be detailed, accurate and material list
    -used as basis of testing and evaluation
58
Q
  1. Test Design
A

strength and stress testing
safety testing
does it work?
after testing, modifications may be made

59
Q
  1. Environmental Challenges
A

new methods of using waste materials and recycles material, reducing use of limited material, lowering energy consumption

DT Section B Metals (2 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions