Laminated veneer lumber LVL

Typical features of a plywood resole formulation are a formaldehyde-to-phenol molar ratio in the 2.0 1 to 2.5 1 range, programmed formaldehyde, an alkali content from 4 to 8 wt% (calculated as sodium hydroxide), and pan solids of 40-50%. Resins used for laminated veneer lumber (LVL) tend to be similar to plywood resins in composition and molecular weight, though they are often designed for high-end cure speed. 

Figure 10.18. Three examples of structural composite lumber (top to bottom) laminated veneer lumber (LVL), parallel strand lumber (PSL), and oriented strand lumber (OSL).

Veneers - for plywood, laminated veneer lumber (LVL), and parallel strand... 

The intrinsie effieieney of peeling logs to yield veneer has suggested that the same proeess should be applieable to the manufaeture of laminated struetural members. Laminated veneer lumber (LVL) was first produeed in the early 1970s, and sinee then has been eommereially available in many eountries. It is now the most widely used struetural eomposite lumber produet in the US residential housing market. 

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. 

Plywood panels produced in Europe for building purposes use urea-formaldehyde (UF), melamine-urea-formaldehyde (MUF) and phenol-formaldehyde (PF) adhesives. Standards requirements are not focused on direct properties of these adhesives but properties of the end-products (closely linked to adhesive properties and process parameters). Nevertheless, EN 314-1 (2005) [1] defines a test method for the evaluation of the bonding quality of plywood panels, but also blockboards, laminated boards and laminated veneer lumbers (LVL), by shear testing before and after ageing treatments. Relevant requirements are specified in EN 314-2 (1993) [5] which also defines the ageing treatments required for the intended service class of the tested panel as shown in Table 1. 

Laminated veneer lumber (LVL) a flat pressed multilayer wood panel similar to plywood composed of oriented wood veneers but differently from plywood oriented all in the same direction in all the layers and bonded by hot-pressing by using thermosetting adhesive resins. 

Laminated veneer lumber (LVL) Softwood veneer PP, pMDI S Floor and roof joists, roof ridge beams, roof truss chords, window and doorheaders, wood I-joist flanges, concrete form, scaffold planking, window and door joinery 19-75 (f-3 in.), 27-50 in. wide, up to 24.4 m (80 ft) long ... 

Structural pre-fabricated engineered wood composites (e.g., FiRP reinforcement technology used to produce structural members, beams and I-beams, made from derived wood products, such as glulam and laminated veneer lumber (LVL) with an internal bonded passive reinforcement, like CFRP, GFRP or AFRP). The reasoning behind its development was to allow the use of smaller cross-sections, to obtain more homogeneous... 

Veneer and solid wood composite products are manufactured for building and construction commodity markets and for specialty markets such as marine applications and aesthetic decor. Bonding systems vary based upon the service demands placed upon the final product, interior versus exterior. Construction and decorative plywood are veneered panel products. Laminated veneer lumber (LVL) is a veneer product which competes with lumber. Lumber laminates form majestic beams often for dual structural and aesthetic applications. 

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