230 likes | 315 Views
UNIT 3 TECHNICAL MATERIALS. WOODS. CLASSIFICATION. SOFTWOODS - PROPERTIES. CONIFEROUS ARE FAST GROWING (20-30 years to mature) TIMBER THAT COMES FROM CONIFEROUS TREES IS OPEN GRAINED IT SPLITS EASILY IT IS WEAK IT IS CHEAP. HARDWOODS - PROPERTIES.
E N D
SOFTWOODS - PROPERTIES • CONIFEROUS ARE FAST GROWING (20-30 years to mature) • TIMBER THAT COMES FROM CONIFEROUS TREES IS OPEN GRAINED • IT SPLITS EASILY • IT IS WEAK • IT IS CHEAP
HARDWOODS - PROPERTIES • DECICIOUS TREES ARE LOW GROWING (100 years to mature) • TIMBER THAT COMES FROM DECIDIOUS TREES IS CLOSE GRAINED • IT DOES NOT SPLIT EASILY • IT IS STRONG • IT IS EXPENSIVE
SOFTWOODS EXAMPLES PINES FURNITURE FLOORS
HARDWOODS EXAMPLES MAHOGANY CAOBA PARTS OF BUILDINGS QUALITY FURNUTURE
HARDWOODS EXAMPLES OAK ROBLE PARTS OF BUILDINGS QUALITY FURNITURE
HARDWOODS EXAMPLES TEAK TECA GARDEN FURNITURE
BLOCKBOARD • IT IS MADE FROM SOFTWOOD STRIPS • BONDED WITH AN ADHESIVE. • IT IS USED FOR FURNITURE MANUFACTURING • (internal parts)
CHIPBOARD • IT IS MADE FROM SMALL CHIPS OF WOOD BONDED WITH A RESINE • IT IS USED IN FURNITURE MANUFACTURING. • IT IS CHEAP
MEDIUM DENSITY FIBRE BOARD MDF = DM • IT IS MADE FROM WOOD DUST AND RESIN, AND THEN PRESSURED INTO A BOARD. • IT IS EASY TO WORK (machine, cut, paint...) • IT IS USED IN CHEAP FURNITURE (internal parts)
PLYWOOD • IT IS MADE FROM VENEERS OF TIMBER BONDED BY A RESIN. • THE GRAINS OF THE VENEERS ARE PERPENDICULAR EACH OTHER.
WORKING WITH WOODS • TO MEASURE & DRAW, WE USE...
TO SAND & RASP, WE USE ... SANDING PAPER SET OF RASPS
TO JOIN, WE USE... GLUE GUN & GUN ROD
PHSICAL PROPERTIES The relationship between MASS and VOLUME DENSITY The ABILITY of being sratched by other material HARDNESS
The property of resisting PULLING forces TENSILE STRESS PULL The property of resisting PUSHING forces COMPRESSION STRESS PUSH
The property of being BENT... FLEXIBILITY The ability of resisting the action of living organisms, moisture ... DURABILITY
THERMAL CONDUCTIVITY The ability to TRANSFER HEAT The ability to allow the FLOW OF ELECTRONS ELECTRIC CONDUCTIVITY WOODS ARE GOOD THERMAL & ELECTRICITY INSULATORS