year 9 term3 Flashcards
materials
What are the primary sources of materials for producing papers and boards?
Wood, bamboo, flax, hemp, kenaf, straw, sugarcane
Wood fibres are primarily sourced from faster growing softwoods rather than hardwoods.
What is the first stage in the production of paper and board?
Making pulp
The natural cellulose fibres are mixed with water and cooked to produce a fibrous liquid known as pulp.
What factors determine the final finish of paper or board?
- Type of fibre used
- Chemicals added during manufacturing
- Addition of layers, coatings, or laminates
- Bleaching level
Bleached pulp is used for high quality ‘bright’ paper.
How is paper weight measured?
Grams per square metre (GSM)
Understanding different types of paper helps in selecting the right material for specific jobs.
What is bleedproof paper?
Smooth paper with a special coating to reduce absorbency
It resists bleeding and feathering, typically weighing around 70-80gsm.
What is cartridge paper used for?
Pencil and ink drawings, paintings
Heavier cartridge paper (200gsm) is more suitable for watercolour and acrylic painting.
What does grid paper help with?
Drawing graphs, diagrams, plotting mathematical functions, adding scientific data
Printed squares or isometric grids aid in accuracy.
What are layout and tracing papers used for?
Working sketches and ideas
Layout paper is lightweight and smooth; tracing paper increases translucency.
How is cardboard characterized?
Heavy duty paper available in various thicknesses and strengths
Board is measured in microns; 1000 microns equal 1mm.
What is corrugated cardboard made up of?
One or two outer flat layers and a corrugated layer
It is lightweight but strong, commonly used for delivery containers.
What is foil lined board used for?
Food-safe cartons for liquids
It has a waxy coating making it resistant to oils and liquids.
What is duplex board?
Made up of two layers with a wax coating for moisture barrier
Its smooth surface is suitable for offset printing.
What is foam board or foamcore used for?
Backing material for graphic signage, architectural models
It is rigid, lightweight, and cuts cleanly with a sharp blade.
What is solid white board characterized by?
High quality board with a bright white finish, suitable for book covers
Weights range from 200gsm – 500gsm.
What is ink jet card designed for?
Use with an inkjet printer
It has a special coating for increased stability and even ink coverage.
What are the primary sources of materials for producing natural and manufactured timbers?
Natural and manufactured timbers
Natural timbers come from trees, while manufactured timbers are made from processed wood products.
How is natural wood categorized?
Natural wood is categorized as either hardwood or softwood
Each type has distinct characteristics and uses.
What are the characteristics of hardwood trees?
Deciduous, drop leaves in autumn, slow growing, variety of colors and grains
Hardwood trees include species like oak and mahogany.
What are the characteristics of softwood trees?
Coniferous, evergreen, faster growing, wider grain
Common softwoods include pine and spruce.
What makes wood a sustainable resource?
Can be grown and harvested responsibly in managed forests
This makes wood biodegradable and renewable.
What is the role of felling in timber production?
Felling is the process of cutting down a tree
Traditional methods include saws and axes, while modern methods use chainsaws.
What are the working properties of timber?
Strength, toughness, elasticity, hardness
These properties affect the performance of the timber in various applications.
Fill in the blank: Softwood comes from _______.
coniferous trees
What is Balsa wood known for?
Soft, lightweight, strong in relation to weight
Used for prototypes and model aircraft.
What are some common uses of hardwood?
Furniture, musical instruments, boats, interior panelling
Mahogany is a popular choice due to its aesthetics and durability.
What are the advantages of using softwood in construction?
Cost-effective, readily sourced, lightweight
Examples include pine and larch.
What is tonewood?
Wood with tonal properties ideal for stringed instruments
Examples include spruce and mahogany.
How are manufactured boards created?
Made from sawmill scraps, recycled wood, and adhesives
Common types include MDF and plywood.
What are some advantages of using manufactured boards?
Large board sizes, tough, relatively inexpensive
Ideal for applications like flooring and kitchen worktops.
What is a common natural defect found in timbers?
Knot
Knots can affect the appearance and strength of the wood.
Which types of timber are used for window frames?
Pine, oak, cedar, beech
Selection depends on durability and aesthetics.
What materials are typically used for timber external cladding?
Larch, cedar, oak, pine
These materials provide weather resistance and aesthetics.
What is the significance of the strength-to-weight ratio in timber?
Indicates how much load the timber can support relative to its weight
Important for applications requiring lightweight yet strong materials.
True or False: Hardwood grows faster than softwood.
False
What are the primary sources of materials for producing metals and alloys?
The Earth’s crust contains metallic minerals found in rock or ore.
What does the word ‘metal’ originate from?
The ancient Greek word ‘metallon’, which means to mine, excavate or extract from the ground.
What is ore and how is it obtained?
Ore is obtained by mining and contains metals that are extracted.
What factors influence the cost of extracting metals?
The reactivity of the metal with air, water, or acids; more reactive metals are more expensive to extract.
What is the process used to extract metals such as copper, iron, and zinc?
These metals are heated with carbon to extract the metal.
How is iron extracted from iron ore?
Iron is extracted using a blast furnace and the process of smelting.
What is ‘hot metal’ in the context of metal extraction?
Hot metal is the liquid state of metals drawn off during the smelting process.
What is rust and how is it formed?
Rust is iron oxide formed when iron reacts with oxygen in the presence of moisture.
What are ferrous metals?
Ferrous metals contain iron and may rust.
What is ductility?
Ductility is the ability of a metal to stretch without being damaged.
What is malleability?
Malleability is the ability of a metal to be hammered into shape without breaking.
What is the difference between hardness and toughness in metals?
Hardness is a material’s ability to withstand abrasion; toughness is how well a metal can absorb energy and resist fracturing.
What is tensile strength?
Tensile strength is the amount of tensile stress a material can withstand before breaking.
What is the main element combined with iron to produce steel?
Carbon.
What are the properties of low carbon steel?
Tough, ductile, and easily welded.
What are non-ferrous metals?
Metals that do not contain iron.
List some desirable properties of non-ferrous metals
- Lightweight
- Good conductivity
- Ductile and malleable
- Resistant to corrosion
What is galvanising?
The process of adding a protective coat of zinc to iron and steel to prevent rusting.
What is electrical conductivity?
How easily an electrical current can flow through a metal.
What are some common non-ferrous metals?
- Aluminium
- Copper
- Tin
- Zinc
What is tin commonly associated with?
Tin can is actually a steel can with a thin coating of tin, known as ‘tin plating’.
What is an alloy?
A combination of two or more elements to improve working properties and appearance.
What is stainless steel made from?
Iron, a small amount of carbon, and chromium.
How is tin used in household items?
Tin is used in ‘tin cans’ and is soft, ductile, and malleable.
What is the technique called that involves working with recycled cans?
Kapoaka.
What is oxidisation in metals?
A process where non-ferrous metals like copper and bronze may develop a thin layer of tarnish over time.
What is patina?
A thin layer of tarnish that appears on the surface of oxidised metals.
What is Verdigris?
A natural patina occurring on copper, often green in hue.
What are the primary sources of materials for producing polymers?
Finite resources such as coal, natural gas, crude oil and renewable materials like vegetable starches
Renewable materials are used to create bio-plastics.
What are the two types of plastics?
- Thermoforming
- Thermosetting
What happens to thermoplastics when heated?
They become soft and flexible, allowing remoulding without affecting physical properties.
What are thermosets?
Plastics that cannot be reformed once set into shape due to strong chemical bonds.
What is plastic memory?
The tendency of thermoplastics to try to return to their original shape after reheating.
What are the pros of thermoplastics?
- Repeatedly heated and moulded
- Good surface finish
- Can be recycled
What are the cons of thermoplastics?
Not suitable for areas of heat or UV sensitivity.
What are the pros of thermosets?
- Hard and durable
- Good structural rigidity
- Waterproof when solid
- Good electrical insulator
What are the cons of thermosets?
Cannot be remoulded.
What is blow moulding?
A process for forming hollow plastic items.
What is extrusion?
Creating objects with a cross-section profile.
What is injection moulding?
Injecting softened plastic into a mould.
What is vacuum forming?
Forcing a sheet of softened plastic onto a mould.
What is polyethylene?
The most common thermoplastic with over 80 million tonnes produced globally each year.
What are the types of polyethylene?
- Polyethylene terephthalate (PETE)
- High density polyethylene (HDPE)
- Low density polyethylene (LDPE)
What are the uses of polyethylene terephthalate?
Lightweight, chemically resistant, stable, easily blow moulded.
What are the uses of high density polyethylene?
Lightweight, rip and chemical resistant, stiff, recyclable, tough.
What are the uses of low density polyethylene?
Flexible, tough, high strength to weight ratio, easily extruded into sheets.
What is polyvinyl chloride (PVC)?
A thermoplastic widely used for packaging, pipes, outerwear, electrical tapes, and children’s toys.
What are the properties of polypropylene?
- Lightweight
- Ductile
- Chemically resistant
- Easily cleaned
What is high impact polystyrene (HIPS)?
A thermoplastic that is shatterproof, flexible, and lightweight.
What is acrylic polymethyl-methacrylate?
A versatile and hard-wearing thermoplastic available in various thicknesses and colours.
What are resin identification codes used for?
To easily separate thermoplastics for recycling.
What are epoxy resins?
A class of thermosetting polymers supplied as two liquids: a resin and a hardener.
What is polyester resin used for?
- High-performance coatings
- Object embedding
- Composite materials
What is formaldehyde in the context of thermosetting plastics?
An early compound used to create thermoset products like melamine and phenol formaldehyde.
What are the properties of melamine formaldehyde?
- Hard thermoset
- Good resistance to heat, chemicals, and moisture
- Prone to chipping
What is urea formaldehyde used for?
- Manufacturing electrical fittings
- Treating textiles for easy care properties
- Improving tear strength in paper
what is the common textile we use everyday?
wool, cotton, polyester, silk , leather
natural fibre
wood, silk, cotton
Textile categories
natural fibre, synthetic fibre, blended and mixed fibre, wool and non-wool andfibreknittextile
synthetic fibre
polyester, elastane, nylon
cotton
a fruit harvested from a cotton plant
silk
cocoon of the larvae of a silkworm
