Construction of the mathematical model of the strength of post-consumer wood made blockboard of different designs

It is substantiated that any wood resources should be used rationally and comprehensively, in particular this applies to wood residues from various stages of primary wood processing – from logging to the creation of finished products. Secondly, according to the principles of the circular economy, th...

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Main Authors: Serhiy Gayda, Lyubomyr Medvid
Format: Article
Language:English
Published: Ukrainian National Forestry University 2024-10-01
Series:Наукові праці Лісівничої академії наук України
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Online Access:http://fasu.nltu.edu.ua/index.php/nplanu/article/view/837
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author Serhiy Gayda
Lyubomyr Medvid
author_facet Serhiy Gayda
Lyubomyr Medvid
author_sort Serhiy Gayda
collection DOAJ
description It is substantiated that any wood resources should be used rationally and comprehensively, in particular this applies to wood residues from various stages of primary wood processing – from logging to the creation of finished products. Secondly, according to the principles of the circular economy, the issue of processing post-consumer wood (PCW) as an additional resource of wood, which has already lost its consumer characteristics in products, and which, with proper processing, minimizes the negative impact on the environment, has become more relevant than ever. Thirdly, this partially solves the problems related to the increase of wood residues and waste, the accumulation of used wood in landfills, as well as environmental problems. A batch of pine PCW-made blockboards was prepared by implementing a second-order B-plan, where the variables were the width of the strips of tangential and radial sawing. The strength limit during static bending for pine PCW-made blockboard was determined experimentally and an adequate mathematical (regression) model was constructed depending on the alternate laying of radial (Вrad) and tangential (Вtan) strips with widths of 32, 52 and 72 mm. It was found that the width of the strips in blockboard structures with 22 mm thick PCW significantly affects the strength characteristics of the blockboard cores. It was found that an increase in width from 32 to 72 mm during the determination of the strength limit in static bending leads to a decrease in the indicator for radial strips by 13.29-16.70%, and for tangential strips by 24.83-27.79%. It was established that the strength limit during static bending of all pine PCW-made blockboards, regardless of their design, meets the regulatory requirements. According to the results of experimental studies, it was established that the maximum value of the strength limit during static bending σu = 39.199 MPa can be obtained by fixing the dimensions of the widths of the strips of pine PCW-made blockboard of combined laying at the level: Brad (x1) = 32 mm, Btan (x2) = 32 mm. Based on practical experience, it is recommended to use post-consumer wood (PCW) for the production of blockboards with a cross-section of strips in a ratio of no more than 1:5 in the case of combined radial and tangential laying, and in case of random laying – in a ratio of no more than 1:3. Practical recommendations for the production of PCW-made blockboard have been developed: moisture content of strips – 8±2%; for rails: the width should be 3-5 times the thickness; arrangement of strips – radial or at an angle of more than 45o; facing – 3 mm thick plywood; consumption of glue for the blockboard core – 200-250 g/m2; glue consumption for the blockboard facing – 150-200 g/m2; the temperature of the clamp for the blockboard core is 85-90 ºС; the temperature of the press for PCW-made blockboard – 115-125 ºС; the exposure time under pressure for the blockboard core is 30-40 minutes; holding time under pressure for PCW-made blockboard – 4-6 minutes; pressure for blockboard core – 0.5-1.0 MPa; for PCW-made blockboard – 1.2-1.3 MPa . Sorted and sawn to the appropriate cross-sectional dimensions, strips made from PCW of various species can be used to manufacture glued panel elements, in particular, blockboards and furniture panels. Therefore, the development of practical recommendations is certainly the basis for the rapid introduction of PCW into production processes.
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spelling doaj-art-b1bb4eefa5b7454c9ad7958887b659232025-02-06T08:51:44ZengUkrainian National Forestry UniversityНаукові праці Лісівничої академії наук України1991-606X2616-50152024-10-012727189198https://doi.org/10.15421/412426837Construction of the mathematical model of the strength of post-consumer wood made blockboard of different designsSerhiy Gayda0https://orcid.org/0000-0001-7468-5661Lyubomyr Medvid1https://orcid.org/0009-0006-6654-9348Ukrainian National Forestry UniversityUkrainian National Forestry UniversityIt is substantiated that any wood resources should be used rationally and comprehensively, in particular this applies to wood residues from various stages of primary wood processing – from logging to the creation of finished products. Secondly, according to the principles of the circular economy, the issue of processing post-consumer wood (PCW) as an additional resource of wood, which has already lost its consumer characteristics in products, and which, with proper processing, minimizes the negative impact on the environment, has become more relevant than ever. Thirdly, this partially solves the problems related to the increase of wood residues and waste, the accumulation of used wood in landfills, as well as environmental problems. A batch of pine PCW-made blockboards was prepared by implementing a second-order B-plan, where the variables were the width of the strips of tangential and radial sawing. The strength limit during static bending for pine PCW-made blockboard was determined experimentally and an adequate mathematical (regression) model was constructed depending on the alternate laying of radial (Вrad) and tangential (Вtan) strips with widths of 32, 52 and 72 mm. It was found that the width of the strips in blockboard structures with 22 mm thick PCW significantly affects the strength characteristics of the blockboard cores. It was found that an increase in width from 32 to 72 mm during the determination of the strength limit in static bending leads to a decrease in the indicator for radial strips by 13.29-16.70%, and for tangential strips by 24.83-27.79%. It was established that the strength limit during static bending of all pine PCW-made blockboards, regardless of their design, meets the regulatory requirements. According to the results of experimental studies, it was established that the maximum value of the strength limit during static bending σu = 39.199 MPa can be obtained by fixing the dimensions of the widths of the strips of pine PCW-made blockboard of combined laying at the level: Brad (x1) = 32 mm, Btan (x2) = 32 mm. Based on practical experience, it is recommended to use post-consumer wood (PCW) for the production of blockboards with a cross-section of strips in a ratio of no more than 1:5 in the case of combined radial and tangential laying, and in case of random laying – in a ratio of no more than 1:3. Practical recommendations for the production of PCW-made blockboard have been developed: moisture content of strips – 8±2%; for rails: the width should be 3-5 times the thickness; arrangement of strips – radial or at an angle of more than 45o; facing – 3 mm thick plywood; consumption of glue for the blockboard core – 200-250 g/m2; glue consumption for the blockboard facing – 150-200 g/m2; the temperature of the clamp for the blockboard core is 85-90 ºС; the temperature of the press for PCW-made blockboard – 115-125 ºС; the exposure time under pressure for the blockboard core is 30-40 minutes; holding time under pressure for PCW-made blockboard – 4-6 minutes; pressure for blockboard core – 0.5-1.0 MPa; for PCW-made blockboard – 1.2-1.3 MPa . Sorted and sawn to the appropriate cross-sectional dimensions, strips made from PCW of various species can be used to manufacture glued panel elements, in particular, blockboards and furniture panels. Therefore, the development of practical recommendations is certainly the basis for the rapid introduction of PCW into production processes.http://fasu.nltu.edu.ua/index.php/nplanu/article/view/837regression modelstatic bending strengthbonding strengthtechnologyglued structuresfurniture panelrecyclingscots pine (pinus sylvestris l.)circular economy
spellingShingle Serhiy Gayda
Lyubomyr Medvid
Construction of the mathematical model of the strength of post-consumer wood made blockboard of different designs
Наукові праці Лісівничої академії наук України
regression model
static bending strength
bonding strength
technology
glued structures
furniture panel
recycling
scots pine (pinus sylvestris l.)
circular economy
title Construction of the mathematical model of the strength of post-consumer wood made blockboard of different designs
title_full Construction of the mathematical model of the strength of post-consumer wood made blockboard of different designs
title_fullStr Construction of the mathematical model of the strength of post-consumer wood made blockboard of different designs
title_full_unstemmed Construction of the mathematical model of the strength of post-consumer wood made blockboard of different designs
title_short Construction of the mathematical model of the strength of post-consumer wood made blockboard of different designs
title_sort construction of the mathematical model of the strength of post consumer wood made blockboard of different designs
topic regression model
static bending strength
bonding strength
technology
glued structures
furniture panel
recycling
scots pine (pinus sylvestris l.)
circular economy
url http://fasu.nltu.edu.ua/index.php/nplanu/article/view/837
work_keys_str_mv AT serhiygayda constructionofthemathematicalmodelofthestrengthofpostconsumerwoodmadeblockboardofdifferentdesigns
AT lyubomyrmedvid constructionofthemathematicalmodelofthestrengthofpostconsumerwoodmadeblockboardofdifferentdesigns