Izdelava biokompozita iz skorje z uporabo mokrega postopka stiskanja

Tajher, Urban (author), Medved, Sergej (mentor)

V lesarstvu in tudi drugih gospodarskih panogah se materiali hitro razvijajo, kar lahko pripišemo znanju strokovnjakov, ki delujejo na teh področjih, kot tudi tehnologiji in digitalizaciji, ki se razvija iz dneva v dan in praktično sega že na vsa področja našega življenja. Če se osredotočimo le na lesarstvo, imamo na področju pohištvene industrije veliko izbire med masivnim lesom kot tudi številne lesne kompozite, kot je npr. iverna plošča, vlaknena plošča, furnirna plošča itd. Pri konstrukcijah se veliko uporabljajo OSB plošče, ki imajo dobre mehanske lastnosti. V vseh omenjenih kompozitih je les osnoven material. Les je naraven in pogojno obnovljiv material z dokazano pozitivnim učinkom na zdravje in počutje ljudi. Z lesom pa je tesno povezana lesna skorja, katere uporaba je zelo omejena in neizkoriščena. Le ta se največkrat uporabi kot energent (biomasa), pri urejanju krajine, pri strojenju kože in v farmaciji. Pri proizvodnji kompozitov na osnovi iveri in vlaken se srečamo s številnimi izzivi, med njimi tudi kakšno surovino uporabiti za izdelavo gradnikov in kako zmanjšati porabo energije, še posebej energijo potrebno za sušenje gradnikov. Zato smo izdelali iverne plošče iz skorje po mokrem postopku stiskanja, kjer so bile ciljne začetne vlažnosti gradnikov 0 %, 10 %, 20 % in 50 %, le te pa smo ločili na majhne gradnike, srednje velike in velike gradnike. Ivernim ploščam smo določili sorpcijske in mehanske lastnosti, pri čemer smo ugotovili, da slabše prenašajo upogibne obremenitve, boljše pa razslojne obremenitve, poleg tega ima skorja dobre sorpcijske lastnosti, kot sta debelinski nabrek in vpijanje vode. Slabše mehanske lastnosti smo zaznali pri visoki začetni vlažnosti gradnikov (50 %), do vlažnosti 20 % pa ni bilo videti razlik, kar je zelo pozitivno z vidika ekonomičnosti in porabe energije za sušenje gradnikov. Iz ugotovitev lahko zaključimo, da bi se plošče iz skorje lahko uporabile kot alternativa že uveljavljenih materialov oz. lesnim ploščam v pohištveni industriji in v gradbeništvu. Smotrno bi jih bilo uporabiti tudi v prostorih s povišano vlažnostjo oz. kjer je potreba po višji odpornosti na vlago.

• Language: Slovenian
• Keywords: skorja, iverne plošče, moker postopek stiskanja, sorpcijske lastnosti, mehanske lastnosti
• Work type: Bachelor thesis/paper
• Typology: 2.11 - Undergraduate Thesis
• Organization: BF - Biotechnical Faculty
• Publisher: [U. Tajher]
• Year: 2025
• PID: 20.500.12556/RUL-173593
• UDC: 630*862:630*282
• COBISS.SI-ID: 249585411
• Publication date in RUL: 19.09.2025

Secondary language

• Language: English
• Title: Manufacturing of bark based biocomposite by wet process pressing

Abstract

In the woodworking industry, as well as in other economic sectors, materials are rapidly evolving. This can be attributed both to the expertise of professionals working in these fields and to the continuous development of technology and digitalization, which increasingly permeates all aspects of our lives. Focusing solely on woodworking, the furniture industry offers a wide selection of materials, ranging from solid wood to various wood-based composites such as particleboard, fiberboard, plywood and more. In construction, OSB panels are commonly used due to their good mechanical properties. In all of these composites, wood serves as the base material. Wood is a natural and conditionally renewable material, with proven positive effects on human health and well-being. Closely linked to wood is bark, a material whose potential remains largely untapped and underutilized. Bark is most often used as a source of energy (biomass), in landscaping, leather tanning and the pharmaceutical industry. When producing wood-based composites like particleboard and fiberboard, we face numerous challenges, among them, selecting suitable raw materials for wood particles and minimizing energy consumption, particularly the energy required for drying. To address this, we produced particleboards using bark by wet pressing method, with target initial moisture contents of 0 %, 10 %, 20 %, and 50 %. The particles were categorized into small, medium, and large sizes. We measured the sorption and mechanical properties of particleboards and found that they have lower bending strength but better internal bond strength. Additionally, particleboards showed good sorption characteristics, such as thickness swelling and water absorption. Inferior mechanical performance was observed at the highest initial moisture content (50 %), while up to 20 % moisture, no significant differences were noted, which is very promising from the energy efficiency standpoint and cost-effectiveness in drying. Based on results, we can conclude that bark-based panels could serve as an alternative to conventional materials or wood-based boards in the furniture and construction industries. They may also be particularly suitable for use in environments with elevated humidity or where increased moisture resistance is required.

• Keywords: bark, particle boards, wet process pressing, sorption properties, mechanical properties