Year 10 - Design and Technology - Unit 3 - Materials and Their Working Properties

- Wood - Metals - Papers and board

What is paper and board?

Papers and boards are formed from wood pulp, which comes from trees. This squishy wood pulp is rolled out into thin sheets in paper will factories to form the papers and boards that we use.

What is a pulp?

Pulpis a soft, wet mass, often produced by crushing something. For example, wood pulp comes from trees and helps to produce paper and board.

What kind of treatment and finishes can be used on paper and boards?

The final finish of paper or boards depends upon:

• The type of fibre used to make the pulp.

• Any chemicals added during the manufacturing process.

• The addition of layers, different coatings or laminates.

• Bleaching level which decreases the natural colour so it becomes whiter. When a high quality 'bright' paper is required, bleached pulp would be used.

What is GSM and how does this relate to paper?

GSM stands for 'grams per square metre'. It refers to the weight of the paper. The heavier the paper, the higher the number of grams per square metre and, generally, the higher the percieved quality of the stock.

What is the GSM of tissue paper / crepe paper?

10-35 GSM

What is the GSM of Bible pages?

35-70 GSM

What is the GSM of office printer paper?

70-100 GSM

What is the GSM of high-quality letterhead paper?

100-120 GSM

What is the GSM of paper used for flyers, posters and brochures?

150-200 GSM

What is the GSM of paper used for greetings cards?

250 GSM+

Describe the appearance of bleed proof paper.

• Smooth.

• Has a special coating to reduce absorbency.

What are some characteristics of bleed proof paper?

• When drawing with a marker pen or writing with ink, the paper keeps the ink on the surface, which creates a crisper line or mark.

• Resists bleeding and feathering.

• Lightweight => 70-80 GSM

What are the uses of bleed proof paper?

Art:

• spray paint

• paint pens

• alcohol / solvent based markers

Describe the appearance of cartridge paper.

• Thick

• Quality

• Rough surface

• Opaque

What are some characteristics of cartridge paper?

• Available from 120-150 GSM.

• More expensive than copier paper.

What are the uses of cartridge paper?

• Watercolour painting

• Acrylic painting

Describe the appearance of grid paper.

• White paper with printed squares, isometric grids or other patterns.

• Lines are faint.

• Lines can be printed on different weights.

What is a characteristic of grid paper?

Usually printed on 80 GSM paper.

What are the uses of grid paper?

• Draw graphs, diagrams, 3D drawings.

• Plot mathematical functions.

• Add scientific data.

Describe the appearance of layout paper.

• Off white

• Medium opacity

• Smooth finish

• Translucency decreases as GSM increases

What are some characteristics of layout paper?

• Lightweight => Around 40-60 GSM.

• Accepts pencil and most other media as well.

What are the uses of layout paper?

• Sketching

• Quick ink

• Technical drawing

• Tracing

• Designing

Describe the appearance of tracing paper.

• Off white

• Low opacity

• Smooth

What are some characteristics of tracing paper?

• Sold in pads / rolls

• 40-280 GSM

• Passed through a bath of acid which partially dissolves the paper.

• Increases translucency

• Increases stability

• Takes pencil + most colours well

What are the uses of tracing paper?

• Drawing

• Sketching

• Designing

• Tracing

• Maths

Define corrugated.

Folded or wrinkled.

Describe the appearance of corrugated cardboard (fibreboard).

• Natural brown

• Made of 1-2 flat layers + corrugated layer.

• 1,000-5,000 microns.

What are some characteristics of corrugated cardboard (fibreboard)?

• Lightweight.

• Strong

• Rigid perpendicular to corrugations

• Insulative properties

• Smooth surface

What are the uses of corrugated cardboard (fibreboard)?

• Cardboard boxes

• Boxes

• Packaging

• Delivery boxes

Describe the appearance of duplex boards.

• Exterior layer often white with a wax coating to provide a moisture barrier and give it a glossy sheen.

• Two layers of card surface.

• Smooth white.

What are some characteristics of duplex board?

• Smooth white surface makes it suitable for offset printing

• Lightweight and stiff

• 200-500 GSM

What are the uses of duplex board?

• Folding

• Die cutting

• Containers

Describe the appearance of foil lined board.

Stiff card lined with aluminium foil on one side.

What are some characteristics of foil lined board?

• 200-400 GSM

• Foil reflects heat

• Waxy coating to resist water and oils

• The coating enables cartons containing liquid to be safe.

What is the use of foil lined board?

Food storage.

Describe the appearance of foam core board.

• Sheet of polystyrene foam sandwiched between outer layers of paper.

• Smooth board back and front.

What are some characteristics of foam core board?

• Rigid + lightweight

• Limited variety of colours

• 3-10mm thick

• Can crease and crack under pressure

• Cuts clearly with a sharp blade

What are the uses of foam core board?

• Prototypes

• Architectured models

Describe the appearance of ink jet card.

• Brilliant white card

• Matte or gloss coating

What are some characteristics of ink jet card?

• Designed for use with an ink jet printer.

• Special coating is applied to increase the stability of the print

• Smooth finish which ensures even ink coverage

• 120-150 GSM

• Ink dries on surface to create deeper colours

Describe the appearance of solid white board.

High quality bboard with a bright white finish.

What are some characteristics of solid white board?

• 200-500 GSM

• Strong + stiff

• Accepts printing + surface finishes

• Easily cut + creased

What are the uses of solid white board?

• Book covers

• Cosmetics

• Packaging

What are the two catergories of natural wood?

Hardwoods and softwoods.

Explain what a hardwood is.

Hardwoods are a type of wood that comes from angiosperm trees. These trees are known for their borad leaves and the fact that they produce flowers and fruits. Unlike softwoods, which come from carniferous trees, hardwoods tend to be denser, stronger, and more durable. Its leaves fall off in autumn / winter and change colour.

Explain what a softwood is.

Softwoods are a type of wood that comes from carniferous trees. These trees are characterised by their needle-like leaves and the fact that they produce cones instead flowers. Some characteristics of softwoods are: lighter, softer, faster growth, evergreen and less durable.

What term is used for cutting down a tree?

Felling.

Define felling.

Cutting down a tree.

Describe the appearance of an ash tree.

• Tall

• Straight trunks

• Feathering leaves

• Winged seeds

What are some characteristics of an ash wood?

• Hard

• Strong

What are the uses of ash wood?

• Tool handles

• Sporting equipment

• Furniture

• Flooring

Describe the appearance of mahogany trees.

• Reddish-brown wood

• Smooth bark

• Large size

• Heart-shaped leaves

What are some characteristics of mahogany wood?

• Strong

• Durable

What are the uses of mahogany wood?

• Furniture

• Musical instruments

• Boatbuilding

Describe the appearance of balsa trees.

• Smooth

• Grey-white bark

• Approx. 40m tall

What are some characteristics of balsa wood?

• Lightweight

• Soft and easy to work with

• Strong

• Floats

• Flexible

• Fine grain

What are the uses of balsa wood?

• Model airplanes

• Craft projects

• Toys

• Science projects

• Fishing lures

Describe the appearance of an oak tree.

• Soft

• Pale-yellowish brown

• Has light / dark spots

• Smooth

What are some characteristics of oak wood?

• Light

• Fine grain

• Easy to cut

• Tough

• Durable

What is the use of oak wood?

Furniture.

Describe the appearance of beech trees.

• Pinkish

• Even

• Light

• Pale

• Cream or reddish-brown

• Smooth

What are some characteristics of beech wood?

• Close- grained

• Hard-wearing

• Strong

What are the uses of beech wood?

• Furniture

• Toys

• Kitchen utensils

• Flooring

Give one advantage of using ash to make a set of cricket stumps.

Ash is straight, hard and strong.

Describe the appearance of larch wood.

• Pale to reddish brown

• Contrasting grain

What are some characteristics of larch wood?

• Durable

• Tough

• Food / water resistance

• Good surface finish

• Machines well

• Has problems with loose knots

What are the uses of larch wood?

• Furniture

• Toys

Describe the appearance of pine wood.

• Pale yellow to pale brown

• Attractive grain that darkens with age

What are some charcateristics of pine wood?

• Lightweight

• Easy to work with

• Can split

• Resin can leak near knots

What are the uses of pine wood?

• Furniture

• Musical instruments

Describe the appearance of spruce wood.

• White / cream

• Fine, even grain

What are some characteristics of spruce wood?

• Easy to work with

• High stiffness to weight ratio

• Variable results when staining

What are the uses of spruce wood?

• Furniture

• Building

Explain what is meant by manufacturing boards in bullet points.

• Manufactured boards are usually sheets of processed natural timber waste products or veneers combined with adhesives.

• They are made from waste wood; sawmill scraps, recycled wood, low grade timbers and even sawdust.

• Wood pieces are bound together with adhesives to make manufactured board.

• Boards are rigid, stable and supplied in large sheets.

• Manufactured board can be susceptible to moisture.

What does MDF stand for?

Medium Density Fibreboard

Describe the appearance of MDF.

• Smooth, dull light brown finish.

• Smooth surface.

• Edges can be hard to finish.

What are some characteristics of MDF?

• Very dense

• Tough

• Rigid

• Stable

• Good value

• Easy to finish surface

• Very absorbent

• Available in different thicknesses.

What are the uses of MDF?

• Furniture

• Cabinets / shelving

• Soundproofing

• Fire resistance

• Flooring

Describe the appearance of chipboard.

• Pale / grey / brown

• No grain

• Frequently covered with a laminate such as melamine formaldehyde

What are some characteristics of chipboard?

• Good compressive strength

• Good value, but edges chip easily

• Not water resistant, unless treated

What are the uses of chipboard?

• Kitchen worktops

• Kitchen cabinets

• Flooring

• Insulation

• Furniture

Describe the appearance of plywood.

• Made up of alternative rotated layers of glued wood veneers.

• The outer layer is usually high quality to add to the aesthetic.

What is a characteristic of plywood?

Very stable in all directions due to alternative layers.

What are the uses of plywood?

• Floors

• Walls

• Rods

• Crates

• Boxes

• Furniture

What does PAR stand for?

Planed all round

What are the two main types of finish which timber is supplied?

Surface finishes, Penetrating finishes

What does the term 'timber conversion' refer to?

The process of cutting timber into standard sized planks.

What are the two methods of seasoning?

Air drying and kiln drying.

What are two different methods of veneer production?

Rotary cutting and slicing.

Explain the rotary process.

Rotary cutting is a method of producing wood veneer by rotating a log against a knife blade to peel off thin layers. It is efficient, cost-effective and produces a wide grain pattern.

Advantages of manufactured boards

Consistent, stable, cost-effective, versatile, sustainable, easy to work with, durable, aesthetically appealing, reduced waste, available

Disadvantages of manufactured boards

Weak, may not look appealing, sustainability concerns, may emit chemical emissions, expensive, maintenance

How many microns is one 1mm of thickness equivalent to?

1,000 microns

Define oxidation.

Gain of oxygen, loss of electrons.

Define rusting.

The corrosion of iron or steel.

What is the difference between oxidation and rusting?

Corrosion is the general term used to describe the degradation of metal surfaces whereas rusting is the specific type of corrosion that happens to iron.

What are metals?

Metals are lustrous, conductive elements typically characterised by high density and malleability, commonly used in construction, manufacturing and electronics.

Where is metal found?

Metals are primarily found in the Earth's crust, often within ores, minerals and natural deposits.

What are some common extraction methods of metals?

Mining, extracted from an ore (large furnaces, heated with carbon, electrolysis), blast furnace (smelting)

Define hard in terms of metals.

A material's ability to withstand abrasion.