Structural adhesive laminated wood

The book opens with a paper on the structure and composition of wood to define the material under discussion and then considers molds, permeability, wood preservation, thermal deterioration and fire retard-ance, dimensional stability, adhesion, reconstituted wood boards such as fiberboard and particleboard, plywood, laminated beams, wood finishes, wood-polymer composites, and wood softening and forming. A final paper treats the common theme of wastewater management. Only one of the papers presented at the meeting is not included in this volume, and its subject of conventional wood preservation methods is adequately treated in detail elsewhere (e.g., Nicholas, D. D., Ed Wood Deterioration and Its Prevention by Preservative Treatments, 2 vols., Syracuse University Press, 1973). 

D 2559 Specification for Adhesive for Structural Laminated Wood Products for Use... 

D 3024 Specification for Protein Base Adhesive for Structural Laminated Wood... 

The combination of an adhesive and adherend is a laminate. Commercial laminates are produced on a large scale with wood as the adherend and phenolic, urea, epoxy, resorcinol, or polyester resins as the adhesives. Many wood laminates are called plywood. Laminates of paper or textile include items under the trade names of Formica and Micarta. Laminates of phenolic, nylon, or silicone resins with cotton, asbestos, paper, or glass textile are used as mechanical, electrical, and general purpose structural materials. Composites of fibrous glass, mat or sheet, and epoxy or polyester resins are widely employed as reinforced plastic (FRP) structures. 

Chem. Descrip. Polyvinyl butyral resin Chem. Analysis 80% (polyvinyl butyral) 2.5% max. (polyvinyl acetate) Uses Polyvinyl butyral for coatings tor wood or metal substrates, binders, structural adhesives, structural composites and laminates indirect food additive... 

Recently, adhesives that include lignin in their formulation have shown several properties similar to phenol-formaldehyde resins [11, 12] and are extensively utilized in the plywood, particleboard, fiberboard and laminated wood industries. The chemistry of the lignin-based adhesives has been studied from an empirical point of view [13] however, the molecular mechanism and the interactions of the structural cross-linked 4-hydroxyphenylpropanoids of lignin that drive the adhesion phenomenon remain unclear. 

The increasing amount of research in waterborne systems should some day overcome technological difficulties. Howeverr the change-over from some solvent-borne to waterborne systems has presented difficulties (107), for exampler poor coating quality, excessive foam, insufficient water resistance, and even some corrosion and clean-up problems. Despite the problems, some waterborne systems have already been adopted for the manufacture of PSA s, contact adhesives, laminating adhesives, and wood adhesives. However, few applications of the waterborne systems as structural adhesives, especially as aerospace structural adhesives have been found. 

D-2559 Adhesives for structural laminated wood products for use under exterior (wet use) exposure conditions. 

D-1101 Integrity of glue joints in structural laminated wood products for exterior use. D-1183 Resistance of adhesives to cyclic laboratory aging conditions. 

Structural composites and the principles of their construction have been known and used for literally thousands of years. Adobe brick, concrete, and laminated wood are the earliest known examples. The Assyrians and Babylonians are known to have used a type of concrete based on clay. A more robust type of concrete made from heated powdered clam and oyster shells that used lime (calcium oxide) as the binding agent was developed in ancient Egypt. Laminated structures such as wood pieces that have been mechanically fastened together or bonded together with an adhesive material of some kind have a similarly long history. 

ASTM D 2559-76, Std. Spec, for Adhesives for Structural Laminated Wood Products for Use Under Exterior (wet use) Exposure Conditions. 

D-2559. Specification for Adhesives for Structural Laminated Wood Products for Use Under Exterior (Wet Use) Exposure Conditions. Sample beams, made under various assembly time extremes, are tested for (a) basic dry glueline shear strength and wood failure and (b) resistance of glueline to delamination after accelerated aging. It also requires testing the adhesive s diy creep resistance. Used in qualifying new adhesives for use in exterior laminated beams. 

D-3024. Specification for Protein-Base Adhesives for Structural Laminated Wood Products for Use Under Interior (Diy Use) Exposure Conditions. Employs the D-0>905 block shear, D-0906 plywood shear, and D-4300 mold resistance tests to evaluate mostly casein-base adhesives for use in interior grade laminated beams. 

Structural Adhesives for Fingeijointing Lumber. A recent standard detailing the testing of finger joints when used as end joints in structural glued, laminated timbers (see also D-2559 in wood adhesive specifications). 

D-1101. Test Methods for Integrity of Glue Joints in Structural Laminated Wood Products for Exterior Use (previously in ASTM Book of Standards, Part 4.09 on Wood but now to be in Part 15.06 on Adhesives). 

Although aircraft structures comprise thousands of components produced from a myriad of basic materials, the most common substrates for structural adhesive bonding are wood, aluminium, titanium, stainless steel and the composite materials such as bonded sandwich structures, fibre reinforced plastic (FRP) laminates and fibre-metal laminates (FML) where the metal is usually aluminium. 

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