Sodium metabisulphite as a scavenger of air pollutants for wood-based building materials

Abstract

This paper reports on different applications of sodium metabisulphite as a formaldehyde scavenger. The reduction in formaldehyde emission and the effect on physicomechanical properties of particleboards were studied. The scavenger was mixed with urea-formaldehyde resins with different formaldehyde to urea molar ratios and added separately in the production of particleboards. Several differences between the formaldehyde content and physicomechanical properties of boards were found. When applied to melamine-formaldehyde resins, the changes in formaldehyde emission were less significant, probably due to the incorporation of sodium bisulphite in polymeric matrix. The type of formaldehyde-based resin and the form of scavenger addition are the major factors affecting formaldehyde scavenging efficiency.

Modified plywood binder preparation process: The effect of urea formaldehyde mole ratio

“…At the resin synthesis level, improvements can be made through reformulation involving the addition of melamine [15]. At the glue mix manufacturing stage, further emission reduction efforts can be made through the addition of formaldehyde scavengers that will react with free formaldehyde in all parts of the panel during the manufacturing process such as sodium metabisulfite and diatomaceous earth [16,17]. Further emission reductions can also be obtained through post treatment after the plywood has been produced through the use of catcher coatings.…”

Statistical evaluation of the effect of urea-formaldehyde resins synthesis parameters on particleboard properties

“…legislation, forced resin producers to develop a new generation of resins that lead to a decrease in formaldehyde emissions to the levels of natural wood [4]. Several strategies have been explored for reducing the formaldehyde release including the addition of formaldehyde scavengers directly to the resin or wood particles, the treatment of final wood panels with scavengers or impermeable coatings and the improvement of improved resin formulations [5][6][7][8][9].…”

“…However, the reversibility and the occurrence of intramolecular reactions leads to the formation of a great variety of chemical structures such as methylene bridges, methylene ether, methylols and even cyclic amide derivative groups, which makes the prediction of the properties of these resins a complex task [12]. The impact of the formulation of these resins in the performance of wood products was the subject of several studies, some of which used statistical tools to optimize the resins synthesis parameters in order to produce panels with maximum internal strength and minimum formaldehyde emissions [5,6,9,[13][14][15][16][17][18].…”

Production of water tolerant melamine–urea–formaldehyde resin by incorporation of sodium metabisulphite

“…Sodium metabisulphite (MTBS), in particular, has actually been described in some studies as an effective formaldehyde scavenger [8,9]. MTBS, with molecular formula of Na 2 S 2 O 5 , forms sodium bisulphite after contact with water (equation 1) [8].…”