Accuracy Through Moisture Sensing

Wood fibers are usually cellulosic elements that are extracted from trees and used to make materials including paper, and paper products but also in uncommon applications as well. Reliable and real-time moisture sensors for these processes can improve quality control as well as increase production. Energy is not wasted by over-drying the wood fiber, and the rejected material is significantly reduced.

The strength of wood is often dependent on water, but this does not mean that wood cannot be exposed to moisture. In fact, wood and water generally coexist peacefully. Wood is a hygroscopic material, meaning it naturally absorbs and releases water to adjust to its environment. Wood can absorb substantial amounts of water without reaching moisture levels that would attract decay fungi.

Fiber saturation averages around 28%. Fiber saturation is a critical parameter for understanding both shrinkage and decay processes. The elongated cells of wood resemble tapered drinking straws. Initially, water is absorbed by the cell walls. Once the cell walls reach their capacity, any excess water is stored in the cavities of these tubular cells. At fiber saturation, the moisture content is at a level where the cell walls are saturated with water. Decay typically begins when the wood’s moisture content exceeds fiber saturation. Additionally, fiber saturation marks the threshold for wood shrinkage.