natgillin/translations-raw huggingface dataset:
The procedure consisted of gradual heating of samples to the temperature of ± 2 ºC to 0 % of water content.
Postupak se sastojao od postupnog zagrijavanja uzoraka na temperaturu 103 ± 2 ºC do 0 % sadržaja vode.
Then the temperature gradually increased to 160 ºC in the time period from 30 to 40 min.
Zatim se temperatura postupno povećavala do 160 ºC u vremenskom periodu od 30 do 40 min.
At temperatures of 160 ºC, wood was thermally modified for 10 h.
Na temperaturi od 160 ºC drvo je bilo toplinski modificirano 10 h.
Gravimetric method was used to determine the water content and the loss of wood mass.
Gravimetrijskom metodom određen je sadržaj vode i gubitak mase drva.
Average loss of mass amounted to 2,57 % (1,39 % to 3,52 %), and after a sufficiently long conditioning in laboratory conditions, the average content of water in the samples amounted to 6,38 % (4,20 % to 7,67 %).
Prosječni gubitak mase iznosio je 2,57 % (1,39 % do 3,52 %), a nakon dovoljno dugog kondicioniranja u laboratorijskim uvjetima prosječni sadržaj vode u uzorcima iznosio je 6,38 % (4,20 % do 7,67 %).
Dowels were welded into samples modified in this manner.
U tako modificirane uzorke zavarivani su moždanici.
The second series of samples was impregnated with citric acid.
Druga serija uzoraka impregnirana je limunskom kiselinom.
Citric acid is a monohydrate prepared as water solution (10.5%) of citric acid with addition of 7.5 % of SHP (NaH2PO2) catalyst.
Limunska kiselina je monohidrat pripremljen kao vodena otopina 10,5 % limunske kiseline uz dodatak 7,5 % SHP (NaH2PO2) katalizator.
After the impregnation, they were wiped with a mop and left for ten days in laboratory conditions to dry and condition.
Nakon impregnacije obrisani su krpom i ostavljeni deset dana u laboratorijskim uvjetima na sušenju i kondicioniranju.
They were placed in a dryer and the temperature gradually increased to 103 ± 2 ºC.
Stavljeni su u sušionik i temperatura se postupno povećavala do 103 ± 2 ºC.
Care was taken not to reach sudden drying of samples and appearance of cracks.
Pri tome se pazilo da ne dođe do naglog sušenja uzorka i pojave pukotina.
Average water content was 6,00 % (5,42 to 6,52 %) after the conditioning.
Nakon kondicioniranja prosječni sadržaj vode iznosio je 6,00 % (5,42 do 6,52 %).
Dowels welded in such a manner were welded into non-modified base.
Tako pripremljeni moždanici zavarivani su u nemodificiranu podlogu.
Testing method
Metoda ispitivanja
Shift for time of testing was 5 mm/min.
Pomak za vrijeme ispitivanja iznosio je 5 mm/min.
Force and shift measurements were done with the help of computer, and all values were precisely and accurately taken.
Pomoću računala vršena su mjerenja sile i pomaka, pa su sve vrijednosti točno i precizno izmjerene.
RESEARCH RESULTS
REZULTATI ISTRAŽIVANJA
Wood modified in the stated manner has increased its dimensional stability (positive property), and the cutting property (negative property) which is relevant for the rotational welding.
Tako modificiranom drvu povećana je dimenzijska stabilnost (dobro svojstvo), ali i cjepivost drva (negativno svojstvo) koja je bitna za rotacijsko zavarivanje.
With the presence of water, oxygen and acid, thermal decomposition of cellulose can be accelerated.
Uz prisutnost vode, kisika i kiseline toplinska razgradnja celuloze može se ubrzati.
Lignin is also a component which points to significant thermal changes (Stamm et al 2006)
Lignin je isto komponenta koja pokazuje značajne termalne izmjene (Stamm i dr., 2006).
Ksylan is stabler than mannan thanks to the difference in molecular structure.
Ksilani su postojaniji od manana zahvaljujući razlikama u molekularnoj strukturi.
Windeisen and Wegener (2008) were researching the actions of lignin during thermal processing of wood.
Ponašanje lignina za vrijeme toplinske obrade drva istraživali su Windeisen i Wegener (2008).
Considering that temperature is different for every processing, different data of lignin change were realized.
Obzirom da je kod svakog procesa obrade drugačija temperatura, dobiveni su i različiti podaci promjene lignina.
There is no important difference between the samples MPV and 8,5 RTV, although there is an increase in the embedded force in favour of 8,5 RTV.
Između uzoraka MPV i 8,5 RTV nema statistički značajne razlike iako postoji porast izvlačne sile u korist 8,5 RTV.
Tightness was 1.6 mm at all compared samples.
Kod svih uspoređenih uzoraka zador je iznosio 1,6 mm.
Descriptive statistics of the results of embedded force in the dependence on the course of welding and type of modification
Deskriptivna statistika rezultata izvlačne sile u ovisnosti o smjeru zavarivanja i vrsti modifikacije
Effect of modified and non-modified wood on the embedded force at welding of dowel (in the direction of fibres and vertically to them)
Utjecaj modificiranog i nemodificiranog drva na izvlačnu silu kod zavarivanja moždanika (u smjeru i okomito na smjer vlakanaca)
Wood welding is a mechanical, physical and chemical process during which melt is produced, which then turns into a solid joint after cooling.
Zavarivanje drva je mehanički, fizikalni i kemijski proces u kome nastaje talina, a hlađenjem tako nastale taline dobiva se čvrsti spoj.
The paper shows current world-wide knowledge on welding of modified wood and the results of wood welding were received from the Faculty of Forestry in Zagreb.
U radu su prikazane dosadašnje svjetske spoznaje o zavarivanju modificiranog drva i rezultati zavarivanja drva dobiveni na Šumarskom fakultetu u Zagrebu.
Research was made on the effect that the modification (thermal and chemical) has on the strength of the rotationally welded joint.
Istraživao se utjecaj modifikacije (toplinske i kemijske) drva na čvrstoću rotacijski zavarenog spoja.
Research results show that dowels welded in the direction of wood fibres have greater embedded force than the dowels welded vertically onto the direction of fibres at modified as well as non-modified wood.
Rezultati istraživanja pokazuju da moždanici zavareni u smjeru drvnih vlakanaca imaju veću izvlačnu silu nego zavareni moždanici okomito na smjer vlakanaca kako kod modificiranog tako i kod nemodificiranog drva.
Modification of wood increases the brashness and some mechanical properties of wood are reduced which effect the reduction of the strength of welded joint.
Modifikacijom drvu se povećava krtost te se smanjuju neka mehanička svojstva drva koja utječu na smanjenje čvrstoće zavarenog spoja.
One of the main factors of reduction of joint strength is the inability to use the optimal tightness which is in the span from 2 to 2.6 mm and duration of the welding process (depending on the frequency of spin and the shift of dowel along the transversal axle).
Jedan od glavnih čimbenika smanjenja čvrstoće spoja je nemogućnost korištenja optimalnog zadora koji se kreće u rasponu od 2 do 2,6 mm i vremensko trajanje procesa zavarivanja (ovisi o frekvenciji vrtnje i pomaku moždanika po uzdužnoj osi).
By comparing the welding of dowel into non-modified beech wood and thermally treated beech wood (160 °C) in the direction of fibres, for 25 % of the reduction of embedded force was noted.
Usporedbom zavarivanja moždanika u nemodificiranu bukovinu i toplinski tretiranu bukovinu (160 °C) u smjeru vlakanaca, zabilježeno je smanjenje izvlačne sile za 25 %.
If the samples are also chemically treated, the embedded force i.e. the strength of joint will reduce for additional 7% (total of 32%).
Ukoliko su uzorci i kemijski tretirani izvlačna sila odnosno čvrstoća spoja se smanjuje za dodatnih 7 % (ukupno 32 %).
When welding the dowels vertically to fibres, the difference in the strength of joint (reducing of embedded force) of non-modified and thermally modified samples is 36%.
Kod zavarivanja moždanika okomito na vlakanca razlika u čvrstoći spoja (smanjenje izvlačne sile) nemodificiranih i toplinski modificiranih uzoraka iznosi 36 %.
welding, modification, beech wood, dowel, joint strength, embedded force
zavarivanje, modifikacija, bukovina, moždanik, čvrstoća spoja, izvlačna sila
Modification of wood is achieved through the actions of chemical, biological and physical factors on wood, and the results of such actions is the change in the chemical compound with the purpose of improving certain properties (Hill, 2006).
Modifikacija drva postiže se djelovanjem kemijskih, bioloških ili fizikalnih čimbenika na drvo, a rezultat tog djelovanja jest promjena kemijskog sastava s ciljem poboljšanja određenih osobina (Hill, 2006).
By combining the types of heating media, the duration of the process, the final temperature and the type of wood to be modified (main parameters of modification), we receive the desired characteristics of modified wood.
Kombiniranjem vrste grijućeg medija, vremena trajanja procesa, završne temperatura te vrste drva koja će biti modificirana (glavnih parametara modifikacije), dobivaju se željena svojstva modificiranog drva.
By modifying the chemistry of the cell wall, its affinity towards water is reduced, which brings to the improvement of dimensional stability.
Promjenom kemizma stanične stijenke smanjuje se njezin afinitet prema vodi, što dovodi do poboljšavanja dimenzionalne stabilnosti.
By reducing the size of swelling and tightening, the strain in the system of coating and surface is reduced, and the lifespan of wood is increased, as well as of the products made from modified wood (Hasan and Despot, 2008).
Smanjenjem veličina bubrenja i utezanja smanjuju se naprezanja u sustavu premaz - površina drva te se produljuje vijek trajanja drva, ali i proizvoda izrađenih od modificiranog drva (Hasan i Despot, 2008).
(2008), there was a great reduction of the fibre saturation point (in average for 15%) and room balanced water contents (in average for 3.5 to 5%) of overheated wood in relation to natural one.
(2008), dobiveno je veliko smanjenje točke zasićenosti vlakanaca (prosječno za 15 %) i sobnoga ravnotežnog sadržaja vode (prosječno za 3,5 do 5 %) pregrijanog drva u odnosu prema prirodnome.
Shrinking gradients of overheated wood are not reduced in comparison with the non-modified, but the absolute reduction of water absorption for 50% resulted in the increase of dimension stability for 60%.
Koeficijenti utezanja pregrijanog drva nisu smanjeni u usporedbi s nemodificiranim, ali je apsolutno smanjenje vodoupojnosti za 50 % rezultiralo povećanjem dimenzijske stabilnosti za 60 %.
Jones and Pizzi (2007) researched how cold and hot water affect the strength of welded joint of modified wood of sitka spruce.
Jones i Pizzi (2007) istraživali su kako hladna i kipuća voda utječu na čvrstoću zavarenog spoja modificiranog drva sitkanske smreke.
Research results have showed greater embedded force of joint of thermally and chemically (alcohol-based) modified wood during xposure in hot water (2h).
Rezultati istraživanja pokazali su veću izvlačnu silu spojeva toplinski i kemijski (na bazi alkohola) modificiranog drva za vrijeme izlaganja u kipućoj vodi (2 h).
Non-modified samples had the greatest embedded force in normal conditions, while chemically modified samples (modified by acetylation agent) had the greatest embedded force at exposure in hot water.
Nemodificirani uzorci imali su najveću izvlačnu silu u normalnim uvjetima, dok su kemijski modificirani uzorci (modificirani acetilacijskim sredstvom) imali najveću izvlačnu silu pri izlaganju u hladnoj vodi.
Welding process of modified wood proved to be applicable and it improved the strength of the welded joint if the joints were exposed to the influence of moisture and water.
Postupak zavarivanja modificiranog drva pokazao se primjenjivim i poboljšavao je čvrstoću spoja ako su zavareni spojevi bili izloženi utjecaju vlage i vode.
Results of testing show that the use of modified wood at welding can result in joint that can sustain the greater influence of water.
Rezultati ispitivanja pokazuju da upotreba modificiranog drva pri zavarivanju može rezultirati spojem koji može izdržati veći utjecaj vlage.
This opens up new possibilities for the application of wood welding process.
To otvara nove mogućnosti primjene postupka zavarivanja drva.
Influence of pre-heating of wood and the intersection on linear vibration welding have been researched by Omrani et al.
Utjecaj predgrijavanja drva i presjeka na linearno vibracijsko zavarivanje istraživali su Omrani i dr.
Research results have shown that pre-heating of surface prior to welding in beech wood contributes to the increase of shear strength with increase of pre-heating, while for oakwood, a reduction of shear strength was noted at the increase of pre-heating and a deviation of embedded force is increased.
Rezultati istraživanja pokazali su da predgrijavanje površine prije zavarivanja u bukovine pridonosi povećanju posmične čvrstoće s povećanjem predgrijavanja, dok je u hrastovine s povećanjem predgrijavanja zabilježen pad posmične čvrstoće te se povećava standardna devijacija izvlačne sile.
(2009) researched the welding of dowel into the base of heat-treated and untreated hornbeam wood.
(2009) istraživali su zavarivanje moždanika u podlogu od toplinski tretirane i netretirane grabovine.
Temperature of heat treatment was 200 °C in duration of 48 h.
Temperatura toplinske modifikacije iznosila je 200 °C u trajanju 48 h.
Frequency of spinning the beech dowel was 1 520 min-1.
Frekvencija vrtnje bukova moždanika iznosila je 1 520 min-1.
The research shown that the dowels welded into the hornbeam wood base which was not thermally modified has greater embedded force (in average 84%, which is statistically a significant difference) than the dowels welded in the thermally modified base.
Istraživanje je pokazalo da moždanici zavareni u podlogu od grabovine koja nije bila toplinski modificirana imaju veću izvlačnu silu (prosječno 84 %, što je statistički značajna razlika) nego moždanici zavareni u toplinski modificiranu podlogu.
(2011) also researched the effect of thermal modification on the strength of turned elements welded into length.
(2011) istraživali su utjecaj toplinske modifikacije na čvrstoću dužinski zavarenih tokarenih elementa.
According to the results of the research, it is evident that with the increase of the temperate of modification from 140, 160 and 180 °C, there is a reduction in the strength of joint but also an increase of weight loss.
Prema rezultatima istraživanja proizlazi da povećanjem temperature modifikacije od 140, 160 i 180 °C dolazi po smanjenja čvrstoće spoja ali i do povećanja gubitka mase.
Samples welded in such a manner were immersed in cold water with negative influence on thermally modified wood, but on non-modified wood as well (embedded force in the samples immersed in water is reducing in average from 40 to 50%).
Tako zavareni uzorci bili su potapani u hladnu vodu koja ima negativan utjecaj na toplinski modificirano, ali i na nemodificirano drvo (izvlačna sila u uzoraka potapanih u vodu prosječno se smanjuje od 40 do 50 %).
The purpose of this paper is to determine the option of welding of thermally and chemically modified wood and to compare the results with welding of non-modified wood.
Cilj rada bio je utvrditi mogućnosti zavarivanja toplinski i kemijski modificiranog drva te dobivene rezultate usporediti sa zavarivanjem nemodificiranog drva.
It is a well-known fact that modification reduces some mechanical properties (like brashness of wood) which are relevant for the process of welding.
Poznato je da se modifikacijom drvu smanjuju neka mehanička svojstva (povećava se krtost drva) koja su bitna za proces zavarivanja.
Samples and welding parameters
Uzorci i parametri zavarivanja
Research of welding dowels in bore has been done at the Faculty of Forestry of the University in Zagreb.
Istraživanja zavarivanja moždanika u provrt provedena su na Šumarskom fakultetu Sveučilišta u Zagrebu.
For welding of dowel vertically to the direction of fibres, the samples were beech wood 200 x 30 x 30 mm and three holes were drilled in every sample.
Za zavarivanje moždnika okomito na smjer vlakanaca uzorci su bili od bukovine 200 x 30 x 30 mm i u svakom uzorku su bušene po tri rupe.
With the samples where the dowel was welded in the direction of fibres, two holes were drilled (into every face of the sample) which had the dimensions 30 x 30 x 64 mm.
Kod uzoraka gdje je moždanik zavaren u smjeru vlakanaca bušene su po dvije rupe (u svako čelo uzorka) koji je bio dimenzija 30 x 30 x 64 mm.
Average density (ρ0) of beech wood was 0,67 g/cm³ determined according to HRN ISO 3131 :
Prosječna gustoća (ρ0) bukovine iznosila je 0,67 g/cm³ određena prema HRN ISO 3131 :
Water content was 9.1% for untreated samples, determined according to HRN ISO 3130 :
Kod netretiranih uzoraka sadržaj vode je iznosio 9,1% određen prema HRN ISO 3130 :
Welding was conducted with average tightness of 1.6 mm in order for welding times to be the same at treated and untreated samples.
Zavarivanje je provedeno s prosječnim zadorom od 1,6 mm kako bi vremena zavarivanja bila ista kod tretiranih i netretiranih uzoraka.
The length of grooved dowels was 120 mm and they were welded into bore on the depth of 20 mm with frequency of spinning which was 1 520 min-1 (used for welding of all types of samples).
Duljina nažljebljenih moždanika iznosila je 120 mm i zavarivani su u provrt na dubinu 20 mm pomoću frekvencije vrtnje koja je iznosila 1 520 min-1 (korištena za zavarivanje svih tipova uzoraka).
Test sample (thermally treated) for determining the embedded force at welding the dowel vertically to the direction of fibres and the appearance of cracks during the welding process (Župčić, 2010)
Ispitni uzorak (toplinski tretiran) za određivanje izvlačne sile kod zavarivanja moždanika okomito na smjer vlakanaca te pojava pukotina za vrijeme trajanja procesa zavarivanja (Župčić, 2010)
Test sample (thermally and chemically treated) for determining the embedded force at welding the dowel vertically to the direction of fibres and the appearance of cracks during the welding process (Župčić, 2010)
Ispitni uzorak (toplinski i kemijski tretiran) za određivanje izvlačne sile kod zavarivanja moždanika u smjeru vlakanaca te pojava pukotina za vrijeme trajanja procesa zavarivanja (Župčić, 2010)
Dowel welded into untreated base in the direction of fibres
Moždanik zavaren u netretiranu podlogu u smjeru vlakanaca
Dowel welded into untreated base vertically to the direction of fibres
Moždanik zavaren u netretiranu podlogu okomito na smjer vlakanaca
After 10 h, the temperature was gradually reduced to 103 ± 2 ºC (between 30 and 40 min) and the mass of samples was determined by weighing.
Nakon 10 h temperatura se postupno smanjivala na 103 ± 2 ºC (između 30 i 40 min) i vaganjem je određena masa uzorka.
Samples were immersed into prepared solution of acid and then vacuumed for 2 h in a chamber.
Uzorci su potopljeni u pripremljenu otopinu kiseline i vakumirani 2 h u komori.
This was followed by compression at 4 bars for 2 h.
Zatim je uslijedilo tlačenje na 4 bara isto 2 h.
After the drying passed well, the temperature was increased to 160 ºC and it was maintained for up to 10 h.
Pošto je sušenje prošlo u redu, temperatura je povećana na 160 ºC i održavana 10 h.
After the modification was completed, the temperature was gradually reduced to 103 ± 2 ºC.
Nakon završetka modifikacije temperatura se postupno smanjila na 103 ± 2 ºC.
After sufficient duration of the conditioning process, the average water content in the samples was 5.98 % (5.05 % to 6.59 %).
Nakon dovoljno dugo kondicioniranja u laboratorijskim uvjetima prosječni sadržaj vode u uzorcima iznosio je 5,98 % (5,05 % do 6,59 %).
Dowels were welded or glued into thus modified samples.
U tako modificirane uzorke zavarivani su ili lijepljeni moždanici.
Dowels were also modified with citric acid by the same procedure.
Moždanici su isto modificirani limunskom kiselinom istim postupkom.
After the welding, the samples were conditioned (temperature 23 °C, relative humidity of 50%) for 15 days which was followed by the testing of embedded force on universal testing machine.
Nakon zavarivanja uzorci su kondicionirani (temperatura 23 °C, relativna vlaga zraka 50 %) 15 dana i pristupilo su ispitivanju izvlačne sile na univerzalnoj kidalici.
Total of 177 samples was used in this research which were properly welded and there were no cracks which reduce the strength of joint.
U ovom istraživanju ukupno je korišteno 177 uzoraka koji su bili pravilno zavareni i nije bilo pukotina koje smanjuju čvrstoću spoja.
The purpose of this research was to determine the possibility to weld thermally treated wood and wood treated with citric acid.
Cilj ovih istraživanja bio je utvrditi mogućnost zavarivanja toplinski tretiranog drva te drva tretiranog limunskom kiselinom.
Considering that the application of thermally treated wood is on the rise, taken researches definitely contribute to the possibility of welding of such wood.
Obzirom da je primjena toplinski tretiranog drva u porastu, provedena istraživanja svakako pridonose spoznaji o mogućnosti zavarivanja takvog drva.
Welding of wood was followed by increased temperature depending on the type of welding (rotational or vibrational), welding temperature was over 200 ºC.
Zavarivanje drva popraćeno je povišenom temperaturom ovisno o vrsti zavarivanja (rotacijsko ili vibracijsko), temperatura zavarivanja prelazi 200 ºC.
By influencing the modification in the wood structure, there were changes and reactions, and at the time of welding, there was once more a change of structure and reaction on the location around the joint.
Utjecajem modifikacije u strukturi drva događaju se promjene i reakcije, a prilikom zavarivanja ponovo dolazi do promjene strukture i reakcija na području oko spoja.
Due to the effect of increased temperature, there was a change in the property of wood and decomposition of wood components, but in a very fine layer around the joints.
Uslijed djelovanja te povišene temperature dolazi do promjena svojstava drva i razgradnje komponenti drva, ali u vrlo tankom sloju oko sljubnice.
Different parts of wood act in differently at welding temperature.
Različiti dijelovi drva različito se ponašaju kod temperature zavarivanja.
Thus cellulose shows a good resistance to thermal processing, while polyoses are the first ones to decompose.
Tako celuloza pokazuje dobru otpornost na termalne obrade, dok se polioze prve razgrađuju.
Decomposing of cellulose starts at temperatures between 260 and 350 ºC (LeVan and Winandy, 1990).
Razgradnja celuloze počinje na temperaturama između 260 i 350 ºC (LeVan i Winandy, 1990).
At friction welding, polyoses are less stable and are recognizable only in modified zones in very small amounts.
Kod zavarivanja trenjem polioze su manje stabilne te su prepoznatljive samo u promijenjenim zonama u vrlo malim količinama.
Lignin undergoes certain changes, such as increase of free phenol groups and the reduction of typical joints between the phenolpropane units.
Lignin doživljava određene promjene kao što je povećanje slobodnih fenolnih grupa i smanjenje tipičnih veza između fenolpropanskih jedinica.
Cause of changes of certain wood components due to heat effect is breaking of macromolecules to smaller, solvable components.
Razlog promjena pojedinih drvnih komponenti uslijed djelovanja topline je pucanje makromolekula na manje, topive komponente.
They investigated the changes which happen on lignin due to heat effect whether the wood was exposed to thermal processing, welding or burning (combustion).
Istraživali su promjene koje nastaju na ligninu uslijed djelovanja topline bilo da je drvo podvrgnuto toplinskoj obradi, zavarivanju ili izgaranju (sagorijevanju).
Lignin is thermally more unstable than cellulose, and it disintegrates at temperatures between 150 and 300 ºC, when breaking of α a β-aryl-alkyl ether connections happens first.
Lignin je toplinski nestabilniji od celuloze, a razgrađuje se između 150 i 300 ºC, prvo počinje pucanje α i β-aril-alkil eternih veza.
Researches were taken on samples with treated base only and untreated dowel.
Istraživanja su provedena na uzorcima kod kojih je bila tretirana samo podloga dok je moždanik bio netretiran.
Welding of treated dowel into the treated base is not possible due to breaks in base or dowel, therefore such research was not taken.
Zavarivanje tretiranog moždanika u tretiranu podlogu nije moguće zbog lomova podloge ili moždanika pa takva istraživanja nisu provedena.