Potential of pulp and paper sludge as a formaldehyde scavenger agent in MDF resins

Abstract Sludge of pulp and paper mills have natural adhesive properties. The primary sludge (PS, contains fibers) and secondary sludge (SS, contains proteins) could also be suitable for manufacturing medium-density fiberboard (MDF). Protein in SS can react with formaldehyde (HCHO), and as an additive in urea-formaldehyde (UF) resins it can reduce formaldehyde emission. Thus, SS was investigated in the present study. PS and SS were collected from two mills and characterized in terms of chemical composition, fiber length distribution, pH, and buffering capacity. MDF samples were processed according to an experimental design, in which UF resin content was reduced from 12% to 8% and replaced by SS in the range of 5%–15%. Gel time measurement showed high SS reactivity with UF resin. The SS reduced HCHO emissions by up to 68% compared to control panels, without compromising internal bond strength. The bonding effect of SS was lower than expected due to the high pH, thus the buffering capacity reduced UF performance. Moreover, sludge reduced bending performance. Dimensional stability was the greatest disadvantage of sludge panels.

[1]  S. Y. Zhang,et al.  Medium-density fiberboard produced using pulp and paper sludge from different pulping processes. , 2010 .

[2]  S. Y. Zhang,et al.  CHARACTERISTICS OF PAPER MILL SLUDGE AND ITS UTILIZATION FOR THE MANUFACTURE OF MEDIUM DENSITY FIBERBOARD , 2007 .

[3]  M. Jackson,et al.  Organic Composition of a Pulp and Paper Mill Sludge Determined by FTIR, 13C CP MAS NMR, and Chemical Extraction Techniques , 1997 .

[4]  M. Kuo,et al.  Comparison of protein-based adhesive resins for wood composites , 2006, Journal of Wood Science.

[5]  Barry Goodell,et al.  The Incorporation of Paper Deinking Sludge into Fiberboard , 2003 .

[6]  Thomas M. Maloney,et al.  Modern Particleboard & Dry Process Fiberboard Manufacturing , 1993 .

[7]  B. Riedl,et al.  Measurement of urea-formaldehyde resin distribution as a function of MDF fiber size by laser scanning microscopy , 2004, Wood Science and Technology.

[8]  Antonio Pizzi,et al.  Handbook of adhesive technology , 1994 .

[9]  A. Erdinçler,et al.  The role of carbohydrate and protein parts of extracellular polymeric substances on the dewaterability of biological sludges. , 2004, Water science and technology : a journal of the International Association on Water Pollution Research.

[10]  J. Dutkiewicz.  Preparation of cured urea–formaldehyde resins of low formaldehyde emission , 1984 .

[11]  H. R. Amberg,et al.  Sludge dewatering and disposal in the pulp and paper industry , 1984 .

[12]  X. Geng,et al.  Paper mill sludge as a component of wood adhesive formulation , 2007 .

[13]  L. Lorenz,et al.  The effect of soy protein additions on the reactivity and formaldehyde emissions of urea-formaldehyde adhesive resins , 1999 .

[14]  C. Frihart,et al.  High-soy-containing water-durable adhesives , 2006 .

[15]  S. Y. Zhang,et al.  Medium-density fiberboard performance as affected by wood fiber acidity, bulk density, and size distribution , 2006, Wood Science and Technology.

[16]  S. Y. Zhang,et al.  Effect of wood acidity and catalyst on UF resin gel time , 2004 .

[17]  J. A. G. O. D. Alda,et al.  Feasibility of recycling pulp and paper mill sludge in the paper and board industries , 2008 .

[18]  A. Taramian,et al.  Particleboard manufacturing: an innovative way to recycle paper sludge. , 2007, Waste management.

[19]  Talat Mahmood,et al.  A review of secondary sludge reduction technologies for the pulp and paper industry. , 2006, Water research.

[20]  Antonio Pizzi,et al.  Recent developments in eco-efficient bio-based adhesives for wood bonding: opportunities and issues , 2006 .

[21]  Gill G. Geesey,et al.  Bacterially derived wood adhesive , 2006 .

[22]  S. Y. Zhang,et al.  EFFECTS OF HOT-PRESSING PARAMETERS AND WAX CONTENT ON THE PROPERTIES OF FIBERBOARD MADE FROM PAPER MILL SLUDGE , 2007 .

[23]  George E. Woodson,et al.  Fiberboard manufacturing practices in the United States , 1987 .