Pub Date : 2016-01-01DOI: 10.12841/WOOD.1644-3985.144.13
S. Adamopoulos, A. Karageorgos, Elli Rapti, D. Birbilis
The difficulty in predicting the properties and behaviour of paper products produced using heterogeneous raw materials with high percentages of recovered fibres poses restrictions on their efficien ...
难以预测使用含有高回收纤维百分比的异质原料生产的纸制品的性能和行为，这限制了它们的效率。
{"title":"Predicting the Properties of Corrugated Base Papers Using Multiple Linear Regression and Artificial Neural Networks","authors":"S. Adamopoulos, A. Karageorgos, Elli Rapti, D. Birbilis","doi":"10.12841/WOOD.1644-3985.144.13","DOIUrl":"https://doi.org/10.12841/WOOD.1644-3985.144.13","url":null,"abstract":"The difficulty in predicting the properties and behaviour of paper products produced using heterogeneous raw materials with high percentages of recovered fibres poses restrictions on their efficien ...","PeriodicalId":50566,"journal":{"name":"Drewno","volume":"59 1","pages":"61-72"},"PeriodicalIF":0.8,"publicationDate":"2016-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66329667","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2016-01-01DOI: 10.12841/WOOD.1644-3985.150.06
T. Nowak, J. Jasieńko, Ewa Kotwica, S. Krzosek
This paper reviews selected historical and modern methods of strengthening timber structures using steel plates. The results of experimental testing are also presented, emphasizing that the differences in the results obtained were a result of the application of different strengthening methods, test specimens, etc. The need to develop design guidelines related to reinforcement methods is also emphasized. Appropriate reinforcement depends on the application, arrangement and ratio of the reinforcement. The increase in the load-bearing capacity of the beams reinforced by bonded or glued-in plates in comparison to the unreinforced elements was found to be similar to the models reinforced with fibre reinforced polymer (FRP). The increase in stiffness was, however, higher than in the case of the FRP reinforcement. Due to the influence of temperature and humidity on the strength and deformation of the bonding if glued-in or bonded plates are used, additional strengthening of the connection using a mechanical connector is recommended. These connectors also protect against rapid destruction in the case of fire.
{"title":"Strength enhancement of timber beams using steel plates – review and experimental tests","authors":"T. Nowak, J. Jasieńko, Ewa Kotwica, S. Krzosek","doi":"10.12841/WOOD.1644-3985.150.06","DOIUrl":"https://doi.org/10.12841/WOOD.1644-3985.150.06","url":null,"abstract":"This paper reviews selected historical and modern methods of strengthening timber structures using steel plates. The results of experimental testing are also presented, emphasizing that the differences in the results obtained were a result of the application of different strengthening methods, test specimens, etc. The need to develop design guidelines related to reinforcement methods is also emphasized. Appropriate reinforcement depends on the application, arrangement and ratio of the reinforcement. The increase in the load-bearing capacity of the beams reinforced by bonded or glued-in plates in comparison to the unreinforced elements was found to be similar to the models reinforced with fibre reinforced polymer (FRP). The increase in stiffness was, however, higher than in the case of the FRP reinforcement. Due to the influence of temperature and humidity on the strength and deformation of the bonding if glued-in or bonded plates are used, additional strengthening of the connection using a mechanical connector is recommended. These connectors also protect against rapid destruction in the case of fire.","PeriodicalId":50566,"journal":{"name":"Drewno","volume":"59 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2016-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66329883","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2016-01-01DOI: 10.12841/WOOD.1644-3985.179.10
M. Gabrič, T. Bončina, M. Humar, F. Pohleven
The effects of laccase from the white-rot basidiomycete fungus Trametes versicolor on Norway spruce wood (Pices abies) surface were studied. Experiments were performed at room temperature and at pH 4.6, without the addition of mediators. Biological, chemical and physical properties of the treated wood surface were examined by a wood decay test, a scanning electron microscopy (SEM), a Fourier transform infrared (FTIR) spectroscopy and a copper leaching test. Laccase pre-treatment of Norway spruce wood surface was shown to reduce wood decay by brown-rot fungus, Gloeophyllum trabeum and white-rot fungus, Trametes versicolor. SEM images showed expanded wood cell walls, closed pits and a more even surface after laccase treatment. FTIR analysis indicated that laccase not only catalyse depolymerisation of lignin, but also affect other wood cell wall components, such as hemicellulose and cellulose. We showed that laccase treatment altered wood properties in a way that improved wood resistance to decay and prevented leaching of copper from impregnated wood.
{"title":"Laccase treatment of Norway spruce wood surface improves resistance and copper fixation of treated wood","authors":"M. Gabrič, T. Bončina, M. Humar, F. Pohleven","doi":"10.12841/WOOD.1644-3985.179.10","DOIUrl":"https://doi.org/10.12841/WOOD.1644-3985.179.10","url":null,"abstract":"The effects of laccase from the white-rot basidiomycete fungus Trametes versicolor on Norway spruce wood (Pices abies) surface were studied. Experiments were performed at room temperature and at pH 4.6, without the addition of mediators. Biological, chemical and physical properties of the treated wood surface were examined by a wood decay test, a scanning electron microscopy (SEM), a Fourier transform infrared (FTIR) spectroscopy and a copper leaching test. Laccase pre-treatment of Norway spruce wood surface was shown to reduce wood decay by brown-rot fungus, Gloeophyllum trabeum and white-rot fungus, Trametes versicolor. SEM images showed expanded wood cell walls, closed pits and a more even surface after laccase treatment. FTIR analysis indicated that laccase not only catalyse depolymerisation of lignin, but also affect other wood cell wall components, such as hemicellulose and cellulose. We showed that laccase treatment altered wood properties in a way that improved wood resistance to decay and prevented leaching of copper from impregnated wood.","PeriodicalId":50566,"journal":{"name":"Drewno","volume":"59 1","pages":"19-33"},"PeriodicalIF":0.8,"publicationDate":"2016-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66330289","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2016-01-01DOI: 10.12841/WOOD.1644-3985.C37.01
D. Janiszewska, I. Frąckowiak, N. Bielejewska
This work presents the characteristics of wood liquefied using different types of solvents in terms of its application for binding particleboards. Standard pine particles from barked wood were used for the liquefaction experiments. The liquefaction reaction was carried out in high temperature conditions using a mixture of solvents from the polyhydroxy alcohol group, including glycerine, ethylene glycol, propylene glycol, diethylene glycol, and dipropylene glycol. The microstructure of both the liquefied wood and the liquefaction residues was determined by means of optical microscopy analysis. The basic parameters of the adhesive mixture modified with the liquefied wood, such as viscosity, pH and gel time were determined. Particleboards containing liquefied wood were produced. The following physicochemical and mechanical properties of the particleboards were measured: tensile strength, bending strength, modulus of elasticity, and formaldehyde content . The influence of the liquefying agent on the board properties was investigated. In all the tests, a control particleboard, bonded with a urea-formaldehyde adhesive resin with no inclusion of liquefied wood, was used for the purposes of comparison.
{"title":"APPLICATION OF SELECTED AGENTS FOR WOOD LIQUEFACTION AND SOME PROPERTIES OF PARTICLEBOARDS PRODUCED WITH THE USE OF LIQUEFIED WOOD","authors":"D. Janiszewska, I. Frąckowiak, N. Bielejewska","doi":"10.12841/WOOD.1644-3985.C37.01","DOIUrl":"https://doi.org/10.12841/WOOD.1644-3985.C37.01","url":null,"abstract":"This work presents the characteristics of wood liquefied using different types of solvents in terms of its application for binding particleboards. Standard pine particles from barked wood were used for the liquefaction experiments. The liquefaction reaction was carried out in high temperature conditions using a mixture of solvents from the polyhydroxy alcohol group, including glycerine, ethylene glycol, propylene glycol, diethylene glycol, and dipropylene glycol. The microstructure of both the liquefied wood and the liquefaction residues was determined by means of optical microscopy analysis. The basic parameters of the adhesive mixture modified with the liquefied wood, such as viscosity, pH and gel time were determined. Particleboards containing liquefied wood were produced. The following physicochemical and mechanical properties of the particleboards were measured: tensile strength, bending strength, modulus of elasticity, and formaldehyde content . The influence of the liquefying agent on the board properties was investigated. In all the tests, a control particleboard, bonded with a urea-formaldehyde adhesive resin with no inclusion of liquefied wood, was used for the purposes of comparison.","PeriodicalId":50566,"journal":{"name":"Drewno","volume":"59 1","pages":"223-230"},"PeriodicalIF":0.8,"publicationDate":"2016-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66331473","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2016-01-01DOI: 10.12841/WOOD.1644-3985.171.11
A. Gençer, S. M. Onat, A. Can, Ufuk Özgül, H. Sivrikaya, F. Yurdakurban
This study aimed to decelerate the weathering of paper from light by utilizing the antioxidant property of sodium ascorbate (SA), which is an ascorbic acid salt. Three different sessions of cooking were carried out by adding 2.5%, 5.0% and 7.5% of SA in proportion to the weight of a completely dried chip in addition to 24% NaOH in order to identify the influence of SA on cooking. It was observed that the pulp yield decreased when SA was added to the cooking. For that reason, it was decided to add SA into the control pulps instead of adding the digester. The same amount of SA was added to the control. The SA-added pulps were held in the agitator initially first for 2 hours and then 12 hours before making paper. So as to determine the influence of the treatment on the process. The paper was treated for 72, 144 and 256 hours and values of ∆L, ∆a, ∆b and ∆E were identified in order to determine the period of the SA’s efficacy against weathering. The total discoloration in all the samples of paper, displayed an increase with an extension of the time period. The lowest discoloration after a 256-hour time period was seen in the sample group where 7.5% of SA was added and soaked in the water. The final results indicated that the most appropriate concentration was 5% and that pulp suspension must be retained for 12 hours to improve mechanical properties.
{"title":"Effect of sodium ascorbate on weathering performance of NaOH pulping and paper","authors":"A. Gençer, S. M. Onat, A. Can, Ufuk Özgül, H. Sivrikaya, F. Yurdakurban","doi":"10.12841/WOOD.1644-3985.171.11","DOIUrl":"https://doi.org/10.12841/WOOD.1644-3985.171.11","url":null,"abstract":"This study aimed to decelerate the weathering of paper from light by utilizing the antioxidant property of sodium ascorbate (SA), which is an ascorbic acid salt. Three different sessions of cooking were carried out by adding 2.5%, 5.0% and 7.5% of SA in proportion to the weight of a completely dried chip in addition to 24% NaOH in order to identify the influence of SA on cooking. It was observed that the pulp yield decreased when SA was added to the cooking. For that reason, it was decided to add SA into the control pulps instead of adding the digester. The same amount of SA was added to the control. The SA-added pulps were held in the agitator initially first for 2 hours and then 12 hours before making paper. So as to determine the influence of the treatment on the process. The paper was treated for 72, 144 and 256 hours and values of ∆L, ∆a, ∆b and ∆E were identified in order to determine the period of the SA’s efficacy against weathering. The total discoloration in all the samples of paper, displayed an increase with an extension of the time period. The lowest discoloration after a 256-hour time period was seen in the sample group where 7.5% of SA was added and soaked in the water. The final results indicated that the most appropriate concentration was 5% and that pulp suspension must be retained for 12 hours to improve mechanical properties.","PeriodicalId":50566,"journal":{"name":"Drewno","volume":"59 1","pages":"49-60"},"PeriodicalIF":0.8,"publicationDate":"2016-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66330604","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2016-01-01DOI: 10.12841/WOOD.1644-3985.149.01
Daniel Nilsson, R. Pettersson, T. Thörnqvist, M. Nylinder
Bioenergy from logging residues is an important contributor to Swedish energysupplies. Thus, accurate measurements of delivered logging residues’ energycontents are very important for both sellers ...
{"title":"The importance of accurate measurement of comminuted logging residues’ moisture contents for small-scale forest owners","authors":"Daniel Nilsson, R. Pettersson, T. Thörnqvist, M. Nylinder","doi":"10.12841/WOOD.1644-3985.149.01","DOIUrl":"https://doi.org/10.12841/WOOD.1644-3985.149.01","url":null,"abstract":"Bioenergy from logging residues is an important contributor to Swedish energysupplies. Thus, accurate measurements of delivered logging residues’ energycontents are very important for both sellers ...","PeriodicalId":50566,"journal":{"name":"Drewno","volume":"59 1","pages":"99-110"},"PeriodicalIF":0.8,"publicationDate":"2016-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66329799","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2016-01-01DOI: 10.12841/WOOD.1644-3985.135.04
J. Zawadzki, J. Gawron, A. Antczak, T. Kłosińska, A. Radomski
Pinewood (Pinus sylvestris L.) was thermally modified at temperatures of 160oC and 200oC for 2, 6 and 10 hour periods, respectively. The severe conditions of the heat treatment resulted in decreased mechanical properties (compressive strength and modulus of elasticity) and a decrease in the degree of cellulose polymerization. A comparison of selected mechanical properties and the degree of cellulose polymerization indicated that there was a relationship between them and the temperature and duration of the heat treatment.
{"title":"The influence of heat treatment on the physico-chemical properties of pinewood (Pinus sylvestris L.)","authors":"J. Zawadzki, J. Gawron, A. Antczak, T. Kłosińska, A. Radomski","doi":"10.12841/WOOD.1644-3985.135.04","DOIUrl":"https://doi.org/10.12841/WOOD.1644-3985.135.04","url":null,"abstract":"Pinewood (Pinus sylvestris L.) was thermally modified at temperatures of 160oC and 200oC for 2, 6 and 10 hour periods, respectively. The severe conditions of the heat treatment resulted in decreased mechanical properties (compressive strength and modulus of elasticity) and a decrease in the degree of cellulose polymerization. A comparison of selected mechanical properties and the degree of cellulose polymerization indicated that there was a relationship between them and the temperature and duration of the heat treatment.","PeriodicalId":50566,"journal":{"name":"Drewno","volume":"59 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2016-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66329848","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2016-01-01DOI: 10.12841/wood.1644-3985.174.08
M. Juszczak, W. Cichy, Katarzyna Pałaszyńska
The benefits of applying automatic air flow control system with oxygen sensor in a 20 kW heating boiler with a retort furnace supplied periodically with wood pellets were examined. Boiler combustion chamber was not lined with ceramic blanket and therefore the fuel supply cycle duration (operation and stand-by) was set by the producer to just 20 seconds. Variation in time of carbon monoxide, nitric oxide, nitrogen oxides and oxygen concentrations in the flue gas, as well as correlations between: pollutant concentrations and temperature in the combustion chamber or oxygen concentration, temperature in the combustion chamber and oxygen concentration, nitric oxide and carbon monoxide concentrations were compared for different scenarios: with automatic air flow control and with constant air flow. It was concluded that applying automatic air flow control system with oxygen sensor did not significantly reduce carbon monoxide concentration (only by 10-15%). Most probably it is because the stand-by in fuel feeding is too short for the air supply fan to react. In order to reduce carbon monoxide concentration, instead of applying automatic air flow control it is preferable to obtain higher heat outputs (above 60% of its maximum value) and use higher capacity water heat storages.
{"title":"Usefulness assessment of automatic air flow control system with oxygen sensor in a 20 kW boiler with periodic wood pellet supply","authors":"M. Juszczak, W. Cichy, Katarzyna Pałaszyńska","doi":"10.12841/wood.1644-3985.174.08","DOIUrl":"https://doi.org/10.12841/wood.1644-3985.174.08","url":null,"abstract":"The benefits of applying automatic air flow control system with oxygen sensor in a 20 kW heating boiler with a retort furnace supplied periodically with wood pellets were examined. Boiler combustion chamber was not lined with ceramic blanket and therefore the fuel supply cycle duration (operation and stand-by) was set by the producer to just 20 seconds. Variation in time of carbon monoxide, nitric oxide, nitrogen oxides and oxygen concentrations in the flue gas, as well as correlations between: pollutant concentrations and temperature in the combustion chamber or oxygen concentration, temperature in the combustion chamber and oxygen concentration, nitric oxide and carbon monoxide concentrations were compared for different scenarios: with automatic air flow control and with constant air flow. It was concluded that applying automatic air flow control system with oxygen sensor did not significantly reduce carbon monoxide concentration (only by 10-15%). Most probably it is because the stand-by in fuel feeding is too short for the air supply fan to react. In order to reduce carbon monoxide concentration, instead of applying automatic air flow control it is preferable to obtain higher heat outputs (above 60% of its maximum value) and use higher capacity water heat storages.","PeriodicalId":50566,"journal":{"name":"Drewno","volume":"59 1","pages":"111-130"},"PeriodicalIF":0.8,"publicationDate":"2016-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66330172","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2016-01-01DOI: 10.12841/WOOD.1644-3985.C01.05
Jan H. Blohm, R. Evans, G. Koch, U. Schmitt
More than one-third of Germany s Douglas-fir resources, stock in age-classes from twenty-one to fifty-nine years. As such timber increasingly enters markets, detailed knowledge of the anatomy and properties of its wood is of importance to forest managers and wood processors. Anatomical and mechanical wood analyses in this study were carried out on twenty trees from four scientifically managed plantations in Southern Germany. The age of the trees selected was forty-two years whereby varying growth conditions were considered. Juvenile and adult woods were identified by segmented linear regression of radial profiles of anatomical characteristics, such as latewood percentage, tracheid wall thickness microfibril angle and density. Additionally, the width of earlywood, latewood and growth rings as well as bending modulus of elasticity were determined. Variance was dependent on the trait used for differentiation, j uvenile wood comprised of an eleven to thirty-one growth rings resp. radial amounts of fifteen to sixty-five percent. When compared to adult wood, juvenile wood showed corresponding features of approximately thirty percent wider growth rings, th irty four percent lower latewood percentage, fourteen percent thinner tracheid walls, and eighty percent larger microfibril angles, eleven percent lighter wood and fifty -seven percent lower bending modulus of elasticity. As the assortment features fast grown trees, adult heartwood characteristics were slightly inferior to the characteristics of European Douglas-fir.
{"title":"Identification and characterisation of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) juvenile and adult wood grown in Southern Germany","authors":"Jan H. Blohm, R. Evans, G. Koch, U. Schmitt","doi":"10.12841/WOOD.1644-3985.C01.05","DOIUrl":"https://doi.org/10.12841/WOOD.1644-3985.C01.05","url":null,"abstract":"More than one-third of Germany s Douglas-fir resources, stock in age-classes from twenty-one to fifty-nine years. As such timber increasingly enters markets, detailed knowledge of the anatomy and properties of its wood is of importance to forest managers and wood processors. Anatomical and mechanical wood analyses in this study were carried out on twenty trees from four scientifically managed plantations in Southern Germany. The age of the trees selected was forty-two years whereby varying growth conditions were considered. Juvenile and adult woods were identified by segmented linear regression of radial profiles of anatomical characteristics, such as latewood percentage, tracheid wall thickness microfibril angle and density. Additionally, the width of earlywood, latewood and growth rings as well as bending modulus of elasticity were determined. Variance was dependent on the trait used for differentiation, j uvenile wood comprised of an eleven to thirty-one growth rings resp. radial amounts of fifteen to sixty-five percent. When compared to adult wood, juvenile wood showed corresponding features of approximately thirty percent wider growth rings, th irty four percent lower latewood percentage, fourteen percent thinner tracheid walls, and eighty percent larger microfibril angles, eleven percent lighter wood and fifty -seven percent lower bending modulus of elasticity. As the assortment features fast grown trees, adult heartwood characteristics were slightly inferior to the characteristics of European Douglas-fir.","PeriodicalId":50566,"journal":{"name":"Drewno","volume":"59 1","pages":"41-47"},"PeriodicalIF":0.8,"publicationDate":"2016-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66331070","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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