Moisture Measurement in Particleboard

The continuous measurement of moisture is a key consideration in the production of particleboard. The proper moisture level of particleboard guarantees safety and high product quality.

Particleboard Production Process

Raw materials are passed through chippers, flakers and size reduction mills to create a relatively uniform particle size. The mix passes through screeners which remove fines, before they enter the dryer. During the drying phase, the moisture content is reduced from a high of 75% to less than 10% moisture. The dried material is then graded and separated into core and surface product. The products pass through different blenders as a function of their different requirements for resin. After the blender, the furnish is formed then pressed into boards.

Measurement Location and Installation

Measurements can be made at five different location; on the raw material, pre-dryer, post dryer, post blender and on the former. The sensor can be positioned to look through a viewing window at a 15? angle in the side of a storage bin of gravity chute. The sensor can also be positioned over a conveyor/weigh belt, or on the side of a formed mat. Whatever the location the moisture sensor should be mounted approximately 200cm from the product. The most common location for a moisture sensor is over the forming line.


Self-Contained, Non-Contact Infrared Temperature Sensor

Process Sensors Corporations significant design innovations and installation simplicity combined with formidable industrial packaging allows for seamless integration into existing systems. The new DT-44G and DT-44GH line of digital, self-contained, non-contact infrared temperature sensors are exceptional performers in glass and solar cell production applications for measurement of glass surfaces and substrate materials. They have also proven to be equally beneficial in the ceramics and semiconductor industries.

High speed, accuracy and repeatability, along with 4-20mA output RS485 interface capability, make the Model DT-44G and high-speed version DT-44GH the instruments of choice for system integrators, OEM’s and engineering companies. The DT-44G response time is 30ms, and the DT-44GH boasts a 10ms response.

An integrated green LED aiming light facilitates pin-point target alignment. The projected size of the LED is identical to the measuring spot and is clearly visible on hot targets. Alternatively, the Models DT-44G and high-speed DT-44GH can be equipped with a red laser.

The DT-44 series offers three temperature range choices (100 to 1300?C, 200 to 1400?C, and 500 to 2500?C) and features USB interface that makes adjustment of all sensor parameters easily accessible via PC, with optional software and connecting cable up to 30m long.

The robust stainless steel housing and cooling jacket with air purge stand up to the most severe industrial conditions and ensure consistent sensor operation regardless of environmental hostility.

Process Sensors Corporation is a company totally dedicated to customer support. Experienced infrared application specialists provide unique sensor solutions for a myriad of temperature measurement applications. The company continuously endeavors to combine product training, installation guidance assistance, and ongoing technical and commercial support to effectively address customers needs.

Paper Converting Process

The continuous measurement of moisture in the paper converting process is a key consideration. The proper moisture level can have a large impact on the curl properties of the paper. By installing the MCT Moisture Transmitter in line, a converter can continuously monitor the moisture level and manually or automatically control the moisture content.

Installation

The Transmitter is routinely used to measure finished moisture prior to wind up. It is also used for measurement and control of water addition by various means: spray addition, steam, rolls, and knives. The location is dependent to a large degree on the availability of space on the converting machinery. The location is also determined by the requirements of the control strategy. PSC can make the appropriate suggestions on proper location upon discussion. The Transmitter should be mounted about 12 from the web. This distance can be optimized for machine limitations. If the paper is glossy or wet the Transmitter should be angled about 15 degrees off of the perpendicular, relative to the web. It is important to keep environmental temperature in mind. If the Transmitter is used in close proximity to a dryer outlet or heater, cooling may be required. Air or watercooling devices, supplied by PSC, can be used for cooling. An air purge assembly over the optical window may be required, especially if the environment is steamy enough to cause condensation on the window.

Measurement Performance

Moisture in paper is a very well understood and documented application.
Measurement wavelengths, algorithms, and sensor optical parameters are pre-set at the PSC factory. Calibrations are also pre-set at the factory. Typical accuracy is about ?0.2% moisture. It is possible to improve that with careful sample handling and lab methodology. Very different basis weights can require different calibration settings. The same is true for dramatic color differences. PSC can advise. Typical analog output range is 0-10% moisture. The Transmitters output range can easily be adjusted for the best PLC or controller operation. Process Sensors is very experienced with the requirements of this application.