Cornstarch and tannin in phenol–formaldehyde resins for plywood production

Published Date
September 2009, Vol.30(2):188–193, doi:10.1016/j.indcrop.2009.03.005

Author 

Amine Moubarik ^a,c,,

Antonio Pizzi ^b

Ahmed Allal ^c

Fatima Charrier ^a

Bertrand Charrier ^a

• aSylvadour, IUT des Pays de l’Adour, Mont de Marsan, France
• bENSTIB, Université de Nancy 1, Epinal, France
• cIPREM-EPCP (UMR 5254), Université de Pau et des Pays de l’Adour, 2, avenue Pierre Angot, 64053 Pau cedex 9, France

Received 31 October 2008. Revised 9 March 2009. Accepted 9 March 2009. Available online 17 April 2009.

Abstract

The aim of this work is to demonstrate the performances of cornstarch–quebracho tannin-based resins designed as adhesive in the plywood production. In this way, the cornstarch and quebracho tannin was introduced in the classic adhesive formulation in order to supply a part of phenol–formaldehyde (PF). The physical properties (rheological characterization, thermogravimetric analysis and solid phase ¹³C NMR analysis) of the formulated resins were measured. In order to evaluate the mechanical performances of optimal cornstarch–quebracho tannin-based resins, plywood panels were produced and mechanical properties were investigated. These mechanical properties included tensile strength, wood failure and 3-point bending strength. The performance of these panels is comparable to those of plywood panels commercial PF made.

The results showed that plywood panels bonded with cornstarch–quebracho tannin–PF resins (15:5:80, w/w/w) exhibited better mechanical properties than plywood panels commercial PF made. The introduction of small proportions of cornstarch and quebracho tannin in PF resins contributes to the improvement of the boiling water performance of these adhesives. The formaldehyde emission levels obtained from panels bonded with cornstarch–quebracho tannin–PF were lower to those obtained from panels bonded with control PF. Solid state CPMAS NMR spectra indicates that no reaction at all between PF resins and cornstarch and quebracho tannin. Even when reaction does evidently not occur, the addition of cornstarch and quebracho tannin improves markedly the water resistance of PF resins.

Keywords

Cornstarch

Quebracho tannin

Phenol formaldehyde

Plywood

Wood adhesive

---

Fig. 1.

Fig. 2.

 Table 1

Table 1.

 Table 2

Table 2.

Fig. 3.

Fig. 4.

Fig. 5.

 Table 3

Table 3.

Fig. 6.

• ⁎ 
  Corresponding author at: Laboratoire Sylvadour, IUT des Pays de l’Adour, 371 rue du Ruisseau, BP 201, 40004 Mont de Marsan, France. Fax: +33 5 58 51 37 37.

For further details log on website :
http://www.sciencedirect.com/science/article/pii/B9781782424543000044

The effects of ply organization and loading direction on bending strength and modulus of elasticity in laminated veneer lumber (LVL) obtained from beech (Fagus orientalis L.) and lombardy poplar (Populus nigra L.)

Published Date
August 2007, Vol.21(8):1720–1725, doi:10.1016/j.conbuildmat.2005.05.002

Author 

• Erol Burdurlu ^,
• Murat Kilic
• Abdullah Cemil Ilce
• Ozan Uzunkavak

• Hacettepe University, School of Vocational Technology, Department of Wood Products Industrial Engineering, 06532, Beytepe, Ankara, Turkey

Received 7 April 2005. Revised 19 April 2005. Accepted 31 May 2005. Available online 29 September 2006. 

Abstract

The effects of ply organization and loading direction on bending strength and modulus of elasticity in laminated wood materials produced from 3 mm thick veneers, of beech (Fagus orientalis L.) and lombardy poplar (Populus nigra L.) placed one on top of the other in various arrangements were examined in this study. Kleiberit 303 (PVAc), a vinyl (polyvinyl acetate – PVAc) based glue was used in lamination. Eight hundred samples were prepared in order to measure oven-dry specific gravity, bending strength and modulus of elasticity values perpendicular and parallel to the glue line of a total of 10 different arrangements, eight of which have different laminated ply organizations, namely (AAAAAAA) (7A), (BBBBBBB) (7B), (ABBBBBA), (ABABABA), (AABBBAA), (AABABAA), (ABBABBA), (BABABAB), in which (A) represents beech wood and (B) represents poplar wood and the other two, which consist of solid beech and solid poplar wood in same dimensions as control samples. The samples were subjected to tests perpendicular and parallel to the glue line in accordance with the ISO 16978 standard. As a result of statistical analysis of the data obtained from the tests, the bending strength and modulus of elasticity values of solid woods both perpendicular and parallel to the glue line were observed to be smaller than those values of laminated woods made of the same species of woods. It was also observed that as contribution rate of beech in lamination increases, the bending strength and modulus of elasticity values increase.

Keywords

Laminated veneer lumber (LVL)

Beech

Lombardy poplar

Bending strength

Modulus of elasticity

Specific gravity

Glue

---

Fig. 1.

Fig. 2.

 Table 1

Table 1.

 Table 2

Table 2.

 Table 3

Table 3.

• ⁎ 
  Corresponding author. Tel.: +90 312 2978950; fax: +90 312 2976885.

For further details log on website :
http://www.sciencedirect.com/science/article/pii/B9781782424543000044

Evaluation of sorghum flour as extender in plywood adhesives for sprayline coaters or foam extrusion

Published Date
July 2011, Vol.34(1):1168–1172, doi:10.1016/j.indcrop.2011.04.005

Author 

• Mila P. Hojilla-Evangelista ^a,,
 
• Scott R. Bean ^b

• aPlant Polymer Research Unit, National Center for Agricultural Utilization Research (NCAUR), USDA Agricultural Research Service (ARS), 1815 N. University St., Peoria, IL 61604, United States
• bCenter for Grain and Animal Health, Grain Marketing and Production Research Center, USDA, ARS, 1515 College Ave., Manhattan, KS 66502, United States

Received 5 January 2011. Revised 4 April 2011. Accepted 6 April 2011. Available online 14 May 2011.

Abstract

This study was conducted to evaluate sorghum flour as protein extender in phenol–formaldehyde-based plywood adhesive for sprayline coaters or foam extrusion. Defatted sorghum flour, containing 0.2% (db) residual oil and 12.0% (db) crude protein, was analyzed for solubility and foaming properties. Sorghum flour proteins were least soluble (≤12%) under acidic pH, most soluble (72%) at pH 10, and produced substantial and highly stable foam at pH 10. Sorghum flour was substituted (on protein content basis) for wheat flour in the standard glue mix. Mixing properties and bond strength of the sorghum-based glue were compared with those of the industry standard glue. The sorghum flour-based adhesive had mixing properties and appearance that were superior to those of the standard wheat flour-based plywood glue, but its viscosity and bond strength were markedly less. Doubling the amount of protein contributed by sorghum flour in the glue mix markedly improved both viscosity (1104 cP) and adhesion strength (1.37 MPa) of the sorghum-based plywood glue to acceptable levels. The modified sorghum flour-based plywood glue also produced foam that remained stable up to 3 h. These results demonstrated that sorghum flour is a viable extender in plywood glues for sprayline coater or foam extrusion.

Highlights

► Sorghum flour as alternative protein extender in plywood adhesives. ► Sorghum flour proteins were most soluble and produced stable foam at pH 10. ► Sorghum flour-based adhesive had superior mixing and appearance than industry glue. ► Sorghum-based plywood glue also met adhesion strength standards. ► Sorghum-based plywood glue produced acceptable foam for extrusion application.

Keywords

Sorghum

Sorghum flour

Plywood adhesive

Protein extender

Protein functionality

---

 Table 1

Table 1.

 Table 2

Table 2.

 Table 3

Table 3.

• ⁎ 
  Corresponding author. Tel.: +1 309 681 6350; fax: +1 309 681 6691.
  
  

For further details log on website :
http://www.sciencedirect.com/science/article/pii/B9781782424543000044

The preparation and application of a new formaldehyde-free adhesive for plywood

Published Date
September 2011, Vol.31(6):507–512, doi:10.1016/j.ijadhadh.2011.04.005

Author 

• Liang Tang ^a
• Zhao-gang Zhang ^b
• Jiao Qi ^b
• Ji-ruo Zhao ^b,,
• Ying Feng ^b

• aCollege of Automation Electronic Engineering, Qing Dao University of Sci. & Tech., Qing Dao 266042, China
• bKey Laboratory of Rubber-Plastics, Ministry of Education / Shandong Provincial Key Laboratory of Rubber-Plastics, Qing Dao University of Sci. & Tech., Qing Dao 266042, China

Accepted 15 April 2011. Available online 23 April 2011. 

Abstract

In this study, we developed a new formaldehyde-free adhesive prepared by in-situ chlorinating graft copolymerization for plywood. The main ingredients of this adhesive include maleic anhydride (MAH) and high density polyethylene (HDPE) that is MAH grafted onto HDPE (PE-cg-MAH). The reaction between this adhesive and veneer, the optimum formulation to bond veneer and the optimum hot-press conditions to prepare the plywood were investigated. A boiling water test was employed to evaluate the strength and water resistance of plywood bonded with this adhesive. The results showed that the properties of the resulting plywood using PE-cg-MAH as an adhesive can meet the standard of Type I plywood and the optimum hot-press conditions were 160–165 °C and 5 min. When the chlorine contents of PE-cg-MAH was about 3% (wt%), the plywood panels had a higher shear strength after boiling water test above the hot-press conditions.

Keywords

In-situ chlorinating graft copolymerization

Adhesives for wood

Novel adhesives

Polyolefins

---

Fig. 1.

Fig. 2.

Fig. 3.

Fig. 4.

Fig. 5.

Fig. 6.

 Table 1

Table 1.

 Table 2

Table 2.

 Table 3

Table 3.

 Table 4

Table 4.

Fig. 7.

 Table 5

Table 5.

 Table 6

Table 6.

• ⁎ 
  Corresponding author.
  
  

For further details log on website :
http://www.sciencedirect.com/science/article/pii/B9781782424543000044