Plastics, wood, el. appliances Flashcards
(77 cards)
1
Q
What is wood
A
- Wood is hard fibrous material making the trunk and branches of trees or bushes
- Organic and hygroscopic material (it naturally absorbs and releases water)
- Renewable and sustainable resource
- Recyclable and biodegradable
2
Q
Types of trees
A
o Conifer trees
o Decidous trees
3
Q
Parts of tree
A
o A tree is a perennial plant with roots, a trunk, side branches and twigs
o A branch system forms a crown
o The trunk carries water with dissolved minerals upwards and downwards
o The leaves turn sunlight into their energy (glucose), they also make the oxygen in the air
4
Q
Wood components
A
Cellulose – an orgainc compound derived from glucose, gives the wood its strenght
Hemicellulose – gives wood its flexibility
Lignin – the glue which holds fibres together, gives wood its stiffness
Water
5
Q
Wood characteristics
A
o Physical properties
Low weight
Typical smell and colour
Perfect insulator
Poor electrical and heat conductivity
o Mechanical properties
Strong
Durable
Hardness
Tension
Density
o Chemical properties
Flammability
Reactivity with oxygen, water and acid
6
Q
Hardwood
A
o Comes from flowering plants (oak, beech, maple)
o Last longer, they are denser
o More expensive
o Used for high quality furniture, musical instruments, floors, counstruction and boatbuilding
7
Q
Softwood
A
o Come from evergreen conifers (pine, spruce)
o Grow rapidly, less stable
o Cheaper, easier to work with
o Used for manufacturing of windows, interior mouldings amd MDF (medium density fiberboard)
8
Q
Wood products
A
o Primary
o Secondary
9
Q
Primary wood products
A
Logs are used as raw materials
* Lumber
* Pulp
* Panel products
* Paper
10
Q
Lumber
A
o Dimensional lumber
o Laminated lumber
o Decking
o Timber
11
Q
- Panel products
A
Veneered products – Plywood
o Non-veneered products – Fiberboard, particleboard
12
Q
Secondary wood products
A
Manufactured wood products
* Furniture
* Pallets
* Moldings
* Others
13
Q
What is plastic
A
- The word comes from Greek word “plastikos” meaning capable of being shaped or moulded
- Main ingredient polymers
- All plastics are based on carbon, most plastics are derived from fossil fuel-based chemicals (natural gas or oil)
14
Q
Pros of plastics
A
Lightweight, flexible and durable material
Non-corrosive material, easily moulded
Safe and tough packaging material
Strong, non-reactive to air and water
Resistant to heat, chemicals, oil and grease
Low processing cost
Good insulation and low thermal conductivity
15
Q
Cons of plastics
A
Poor mechanical strength
Both the production and recycling of plastics pollute the environment
Difficult disposal after use (natural decomposition lasts very long and some are non-degradable)
Plastic materials affect water bodies like oceans, seas, lakes
Many animals consume plastic products and are dying
16
Q
Classification of plastics
A
o By their behaviour in the manufacturing process - Thermoplastics and thermosets
o Commodity plastics:
17
Q
Thermoplastics:
A
- Do not undergo a chemical change in their composition when heated, can mould several times
- Example: PP, PE, PVS and PS
18
Q
Thermosets:
A
- Can melt and mould into any shape only once, they cannot be returned to their original state
- Example: Rubber, acrylic, silicone
19
Q
o Commodity plastics
A
Six major types
They are masked with a triangle of 3 “chasing” arrows, with a number giving the plastic type (3 parts of recycling process – Collection, remanufacturing and resale)
PET, HDPE, PVC, LDPE, PP, PS, Other types
20
Q
- PET (PETE) – polyethylene terephthalate
A
- Use: soda bottles, water bottles, polyester film, containers for food, jars, fibre for clothing
- Recycled: Commonly – into fleece, fiber, bags, furniture, carpets
1
21
Q
- HDPE – high-density polyethylene
A
- Use: detergent containers, plastic bottles, piping for water and sewer, snowboards, boats
- Recycled: Commonly – into detergant/oil bottles, pens, floor tile, drainage pipe
2
22
Q
- PVC – polyvinyl chloride
A
- Use: Window frames, plumbing products, electrical cable insulation, clothing, medical tubing
- Recycled: Rarely – never burn PVC
3
23
Q
- LDPE – low-density polyethylene
A
- Use: Shopping bags, plastic bags, clear food containers, disposable packaging
- Recycled: Sometimes – into trash bins and cans, compost bins
4
24
Q
- PP – polypropylene
A
- Use: laboratory equipment, automotive parts, medical devices, food containers
- Recycled: Sometimes – into brooms, brushes, pallets, trays
5
25
6. PS – polystyrene
* Use: CD and DVD cases, packing peanuts, single-use disposable cutlary trays
* Recycled: Rarely – sometimes into insulation, egg cartons, foam packing
6
26
7. Other types
*PUR, PES, ABS, Polyerethane, Polycarbonate, Lexan
Use: Baby feeding bottles, car parts, water cooler bottles, sippy cups
* ABS Use: Monitor/TV cases, coffee makers, cell phones, calculators, most computer plastic, lego bricks
* Recycled: Sometimes – Custom-made products
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27
Enviromental impact of plastics
o Waste – the highest negative enviromental impact
o Single-use plastics accounts for 40% of the plastic produced every year
o Harm to wildlife – plastics have been consumed by both water and land animals, sometimes causing death
o other impacts occur during the resource extraction, production, consumption and end-of-life phases of plastics
o Pollution of air, water and soil
o Impact on human health
28
Possible solutions
o Reuse it where possible
o Bring your own bags for grocery shopping
o Avoid single-use plastics
o Use renewable plant materials such as cellulose and starch for plastics manufacture
o Use biodegradable plastics – they can degrade or break down when exposed to sunlight or ultraviolet radiation, bacteria, certain enzymes, dampness or water
29
Recycling process
o 3 parts
Collection
Remanufacture
Resale
o Only about 40% of plastic packaging waste is recycled in the EU-28
o Through municipal recycling programs, specific types of plastics are collected, sorted out, and processed for recycling
30
What are electrical appliances
* Electrical/mechanical devices use or generate electricity and transform it into another form of energy
* They usually accomplish household functions, such as cooking, cleaning or entertainment
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Basic types of electrical appliances
o Electrothermal (ET)
o Electromechanical (EM)
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* Classification of home appliances
o Major appliances = white / heavy appliances
o Small appliances
Consumer electronics
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o Major appliances = white / heavy appliances
ET - cooker, fridge, freezer, oven, dishwasher, water heater, heating appliances
EM - Washing machine, grass mower, vacuum cleaner
34
Cooker
o A standard cooker can have 4 burners and up to 2 ovens
35
Types of cooker
Gas – uses natural gas, propane, butane
Ceramic
Electric – an electric powered device
Induction – requires special material of cooking vessels – ferromagnetic metal such as cast iron or stainless steel
Cook stove – heated by burning wood, charcoal, animal dung
36
Fridge
o It uses electricity to preserve food at a cold temperature (from 3 to 7 °C)
o It consists of a thermal insulated compartment and a heat pump that transfers heat from its inside to its external environment
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Fridge heatpump
Mechanical
Electronic
Chemical
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Fridge history
1930s – Not flammable synthetic refrigerant such as Freon-12 were introduced.
However R-12 damaged the ozone layer.
Since 1990 less harmful tetrafluoroethene (R-134) has been in common use.
Nowadays, the most common used coolant is R-600a, or isobutane.
39
How it works - fridge
Compressor – heart of the fridge (it circulates the refrigerant throughout the system and makes it hot)
Condenser – the refrigerant is cooled down inside and condenses here – it turns from a gas back into a liquid
Evaporator
Capillary
Thermostat
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Types of fridges
Compressor fridge
Absorption fridge
Solar fridge
American style fridge
Magnetic fridge
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Compressor fridge
* The most common type
* The most efficient
* Give greatest cooling effect
* They make a noticeable noise
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Absorption fridge
* May be used in caravans, trailers and places without electricity
* Is powered by gas, kerosene or 12V batteries
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Solar fridge
* They do not use refrigerants
* Use ammonian as the working gas and solar panels
44
American style fridge
* Very spacious
* Popular for its unusual features, e.g. ice maker, instaview, built-in camera, SodaStream
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Magnetic fridge
* They work on the magnetocaloric effect
46
o Special features - fridge
Auto-defrost, self-defrosting – it regularly defrosts the evaporator
Adjustable shelves and trays
Door locks and alarms
In-door ice maker, coffee maker
Smart fridges knows what kind of products are being stored inside and keep a track of the stock through barcode or RFID scanning
47
Energy label - fridge
shows the energy efficiency scale A-G
o Noise emission class
o Total volume of a fridge/freezer in litres
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Freezer
o A refrigerated cabinet or room for preserving food at very low temperature
o It is designed to hold food at -18°C for a long term storage
o The majority of freezers are bottom freezers, having the freezer compartment below the refrigerator compartment
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Types of freezers
Upright freezer
Under-counter freezer
Chest freezer
Drawer freezer
50
Special features - freezer
Fast freeze function
No frost/frost free
Temperature alarm
Freezer defrost
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Rating system - freezer
* -6°C
** - 12°C
*** -18°C
**** -18°C (with fast freezing function)
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Oven
o Electrothermal appliance based on the generation of heat by passing current through a conductor
53
Types of oven
Built-in oven
Free-standing
Steam oven
Light oven
o Gas ovens are more expensive to purchase than electrical ovens, but they cost less to run
54
Special features - oven
Dehydration options
Touch screens
Speed cooking
Wireless connection
Ventilation
55
Dishwasher
o The first dishwasher woth electric motor was invented by Miele in 1929
o Mechanical machine that cleans off dishes through spraying bursts of hot water (45°C – 75°C) and detergent at the dishes
56
How does a dishwasher work
Mix of water and detergent is pumped to one or more rotating spray arms.
Once the wash is finished, the water is drained, and the rinse cycle begins.
After the rinse cycle finishes and the water is drained, the dishes are dried.
57
Dishwasher - advantages
More efficient than hand washing – it uses around six times less energy, water and detergent
Saves your energy – you may wait several days for it to be full before running it
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Dishwasher - disadvantages
You cannot wash certain items in a dishwasher (made of wood, aluminium, children’s dishes with design, fine china dishware)
59
Dishwasher - special features
Anti-flood protection
Fan or auto-open
Adjustable plate racks
Height-adjustable baskets
Cutlery tray
Child lock
Sensor-assisted wash cycles – adjust the wash duration to the number of dirty dishes
60
Types of dishwashers
Built-in
Double
Portable
Countertop
61
Energy label - dishwasher
water and energy rating, the new labe shows the energy consumption in kWh/100 washing cycles
62
* Washing machine
o An electrical appliance used to wash laundry
o Early Miele washing machine with a mangle (probably 1930)
63
How does it work - washing machine
There are 2 drums, one inside the other
Bigger drum holds the water while the inner drum (in a front loader) or the agitator (in a toploader) rotates
Operation of washing machine is split into 3 cycles:
* Wash cycle – here clothes are washed in water with detergent
* Rinse cycle – here dirt which is separated from clothes is drained
* Dry cycle – here clothes are made to be dried
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Types of washing machines
Top-loading
Front-loading
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Top loading washing machine
* Have shorter cycle times
* Operate more quietly
* Easy to add clothes
* Use more water, energy, and washing detergent
* Cost more to run
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Front loading washing machine
* They usually use less energy, water and detergent
* Their maximum spin speeds are higher – up to 2000 RPM (revolutions per minute)
* More expensive and louder
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Special features - washing machine
Delayed start
Predefined programmes for different laundry types
Variable temperatures, including cold wash
Time remaining indication
Rotation speed settings
Wi-Fi connectivity
Child lock
Steam washing
68
Energy label - washing machine
Washing performance and spin efficiency are graded in the range A – G, other information include noise level of spinnig cycle, maximum wash time and capacity
69
Small appliances
ET - Electrical kettle, Coffee maker, Deep fryer, Grill, Toaster ,Curling iron, Hair straightener, Microwave oven
EM - Blender, Food processor, Grinder
70
Microwave oven
o Used mainly for defrosting, cooking, heating or melting
o Inside the solid metal box, there is a microwave generator called a magnetron
o Magnetron tube – converts high voltage energy into electromagnetic energy
o Microwaves aren’t dangerous because she electromagnetic waves stop as soon you cut off the power and open the door, and they don’t remain in the food and make it radioactive
o Microwave radiation is not dangerous to humans, but can sometimes cause interference to Wi-Fi and Bluetooth
71
Microwave oven - advantages
Melting and defrosting process is easy
Heating is simpler, without burning
Cooking time is shorter
72
Microwave oven - disadvantages
Not suitable for all food
Certain cookware can’t be used
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Devices for entertainment
* TV
* DVD player
* Game console
* Remote control cars
74
Consumer electronics
Devices for entertainment
Devices for communication
Devices for home-office activities
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Devices for communication
* Smartphone
* Headphones
* Laptop
* Tablet
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Devices for home-office activities
* Desktop computer
* Printers
* Paper shredders
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Energy label - in general
o Provides information about the product’s energy consumption and other specific data (the product’s noise, emissions, or water consumption)
o A new generation of labels was released on 1st March 2021
o Changes:
The QR code
The rescaled energy efficiency class
The annual energy consumption
