samenvatting Materiaalleer 3: deel Dries Posen: H3 hout

Materiaalleer 3
Hoofdstuk 3: hout
Deel Dries Posen_2022-2023


Inhoud
Anatomie .............................................................................................................................................................. 3
 Houtcel ..................................................................................................................................................... 3
 Structuur................................................................................................................................................... 3
- Weefseltypes ........................................................................................................................................ 3
- Verschillende lagen .............................................................................................................................. 4
→ Weefseltypes ................................................................................................................................................ 4
 Transportweefsel ...................................................................................................................................... 4
- Houtvaten (loofhout)............................................................................................................................ 4
- Tracheïden (naaldhout) = ook steunweefsel!!...................................................................................... 5
 Voedselopslagweefsel .............................................................................................................................. 5
- Houtstralen (loofhout + naaldhout) ..................................................................................................... 5
- Axiaal parenchym (loofhout + naaldhout) ........................................................................................... 6
 Steunweefsel ............................................................................................................................................ 7
- Houtvezel (loofhout)............................................................................................................................. 7
Andere kenmerken ............................................................................................................................................... 7
 Kern & spinthout ...................................................................................................................................... 7
 Groeizones (jaarringen) ............................................................................................................................ 8
 Hars en gomgangen .................................................................................................................................. 9
 Draad ........................................................................................................................................................ 9
 Nerf ........................................................................................................................................................ 10
 Tekening ................................................................................................................................................. 10
 Glans ....................................................................................................................................................... 10
 Inhoudstoffen ......................................................................................................................................... 10
Houtsoorten & toepassingen ............................................................................................................................. 11
 Tropische houtsoorten ........................................................................................................................... 11
 Buitenschrijnwerk ................................................................................................................................... 11
Fysische eigenschappen ..................................................................................................................................... 11
 Volumieke massa .................................................................................................................................... 11
 Vochtgehalte .......................................................................................................................................... 11
- Drogen ................................................................................................................................................ 11
- Hysteresis ........................................................................................................................................... 12
- Krimpen & zwellen .............................................................................................................................. 12

Pagina 1 van 18

,  Zaagwijzen .............................................................................................................................................. 12
Natuurlijke duurzaamheid .................................................................................................................................. 13
 Duurzaamheidsklassen ........................................................................................................................... 13
Hout aantastende organismen ........................................................................................................................... 13
 Levensvoorwaarden schimmels: hoe ontstaan ze? ................................................................................ 13
 Hout aantastende schimmels ................................................................................................................. 13
- Schimmels levende boom ................................................................................................................... 13
- Schimmels gezaagd & verwerkt hout.................................................................................................. 13
 Hout aantastende insecten .................................................................................................................... 15
- Nathoutboorders ................................................................................................................................ 15
- Drooghoutboorders ............................................................................................................................ 15
- Levenscyclus hout aantastende insecten ............................................................................................ 15
 Voorzorgsmaatregelen tegen aantasting v. schimmels/insecten ........................................................... 16
Gevelbekledingen ............................................................................................................................................... 16
 Vereisten voor hout buiten .................................................................................................................... 16
 Kleurverschillen ...................................................................................................................................... 16
 Uitklikken................................................................................................................................................ 17
 Schimmelvorming ................................................................................................................................... 17
Houten terrassen................................................................................................................................................ 17
Productontwikkeling met hout ........................................................................................................................... 17
 Thermisch gemodificeerd hout............................................................................................................... 17
 CLT-panelen ............................................................................................................................................ 17
 Systimber houtschakelbouw .................................................................................................................. 18
 Paal- & balkbouw + invulling .................................................................................................................. 18




Pagina 2 van 18

, Anatomie
 Houtcel
- Verschillend v. soort tot soort
- Opbouw: v. buiten n. binnen
∙ Middellamel
∙ Primaire wand: heel dun vliesje
∙ Secundaire wand: w in 3 stappen opgebouwd
→ S1 / S2 / S3
= Dikste
→ Zitten alle goede eig. + problemen v.h. hout
→ Moleculenstructuur zit als veer rond cel
◦ Zorgt voor elastische werking hout
∙ Celholte


 Structuur
- Weefseltypes LOOFHOUT NAALDHOUT

Transportweefsel Houtvaten Tracheïden
= Saptransport voor
bladeren/naalden

Voedselopslagweefsel Houtstralen (in dikte hout) Houtstralen (in dikte hout)
= In 2 richtingen (dikte + lengte) Axiaal parenchym (in lengte hout) Axiaal parenchym (in lengte hout)

Steunweefsel Houtvezel Tracheïden
= Verhout deel dat zorgt dat → 2 functies bij naaldhout
boom blijft staan


- Weefseltypes in alle richtingen v.h. hout zichtb. (hout = 3D)
∙ Kopshout
◦ Transversaal vlak




∙ Kwartier hout
◦ Radiaal vlak
◦ In richting v.h. hart
◦ Evenwijdige lijnen




Pagina 3 van 18