Chapter 2 Wood Flashcards
What should you consider when selecting woods in product design
Colour, grain, durability, outdoor use, ease of working, cost and commercial forms and sizes
What do you need to consider when it comes to colour
That it can change when exposed to light
What do you need to consider when it comes to grain
Grain pattern
What do you need to consider when it comes to durability
Hardwoods tend to be more resistant to scratching and have a longer life span
Forms and sizes of wood
•Sheet, rod, dowel, decorative mouldings
•rough sawn (used as originally cut without sanding or smoothing
•PAR- planned all round and sizes Available
Conditions in which hardwoods grow
From deciduous trees grown in warmer temperate regions
Conditions in which soft woods grow
From conifers grown in the cooler regions
Types of hardwood
Beach, oak, ash, mahogany,elm
Properties of a hard wood
Generally harder, darker in colour more decorative and expensive
Properties of beech
Hard, tough and strong, works and finishes well. Prone to warping, not durable outside, prone to attack from fungi. No taste or odour so used for kitchen utensils and child toys
Properties of oak
Very strong, heavy, durable, hard and though also finishes well. Contains and acid that corroded iron/ steel finishes. Used to make high class furniture and fittings
Properties of ash
Hard, dense, tough and very strong but elastic, high compressive and bending strength, great finishing qualities and machining qualities. Good resistance to shock and very stable hence why it’s used for bows and tool handles
Properties of mahogany
Straight grained reddish brown wood which is expensive and attractive. Prized for its beauty, durability and colour. Excellent workability and is tough, durable and resist wood rotting. Used for musical instruments and furniture
Properties of softwoods
Generally cheaper, lighter in colour and less expensive than hard woods
Types of soft woods
Pine, redwood, spruce
Advantages of manufactured boards
Availability, veneers can be applied, large stable sheets and uniform thickness and quality
Definition and properties of veneers
Applying a thin sheet of decorative wood onto a plain ground base. Used commonly on furniture. Makes materials more attractive.
Definition of ply wood
Formed using a odd number of thin layers with the grain of each running at right angles to its neighbour. Water proof glue is used to attach thin layers together
Properties of plywood
High uniform strength, resistance to splitting, balance of stresses, no shrinking across the grain.
What does MDF stand for
Medium density fibre board
Definition of MDF
Is made from saw dust glued and compressed together under heat and pressure
Properties of MDF
Cost effective, dense, thick, very heavy, smooth, unaffected by heat, good electrical insulator, paints well, produces to much dust, easy to work with
Definition of a hard board
Made from soft wood which is formed into sheets under high pressure
Properties of hardboard
Cheap sub for ply wood, absorbs moisture easily, not very rigid, susceptible to buckling
Definition of chipboard
Made from chips of wood mixed with synthetic glue, the mixture is squeezed between rollers and then dried between metal plates under high pressure and heat
Properties of chipboard
Similar strength properties in both directions, relatively weak, strength can be improved by using a veneer or melamine coating over the surface
Definition of block board
Made of core of soft wood strips, up to 25mm wide. Strips are placed edge to edge and sandwhich Ed between veneers of hard wood which is glued together under high pressure.
Properties of block board
Light weight, easily transported and less costly
Finishes for wood
Stains, oils, polishes, paints, synthetic resins, laminates, veneers
Definition of stains
Used for exterior timbers where protection is required as well as an attractive finsih
Properties of stains
Leave an attractive finish, include a fungicide to prevent mould growth. Change the colour of the wood whilst leaving the natural grain visible. Don’t provide protection against moisture
Definition of oils
Wood oils provide a waterproof finish and enhance the colour of the wood
Properties of oils
Waterproof finish, enhance the colour of the wood, provides longer lasting protection
Definition of polishes
Provides a high gloss finish
Properties of polishes
High gloss finish and colour, protection not as durable as other finishes
Definition of paints
Colours and protects the wood
Properties of paints
Colours and paints the wood, covers knocks and bumps and other blemishes
Definition of synthetic resins
A thick liquid capable of hardening.
Properties of synthetic resins
Thick liquid that can harden, provides a very tough surface that is seamless and waterproof
Definition of laminates
Laminates are commonly used on manufactured boards such as MDF and chip board. It involves the addition of a Formica layer around the surface.
Properties of laminates
Aesthetic, addition fictional requirements such as water resistance, toughness and durability
Definition veneers
veneers are thin slices of wood and sometimes bark, usually thinner than 3mm, typically glued onto core panels to produce flat panels such as doors, floors and furniture
Properties of veneers
Adds to aesthetics and makes product more attractive
