Finger-jointing wood

Tannin-Based Adhesives for Finger-Jointing Wood... 

Plywood requirements—includes wood species used, synthetic repair requirements, veneer grades, veneer layers and thicknesses, panel grades with respect to end-use, adhesive bond requirements, panel constmetion and workmanship, scarf and finger-jointed panels, dimensional tolerances, moisture content, and packaging and loading... 

Wattle tannin resins are also used to manufacture other resins, such as foams comparable to phenolics, as waterproofing additives, and binders for corrugated cardboard or charcoal briquettes. This discussion, however, deals only with particleboard, plywood, glulam, and finger-jointing exterior-grade wood adhesives. Formulations of the adhesives will be mentioned ad hoc, if at all necessary, as they have already been extensively discussed in articles and reviews in the relevant literature.(7)... 

Finger joint- A manufacturing process of interlocking two shorter pieces of wood end to end to create a longer piece of dimensional lumber or molding. Often used in jambs and casings and are normally painted (instead of stained). 

EPI, Emulsion Polymer Isocyanate, MDI, pMDI, wood adhesives, solid wood panel, parquet, window frame, furniture, plywood, finger joint, glulam beam, I-betim, cross-laminated timber... 

Figure 13. Contactless application of EPI for gluing of finger joints. Adhesive ribbons on the tips of the fingers are applied without contact between the application head and the wood fingers.

I-beams are glued very similarly to finger joints but with different joint profiles. The most common wood type for the upper and lower parts in the I-beam (flench) is spruce or laminated veneer lumber (LVL) or Douglas fir (Fig. 14). In the middle part (web) oriented strain board (OSB) is most common medium density fiberboard (MDF) can also be used. 

MUF honeymoon adhesive systems for bonding of timber of high moisture content (wet gluing) to produce laminated wood (glulam) and finger-jointing are composed of two components (1) a MUF resin at a pH of approximately 10 with no fillers added, and (2) a low pH aqueous solution of carboxymethylcellulose and formic acid lacking resorcinol in the system (82-85). 

Kreibich R E, Hemingway R W (1989) Tannin-based, wood finger-jointing adhesives. In Hemingway R W, Conner A H (eds) Adhesives from renewable resources. ACS Symp Ser Washington DC 203-216... 

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). 

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