Kase südamikuspoonist valmistatud vineeri tugevusomaduste ülevaade
Laen...
Kuupäev
2015
Kättesaadavus
Autorid
Ajakirja pealkiri
Ajakirja ISSN
Köite pealkiri
Kirjastaja
Abstrakt
Käesolev bakalaureusetöö võrdleb kase südamikuspoonist valmistatud vineeri paindetugevuse ja
paindeelastsusmooduli näitajad kase-, musta lepa ning neist kombineeritud vineeri näitajatega
tarbijakuivas olekus paksusvahemikus 9 – 15 mm. Samuti võrreldakse omavahel Casco ja KFE
liimiga tehtud ühesuunalise vineeri paindetugevuse ja paindeelastsusmooduli näitajaid. Töö
põhieesmärgiks on selgitada välja kase südamikuspoonist tehtud vineeri võimalikud kasutusalad.
Kõrvaleesmärgiks on selgitada välja ühesuunalise vineeri tugevusomaduste sõltuvus liimist.
Bakalaureusetöö metoodika koosnes vineeri valmistamisest, katsekehade mõõtu saagimisest ja
katseprotsessi läbiviimisest rahvusvaheliste standardite kohaselt. Proovi võtmine ning katsekehade
asukoha valik proovist oli juhuslik.
Katsetulemused näitasid, et südamikuspoonist tehtud vineeri tugevusomadused ja elastsus paksuste
9 mm – 15 mm korral on oluliselt väiksemad võrreldes kombineeritud ja kasevineeriga. Kõige
sarnasemaid omadusi südamikuvineerile omas musta lepa vineer, millega keskmine erinevus
paindetugevuses oli 5%. Casco ja KFE liimiga tehtud ühesuunalise vineeri võrdluses omas paksuste
8,4 mm – 16,8 mm paremaid näitajaid Casco liimiga tehtud vineer.
Kase südamikuvineeri tootmine on kindlasti majanduslikult efektiivne, sest varasemalt kasutati sama
materjal ära hakke tootmisel. Praegusel kujul on selle vineeri tugevusomadused aga madalad ning
seda saaks kasutada ainult madalaid tugevusomadusi nõudvate konstruktsioonide valmistamiseks,
näiteks kaubaaluste kraede valmistamiseks. Tugevusomaduste parandamiseks oleks soovitav
kasutada vineeri koostamisel pooltes kihtides tavalist kasespooni.
The aim of this Bachelor’s thesis is to compare the bending strenght and the modulus of elasticity in bending of birch heartwood plywood with the same characteristics of birch, black alder and combined plywood in consumer dry condition in the thickness range of 9 to 15 mm. Also the bending strenght and the modulus of elasticity in bending of the flexible plywood materials made with Casco and KFE adhesives were compared. The main goal of this thesis is to determine the possible fields to use for plywood made from birch heartwood. The secondary goal is to reveal how different adhesives affect the strenght characteristics of flexible plywood. The methods of this Bachelor’s thesis included sampling, cutting and testing of the test subjects according to international standards. The samples and test pieces were chosen at random. The test results revealed that the elasticity and bending strenght of plywood made from birch heartwood in the material thickness range of 9 to 15 mm were significantly smaller compared to birch plywood and combined plywood. The bending strenght of heartwood plywood is most similiar with the characteristics of black alder plywood, with the difference being only 5%. In the comparison of flexible plywoods, the test pieces made with the Casco adhesive showed higher bending strenght and elasticity than the ones made with KFE adhesive. The production of plywood made from birch heartwood is economically efficient, because the heartwood material was previously used for the production of wood chips. The strenght characteristics of current heartwood plywood are weak, but they can still be used for constructions, that do not require high bending strenght such as pallet collars. In order to improve the bending strenght and elasticity, birch veneer should be used for half the layers when combining the heartwood plywood.
The aim of this Bachelor’s thesis is to compare the bending strenght and the modulus of elasticity in bending of birch heartwood plywood with the same characteristics of birch, black alder and combined plywood in consumer dry condition in the thickness range of 9 to 15 mm. Also the bending strenght and the modulus of elasticity in bending of the flexible plywood materials made with Casco and KFE adhesives were compared. The main goal of this thesis is to determine the possible fields to use for plywood made from birch heartwood. The secondary goal is to reveal how different adhesives affect the strenght characteristics of flexible plywood. The methods of this Bachelor’s thesis included sampling, cutting and testing of the test subjects according to international standards. The samples and test pieces were chosen at random. The test results revealed that the elasticity and bending strenght of plywood made from birch heartwood in the material thickness range of 9 to 15 mm were significantly smaller compared to birch plywood and combined plywood. The bending strenght of heartwood plywood is most similiar with the characteristics of black alder plywood, with the difference being only 5%. In the comparison of flexible plywoods, the test pieces made with the Casco adhesive showed higher bending strenght and elasticity than the ones made with KFE adhesive. The production of plywood made from birch heartwood is economically efficient, because the heartwood material was previously used for the production of wood chips. The strenght characteristics of current heartwood plywood are weak, but they can still be used for constructions, that do not require high bending strenght such as pallet collars. In order to improve the bending strenght and elasticity, birch veneer should be used for half the layers when combining the heartwood plywood.
Kirjeldus
Märksõnad
bakalaureusetööd