scholarly journals Influence of Scots Pine (Pinus sylvestris L.) Veneers Quality on Selected Properties of Layered Composite for Flooring Materials

Forests ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 1017
Author(s):  
Izabela Burawska-Kupniewska ◽  
Paweł Mycka ◽  
Piotr Beer
Keyword(s):  
Mechanical Properties ◽  
Pinus Sylvestris ◽  
Scots Pine ◽  
Modulus Of Elasticity ◽  
Bending Strength ◽  
Deformation Modulus ◽  
Physical And Mechanical Properties ◽  
Production Costs ◽  
Base Layer ◽  
Class A

The article concerns the quality issues in wood industry, and especially the advisability of removing defects from veneers. The research purpose of the study was to analyse the influence of the layered structure of plywood base layer made of low-quality wood on selected mechanical properties of floor composites. The utilitarian purpose is to analyse the possibility of producing floors from low-quality materials reducing waste. Four quality classes of Scots pine veneers (Pinus sylvestris L.) were taken into account: A, B, C, D, from the highest class-A without defects to the lowest class-D characterized by a lot of knots (including broken and falling out ones) and cracks. The base layer of the floors was made of these wood quality classes. The value of the modulus of elasticity in elastic deformation, modulus of elasticity in the dynamic and fatigue tests, stiffness and static bending strength were investigated. The test results showed that, as expected, the samples made of class A had the highest values of the measured parameters (static bending strength, static and dynamic modulus of elasticity, and stiffness). However, the values of the tested parameters for the remaining classes B, C, and D did not significantly differ. It was concluded from the research that the change of the plywood base layer conditions regarding the quality of veneers does not significantly affect the physical and mechanical properties of composites. Hence, it is possible to use wood of lower quality classes for production without verification of which class they belong to, which will significantly reduce the production costs.

scholarly journals Selected physical and mechanical properties of Scots pine (Pinus sylvestris L.) wood from stands of younger age classes as criteria for rational utilization of timber

2021 ◽  
Vol 27 (1) ◽  
Author(s):  
Przemysław Marcin Pikiński ◽  
Jaroslav Szaban ◽  
Gerda Šilingienė ◽  
Robert Korzeniewicz ◽  
Witold Pazdrowski
Keyword(s):  
Mechanical Properties ◽  
Pinus Sylvestris ◽  
Scots Pine ◽  
Bending Strength ◽  
Physical And Mechanical Properties ◽  
Growth Conditions ◽  
Tree Age ◽  
Coniferous Forests ◽  
Forest Site ◽  
Quality Coefficient

The aim of this study was to assess the quality of Scots pine (Pinus sylvestris L.) wood depending on the age of trees, forest site conditions and social class of tree position in the stand. Analyses were based on the determination of specific density and static bending strength, as well as the strength quality coefficient. It was to determine changes in physical and mechanical properties of timber depending on tree age as well as growth conditions reflected in the forest site such as fresh mixed coniferous forests and fresh mixed broadleaved forests. Experimental plots were established in 6 localities with 30, 40 and 60-year-old trees. In each of the stands, a 1-hectare experimental plot was established. Based on the measured DBH and tree height, dimensions of three mean sample trees were calculated, while the classification of social class of tree position in the stand developed by Kraft (1884) was also applied. Analyses were conducted on wood samples with 12% moisture content. Strength tests on wood samples were performed on an Instron 33RH204 universal strength testing machine. A detailed analysis showed properties of pine wood are improved with an increase of tree age in both forest sites. Statistically significant differences were observed for wood density and static bending strength. More advantageous properties were observed for wood of pines from the less fertile forest site, i.e., fresh mixed coniferous forests. Density and static bending strength were markedly determined by tree age and growth conditions. The static bending strength quality coefficient from pines growing in the fresh mixed coniferous forests increased between 30 and 40 years, similarly as it was for the fresh mixed broadleaved forests, while between 40 and 60 years, it deteriorated for the fresh mixed coniferous forests. Wood density from the fresh mixed coniferous forests was by 3% to 7% greater than pines growing in fresh mixed broadleaved forests. In turn, static bending strength of wood from pines growing in fresh mixed coniferous forests was by 4% to 10% greater than trees from the fresh mixed broadleaved forests.  Keywords: Scots pine, wood properties, forest site, Poland

scholarly journals Relationships between Thermoplastic Type and Properties of Polymer-Triticale Boards

Polymers ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 1750 ◽  
Author(s):  
Radosław Mirski ◽  
Pavlo Bekhta ◽  
Dorota Dziurka
Keyword(s):  
Mechanical Properties ◽  
Modulus Of Elasticity ◽  
Bending Strength ◽  
Physical And Mechanical Properties ◽  
Thickness Swelling ◽  
Hydrophobic Properties ◽  
Pine Wood ◽  
Moisture Contents ◽  
The Face

This study examined the effects of selected types of thermoplastics on the physical and mechanical properties of polymer-triticale boards. The investigated thermoplastics differed in their type (polypropylene (PP), polyethylene (PE), polystyrene (PS)), form (granulate, agglomerate) and origin (native, recycled). The resulting five-ply boards contained layers made from different materials (straw or pine wood) and featured different moisture contents (2%, 25%, and 7% for the face, middle, and core layers, respectively). Thermoplastics were added only to two external layers, where they substituted 30% of straw particles. This study demonstrated that, irrespective of their type, thermoplastics added to the face layers most favorably reduced the hydrophobic properties of the boards, i.e., thickness, swelling, and V100, by nearly 20%. The bending strength and modulus of elasticity were about 10% lower in the experimental boards than in the reference ones, but still within the limits set out in standard for P7 boards (20 N/mm2 according to EN 312).

Influence of alder (Alnus glutinosa Gaerthn.) veneers on selected mechanical properties of layered pine (Pinus sylvestris L.) composites

2019 ◽  
Vol 108 ◽  
pp. 13-20
Author(s):  
PIOTR BEER ◽  
IZABELA BURAWSKA-KUPNIEWSKA ◽  
PAWEŁ PACEK ◽  
SYLWIA OLEŃSKA ◽  
ANNA RÓŻAŃSKA
Keyword(s):  
Mechanical Properties ◽  
Pinus Sylvestris ◽  
Modulus Of Elasticity ◽  
Alnus Glutinosa ◽  
Fatigue Tests ◽  
Base Layer ◽  
Three Point Bending ◽  
Properties Of Composites

Influence of alder (Alnus glutinosa Gaerthn.) veneers on selected mechanical properties of layered pine (Pinus sylvestris L.) composites. The aim of the study was to analyse the influence of using hardwood veneers in the base layer on selected mechanical properties of composites made of coniferous veneers dedicated for flooring applications. The modulus of elasticity and stiffness at three-point bending were determined in static, dynamic and fatigue tests. All tested mechanical properties of pine-alder composites showed, to a different extent, higher values than composites with a base layer made only of pine veneers

scholarly journals The effect of mat layers moisture content on some properties of particleboard

2019 ◽  
Vol 70 (3) ◽  
pp. 221-228
Author(s):  
Abdullah Istek ◽  
Ismail Ozlusoylu
Keyword(s):  
Mechanical Properties ◽  
Moisture Content ◽  
Modulus Of Elasticity ◽  
Bending Strength ◽  
Physical And Mechanical Properties ◽  
Core Layer ◽  
Formaldehyde Resin ◽  
Internal Bonding ◽  
The Core ◽  
Internal Bonding Strength

In this study, the effect of mat moisture content on the physical and mechanical properties of particleboard was investigated. The experimental boards were produced by using 40 % softwood, 45 % hardwood chips, and 15 % sawdust. The formaldehyde resin/adhesive was used in three-layers (bottom-top layer 12 %, core layer 8 %). Multi-opening press was used during manufacturing the experimental particleboards. The physical and mechanical properties of boards obtained were identified according to the TS-EN standards. The optimum core layer moisture content was determined as 6 % and 7 % according to the results, whereas the moisture content of bottom and top layers was 14 %. Under these moisture content conditions, the bending strength was found to be 13.3 N/mm², the modulus of elasticity in bending 2466 N/mm², and internal bonding strength 0.44 N/mm². The optimum bottom-top layer moisture content was determined to be between 13 % and 15 % and 6.5 % for the core layer.

scholarly journals Comparative Assessment Of Some Physical And Mechanical Properties Of Wood Of Different Scots Pine Climatypes

2021 ◽  
Vol 24 (2) ◽  
pp. 27-36
Author(s):  
Siarhei Rabko ◽  
Aliaksandr Kozel ◽  
Ivan Kimeichuk ◽  
Vasyl Yukhnovskyi
Keyword(s):  
Mechanical Properties ◽  
Scots Pine ◽  
Bending Strength ◽  
Geographical Origin ◽  
Testing Machine ◽  
Physical And Mechanical Properties ◽  
Forest Steppe ◽  
Siberian Pine ◽  
North Latitude

For a more efficient and rational use in the production of Scots pine wood of various geographical origin, it is necessary to know its physical and mechanical properties. The purpose of this study was to determine the physical and mechanical properties of wood of 17 climatic ecotypes of Scots pine and to carry out a comparative analysis of the indicators obtained for the studied climatypes separately and when they are grouped into subspecies in accordance with the classification of L.F. Pravdin. The range of the geographical origin of the places of seed procurement is from 47 to 62° north latitude and from 22 to 85° east longitude. The modern density universal testing machine MTS INSIGHT 100 was used for research. As a result of the research, it was found that the density of wood in an absolutely dry state varies from 370 kg/m3 (Kursk climatype) to 524 kg/m3 (Volgograd climatype), and at 12% humidity – from 397 kg/m3 (Kursk climatype) to 550 kg/m3 (Volgograd climatype). The index of the strength of wood of the studied climatypes for compression along the fibres was from 32 MPa (Kursk climatype) to 54 MPa (Volgograd climatype), and for static bending – from 55 to 92 MPa for the Vologda and Ulyanovsk climatypes, respectively. Distribution of Scots pine climatypes into subspecies in accordance with the classification of L.F. Pravdin and the obtained data on the physical and mechanical properties of wood have a certain pattern. The maximum density of wood at 12% moisture is typical for the European Scots pine subspecies is 497±8 kg/m3 , the minimum value of this indicator for the Siberian Scots pine subspecies is 423±30 kg/m3 . An intermediate position is occupied by the subspecies of Lapland pine and Forest-steppe pine with values of 483±16 and 464±12 kg/m3 , respectively. The strength index of wood in the studied subspecies for compression along the fibres ranged from 47±1 MPa (European subspecies) to 33±4 MPa (Siberian subspecies), in the Lapland pine subspecies – 44±2 MPa and somewhat lower in the Forest-steppe pine subspecies – 42±2 MPa. The maximum value of the static bending strength of wood is typical for the European pine subspecies – 78±4 MPa, and the minimum – for the Siberian pine subspecies – 61±14 MPa. This indicator turned out to be equal in subspecies of forest-steppe and Lapland pine and amounted to 72±4 MPa. The practical value of the work lies in identifying the existing differences and variability among climatypes according to the studied physical and mechanical properties of wood and selecting the most promising of them for further breeding purposes

scholarly journals Quality and Bending Properties of Scots Pine (Pinus Sylvestris L.) Sawn Timber

Forests ◽  
2020 ◽  
Vol 11 (11) ◽  
pp. 1200
Author(s):  
Izabela Burawska-Kupniewska ◽  
Sławomir Krzosek ◽  
Piotr Mańkowski ◽  
Marek Grześkiewicz
Keyword(s):  
Mechanical Properties ◽  
Scots Pine ◽  
Modulus Of Elasticity ◽  
Bending Strength ◽  
Mechanical Parameters ◽  
Bending Properties ◽  
Characteristic Values ◽  
Sawn Timber ◽  
The Moment

The paper presents the partial research results of a mechanical properties study conducted on Scots pine from the Silesian Forestry Area in Poland. The scope of research included the visual strength grading of the timber according to the PN-D-94021:2013 standard, mechanical testing (according to EN 408:2012) and an attempt to assign visuals to the C strength classes. The EN 1912: 2012 standard assigns the visual sorting classes of individual wood species (according to national sorting standards) to the C strength classes introduced by the EN 338: 2018 standard. At the moment, this standard does not assign Polish visual sorting classes (KW, KS, and KG) to C strength classes. The obtained MOE (modulus of elasticity) and MOR (static bending strength) values were corrected according to the EN 384:2018 standard, and their characteristic values were later calculated. On this basis, we proposed a classification of the grading classes determined on the basis of PN-D-94021 into C classes described in EN 338:2018, which is necessary in the process of the transposition of Polish strength grades (KW, KS, KG, and Reject) and the qualification of them in line with EN 1912:2012. The calculated characteristic values of density, MOR and E0 (the modulus of elasticity parallel to the grain) allowed us to assign Polish visual grades KW, KS, and KG to C35, C30, and C20, respectively. The pine timber under research had high physical and mechanical parameters, which translated into high C classes to which the KW, KS, and KG timber categories were assigned.

scholarly journals Physical and mechanical properties of black locust (Robinia pseudoacacia) wood grown in Belgium

2012 ◽  
Vol 42 (5) ◽  
pp. 831-840 ◽  
Author(s):  
C. Pollet ◽  
C. Verheyen ◽  
J. Hébert ◽  
B. Jourez
Keyword(s):  
Mechanical Properties ◽  
Modulus Of Elasticity ◽  
Bending Strength ◽  
Black Locust ◽  
Robinia Pseudoacacia ◽  
Value Added ◽  
Physical And Mechanical Properties ◽  
Tectona Grandis ◽  
Clear Wood ◽  
Robinia Pseudoacacia L

The objective of this study was to characterize black locust ( Robinia pseudoacacia L.) wood on the basis of its physical and mechanical properties. The results are compared with those reported in the literature for English oak ( Quercus robur L.), teak ( Tectona grandis L. f.), and afzelia ( Afzelia sp.), since black locust is likely to be used for the same purposes as the former species. The variations between sites, trees, and radial positions in the trunk were also studied. The physical and mechanical properties of black locust wood were evaluated on clear wood specimens taken from 27 trees distributed over five sites in Wallonia (Belgium) according to Belgian and French standards. Most of the black locust’s mechanical properties are higher than those of oak and teak. The black locust is classified as a “mid-heavy” (734 kg·m–3) and “half-hard” (5.22) wood type with very high resilience (17.2 J·cm–2), modulus of elasticity (15 700 MPa), and tensile strength in static bending (138 MPa). Its resilience is exceptional, higher than that of teak and afzelia, while its modulus of elasticity and bending strength, which surpass those of teak, are comparable with those of afzelia. Black locust shows high total volumetric shrinkage (16%), placing it in the “nervous” class, average tangential (8.8%) and radial shrinkage (5.5%) as well as average axial compressive (63 MPa) and splitting strength (17.8 N·mm–1). No technological incompatibilities would prevent the use of this wood for many value-added purposes (floor, deck, exterior woodwork, and furniture); however, significant shrinkage makes it necessary to condition the wood to its service moisture.

scholarly journals Currency Note Paper and Banana Fiber Pulp Waste Utilization and its Effect of Density, Moisture and Temperature on Wood Products

2019 ◽  
Vol 8 (3) ◽  
pp. 6484-6487
Keyword(s):  
Mechanical Properties ◽  
Modulus Of Elasticity ◽  
Moisture Absorption ◽  
Bending Strength ◽  
Physical And Mechanical Properties ◽  
Waste Utilization ◽  
Wood Products ◽  
Control Group ◽  
Banana Fiber ◽  
Currency Note

Possibilities for use of banana fiber and currency notes thermally modified groups were evaluated for the production of plywood boards in industrial conditions. Formats of groups were treated at temperatures of 190 °C, 200 °C, 210 °C, and 215 °C for each 9 h to making the pulp process. By combining the treated and non-treated formats of veneer in types of board groups, thirteen different types of board were made. Analysis showed that the examined physical and mechanical properties were influenced by both the type of construction and the applied thermal treatment. Boards composed only of thermally modified group achieved the best results regarding moisture absorption and dimensional stability, and boards composed of the combined currency notes and banana fiber had better mechanical properties. As per the analysis of plywood board when used banana fiber used in pulp of plywood board is suitable at190 °C temperature rather than 215 °C temperature with comparing the other types of board. 25 °C temperature is less requires for control group board. We can consume cost of heat which is used in this process and getting the hard quality of plywood. At 215 °C temperature of processing cost of heat is 10% of plywood cost and when at 190°C of processing the cost of heat is 9.06% of plywood cost so that we can consume 0.94% cost of heat. Moisture content of temperature conditioned boards of control group is 9.01% density of conditioned boards 436.36 kg/m3 . Highest bending strength and modulus of elasticity of boards is 48.07MPa and 6078 MPa in longitudinal direction and bending strength and modulus of elasticity of boards in cross-section 28.40MPa and 2027 MPa.

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