Real Wood Veneer: The Sustainable, High-quality Product Choice

Veneer profile wrapping and laminating boosts wood's green quotient, reduces costs and encourages design creativity.
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Sponsored by Contact Industries

Fabricating the Core. The predominant core material - and the default used if additional performance characteristics are not an issue - is finger-jointed common grades of pine. This material is processed, machined and then finger-jointed and edge-, face- and end-glued into blanks of sufficient dimension to mould into the shape desired. If profiling is needed, these blanks are run through a moulder to fabricate the finished core.

In many cases, the core material requires engineering in order to achieve certain performance characteristics, such as meeting fire codes, or required strength or dimensional stability. Typically these decisions are made jointly by the manufacturer and architect or end customer to determine the product's use, performance expectations, visual appearance, and then value engineered for the optimum combination of performance, aesthetics, environmental impact, and cost factors.

At the Quintiles Pharmaceuticals headquarters in North Carolina's Raleigh-Durham area, architects modified plans for paneling and beams based on stability and cost considerations. The original design called for solid Afromosia tongue and groove paneling and overhead 2-foot x 10-foot beams. As Afromosia is a relatively rare, African hardwood species, using solid lumber for the paneling would have been feasible, but cost-prohibitive and an unnecessary depletion of the Afromosia resource. The 12-foot and 16-foot beams would have been nearly impossible to find in solid wood and even if they could be located, solid wood would have been subject to dimensional stability issues such as warping and checking.

Instead, architects opted for engineering tongue and groove paneling using a pine substrate and Afromosia veneer. The substrate for the beams was fabricated from LVL to address the dimensional stability issues, then wrapped in a two-pass operation in which each beam was end-capped with veneer to give the appearance of a solid piece. The project exemplifies diverse processes, well-conceived engineering, and wood products dovetailing to provide the appropriate product for the job. The wrapped beam met the requirements of dimensional stability, while being cost effective and resource saving, by replacing the originally intended 18-foot solid Afromosia beams.

Afromosia veneer over LVL rather than solid lumber was a cost-effective, dimensionally stable, resource-saving choice at the Quintiles Pharmaceuticals headquarters in North Carolina.

Photo courtesy of Contact Industries

 

Applying Adhesive. In the actual manufacturing process, a roll of veneer is loaded onto the profile wrapping machine and a length of core material is fed into the machine. Adhesive is applied, and the veneer is laid over the core. A series of rollers applies pressure at strategic points to ensure optimum adherence. This is a critical factor as faulty adhesion can compromise the product, with incomplete coverage causing delamination and/or too much adhesive resulting in a faulty bond and excess glue seeping through product edges. It's up to the manufacturer to identify the proper adhesive formulation, viscosity and glue spreads required to assure Type 1 (exterior rated) adhesion. Glue spreads may be electronically monitored depending on the adhesive dispensing system used.

The profile wrapper carriage forms the veneer around the substrate.

Photo courtesy of Contact Industries

 

It is important to match the type of hot melt with the type of substrate because one adhesive type will not successfully wrap all types of substrates. Prior to adhering veneer to alternate material substrates (fiberglass, PVC, aluminum, steel, etc.), the manufacturer must conduct a Dyne test to determine the surface friction of the substrate to assure long-term adhesive integrity. A Dyne measurement is simply the measurement of surface friction on the material, which will then direct the manufacturer to the appropriate adhesive. A measurement of 40 is optimum - anything plus or minus requires some type of pre-profile wrap abrading or other treatment to improve the material's surface friction.

Testing

While not required by code or other standards organization, manufacturers may conduct their own quality assurance testing to confirm that glues will hold in order to avoid delamination on their wrapped products. The test for this purpose is known as the boil test.

Some manufacturers perform a four-hour boil test as an in-house quality check on the previous day's production that has been allowed to cure for a minimum of one day. Random samples are cut from production run material at the ends and center of parts making sure that one inch is trimmed from each end before the samples are cut. The samples are then subjected to four hours of immersion in boiling water and then visually checked for glue failure. In the Type 1 Adhesion Assurance Boil test, similar samples are submerged in boiling water for four hours, placed in a convection oven at 145 °F for twenty hours, and the cycle is then repeated. For the samples to pass they must show no evidence of de-lamination through all stages of the test. Veneer- or vinyl-wrapped products are subject to the same test, but allowed to cure a minimum of two days before being visually checked for glue failure.

In qualifying new high-performance adhesives for use in production, manufacturers may initially subject products to more rigorous tests. In a typical test, samples of products with the new glue or substrate are gathered and cut in to four- to six-inch pieces and allowed to cure for a minimum of seven days. The samples are submerged in boiling water for four hours, they are then placed in an oven at 145 °F for 20 hours, and they are again subjected to a four hour boil, and last placed in ambient water for one hour. For the samples to pass they must show no evidence of de-lamination through all the stages of the test. For optimum performance, some manufacturers take samples from the production run every 60 minutes and subject them to the four-hour boil test to assure proper long-term adhesion.

Photo courtesy of Contact Industries

 

For superior products, architects may want to investigate whether the manufacturer and or/its products have pertinent certifications and have met a variety of testing capabilities.  Among those to be considered are the following:

  • ISO 9001:2008 Certification
    The 2008 version is the fourth edition of the quality management system standard, which was first published in 1987 and continues to be used world-wide.
  • Kitchen Cabinet Manufacturers Association (KCMA) Standards
    These standards concern finish testing and durability. KCMA certification is a testing process designed to challenge the product's durability at an accelerated pace. KCMA tests the ability of the finish to withstand prolonged hot and cold cycles, complete immersion in abusive substances typically found in the kitchen and bath, and exposure to a detergent and water solution for at least 24 hours. In order to pass, "The finish must show no appreciable discoloration, stain, or whitening that will not disperse with ordinary polishing and no indication of blistering, checks, or other film failure."
  • In-line Statistical Process Control (SPC)
    A method for achieving quality control in manufacturing processes, SPC is a set of methods using statistical tools such as mean, variance and others, to detect whether the process observed is under control.
  • Compliance with windows and Doors Manufacturers Association (WDMA) Hallmark I.S.4 Water Repellent Preservative Non-Pressure Treatment for Millwork
    Considered a mark of excellence among architects, contractors and other specifiers and accepted industry-wide, the WDMA-sponsored Hallmark Certification Program provides an easily recognizable means of identifying products manufactured in accordance with appropriate WDMA and other referenced performance standards. 
  • Temperature/Humidity Chamber Testing
    Originally developed as a testing protocol in the airline industry, this test checks for proper adhesion under extreme temperature, humidity and even altitudinal changes.

A Palette of Possibilities

Considering that logs used for solid lumber generally yield pieces that are over an inch thick at minimum, veneers at a fraction of an inch thick greatly enhance the yield of a tree, placing far less stress on a valuable natural resource. Veneer's inherent sustainability, together with continually evolving technology in all aspects of the profile wrapping industry has provided the design industry with an exciting palette of possibilities for bringing the beauty of wood into the built environment in a way that's resource-sensitive, efficient and cost-effective.

Contact Industries

Contact Industries pioneered veneer profile wrapping in the 1980s and has used the technology, along with flat laminating, to produce moulding and millwork products and components ever since. An industry leader in quality assurance and innovation, Contact Industries is FSC Chain of Custody certified as well as ISO9001-2008 registered and holds Hallmark Certification from the Window and Door Manufacturers Association. www.contactind.com

 

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Originally published in GreenSource
Originally published in May 2009

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