503 335w3 10 wood product suite v2

Wood s product suite, properties and use www.csaw.utas.edu.au Wood s product suite, properties and uses Content • The matrix of wood products • The primary product suite www.csaw.ut

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Wood s product suite, properties and use

www.csaw.utas.edu.au

Wood s product suite, properties and uses

Content

•  The matrix of wood products

•  The primary product suite

KDA503/335 Timber, its origin and characteristics

The matrix of wood products

Functionality of products

•  A material derives usefulness, value and marketability through the functions it can perform economically

•  Functions are performed mainly through the sizes, shapes and appearances into which the material can be converted and the physical tasks it can do

From Marra, 1972, Wood products into the future

Limits on the function of timber products

•  Timber product functionality is limited by:

–  The form of the log

•  Its shape, length and diameter

•  Its primary wood properties

–  Size constraints these impose on recovered pieces

–  The directionality of its key properties

–  Its structural consistency (or variability)

Material production processes

•  Wood production is

essentially a reductive

process

•  Most material production is

transformative

Zinc production facility Hardwood mill

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Primary reduction process

•  The log is broken down into a hierarchy of elements,

governed by value

•  Solid wood processing can only convert a portion of

logs to the most valuable elements

•  The remainder is channeled into other, less valuable

element streams

Table of resultant primary wood elements

Long grain elements Poles Timber Scantling Veneer <2.4mm thick

Veneer

>2.4mm thick

Veneer Strips

Short grain

Fiberal Elements Fibre bundles Whole fibers Macerated fibers Fibrils

Chemical

Decreasing width and/or thickness

Increasing formability, decreasing strength/weight ratio, reducing dependence on log quality, increasing homogeneity and isotropy

From Marra, 1972, Wood products into the future

Primary assembly processes

•  Assembly is by various methods to maintain or modify

timber s natural directionality

•  This uses timber dowels or pegs, glues, nails and

dowels, bolts and shear connector, nail plates and

gussets in processing facilities and on site

The primary product suite

Timber rounds - poles

•  Natural or shaved round

timber used with or without

preservative treatment

•  A valuable market for forest

thinnings

Sawn timber & scantling

•  Hard or softwood boards cut from logs and usually dried

•  This is a versatile material used for moulding, frames and exposed structures

•  Board size is restricted by log size and required cutting patterns

•  Apparent consumption in 2010-11 ~ 5.3 million m3

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Timber, its product suite and characteristics

Sawn timber

Glue laminated timber

•  Solid section timber glued together into a larger solid element

•  Increased structural reliability with size limited only by transport capacity

Curved glue laminated timber

•  Solid section timber glued together

into a larger element, curved to

almost any shape

•  The curve achieved depends on

the thickness of the laminates

Cross laminated timber

•  Multiple layers of solid section timber glued together into panels with the grain direction

alternating between layers

•  The panels are custom-made and the number and thickness of layers varies with the panel s intended function

•  Currently, imported into Australia but not produced here

Veneer

•  Thin layers of solid wood

sliced from a flitch or peeled from a log and

dried

•  High quality material is used as a decorative finish

•  Structural grade material

is used to make plywood, LVL and similar products

•  Apparent consumption

in 2010-11 ~ 0.32 million

m3 Veneer leaf

Plywood

•  Layers of veneer glued together in a sheet with the grain

direction alternating between layers

•  Sheets have high impact and shear strength, performing well as a bracing material, shear skin or lining

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Laminated Veneer Lumber (LVL)

•  Layers of veneer glued together in panel with the grain

aligned along the board

•  Can be assembled in continuous lengths in a variety of

thicknesses and resawn to the required size

Laminated strand lumber (LSL)

•  Strands of veneer arranged longitudinally and glued together in a large billet and resawn

•  Available in large sizes and long lengths as imported product Images from www.structuremag.org

I-beams

•  Manufactured elements with solid timber, LVL or LSL flanges

and ply or board webs They are lighter & more versatile than

solid timber

•  Fabricated as an engineered solution and available in long

lengths

flange

web

Oriented flake and strand boards

•  Manufactured panels of long wood flakes or strands aligned into a mat and tied together with glue or other binder

•  Controlled orientation of strands lengthwise and crosswise in the matt influence the board structural properties

•  Available as an imported product

Images from krumber.com

Chip and fiber boards panels

•  Manufactured panels of wood particles or fibers held

together with glue or other binder

•  This includes particleboard, fiberboards (hardboard, MDF,

etc) and core board

•  Apparent consumption in 2010-11 ~ 1 million m3 for

particleboard and ~ 0.7 million m3 for MDF

The secondary product suite

Primary products can be converted into secondary elements and components

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Nail-laminated or nail plated timber

•  Solid section timber joined with nail or nail plates to

make larger sections

•  Nail plated timber is an engineered solution

•  Size constrained to large scantling sizes

Nail plated trusses

•  Solid section timber joined with nail plates to make a truss, lighter &

more versatile than solid timber

•  Fabricated as an custom-made engineered solution

•  Spans to 30m are practical with size limited only by transport capacity

Box and c-section elements

•  Fabricated elements with solid timber or LVL flanges and ply or

board webs They are lighter & more versatile than solid timber

•  An engineered solution that can be made to any curve or shape,

limited only by the flexibility of the flange

flange

Structural insulated panels (SIPS)

•  Fabricated panels with sheet external faces and often a timber frame fully adhered to an expanded polystyrene (EPS) core

•  The panels are custom-made and their thickness and framing varies with the panel s intended function

Images from www.thesipkit.com

Window and doors

•  Fabricated internal and external joinery

components made by specialist joineries

•  available in standard sizes or made to order

Summary

•  A material derives usefulness, value and marketability through the functions it can perform economically

•  Timber product functionality is limited by the form of the log, the size constraints on recovered pieces this impose, the directionality

of properties, and its consistency

•  Wood production is primarily reductive, with the full range of products necessary for profitable and sustainable production

•  There is a wide range of wood product options available for use in buildings

–  Local and imported timber and solid wood products –  Secondary elements and components

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