Chemical and physical changes required for producing dimensionally stable wood-based composites

Hsu, W. E.; Schwald, W.; Schwald, J.; Shields, J. A.

doi:10.1007/bf00386023

Cited by 106 publications

(39 citation statements)

References 5 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…In the case of thickness swelling, the decrease was from 9.081 % in boards with untreated particles to 4.656 % in boards with treated particles. The improvement in dimensional stability recorded in boards manufactured with hygrothermally treated particles is in agreement with the results reported by Hsu et al (1988), who stated that the linear expansion and thickness swelling of particleboards glued with UF, caused by variation in moisture content, were substantially reduced by hygrothermal treatment of the particles. Hsu et al (1988) reported that thickness swelling was reduced from 12.1 % to 3.6 % and linear expansion from 0.48 % to 0.24 %.…”

Section: Swelling and Water Absorption After 2 And 24 Hours 312 Busupporting

confidence: 91%

“…The improvement in dimensional stability recorded in boards manufactured with hygrothermally treated particles is in agreement with the results reported by Hsu et al (1988), who stated that the linear expansion and thickness swelling of particleboards glued with UF, caused by variation in moisture content, were substantially reduced by hygrothermal treatment of the particles. Hsu et al (1988) reported that thickness swelling was reduced from 12.1 % to 3.6 % and linear expansion from 0.48 % to 0.24 %. In the case of boards manufactured with hygrothermally treated particles and UF, the improvement of the dimensional stability could be related to the increase in extractable hydrophobic compounds by hemicelluloses degradation, reported in hygrothermally treated L. philippiana particles by Crespo et al (2013).…”

Section: Swelling and Water Absorption After 2 And 24 Hours 312 Busupporting

confidence: 91%

“…This instability is caused by the incorporation of compressive tensions that are released when the moisture content increases (Suchsland and Enlow, 1968). A treatment with steam before manufacturing could cause a partial hydrolysis in the hemicelluloses, which increases compressibility of the wood, and signifi cantly reduces the increment in internal tension during board pressing, making this process an effective method to produce dimensionally stable boards (Hsu et al, 1988). In this type of treatment, a pressure increment of 200 to 1000 kPa causes important increases in the dimensional stability (Giebeler, 1983).…”

Section: Effect Of Thermal Treatment On Physicalmentioning

confidence: 99%

See 2 more Smart Citations

Physical Properties of Boards Manufactured with Hygrothermally Treated Tepa (Laureliopsis Philippiana Looser) Particles

2016

View full text Add to dashboard Cite

Section: Swelling and Water Absorption After 2 And 24 Hours 312 Busupporting

confidence: 91%

Section: Swelling and Water Absorption After 2 And 24 Hours 312 Busupporting

confidence: 91%

Section: Effect Of Thermal Treatment On Physicalmentioning

confidence: 99%

See 1 more Smart Citation

Physical Properties of Boards Manufactured with Hygrothermally Treated Tepa (Laureliopsis Philippiana Looser) Particles

2016

View full text Add to dashboard Cite

“…The decreased MOR can be interpreted as wood degradation following heat treatment, which imparted a darkened colour and fibre weight loss. Although differences were not significant for static bending properties, our results are in agreement with those published by Hsu et al (1989), who observed slight increases in MOE and slight decreases in MOR for waferboards after heat treatment at 2408C. Although differences were not significant for static bending properties, our results are in agreement with those published by Hsu et al (1989), who observed slight increases in MOE and slight decreases in MOR for waferboards after heat treatment at 2408C.…”

Section: Effect Of Heat Treatment On Panel Mechanical Propertiessupporting

confidence: 92%

“…On the other hand, Tomek (1966) produced particleboards from heat-treated particles and his results showed an increase of 20% in MOR. According to Hsu et al (1989), waferboards heated at 2408C had similar or even slightly increased MOE and IB strength compared to untreated panels. According to Hsu et al (1989), waferboards heated at 2408C had similar or even slightly increased MOE and IB strength compared to untreated panels.…”

Section: Introductionmentioning

confidence: 99%

Dimensional stability of MDF panels produced from heat-treated fibres

Garcia¹,

Cloutier²,

Riedl³

2006

Holzforschung

View full text Add to dashboard Cite

The objectives of this study were to improve the dimensional stability of medium-density fibreboard (MDF) by heat treatment and to determine the effects of the treatment on the mechanical properties and vertical density profile of the panels. MDF panels were produced from untreated fibres and fibres treated at two different temperatures (150 and 1808C) for 15, 30 and 60 min. Panels produced from heat-treated fibres showed an important reduction in thickness swelling and water absorption after water soaking. Linear expansion and contraction were not improved by the treatment. Thickness swelling after repeated cycles of adsorption and desorption increased, while thickness shrinkage under the same conditions was not changed by the treatment. The springback of panels after repeated cycles of adsorption and desorption was not improved, either. Statistical analyses did not show significant differences in the modulus of rupture, modulus of elasticity and internal bond strength of panels following heat treatment. No significant effect was found for the vertical density profile of panels following heat treatment, although the profiles for panels produced from heat-treated fibres were flatter than those produced from untreated fibres.

show abstract

Binderless composites from pretreated residual softwood

Anglès

Reguant

Montané

et al. 1999

J. Appl. Polym. Sci.

View full text Add to dashboard Cite

Residual softwood was thermomechanically pretreated and used to produce composites with no synthetic binders. The lignocellulosic material was steam exploded with a thermomechanical aqueous vapor process in a continuous tubular reactor. The study attempts to use the intrinsic bonding capacity of the steamed fiber, which is due to the plastification of the lignin. Chemical and structural changes in the pretreated substrate were evaluated by analytical characterization and scanning electron micrographs (SEM). The effect of the pressing conditions was evaluated in accordance with the physicomechanical responses of the composites. The physical and mechanical properties of the panels obtained were tested using UNE EN Spanish standard-European standards. In order to get more information about the degree of adhesion between the lignin and the fibers, SEM micrographs were taken of the broken surfaces of the material tested by the internal bond method. The results show that the thermomechanical pretreatment, pressing temperature, and time have a great effect on the mechanical and physical properties of binderless composites. The steam explosion aqueous vapor pretreatment is a good way for conditioning softwood sawdust for production of composites.

show abstract

Chemical and physical changes required for producing dimensionally stable wood-based composites

Cited by 106 publications

References 5 publications

Physical Properties of Boards Manufactured with Hygrothermally Treated Tepa (Laureliopsis Philippiana Looser) Particles

Physical Properties of Boards Manufactured with Hygrothermally Treated Tepa (Laureliopsis Philippiana Looser) Particles

Dimensional stability of MDF panels produced from heat-treated fibres

Binderless composites from pretreated residual softwood

Contact Info

Product

Resources

About