Tim

bers

hardwoods

Softwoods

Oak

Mahogany

Beech

BiRch

Teak

Pine

1. Selecting Materials and Components

Cedar

Larch

Spruce

Fir

Properties: Strong,Tough,Hard,Excellentresistancetomoisture.CommonUses:OutdoorfurnitureandBoats.

Properties: Strong,Easytowork,Highaestheticqualities.CommonUses:Plywood,Veneers,CratesandSpecialitywooditems..

Properties: Finefinish,ToughandDurable.CommonUses:Children’stoys,Models,Furnitureandveneers

Properties: Easytowork,Durable,Excellentfinish.CommonUses:Highendfurniture,Joinery,Veneers.

Properties: Tough,Hard,Durable,Highqualityfinish.CommonUses: Flooring,Furniture,RailwaySleepersandVeneers.

2. Forces and Stresses on Wooden Products

Introduction

3. Ecological and Social Footprint

Specialist Technical Principles

Varioustimbersareusedinarangeofproducts..Intheireverydayuse,theseproductsareregularlyhavingforces appliedtothem.Theseforcesaffect thewaytheproductoperatesanditsoverallfunctionandsafety.Designersandmanufacturersneed toensurethatthematerialstheyselectfortheirproductsareabletowithstandtheforcesandstressestheproductwillbesubjectedto.Iftheygetthiswrongitcouldhaveseriousconsequences.

Tension forces are pulli ng forces that cause anobject to be stretched or pulled apart.

Bending forces act at an angle to an object andmake it bend.

When an object bends it is under compression andtension at the same time. See below…

Compression forces are pushingforces that squeeze an object.Imagine a ‘crushing’ motion.

Shearing forces act acrossa material by creating ashearing action. Scissorsare a good example.

Torsion forces are twisting forcesthat are applied to an object.

Types of Forces and stresses

Properties: Lightweight,Easytowork,Canspliteasily.CommonUses: Interiorconstruction, CheapfurnitureandDecking

Properties:Goodstrengthtoweight,DurableandResistanttodecay.CommonUses:Construction,Boxes, Boats,CladdingandMusicalInstruments.

Properties:Durable,Tough,Goodwaterresistance,Goodsurface finish.CommonUses: Electricalfittings,casings,buttonsandhandles.

Properties: Easytowork,highstiffness,CommonUses:Construction(Interior/Exterior),FurnitureandMusicalInstruments

Properties:Machineswell,Durable,StiffandGoodstrengthtoweight.CommonUses:Construction,Veneers.

Timber Life cycleHardwoods come fromdeciduous trees.Thesearetreeswhichlosetheirleavesinwinter.Hardwoodstakealongtimetogrow.Infact,ifyouweretoplantahardwoodtreetoday,youwouldneedtowaitbetween80-120yearsforittogrowtofullmaturity.Hardwoodstendtobelessporousandmoredense whichmakesthemlessprone towearingandrotting.Hardwoodscomeinavarietyofcolours andareknownfortheiraestheticappeal.

Once tree’sarefelled andconvertedintoStockForms theyareknownas‘Timber’.Timbercomesin2maintypes:RoughSawnandPlanedAllRound(PAR). Timbersareseasoned toreducethemoistureinthem.Thisisdonebydryingthemnaturallyorusingafurnace.Unevenevaporationofthemoisturecauseswarping.Timbercanbeasustainable resourceif itisharvestedresponsiblyandethically.Usethissheetforrevisionandforfurtherresearchintotimberbasedmaterials.

Man-Made boardsManufacturedBoards areusuallysheetsmadefromwaste/off-cuts andrecycledtimber.Manufactured Boardsareusuallycoatedwithathinlayerofnaturaltimbercalledaveneer.Thisaddstotheaestheticappealofthematerialbymakingitlooklikeanaturaltimber.

Chip boardProperties:Goodcompressivestrength,Notwaterresistant,Cheap,Easilydamaged.CommonUses: Flooring,Low-endfurniture,Kitchenunits&tops.

MDFProperties:Rigid,Stable,Cheap,EasytofinishbutVeryabsorbentwhichleadstorotting.CommonUses: Flatpackfurniture,Toys,KitchenUnits&Construction.

Block boardProperties: Lightweight,Stable,EasytoWork,Highresistancetotwistingandwarping.CommonUses:Construction,Low-endfurniture.

Plywood

Properties: Fairlyweak,Onesidesmooth, theotherisfurry.CommonUses: Low-endfurniture

Hard board

Properties:Verystableandstrongduetoalternatelayeringat90°.Aesthetic qualities.Thin,flexibleversionsareavailable.CommonUses: Flooring,Low-endfurniture,Kitchenunitsandtops.

Softwoodscome fromconiferous trees,atreethatusuallyhasneedlesandcones ratherthanbroadleaves.Thesetreesarecommonlyreferredtoasevergreensasmostofthemkeeptheirleavesallyearround.Softwoodsarefastgrowingandcanreachfullmaturitywithin25years.Softwoodsgenerallyhaveamoreporousstructure.Thismeansthatiftheyareleftunprotected,theycanabsorbmoistureandbegintorotmorequickly.Softwoodsdon’t comeinasmanycolourvarietiesasHardwoodshowever,theyareveryeasytostaintomakethemlookliketheirmoreexpensivecounterparts.

Treesabsorb CO2andgiveoutoxygen.ThishelpstopreventGlobalWarmingandprovidesuswithoxygentobreathe.

Treesarefelled.Newseedsshould beplantedtoensurefuturegenerationshaveasustainable supplyoftimber.Iftreesarenotreplantedandthelandisusedfor urbandevelopment,thisisknownasDeforestation.

TreesareprocessedinamillandcuttousefulsizesknownasStockForms.Machineryiscommonlyusedfor thisprocess.TheMachinesrequirealargeamountofenergytorun,usuallyfromfossil fuels(electricity).ThisgivesoffCO2 which contributestoGlobalWarming.

Wastematerialsfromthemill,aswellasreclaimedtimberfromold productsisusedtoproduceManufacturedBoards. Thisallowsustocreatemorematerialswithouttheneedtocutdownmoretrees.

Products areboughtandused.Timberproductsdon’ttendtohaveanimpactontheenvironmentwhenthey'rebeingused.

Attheendoftheproducts’ life,thetimbercanbeusedasfuelinpowerstations.Thisgivesoff CO2,contributingtoGlobalWarming.

Sometimberbasedproducts canbestrippeddownandthewoodcanbe‘reclaimed’.Thesematerialsareusuallygrounddown andconvertedtomanufacturedboards.

The timber lifecycle shows how timbers start out as treesand end up as products which are then disposed of. Eachstage of the life cycle has an impact on the environment.

OF THE WORLD’S TROPICAL FORESTSHAVE BEEN SUBJECT TO DEFORESTATION.

4,500 18M 2110ACRESOFFOREST

FALLTOCHAINSAWS,FLAMES AND

BULLDOZERSEVERYHOUR.

ACRESOFTHEWORLDSFORESTSARELOSTPER

YEAR.

THE YEARWEWILLRUNOUTOFFORESTSIFDEFORESTATION

CONTINUESATTHECURRENTRATE.

1/2IfyouwanttoseethedamagethatisbeingcausedbyDeforestationyouneedlooknofurtherthanthetropicalrainforests.Today,theyarebeingrapidlyclearedforindustriessuchasoilextraction,rubberplantations, cattlegrazing,soyafarming,expandingcities,roads,damsandofcourselogging.

About12%ofallman-madeclimateemissions come fromdeforestation,mostlyintropicalareas.Thefasterthetreesgo,thechanceofslowingorreversingclimatechangebecomesslimmer.Tropicaldeforestationcauses carbondioxide,themaingreenhouse gas,tolingerintheatmosphereandtrapsolarradiation.Thisraisestemperaturesandleadstoclimatechange.DeforestationinLatinAmerica,AsiaandAfricacanaffectrainfallandweathereverywherefromtheUSMidwest,toEuropeandChina.

Rainforests arehometomorethanhalfoftheworld’sanimalsandastheforestscomedown,theanimalsandpeoplewholiveinoraroundthembecomeimpoverished.Withouttheforests,peoplemigratetocities,ormovetorichercountriesinsearchofwork.Theworld’srainforestsnotonlyprovidefood,energy,security,incomesandmedicinalplantsfor300mpeople,buttheyarealsohometotherichestwildlifeintheworld.

DeepReading

• Designersandmanufacturershaveanenormousresponsibility toensurethattheyconsiderthetypeoftimberormanufactured boardfortheproducts theydesign.

• Designersandmanufacturersneed toconsidertheenvironmentalimpactofchoosingmanufactured boardsthatcanbeharmful toproduce.

• Designersshouldensurealltimbersthattheyusecomefromsustainable sourcessuch asFSCmanagedforests.

Whatdotheabovelogosand symbolsmean?

1. Selecting Materials and Components

Createdby:@DTMcLaughlin

Tim

bers

1. Selecting Materials and Components

8. Specialist Techniques and Processes

9. Surface Treatments and Finishes

Specialist Techniques

Steam Bending

Laminating

Name Image Description Name Image Description

Oil(Indoor andOutdoorProducts)

Soaksintotimber.

Protectsandenhancesappearance

Paint(Indoor andOutdoorProducts)

Usuallyneedsaprimer.Widerangeof colours

BeesWax(IndoorProductsonly)

Rubbed intowood.

Enhancesnaturalgrain.

Wood Stain(Indoor andOutdoorProducts)

Permanentlycolours

wood.Doesnotprotect.

Varnish(Indoor andOutdoorProducts)

Protectsfrommoisture.Enhances

appearance.

DistressingandScorching

(Indoorfurnishings)

Givesaworn/vintagelook.Popularinfurnishings.

Steambendingusesheatandmoisturetoloosenthetimberandmakeitmoreflexible.StepOne:Steamisappliedtothetimber.StepTwo:ThetimberisplacedaroundaJigorFormerwhichensuresthattheproductisaccurateandmakesallfutureproductsidentical.ThematerialisusuallyclampedtotheJig/formerwhileitdries.StepThree:Thedriedtimberstaysinitsnewshapeandisreadyforfinishing.

Laminatingistheprocessof’layering’timberstoincreasethesurfaceareaorthickness.StepOne:Thevarioussectionsaremarkedoutandplanedtosize.StepTwo: Thesectionsaregroupedandstraightenedwhilewoodglueisapplied.StepThree: Thesectionsareturnedintooneanothersothatthegluededgestouchthenextpieceof timber.Thepiecesarethenclamped intopositionwhilethegluedries.StepFour:Thelaminatedareaisplaneddownandsandedtomakesureitisflatandsmooth,readyforafinishtobeapplied.

4. Sources and Origins of Timbers 5. Using and working with Materials

Cutting/Shaping Drilling Abrading

6. Stock forms

Stock Form Description Image

SheetMetric isthestandardsizeformeasuringsheets.Sheetstartsat3mmthickandusuallyincreasesthicknessinincrements of 3mm.Sheetshaveavarietyofuses.

BoardBoardsaretypicallyused inlaminating toincrease

surface area.Theyaregooddecorative piecesoftimberandareoftenusedfor claddingandflooring.

Section/LengthSquare Sectionstendtobeusedforframesand

structures. Theytendtobestrongandthicksothatpanelscanbeattachedtothem.

Dowel Dowelissuppliedincylindrical formandcomesinvarioussizes. It ismeasuredbyitsdiameter.

Moulds Wood canbesupplied inmouldingswhichhaveavarietyofshapes.Commonlyused fordecoration.

7. Scales of Production

One Off Production

Mass Production Continuous Production

Batch ProductionInone-off production asingleproduct isdesignedandmadetoaclient'sspecification. Labour andmaterialcostsarehigh,andahighlevelofdesignandmanufacturingskillsareneeded.Prototypesareclassedasone-off’s.

Massproduction istheindustrialscalemanufacture of largequantities of products,usuallyona production line.Standardisedproductionmethodsmeanitissuitableforproducts thatarenotredesignedveryoften.

Inbatchproduction setquantities of aproductaremadetoorder.Materialsarecost-effectiveandmanufacturing costs arelower.SeasonalitemsareusuallyBatchproduced.

Continuous production isthemanufacture ofanitem24/7– 365.Thesystemisusuallycompletelyautomatedusingaproduction line.Duetothescaleonwhichtheitemsaremanufactured, theyareextremelycosteffective.

Joining Methods Fixings

Adhesives

Tenon SawUsedfor cuttingtimberinstraightlines.Thickbladepreventsthebladefrom deviating.

Coping SawUsedfor cuttingunusualanddifficultshapeswiththinablade.

Scroll SawMechanically powered.Thinbladecutsunusual shapes. Goodforcuttingsheetmaterial.

Pillar DrillGood foraccuracy whendrillingtimbers.ThePillarDrillispowerfulenoughtodrilllargeholesthroughthickmaterial.Selectingthecorrectdrillbitandspeed isveryimportant.

Hand DrillHandDrillsaregoodforsmallertasks.Astheyaremanual,theyprovidebetteraccuracythantheirpoweredcounterparts.

Cordless DrillVeryadaptable.TheCordlessDrillhasvariablespeedsandaclutchwhichpreventsovertighteningfixturesand fittings.Theyareergonomicallydesigned.

Disc SanderMechanicalmachinewhichremovesmorematerialthanhandmethods.

RaspA‘filelike’toolwithroughteethforfastremovalofmaterial.Differentprofiles available.

Sand PaperBestfor‘hardtoreachareas.Differentgradesavailable.Goodforsurfacepreparation.

Wire WoolUsedfor ahighqualitysurfacepreparationbefore finishing.Produces averysmoothsurface.

NailsNailsarehammeredinplaceatanglestostopthemloosening.

ScrewsPilotholeisdrilledandscrewisusedtoattachtwopieces.Screwsprovideastronger holdthannails.

Knock Down FittingsUsedinflatpackfurniture.Temporaryjointswhichareeasytoassemble/disassemblewithsimpletools.

Wood Glue (PVA)Wood glueabsorbs intothesurface ofthe2joiningpiecesanddriestoformasolidbond.

Hot GlueHotGlueisnotverystrong.Commonlyusedformodellingorsmallertasks.

Butt JointTwopiecesstucktogetherusingonlywoodglue.LowStrength.

Mitre JointPiecescutat45°.Stucktogetherwithwoodglue.LowStrength.

Dowel JointDowelusedtoprovidestabilityandstrength.HighStrength.

Lap JointGlued.Aestheticallypleasing.Neat.MediumStrength.

Comb JointInterlockingsections.AestheticandHighStrength.

Dovetail JointInterlockingsectionsatangles.Aesthetic.Strongestjoint.

U.K.Willow,Ash,Beech, Birch,Fir,Larch,Oak,Pine,Spruce,Walnut

ScandanaviaSpruce,Beech,Birch,Elm,Oak,Pine

RussiaFir,Ash,Beech,Larch,Maple,Oak,Pine,Spruce

EastAsiaSpruce,Walnut,Birch,Magnolia,Larch,Maple,Oak,Pine,Fir,Teak,

OceaniaPine,Oak,BlackWalnut,Ash,WhiteMahogany,Cedar,Gum

AfricaMahogany,Olive,Rosewood,Teak,Walnut,Bloodwood,Ebony,Podo

WestIndiesBalsa,Lancewood,Rosewood,Mahogany,Cocuswood

SouthAmericaBalsa,Laurel,Willow,Crabwood,Snakewood,Mahogany,Pine,Fir

NorthAmericaCedar,Fir,Larch,Hemlock,Pine,Spruce,Redwood,Sequoia,Walnut,Ash,Beech, Birch,Oak,Poplar,Elm,Maple,Sycamore,Balsa

EuropeFir,Ash,Oak,Walnut,Pine,Larch

Wood isconsideredtobeasustainablematerial,asnewtreescanbegrowntoreplacethoseusedfortimberandfuel. Themainissuefacingtimberproductionisthatitisbeingusedatafargreaterratethanitisbeingreplaced causinghugedamagetothelandinthecountrieswhereitisgrown.TimberisalsoahugeculpritofProductMiles.Differentwoodshavetotravelthousandsofmilestodifferentcountrieswherethosetree’saren’totherwiseavailable.That’swhyit’simportanttotryanduselocallysourcedtimbertohelpreduceenvironmentalimpact.

Band SawMechanically powered.Adultsonly.Cancutsections, boardsandsheetstospecific sizes.Usedforlargerjobswhereamorepowerfulsawisrequired.

Wood PlaneShaves thesurfaceof thewoodtoreducethethicknessofmaterial.Canbeadjustedtotakemoreorlessmaterial.

ChiselUsedtoremovetimber.Usefulforcreatingjointsorhollowingoutareas.

Wood turningWood lathes are used to turn bowls and spindles. The size of the materialbeing turned is important; the speed needs to be reduced as the diameterof the object increases.A special set of chisels are used to shape the wood as it turns. The mostcommonly used tools are the scraper, the gouge and the parting tool.

Bag PressThebagpressusesavacuumsystemtosucksheetsaroundaFormer totakeanewshape.Itisalsocommonly usedwhenapplyingveneerstomanufacturedboards.TheadvantagesofusingaBagPressoverclamps isthatitprovidesanevenpressureacrossthesurfaceofthematerialthatisbeingworked.Thismeansthatveneersarestuckdownmoreefficientlyandtimbersthatarebeingshapedaremoreaccuratewithlesslikelihoodofdeformations.StepOne:Applygluetoveneers andalign.StepTwo:Placeinlargeplasticbag(alongwithFormerifapplicable).Sealtheedgestoensureitisairtight.StepThree:TurnvacuumontoremoveairfromthebagandpresstheveneersagainsttheFormer.StepFour:Waitforgluetodrybeforeremovingtheitem.StepFive:PreparesurfaceandapplyFinish.

Createdby:@DTMcLaughlin