Mechanical and formaldehyde-related properties of medium density fiberboard with zeolite additive

Zeolite was investigated as a potential component in the production of medium-density fiberboard (MDF). A mixture of beech (40%), oak (30%), and pine (30%) wood chips was used for fiber production. Chips were cooked for 4 min in an Asplund defibrator with a vapor pressure of 8 bar, and a temperature of 180 °C. Chemicals were added on fibers in the blow line. The resins were added at 11 wt% based on oven-dried wood fibers. Ammonium sulphate was added at 0.72 wt% based on resins. Paraffin wax was added as 1.8 wt% based on resin. Zeolite was prepared in a separate tank for its use instead of lignocellulosic fibers in the production of 1 m³ MDF. The fibers were dried to 12% moisture. A temperature of approximately 190 °C and a pressure of approximately 32 kg.m-² were applied to the mixture for 280 s to make MDF panels (500 x 490 x 14 mm). Mechanical properties of MDF boards were significantly increased for bending (MOE) and elastic modulus (MOR), but a little negatively affected on internal bond (IB), physical properties were negatively increased thickness swelling (ThS) and water absorption (WA). Consequently, increasing zeolite minerals in MDF boards showed best results of formaldehyde emission properties of MDF.

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Reducing free formaldehyde emission, improvement of thickness swelling and increasing storage stability of novel medium density fiberboard by urea-formaldehyde adhesive modified by phenol derivatives

International Journal of Adhesion and Adhesives ◽

10.1016/j.ijadhadh.2021.102962 ◽

2021 ◽

pp. 102962

Author(s):

Peyman Pouresmaeel Selakjani ◽

Ali Dorieh ◽

Antonio Pizzi ◽

Mohammad Hassan Shahavi ◽

Amir Hasankhah ◽

...

Keyword(s):

Storage Stability ◽

Urea Formaldehyde ◽

Medium Density Fiberboard ◽

Formaldehyde Emission ◽

Medium Density ◽

Thickness Swelling ◽

Phenol Derivatives

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Effect of calcite addition on technical properties and reduction of formaldehyde emissions of medium density fiberboard

BioResources ◽

10.15376/biores.16.2.3718-3733 ◽

2021 ◽

Vol 16 (2) ◽

pp. 3718-3733

Author(s):

Osman Camlibel

Keyword(s):

Liquid Paraffin ◽

Urea Formaldehyde ◽

Medium Density Fiberboard ◽

Formaldehyde Emission ◽

Modulus Of Rupture ◽

Medium Density ◽

Wood Fibers ◽

Hot Press ◽

Ammonium Sulphate Solution ◽

Hot Press Process

Physical, mechanical, and formaldehyde emission properties were studied for medium density fiberboard (MDF) produced with oak (75%) and pine (25%) fibers that had been mechanically refined in the presence of calcite particles. The calcite slurry was prepared at two levels of solids, 1.5% and 3% (10 and 20 kg·m-³). Chips were cooked for 4 min at 185 °C, under 8 bar vapor pressure in an Andritz defibrillator. 1.8% liquid paraffin, 0.72% ammonium sulphate solution, and 11% urea-formaldehyde were added by percentage based on oven-dried wood fibers in the blowline at the exit of the defibrator. The fibers were dried to 11% moisture content. MDF boards (2100 mm × 2800 mm × 18 mm) were created using a continuous hot-press process. The addition of calcite in the course of MDF production resulted in improved physical properties, such as thickness swelling (ThS 24 hours) and water absorption (WA 24 hours). MDF boards prepared with calcite exhibited higher internal bond (IB), modulus of rupture (MOR), and modulus of elasticity (MOE). Resistance to axial withdrawal of screw also was increased by addition of 3% calcite. In addition, the lowest levels of formaldehyde emission were observed for MDF prepared with calcite at the 3% level.

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Effect of Panel Moisture Content on Internal Bond Strength and Thickness Swelling of Medium Density Fiberboard

Polymers ◽

10.3390/polym13010114 ◽

2020 ◽

Vol 13 (1) ◽

pp. 114

Author(s):

Roberto Magalhães ◽

Beatriz Nogueira ◽

Samaritana Costa ◽

Nádia Paiva ◽

João M. Ferra ◽

...

Keyword(s):

Moisture Content ◽

Bond Strength ◽

Internal Bond ◽

Room Temperature ◽

Medium Density Fiberboard ◽

Internal Bond Strength ◽

Medium Density ◽

Thickness Swelling ◽

European Standard ◽

Test Pieces

Wood-based products usually have serious limitations concerning contact with water, both because wood is a hygroscopic material and because the commonly used binder has low moisture resistance. This paper studies the effect of panel moisture content (MC) on the physico-mechanical properties of medium density fiberboards (MDF). Several commercial MDF boards produced in Europe were stored at room temperature and relative humidity (RH) for 9 weeks (approx. range 15–20 °C and 50–85% RH). Every week, a strip of each MDF board was cut out, divided into 5 × 5 cm test pieces and its internal bond strength (IB) was measured. A strong influence of MDF moisture content on internal bond strength was observed and therefore IB test pieces were stored in a climatic chamber (either at 20 °C, 55% RH and at 20 °C, 70% RH). A decreasing linear relation was established between IB and MC. It was found that this effect is reversible: after drying, internal bond strength rises again (following a slight hysteresis). This work reinforces the importance of conditioned storage before board properties analysis, as described in European Standard EN 319.

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ADSORPTION OF NANOWOLLASTONITE ON CELLULOSE SURFACE: EFFECTS ON PHYSICAL AND MECHANICAL PROPERTIES OF MEDIUM-DENSITY FIBERBOARD (MDF)

CERNE ◽

10.1590/0104776020162222146 ◽

2016 ◽

Vol 22 (2) ◽

pp. 215-222 ◽

Cited By ~ 13

Author(s):

Hamid Reza Taghiyari ◽

Roya Majidi ◽

Asghar Jahangiri

Keyword(s):

Mechanical Properties ◽

Density Functional ◽

Medium Density Fiberboard ◽

Physical And Mechanical Properties ◽

Mechanical Tests ◽

National Standard ◽

Medium Density ◽

Wood Fibers ◽

Strong Adsorption ◽

Cellulose Surface

ABSTRACT Effects of nanowollastonite (NW) adsorption on cellulose surface were studied on physical and mechanical properties of medium-density fiberboard (MDF) panels; properties were then compared with those of MDF panels without NW-content. The size range of NW was 30-110 nm. The interaction between NW and cellulose was investigated using density functional theory (DFT). Physical and mechanical tests were carried out in accordance with the Iranian National Standard ISIRI 9044 PB Type P2 (compatible with ASTM D1037-99) specifications. Results of DFT simulations showed strong adsorption of NW on cellulose surface. Moreover, mechanical properties demonstrated significant improvement. The improvement was attributed to the strong adsorption of NW on cellulose surface predicted by DFT, adding to the strength and integrity between wood fibers in NW-MDF panels. It was concluded that NW would improve mechanical properties in MDF panels as a wood-composite material, as well as being effective in improving its biological and thermal conductivity.

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Simple production of medium density fiberboards (MDF) reinforced with chitosan

Holzforschung ◽

10.1515/hf-2017-0101 ◽

2018 ◽

Vol 72 (4) ◽

pp. 275-281 ◽

Cited By ~ 5

Author(s):

Xiaodi Ji ◽

Yue Dong ◽

Ruidong Yu ◽

Wenxin Du ◽

Xue Gu ◽

...

Keyword(s):

Fourier Transform ◽

Photoelectron Spectroscopy ◽

Medium Density Fiberboard ◽

National Standard ◽

Medium Density ◽

Wood Fibers ◽

Hot Press ◽

X Ray ◽

Amide Bonds ◽

Simple Production

AbstractA simple and efficient method was developed for preparing medium density fiberboard (MDF) reinforced with chitosan via the traditional hot-press manufacturing process. The mechanical and dimensional properties of the MDF were investigated as a function of the chitosan amount. At the 4% level of added chitosan, the MDF reached the optimal performance and met completely the requirements of the Chinese national standard GB/T 11718-2009. Fourier transform infrared (FTIR), X-ray photoelectron spectroscopy (XPS) and X-ray powder diffraction (XRD) characterizations revealed that wood fibers and chitosan might interact with each other through the formation of hydrogen and amide bonds during the hot-pressing process. The fracture surfaces of the MDFs are indicative for strong bonds at the interface, which explain the excellent MDF performance.

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Potential Use of Wollastonite as a Filler in UF Resin Based Medium-Density Fiberboard (MDF)

Polymers ◽

10.3390/polym12071435 ◽

2020 ◽

Vol 12 (7) ◽

pp. 1435 ◽

Cited By ~ 4

Author(s):

Hamid R. Taghiyari ◽

Ayoub Esmailpour ◽

Roya Majidi ◽

Jeffrey J. Morrell ◽

Mohammad Mallaki ◽

...

Keyword(s):

Bond Strength ◽

Internal Bond ◽

Urea Formaldehyde ◽

Medium Density Fiberboard ◽

Medium Density ◽

Environmental Footprint ◽

Positive Effects ◽

Uf Resin ◽

Resin Curing ◽

Potential Use

Urea-formaldehyde (UF) resins are primary petroleum-based, increasing their potential environmental footprint. Identifying additives to reduce the total amount of resin needed without adversely affecting the panel properties could reduce these impacts. Wollastonite is a mineral containing calcium and silica that has been used as an additive in a variety of materials and may be useful as a resin extender. Nanoscale wollastonite has been shown to enhance the panel properties but is costly. Micron-scale wollastonite may be a less costly alternative. Medium-density fiberboards were produced by blending a hardwood furnish with UF alone, micron-sized wollastonite alone, or a 9:1 ratio of UF to wollastonite. Panels containing of only wollastonite had poor properties, but the properties of panels with 9:1 UF/wollastonite were similar to the UF-alone panels, except for the internal bond strength. The results suggest that small amounts of micron-sized wollastonite could serve as a resin extender. Further studies are suggested to determine if the micron-sized material has similar positive effects on the resin curing rate.

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