Mehanske lastnosti ergonomsko oblikovanega ročaja lopate iz različnih slojnatih lesnih kompozitov

Sušnik, Evgen (author), Šernek, Milan (mentor)

Ugotavljali smo mehanske lastnosti ergonomsko oblikovanega ročaja lopate iz vezane plošče, letalske plošče, slojnatega furnirnega lesa LVL in krivljenega slojnatega furnirnega lesa. Plošče smo izdelali iz bukovega furnirja debeline 1,2 mm in dimenzij 1300 mm * 430 mm. Prečne furnirje pri vezani plošči smo najprej razžagali in jih širinsko spojili z nitko. Prav tako smo spojili furnirje pri letalski plošči, kjer je bil kot med sosednjima furnirjema 26° in s tem zmanjšali ostanek materiala. Končna debelina 27 slojnih plošč je bila 32,5 mm. Za krivljen slojnat furnirni les smo najprej na CNC stroju izrezali model iz MDF materiala in posamezne dele s pomočjo moznikov in lepila spojili skupaj. Za lepljenje vseh slojnatih lesnih kompozitov smo uporabili eno komponentno poliuretansko lepilo ICEMA R 145/12. Nato smo iz vsakega kompozita naredili po 5 ročajev in testirali njihove mehanske lastnosti. Ker se snežne lopate uporabljajo predvsem pri nizkih temperaturah, smo 2 ročaja testirali pri -18 °C, 2 pa pri sobni temperaturi 22 °C. Ugotovili smo, da nižja temperatura poviša mehanske lastnosti lesa, saj so bile izmerjene sile večje. Največje sile je prenesel krivljen LVL ročaj, sledil mu je ročaj iz letalske plošče, medtem ko sta ročaja iz vezane plošče in LVL zdržala najmanj in približno enako. Testirali smo tudi aluminijasti ročaj, ki se sicer trenutno prodaja na trgu. V primerjavi s slojnatimi lesnimi kompoziti prenese manjše obremenitve, ima pa večji elastični modul.

• Language: Slovenian
• Keywords: ergonomski ročaj, furnir, bukev
• Work type: Bachelor thesis/paper
• Typology: 2.11 - Undergraduate Thesis
• Organization: BF - Biotechnical Faculty
• Publisher: [E. Sušnik]
• Year: 2018
• PID: 20.500.12556/RUL-103357
• UDC: 630*812.7:630*832.281
• COBISS.SI-ID: 2945417
• Publication date in RUL: 16.09.2018

SUŠNIK, Evgen, 2018, Mehanske lastnosti ergonomsko oblikovanega  ročaja lopate iz različnih slojnatih lesnih kompozitov [online]. Bachelor’s thesis. E. Sušnik. [Accessed 7 April 2025]. Retrieved from: https://repozitorij.uni-lj.si/IzpisGradiva.php?lang=eng&id=103357

Secondary language

• Language: English
• Title: Mechanical properties of ergonomic handle for showel produced by different wooden layer composites

Abstract

We studied the mechanical properties of an ergonomically designed handle for a shovel produced from plywood, aviation veneer panel, laminated veneer lumber, and bent laminated veneer lumber. Panels were made from beech veneer with a thickness of 1.2 mm and dimensions of 1300 mm × 430 mm. Cross veneers of plywood were sawed and bonded again at width direction with the thread. The same technique was used with bonding veneers with the aviation veneer panel for which an angle of 26° was needed. The final thickness of the panels was 32.5 mm, so 27 layers were glued. For bent LVL, we first cut the model from the MDF material on a CNC machine and connected the individual parts with dowels and then glued them together. For gluing all layered wood composites, one component polyurethane adhesive ICEMA R 145/12 was used. We produced 5 handles from each panel and tested their mechanical properties. Since snow shovels are mainly used at low temperatures, 2 handles were tested at -18 °C and 2 at room temperature of 22 °C. We determined that low temperature improves the mechanical properties of the wood, since the measured forces applied at the freezing handles were slightly higher. The bent LVL handle was able to bear very high forces, followed by the handle from the aviation panel, while the plywood and LVL handles handled approximately the same force. We also tested an aluminium handle that is currently on the market. In comparison with the layered wood composites, it transfers small loads but has a larger elastic module.

• Keywords: ergonomic handle, veneer, beech