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University of Maryland 2005 Solar Decatholon
Moving Foam in the R-Control Warehouse

R-Control Visit

March 3, 2005

To get a better idea of the capabilities of structural insulated panels (SIPs), members of Maryland's 2005 Solar Decathlon Team visited the R-Control factory in Winchester, Virginia.  Here, R-Control starts with oriented strand board (OSB) and foam pellets, and creates custom-built SIPs for a wide variety of applications.

The process begins with small polystyrene foam pellets; the same foam pellets used to create disposable foam coffee cups.  The polystyrene pellets are introduced to moisture and heated, causing the pellets to expand.  A large molding machine expands a large quantity of pellets to create a large, 4' x 4' x 30' block of expanded polystyrene (EPS) foam.  These blocks cure for several days in temperature-controlled rooms before they are useable.

Next, workers cut the blocks to the correct thickness (usually several inches) for SIPs using a hot wire.  Workers can also cut custom shapes using a computer-controlled machine.  Glue is applied to both sides of the EPS pieces, and OSB is cut to fit each piece of EPS.  The OSB is applied, and the finished SIP is placed in a large press to set.  Once the SIPs are finished, the company sends them to the builder or homeowner for installation.

Because R-Control manufactures their own EPS foam for their SIPs, they also make decorative foam pieces that can be painted and used as part of a home's interior or exterior.

For more information, please visit their website at

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