Formaldehyde emissions from medium-density fiberboard(MDF)are significantly influenced by humidity.However,existing emission models predominantly rely on static humidity or instantaneous equilibration assumptions,ther...Formaldehyde emissions from medium-density fiberboard(MDF)are significantly influenced by humidity.However,existing emission models predominantly rely on static humidity or instantaneous equilibration assumptions,thereby neglecting the effects of dynamic moisture transfer.This study investigated the impact of moisture transfer on formaldehyde emissions using a combined experimental and modeling approach.MDF samples were exposed to equilibrium and moisture transfer conditions in controlled chambers,respectively.Key emission parameters—initial emittable concentration(C0),diffusion coefficient(Dm),and partition coefficient(K)—were regressed based on dynamic measurement data.The results indicated that humidity had a positive correlation with formaldehyde emissions,increasing C0 values more significantly compared to other emission parameters.Moisture transfer introduced directional biases in parameter estimation:inward transfer(from environment to material)reduced Dm by 61%but increased C0 by 136%,whereas outward transfer(from material to environment)elevated Dm by 40%and decreased C0 by 13%.These deviations substantially distorted indoor formaldehyde predictions,with simulations underestimating peak concentrations by 6%for inward transfer scenario and overestimating them by 20%for outward transfer scenario.The findings emphasize the necessity of incorporating transient humidity gradients into emission models to improve the accuracy of indoor air quality assessments.展开更多
We studied the effects of nanoparticles of organo-silane（NOS） compounds in the size range of20–80 nm on physical and mechanical properties in medium density fiberboard,and used NOS at four consumption levels of 0,5...We studied the effects of nanoparticles of organo-silane（NOS） compounds in the size range of20–80 nm on physical and mechanical properties in medium density fiberboard,and used NOS at four consumption levels of 0,50,100,and 150 g kg-1dry wood fibers.Density of all treatments was kept constant at 0.67 g cm-3.The water-repellent property of organo-silane significantly reduced water absorption（WA） and thickness swelling but mechanical properties declined due to the reduced proportion of wood-fiber as organo-silane was added to the matrix：the compression ratio of MDF panels and the integrity among wood-fibers both declined,resulting in reduced mechanical properties.We recommend use of 50 g of NOS/kg wood-fiber to improve WA and thickness swelling while retaining acceptable mechanical properties.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.52278109).
文摘Formaldehyde emissions from medium-density fiberboard(MDF)are significantly influenced by humidity.However,existing emission models predominantly rely on static humidity or instantaneous equilibration assumptions,thereby neglecting the effects of dynamic moisture transfer.This study investigated the impact of moisture transfer on formaldehyde emissions using a combined experimental and modeling approach.MDF samples were exposed to equilibrium and moisture transfer conditions in controlled chambers,respectively.Key emission parameters—initial emittable concentration(C0),diffusion coefficient(Dm),and partition coefficient(K)—were regressed based on dynamic measurement data.The results indicated that humidity had a positive correlation with formaldehyde emissions,increasing C0 values more significantly compared to other emission parameters.Moisture transfer introduced directional biases in parameter estimation:inward transfer(from environment to material)reduced Dm by 61%but increased C0 by 136%,whereas outward transfer(from material to environment)elevated Dm by 40%and decreased C0 by 13%.These deviations substantially distorted indoor formaldehyde predictions,with simulations underestimating peak concentrations by 6%for inward transfer scenario and overestimating them by 20%for outward transfer scenario.The findings emphasize the necessity of incorporating transient humidity gradients into emission models to improve the accuracy of indoor air quality assessments.
基金conducted as a joint research projectfinanced by SRTTU(Iran)UPM(Malaysia)
文摘We studied the effects of nanoparticles of organo-silane（NOS） compounds in the size range of20–80 nm on physical and mechanical properties in medium density fiberboard,and used NOS at four consumption levels of 0,50,100,and 150 g kg-1dry wood fibers.Density of all treatments was kept constant at 0.67 g cm-3.The water-repellent property of organo-silane significantly reduced water absorption（WA） and thickness swelling but mechanical properties declined due to the reduced proportion of wood-fiber as organo-silane was added to the matrix：the compression ratio of MDF panels and the integrity among wood-fibers both declined,resulting in reduced mechanical properties.We recommend use of 50 g of NOS/kg wood-fiber to improve WA and thickness swelling while retaining acceptable mechanical properties.
