Kraft scrap paper pulp as a substitute of wood chips in manufacture of particleboards resinated with hybrid pf/pmdi resin

This study analyzed feasibility of manufacture of composite particleboards resinated with a mixture of phenol–formaldehyde resin and 4,4′-methylenediphenyl isocyanate in the weight ratio 70:30. For this purpose 3-layer particleboards were produced with varying shares of Kraft scrap paper pulp in the core. Experimental boards were manufactured applying 0, 10, 15, 25, 50 and 75% substitution of wood chips with Kraft paper pulp. Analyses were conducted to determine physico-mechanical properties of boards, i.e. bending strength, modulus of elasticity, internal bond before and after the boiling test and swelling in thickness after 24 soaking in water. Based on recorded testing results it was stated that moisture resistant composite boards manufactured with a 25% substitution of wood chips with Kraft paper pulp meet the requirements of the EN 312 standard for boards used in humid conditions in terms of their strength and moisture resistance specified in the internal bond after the boiling test

Wood-Based Materials in Building

Wood is a widely used building material [...

Possibility of using the expanded polystyrene and rape straw to the manufacture of lightweight particleboards

The study investigated the possibility of using rape straw and expanded polystyrene for the production of low density particleboards. Particleboards with the core layer made of wood chips or rape straw, partly substituted with polystyrene (7%), were manufactured within the density range of 500 – 650 kg/ m3, and resinated with MUF resin. Our study confirmed that wood chip-expanded polystyrene (WP) and wood chip-rape straw-expanded polystyrene boards (WRP), of density reduced to 600 kg/m3, metthe mechanical requirements of the subject standard for boards intended for interior design (including furniture) and used in dry conditions. However, further density reduction required an increased resinationof the core layer

Possibility of using the expanded polystyrene and rape straw to the manufacture of lightweight particleboards

The study investigated the possibility of using rape straw and expanded polystyrene for the production of low density particleboards. Particleboards with the core layer made of wood chips or rape straw, partly substituted with polystyrene (7%), were manufactured within the density range of 500 – 650 kg/ m3, and resinated with MUF resin. Our study confirmed that wood chip-expanded polystyrene (WP) and wood chip-rape straw-expanded polystyrene boards (WRP), of density reduced to 600 kg/m3, metthe mechanical requirements of the subject standard for boards intended for interior design (including furniture) and used in dry conditions. However, further density reduction required an increased resinationof the core layer

Kraft scrap paper pulp as a substitute of wood chips in manufacture of particleboards resinated with hybrid pf/pmdi resin

This study analyzed feasibility of manufacture of composite particleboards resinated with a mixture of phenol–formaldehyde resin and 4,4′-methylenediphenyl isocyanate in the weight ratio 70:30. For this purpose 3-layer particleboards were produced with varying shares of Kraft scrap paper pulp in the core. Experimental boards were manufactured applying 0, 10, 15, 25, 50 and 75% substitution of wood chips with Kraft paper pulp. Analyses were conducted to determine physico-mechanical properties of boards, i.e. bending strength, modulus of elasticity, internal bond before and after the boiling test and swelling in thickness after 24 soaking in water. Based on recorded testing results it was stated that moisture resistant composite boards manufactured with a 25% substitution of wood chips with Kraft paper pulp meet the requirements of the EN 312 standard for boards used in humid conditions in terms of their strength and moisture resistance specified in the internal bond after the boiling test

The Influence of Microfungi on Physicomechanical Properties of Particleboards

This study concerns the influence of selected fungi on changes in physical and mechanical properties of type P2 particleboards intended for use in dry conditions. The tested fungi included Aspergillus niger van Tiehgem, Chaetomium globosum Kunze et Fr., Trichoderma viride Persoon ex S.F., Gray aggr., and Penicillium funiculosum Thom. The incubation process lasted for 16 weeks, yet samples for the strength test were selected after a period of four weeks. The degradation level of boards was estimated by measuring the decrement of initial mass and changes in physicomechanical properties. The obtained results showed that mechanical strength of the investigated boards affected by the tested fungi decreased by 15% to 20%. However, the differences in DSC thermographs indicate that it is cellulose that mainly undergoes degradation in the wood of the investigated boards. Based on the changes in mechanical properties and DSC analyses, we consider T. viride and A. niger as the most aggressive fungal species

Effects of Chip Type on the Properties of Chip–Sawdust Boards Glued with Polymeric Diphenyl Methane Diisocyanate

This study investigates the effects of chip type and sawdust percentage on physical and mechanical properties of chip–sawdust boards. The used wood chips varied in linear dimensions and original source. The origin determined the wood quality, which translated into the chips’ linear dimensions. The used materials were chips from sawmill waste processing, aggregate processing of sawmill wood, and chips intended for medium-density boards. The experiment demonstrated that the best boards in terms of mechanical properties were obtained from 4-mm-thick chips with 30% sawdust content and a density of 850 kg/m3. These boards meet the requirements of the EN 312 (2010) standard for P5 boards

The Effect of Periodic Loading of Glued Laminated Beams on Their Static Bending Strength

Engineered wood products (EWP) such as glulam beams are gaining more and more popularity due to several advantages resulting from the wood itself, as well as the constant search for structural materials of natural origin. However, building materials face some requirements regarding their strength. Thus, the study aimed to assess the static bending strength of structural beams produced with the use of pine wood, after the periodic loading of approximately 80 kN for a year. The manufactured beams differed in the type of facing layers, i.e., pine timber with a high modulus of elasticity and plywood. The produced beams, regardless of their structure, are characterized by a similar static bending strength. Moreover, it has been shown that the loading of beams in the range of about 45% of their immediate capacity does not significantly affect their static bending strength and linear modulus of elasticity

Properties of Rigid Polyurethane Foam Filled with Sawdust from Primary Wood Processing

In this study, the possibility of using sawdust, a by-product of primary wood processing, as a filler (WF) for rigid polyurethane (PUR) foams was investigated. The effects of the addition of 5, 10, 15 and 20% of WF particles to the polyurethane matrix on the foaming process, cell structure and selected physical-mechanical properties such as density, thermal conductivity, dimensional stability, water absorption, brittleness, compressive and bending strengths were evaluated. Based on the results, it was found that the addition of WF in the amount of up to 10% does not significantly affect the kinetics of the foam foaming process, allowing the reduction of their thermal conductivity, significantly reducing brittleness and maintaining high dimensional stability. On the other hand, such an amount of WF causes a slight decrease in the compressive strength of the foam, a decrease in its bending strength and an increase in water absorption. However, it is important that in spite of the observed decrease in the values of these parameters, the obtained results are satisfactory and consistent with the parameters of insulation materials based on rigid PUR foam, currently available on the market

Morphological Features of PUR-Wood Particle Composite Foams

The aim of this study was to apply waste wood particles (WP) with different sizes from primary wood processing as a filler for open-cell PUR foams. For this purpose, various wood particle sizes were added as a filler for polyurethane foams (PUR). The effects of the addition of of 0.05–1.25–2.0 of WP to the polyurethane matrix on the density, the kinetics of PUR foaming, the cell structure, and the morphology were investigated. Scanning electron microscope (SEM) and X-ray computer tomography were used. Based on the results, it was found that the addition of WP in the amount of 10% leads to an increase in density with an increase in particle size. The research shows that the morphology of the PUR-WP foam is influenced by its particle size. The difference in the number and size of cells in PUR-WP composites depends on the wood particle size. The addition of dust causes the formation of cells of much smaller sizes; confirmed by SEM images. Moreover, computer tomography clearly demonstrates that the WP are well-dispersed within the foams’ structures