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V okviru zaključne naloge smo spoznavali proces vakuumske infuzije s ciljem ugotavljanja vplivov procesnih parametrov na kakovost izdelanih plošč. Glavni cilj izvedenega eksperimenta je bil ugotoviti nabor parametrov za zagotavljanje najkrajšega proizvodnega časa ter obenem zagotoviti visoko kakovost plošč. Spreminjali smo presek dovodne cevke, temperaturo procesa ter obliko in orientacijo infuzijske tkanine. Za izdelavo kompozita smo uporabili tkanino iz enosmernih steklenih vlaken ter epoksi smolo. Mehanske lastnosti smo testirali s tri-točkovnim upogibnim preizkusom, pri čemer smo izmerili upogibno trdnost, modul elastičnosti in upogibno razteznost v vzdolžni in prečni smeri. Največji vpliv na hitrost infuzije sta imela delovna temperatura ter usmerjenost in oblika infuzijske mrežice. Ugotovili smo, da je najboljša kombinacija za dosego najkrajšega proizvodnega časa in obenem čim manjše zakasnitve impregnacijskih front delovna temperatura 35 C ter zmanjšanje velikosti infuzijske mrežice na sesalni strani. Z upogibnim preizkusom vzorcev smo ugotovili, da se zaradi zmanjševanja debeline plošč od polnilne do sesalne strani povečuje modul elastičnosti in upogibna trdnost. Sprememba procesnih parametrov v raziskanem območju je imela signifikantni vpliv tudi na prečno trdnost plošč, ni pa imela večjega vpliva na vzdolžno trdnost. In the final thesis, we researched the process of vacuum infusion with the aim of determining the influence of process parameters on the quality of the manufactured panels. The main objective of the experiment was to determine a set of parameters to ensure the shortest production time, while at the same time ensuring high quality of the plates. We changed the cross section of the delivery tube, the process temperature, and the shape and orientation of the infusion mesh. One-way fiberglass fabric and epoxy resin were used to make the composite. Mechanical properties were tested with a three-point flexural test. We measured the flexural strength, modulus of elasticity, and flexural elongation in the longitudinal and transverse directions. The greatest influences on the speed of the infusion were the process temperature and the shape and size of the infusion mesh. We found that the best combination to achieve the shortest production time while minimizing the delay of the impregnation fronts is preheating the plates at 35°C and reducing the size of the infusion mesh on the suction side. By flexural testing of specimens, we found that because of the reduction in thickness of the plates from the filling to the suction side, the modulus of elasticity and flexural strength are increased. In the area studied, the change in the process parameters also had a significant effect on the transverse strength of the plates but had no significant effect on the longitudinal strength.

V magistrskem delu je obravnavana problematika obrabe brizgalnega orodja pri brizganju polimera z vsebnostjo steklenih vlaken. Izdelana je podrobna analiza literature, na kateri temelji eksperimentalni del, kjer je obravnavana obrabna obstojnost štirih kavitetnih vložkov različnih toplotnih obdelav in materialov na delovanje taline polimera. Delo temelji na predpostavki, da je stopnja obrabe v posameznih conah kavitetnih votlin različna. Eksperimentalni del naloge je bil izveden na prototipnem orodju, v katerega so bili vgrajeni omenjeni kavitetni vložki. Testiranje je zajemalo 10 000 brizgov, kot brizgani material pa je bil uporabljen termoplast PA66 GF35. Kvantitativni popis stopnje obrabe je izveden s stopnjo hrapavosti Ra in Rz. Za preučevanje prisotnih obrabnih mehanizmov je uporabljena optična mikroskopija in interferomatrija. Največja stopnja obrabe je bila zaznana na ustju kavitetnih vložkov, ki se odraža v popačenju njegove geometrije. Zaznane so bile tudi različne obrabne obstojnosti uporabljenih materialov in toplotnih obdelav. The master’s thesis deals with the problem of the injection mould wear in the process of injecting glass reinforced polymer. The thesis presents a detailed analysis of literature upon which the experimental part is based, where the wear resistance of four cavity inserts of various heat treatments and materials is considered. The work is based upon assumption of a different degree of wear in individual cavity zones. The experimental part was performed on a prototype injection mould in which the said cavity inserts were installed. The test involved 10 000 shots of PA66 GF35 thermoplastic material. Wear rates are quantified with Ra and Rz roughness parameters before and after the experiment was conducted. Optical microscopy and interferometry were also used to observe present wearing mechanisms. The highest wear rate was detected in the region of the tunnel gates of the cavity inserts, which is reflected in the distortion of their geometry. Different wear durability was detected at different materials and heat treatments.

Raziskovali smo lastnosti različnih furnirnih plošč, v katerih smo kombinirali topolov in bukov furnir ter dodajali sintetično mrežo. Uporabili smo 3 standardne kombinacije, in sicer "combo" (vsaka druga plast plošče je bila topolova, vmes je bila bukova), "sendvič" (vrhnji plasti plošče sta bili bukovi, vmes so bile topolove) in "čisto topolovo" furnirno ploščo (vsi furnirji so bili iz topolovine). Dodali smo jim 2 tipa sintetične mreže iz steklenih vlaken. Prvi tip te mreže iz steklenih vlaken, ki je bil impregniran z melaminsko smolo, smo dodali na zunanjo plast furnirne plošče. Neimpregnirano sintetično mrežo iz steklenih vlaken pa smo dodali med prvi in drugi sloj furnirja v plošči. Glavni namen raziskave je bilo iskanje kombinacije z največjo upogibno trdnostjo plošče in kombinacije z najboljšim razmerjem trdnost-gostota plošče. Preskušancem z 9 različnimi kombinacijami smo skladno s standardi SIST EN 310, SIST EN 323 in SIST EN 326-1 izmerili upogibno trdnost, modul elastičnosti in gostoto. Posameznim uporabljenim sintetičnim mrežam smo izmerili tudi natezno trdnost. Prišli smo do zaključka, da ima zaradi večjega deleža bukovega furnirja največjo upogibno trdnost sestava "combo". Ugotovili smo, da je najbolj primerno razmerje trdnost-gostota v sestavi "sendvič" in da fasadna sintetična mreža iz steklenih vlaken brez impregnacije v lepilnem spoju zmanjšuje upogibno trdnost furnirne plošče. Z melaminsko smolo impregnirana fasadna sintetična mreža iz steklenih vlaken izboljša upogibno trdnost furnirnih plošč le z dovolj velikim vtisom ali oprijemom na furnir. The thesis brings a research into the properties of different combinations of poplar and beech plywood in veneer boards with synthetic nets. We used 3 standard combinations for veneer boards - combo (every second layer is poplar with beech wood in between), sandwich (2 outer layers are made of beech wood with poplar layers between) and pure poplar (only poplar plywood is used). To these we added 2 types of glass fibre nets. The first was impregnated with melamine resin and was added on top of outer layers of veneer boards. A non-impregnated synthetic net, however, was added between the first and the second layer of the veneer boards. The main purpose of the research was to find the combination with the highest bending strength and the combination with the best strength/density ratio. Samples with 9 different combinations were measured for bending strength, elastic modulus and density in accordance with SIST EN 310, SIST EN 323 and SIST EN 326-1 standards. Tensile strength of the synthetic nets used was also measured. The results show that, due to the higher share of beech plywood, combo has the highest bending strength, while the most suitable strength/density ratio is in sandwich boards. Non-impregnated glass-fibre nets on the outer layers meanwhile reduce the bending strength of veneer boards in the joint, and melamine resin-impregnatednets on the outer layers improve bending strength of veneer boards only with sufficient sink or absorption.