U.S. Demand for Wood is on the Rise
The construction industry has seen an impressive rebound in the last few years. With the increase in new buildings, both commercial and residential, comes a rise in demand for wood and cement board products. Wood is not only used as a structural component in the building process but also adds a decorative touch to many projects. Wood is easy to work with and durable. It can be pre-fabricated or customized on the job site so provides contractors with the flexibility to make changes as needed.
Manufacturers in the wood industry find it beneficial to pre-finish their materials prior to installation. This provides more consistent, uniform coating results and is mandated by the paint manufacturers in order to offer an extended warranty. The pre-finish coating also helps wood products withstand the elements such as temperature and humidity along with preventing deterioration over time.
Pre-Finishing: An Important Step in Preparing Wood Products for Installation
Pre-finishing consists of applying a coating to the wood at the factory. Some common wood finishes include primer, varnishes, stains, and wet paint. Pre-finishing requires a wood drying system, consisting of a coater, conveying equipment, and a drying oven. Timely coordination between each step is essential for a smooth pre-finish so the process is tightly controlled and automated.
During the first step in the process the wood or cement boards are manually loaded onto a powered roller conveyor that carries them lengthwise through a coater which can be a curtain, vacuum, spray, or roll type. Next they are transferred onto the conveyor system that feeds into the drying oven and enter the flashoff stage where the boards begin to dry. During flashoff, the coating releases a portion of the moisture or solvent passively, prior to entering the oven which is important because it prevents bubbling or popping that can occur if the paint is force-dried immediately after coating.
Once the flashoff is completed the boards enter the drying oven (dryer) that uses high velocity convection air to quickly dry the coating. Since the air is traveling at 4,000 to 5,000 feet per minute when exiting the nozzles, it creates turbulence on the surface of the coating, which wipes away any extra layer of moisture (or solvent) that would otherwise form on the coating surface. Extra moisture must be continuously removed for successful drying.
Wisconsin Oven Pre-Finish Wood Drying Ovens
Wisconsin Oven offers a full line of conveyor ovens for drying primer, sealer and finish coatings on wood and cement board trim and panels. Wood dryers can be heated using natural gas, propane, or electrically heated. They utilize chain conveyors to carry the boards, up to 24’ long, sideways through the oven. Single zone and multiple-zone designs are available based on the customer’s requirements.
Wisconsin Oven wood drying ovens use high velocity convection air technology to efficiently dry the boards. The air is delivered through a fully enclosed, pressurized supply duct located above the boards, and below if necessary. The ducts feature tapered nozzles that impinge the air directly onto the surface of the boards while traveling on the chain conveyor.
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