2 ELLIOTT BAY INDUSTRIES Dry Veneer Moisture Detectors
3 ELLIOTT BAY INDUSTRIES Determining Your Machine Elliott Bay produces two types of Dry Veneer Moisture Detectors.Cross TippleDry ChainThe type that will provide the best fit to your application is determined by the grain direction in relation to the flow of the veneer.
4 ELLIOTT BAY INDUSTRIES The function and general operating principles of these two moisture detectors are the same.However, there does exist some differences in the operation that we will discuss.
5 ELLIOTT BAY INDUSTRIES Cross TippleThe Cross Tipple measures moisture in veneer where the grain direction is oriented in the same direction as the flow.
6 ELLIOTT BAY INDUSTRIES Dry ChainThe Dry Chain measures moisture in veneer where the grain direction is oriented perpendicular to the direction of flow.
7 ELLIOTT BAY INDUSTRIES Theory of OperationAll Elliott Bay moisture detectors are reliable, simple to use instruments. They are based on current computer technology and are completely programmable.The control cabinet is both easy to understand and easy to operate. From a glance an operator can determine the moisture detector’s settings and monitor its performance.
8 ELLIOTT BAY INDUSTRIES Theory of OperationElliott Bay’s Moisture Detectors use a resistive brush type system to sense moisture pockets in veneer. When the brushes make contact with the veneer the system instantly scans the brushes and measures their digital values. The system then compares these values with the set points the user selected and determines whether or not to fire the desired output.Calibration takes place automatically when there is no veneer under the moisture detector. This is determined by the photo sensor(s) on the distribution gutter. When none of the moisture status lights are lit on the front panel the moisture detector will auto-calibrate.
9 ELLIOTT BAY INDUSTRIES Benefits of an Elliott Bay Moisture Detector When run properly the Elliott Bay Moisture Detector will offer many benefits that can be recognized instantly.Moisture detection at full line speeds and provide 100% coverage.Increased throughput of the Dryer, increasing the total production.Reduced moisture related blows and delamination.Reduced glue consumption
10 ELLIOTT BAY INDUSTRIES Understanding Moisture Level SettingsElliott Bay’s Moisture Detector utilizes 3 moisture level settings: “High” and “Low” are located on the front panel and the third level “Auxiliary” is located on the back of the display panel.Although most customers require 2 sorts, dry and wet, they will have the ability to have up to 4 sorts. This allows the moisture detector to expand as your operation expands.
11 ELLIOTT BAY INDUSTRIES Understanding Moisture Level SettingsOne common area of misunderstanding is that these values are not directly associated with the moisture content percentages.The moisture level settings are approximately 2 times the moisture content percentage. This allows fine tuning of the moisture detector. For example, a setting of 21 allows you to mark at 10.5% moisture content.
12 ELLIOTT BAY INDUSTRIES Understanding Moisture Level SettingsAnother common misunderstanding is the difference between hand meters and the Elliott Bay. To understand this relationship we need to understand that there are two factors affecting the moisture level settings.The moisture detector uses two criteria to determine if there is enough moisture to reach the moisture level setting.% Moisture ContentArea
13 ELLIOTT BAY INDUSTRIES Understanding Moisture Level SettingsThis effective method allows the moisture detector to look at the veneer similarly to how a hot press would look at the veneer.Hand meters look at a very small area of the veneer similar to a magnifying glass.The following figure illustrates the moisture detectors criteria.
14 ELLIOTT BAY INDUSTRIES Both of these moisture pockets present a potential problem to your process.When this veneer is scanned, these pockets will look the same to the moisture detector and will be handled the same.
15 ELLIOTT BAY INDUSTRIES Optimizing use of your Moisture DetectorElliott Bay suggests that once your moisture detector is installed you set the moisture level settings at approximately 2 times the desired moisture content percentage.Example: For a desired moisture content percentage of 15%, set the moisture level setting to 30.We further suggest that you use this setting as a base number only. To get the most out of your moisture detector, further adjustments should be made to optimize your process.
16 ELLIOTT BAY INDUSTRIES Optimizing use of your Moisture DetectorIf you find that at your current settings there are no problems, increase the moisture level settings. *Every process is different and each process can tolerate slightly different levels of moisture content.Example: If you operate with a moisture level setting of 30 for a few days and there are no problems- blows at the press, delamination, etc. Then you are most likely not operating as efficiently as possible and could be over drying the veneer. Increase the number 1 or 2 points and operate here for a few days. If there are still no problems, up the settings another 1 or 2 points.
17 ELLIOTT BAY INDUSTRIES Optimizing use of your Moisture DetectorWhen you discover the setting that results in increased problems, this is your process’s threshold and maximum moisture limit.Once you have found this limit, decrease the setting by 1 or 2 points, this is the optimum level of operation.You will be using less energy drying the veneer and leaving the maximum amount of moisture in the wood, producing the best quality veneers.
18 ELLIOTT BAY INDUSTRIES Optimizing use of your Moisture DetectorWith the moisture levels set, it is now time to monitor the RE-DRY %. This number is a direct correlation to your dryer’s performance.Since not all veneers are the same it is difficult to dry them all uniformly. Some may dry quickly and others take time.Elliott Bay has heard reports from numerous customers that when you are operating the dryer at the optimum level you will be re-drying approximately 15% of the veneer.
19 ELLIOTT BAY INDUSTRIES Optimizing use of your Moisture DetectorThis creates the most efficiencies, eliminating over-dried veneers and running the dryer faster, allowing the maximum amount of throughput.While 15% may not be ideal for your operation, it illustrates the idea that some re-dry is beneficial to the drying process.The following figure illustrates this idea.
21 ELLIOTT BAY INDUSTRIES Optimizing use of your Moisture DetectorThis re-adjusts the bell curve and tailors production to fit your needs. You will get more product where you want it.Without the moisture detector the dryer tender will try to minimize redry. This creates an excess of over-dry. Using the moisture detector we can allow a % redry. If we increase redry, less wood will be over-dried and most of the production will be in a usable range.
22 ELLIOTT BAY INDUSTRIES ConclusionElliott Bay Moisture Detectors are being used world-wide and have become the industry standard for veneer moisture detection.They are easy to install, operate, and service and their benefits are numerous and significant.Understanding their operation and how to use them as a tool can result in a return on investment in just a few short weeks, depending upon your operation.