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 front end of the machine process.

Adhesive is applied, and the veneer is laid over the core in the lineal process. A series of profiled rollers applies veneer to core pressure at strategic points to ensure optimum adherence.

This is a critical factor as poor adhesion can compromise the product, with incomplete adhesive coverage causing delamination and/or too much adhesive resulting in a faulty bond and excess glue seeping through product edges.

It is 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.

It is important to match the proper type of hot melt adhesive 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 level of the substrate to assure long-term adhesive integrity.

A Dyne measurement is simply the measurement of that surface friction of the material, which will then direct the manufacturer to the appropriate adhesive.

The profile wrapper carriage forms the veneer around the substrate. Photo courtesy of Contact Industries

 

Adhesive Integrity Testing

While not required by code or other standards organization, manufacturers may conduct their own quality assurance testing to confirm that adhesives will maintain their integrity, long term, to avoid delamination on their wrapped products.

The test for this purpose is known as the Boil test.

Many manufacturers perform a four-hour product 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.

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.

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 Window and Door 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’s resource, 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 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 ISO 9001-2008 registered and holds Hallmark Certification from the Window and Door Manufacturers Association. www.contactind.com