The AEWC Center at The University of Maine

The Advanced Engineered Wood Composites Center

The Advanced Structures and Composites Laboratory

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OSB/OSL Pilot-Scale Production Capabilities at the AEWC Center

 In 2004, the AEWC Center completed an expansion which significantly increased its wood composites manufacturing capacities.  The centerpiece of this expansion is a complete OSB/OSL pilot plant. 

 Companies developing and/or testing OSB/OSL may now conduct their research at the world-renowned AEWC Center and may contract for any, or all, of the following services:

 Log Bucking

Companies can deliver tree length or 5’ logs, the optimal length based on AEWC equipment.   Tree length logs will be bucked to length on site; any log whose diameter exceeds the 12” maximum will be culled.  Logs must be debarked prior to delivery. 

 Log conditioning

Approximately ten 5’ long, 12” diameter logs can be soaked and/or heated in a log tank which can be heated to 150 Fº.

Stranding

The AEWC  Center’s Carmanah 12/48 Laboratory Strander can convert up to 12” diameter logs into strands from 3-12” in length for laboratory-scale OSB/OSL production. The Carmanah strander can quickly produce strands for board production either at the AEWC or other facilities.

 A 48” inside diameter ring holds two knives which protrude into the inner face of the ring.  Each knife is assembled and clamped into place together with a scoring knife holder and counterknife.  Flakes are produced by advancing the log through the rotating ring at a specified rate.  The knives cut the log in the thickness dimension, and the scoring knives part the flake in the length dimension.  Projection of the knives in combination with ring speed determine the flake thickness, while the flake length is determined by the scoring knife spacing.  Desired flake width is achieved by selection of the appropriate counterknife angle.

Carmanah Lab Strander Specifications

Screening

Both an Acrowood Trillium™  as well as Diamond Roll OSB/OSL Strand Screener can be used to separate strands into three size fractions.  The Trillium screen has 18 shafts, each rigged with numerous triangular shaped disks.  The shafts are divided into two zones, each controlled by a variable frequency drive.  The screen’s capability to separate fines from both dry and green strands is increased by the triangular disk shape which produces significantly higher strand agitation as compared to traditional circular disks,  While the Trillium screen works well on dry strands, several manufacturers have expressed an interest in green screening, which removes the fines from the strand stream prior to drying, thereby increasing overall efficiency.  Larger strands pass over the Trillium screen, with the remainder falling through into the Diamond Roll Screen.  This material, in turn, is separated into intermediate and fine size fractions.  A Gilson screen is available to determine screening efficiency. The Acrowood screeners efficiently separate strands into desired size fractions. 

Screening Specifications

                           A Gilson screen is available allowing for analysis of the efficiency of the Trillium and Diamond Roll in removing fines from the strand stream at various loading rates and settings. Screen mesh sizes range from # 60 to 1 1/2".

Drying

The OSB/OSL pilot line also includes a Koch OSB in-line conveyor lab dryer.  The dryer is 10’ long and 3’ wide, with an additional 4’ of infeed and outfeed.  The dryer can evaporate up to 250 lbs of water per hour, at a maximum temperature of 325 Fº and a fan speed of 7,500 cfm.

The AEWC also has a 5,000 board foot, Nyle dehumidification dry kiln which can be used for strand drying as well.  Six drying racks, each capable of holding 100 lbs of (aspen) strands, are available for strand drying, , giving an effective daily rate of 600 lbs of green strands.

Resin Blending

Resin is applied to strands using a Coil Spinning Disk Atomizing Resin Blender.  The blender drum can be rotated at 20 rpm, and the spinning disk atomizer to 15,000 rpm.  Approximately 25-30 lbs of dry strands can effectively be blended at a time.  The resins (normally PMDI or PF) and additives (such as waxes and preservatives) are sent to the blender’s spinning disk by means of a peristaltic pump.

Forming

Plans are underway to add an automated, spinning disc forming line to the laboratory.  Currently, billets are laid up by hand using wooden forms.  Adequate orienting of strands can be accomplished using orienting jigs of aluminum fins or string.

Pressing

Boards are pressed in our 4’ x 8’ Erie Mill & Press, an 1800 ton hydraulic press.  The press is PLC controlled, with complete data collection for printout of press scheduling data and graphs.  The press can be controlled in either position (to within 0.003”) or pressure control.  Energy is provided either by hot oil (up to 450 Fº) heated platens or radio frequency (10 KV, 30 KW system).

Conditioning

Boards/panels can be conditioned prior to testing in one of two environmental chambers.  Most wood composites are placed in the chamber set at 70 Fº and 65% RH (which for most species, gives an approximate EMC of 12%).

Testing

The AEWC is ISO 17025 certified to conduct many wood composite tests (see the ISO link at the bottom of this page for a complete listing), including D1037-Standard Test Method for Evaluating Properties of Wood-Base Fiber and Particle Panel Materials and D5456- Standard Specification for Evaluation of Structural Composite Lumber Products.

For more information and rates contact:

Russell Edgar

Wood Composites Manager

The AEWC Center

5793 AEWC Bldg.

University of Maine

Orono, ME  04469-5793

Phone: (207) 949-1591

Fax: (207) 581-2074

Email: russell.edgar@umit.maine.edu

website: www.aewc.umaine.edu

A Center for Research, Education, and Economic Development at the University of Maine