PDF Publication Title:
Text from PDF Page: 017
Moisture Content Table IV Change in Width for a 3" Wide Piece When MC Changes MC Change -%- 1 3 5 Red Oak Yellow-Poplar White Pine Radial Tang. -inch- -inch- 0.002 0.006 0.006 0.019 0.011 0.031 Radial -inch- 0.005 0.014 0.024 Tang. Radial -inch- -inch- 0.011 0.005 0.033 0.014 0.055 0.024 Tang. -inch- 0.009 0.026 0.043 Wood contains varying amounts of moisture. The amount of water at any time is expressed as a ratio to the amount of dry wood. Mathematically, %MC = (Wet weight ) - (Oven − dry weight ) x 100 (Oven - dry weight ) The wet weight is the weight at any time when the MC must be determined (i.e., green from the sawmill, after or during air drying, after or during kiln drying, after storage, and so on). The oven-dry weight is the weight after all the water has been dried from the piece of wood. Drying is done at 217°F, preferably in an oven with a fan to circulate the hot air. Oven-dryness is reached when the piece of wood stops losing weight (i.e., two successive weight readings taken an hour or two apart during oven-drying are identical). When using an electronic calculator to figure MC, an easier formula is ⎡ (Wetweight ) ⎤ %MC = ⎢⎣(Oven − dry weight ) − 1⎥⎦ x 100 Sometimes, it is inconvenient or impossible to oven-dry a piece of wood in order to determine its MC. In that case, certain other properties of the wood, which are related to MC, can be measured. Most commonly, the electrical resistance of wood is measured. This concept is discussed in more detail in Theory of Operation, LSA. Moisture content is especially important in drying in that it is related to shrinkage and many other properties and characteristics. Further, almost all drying schedules in use today are based on the MC of the wood being dried and the daily rate of MC loss. 17PDF Image | Principles and Practices of Drying Lumber
PDF Search Title:
Principles and Practices of Drying LumberOriginal File Name Searched:
DryingLumber.pdfDIY PDF Search: Google It | Yahoo | Bing
5,000 BF Shipping Container Lumber Dry Kiln For Quality Lumber The 5,000 BF container kiln consists of one 40 foot high-cube aluminum shipping container... More Info
Shipping Container Lumber Dry Kilns by Global Energy Global Energy designed and developed the container kiln back in 1991. The purpose is to give access to portable sawmill owners, furniture makers, and small business the value added profit of dry kiln lumber and quality hardwoods... More Info
Vacuum Kiln Conversion Kit for Lumber and Wood Dry Kilns Convert your existing conventional dry kiln into a fast drying vacuum kiln. Similar to vacuum bagging in the boat building and aircraft industry, we have come up with a proprietary process which allows you to build a very simple vacuum kiln at a fraction of the price, and without the intensive conventional metal chamber structure... More Info
Vacuum Pump Cart System for Bagging Clamping Wood Drying and more Vacuum Cart with 2HP Pump and Dual Pistons with multiple multiplex vacuum ports and liquid reservoir... More Info
Vacuum Bagging Basics Vacuum bagging is a method of clamping, which has traditionally been used in the composites industry, but can also be used for vacuum drying materials, including wood products... More Info
CONTACT TEL: 608-238-6001 Email: greg@globalmicroturbine.com (Standard Web Page)