http://www.practicalefficiency.com/Woods.jpg

Plants and PeoplePlants and People

Lab – 6: Wood, Paper and Lab – 6: Wood, Paper and CushingCushing

Biology 328Biology 328

ObjectivObjectivee

To study wood and its To study wood and its characteristicscharacteristics

To learn how to make paperTo learn how to make paper

WoodWood

The sequence of tissues from the The sequence of tissues from the center outwardcenter outward

PithPith Primary xylemPrimary xylem Secondary xylemSecondary xylem Vascular cambiumVascular cambium Secondary phloemSecondary phloem Primary phloemPrimary phloem PhellodermPhelloderm Phellogen Phellogen Phellem/CorkPhellem/Cork

The tissue sequenceThe tissue sequence

Bark – Phloem (2Bark – Phloem (200 & 1 & 10)0)+ Periderm+ Periderm

Phellogen/cork cambium give Phellogen/cork cambium give rise to periderm (replaces rise to periderm (replaces epidermis) and produces epidermis) and produces

Phellem/Cork (outside)Phellem/Cork (outside)

Phelloderm (inside)Phelloderm (inside)

Wood – Secondary xylemWood – Secondary xylem Heartwood - old, non-functional xylemHeartwood - old, non-functional xylem

Sapwod - new, water conducting xylem Sapwod - new, water conducting xylem (possess ray parenchyma cells to conduct(possess ray parenchyma cells to conductwater)water)

http://www.uic.edu/classes/bios/bios100/lectf03am/treetrunk.jpg

Hardwood and SoftwoodHardwood and Softwood

Hardwood – From Hardwood – From angiospermsangiosperms. . Xylem has both Xylem has both vesselsvessels and and tracheidstracheids

Softwood – From Softwood – From gymnosperms.gymnosperms.Xylem possess only Xylem possess only tracheidstracheids

Tree Rings – Seasonal variationsTree Rings – Seasonal variations

Spring wood/Early wood- Several Spring wood/Early wood- Several largelarge

xylem cells, Lighter in colorxylem cells, Lighter in color

Summer wood/Late wood- Few Summer wood/Late wood- Few xylem xylem

cells, Darker in colorcells, Darker in color

Wood - CharacteristicsWood - Characteristics

Porosity – Number of pores Porosity – Number of pores

Density – Mass/Volume (Measured Density – Mass/Volume (Measured using oven dried wood of volume 1 using oven dried wood of volume 1 cubic cm) cubic cm)

Grain - the structural arrangement of Grain - the structural arrangement of various wood elementsvarious wood elements

Figure - the design or pattern that Figure - the design or pattern that

appears on the surface appears on the surface

XRTXRT

X – Cross sectionX – Cross section

R – Radial (quarter-sawn)R – Radial (quarter-sawn)

T – Tangential (Plain-sawed/slab-T – Tangential (Plain-sawed/slab-cut)cut)

Knots Knots

http://university.floormall.com/wood-flooring-plain-sawn.php

Lumbering and MillingLumbering and Milling

Veneer – Thinly sliced woodVeneer – Thinly sliced wood

Plywood – Glued VeneersPlywood – Glued Veneers

http://www.veneertech.co.za/images/veneer-species.jpg

http://www.lakewoodconferences.com/direct/dbimage/50327244/Film_Faced_Plywood.jpg

Lumbering and MillingLumbering and Milling

Particleboard – Made of saw dust and Particleboard – Made of saw dust and wood chipswood chips

Fiberboard – Made of separated xylem Fiberboard – Made of separated xylem elementselements

Charcoal – Wood burned in limited supply Charcoal – Wood burned in limited supply of oxygenof oxygen

http://www.woollydesigns.com/majacrft/images/mdf_part.jpg

http://www.historyforkids.org/learn/environment/pictures/charcoal.jpg

PaperPaper

Separated plant fibers that have Separated plant fibers that have been been matted together to form a matted together to form a sheetsheet

Plant fibers are separated Plant fibers are separated naturally by soaking and beatingnaturally by soaking and beating chemically by caustic alkali or chemically by caustic alkali or sulphatessulphates

Fibers/cellulose is present along withFibers/cellulose is present along with pectin in primary cell wallpectin in primary cell wall lignin in secondary cell walllignin in secondary cell wall

Pectin and lignin degrade and Pectin and lignin degrade and causing causing yellowing of paperyellowing of paper

Today’s labToday’s lab

Learn how to make Learn how to make paper?paper?

Trip to Cushing library Trip to Cushing library

Paper stripsPaper strips waterwater lye (caustic soda)lye (caustic soda) Mould and DeckleMould and Deckle blenderblender vatvat

Materials requiredMaterials required

Place 2-3 tablespoons of strips into a blender full Place 2-3 tablespoons of strips into a blender full

of water and blend for at least 20 seconds. To size the of water and blend for at least 20 seconds. To size the paper fiber, add 1/5 teaspoon cold-water laundry starch paper fiber, add 1/5 teaspoon cold-water laundry starch with water and add to vat of pulp. with water and add to vat of pulp.

In a large vat, place an amount of water and In a large vat, place an amount of water and blended fibers. blended fibers. To form a sheet of paper, put the mould and deckle To form a sheet of paper, put the mould and deckle together and pull up from the bottom of the vat. Once the together and pull up from the bottom of the vat. Once the deckle is above the water level, gently shake side to side deckle is above the water level, gently shake side to side and front to back to interlock the fibers and to ensure an and front to back to interlock the fibers and to ensure an even sheet of paper. even sheet of paper.

Invert this on a cloth and remove water from the back of Invert this on a cloth and remove water from the back of the deckle with a sponge. The paper will now release from the deckle with a sponge. The paper will now release from the deckle. Then, this can be dried between two clothsthe deckle. Then, this can be dried between two cloths

MethodMethod

SummarySummary

Today’s LabToday’s Lab Studied what wood and paper is, Studied what wood and paper is,

learned how to make paper, observed learned how to make paper, observed different types of books in Cushing different types of books in Cushing LibraryLibrary

Next week’s labNext week’s lab Field trip - FloraField trip - Flora