Distinguishing Between A Manufacturer and Fabricator

In the industry, the terms MCM manufacturer and MCM fabricator are often confused. There are, however, distinct differences between the two.

The MCM manufacturer is responsible for the process of bonding the skins and core together in a continuous process, creating the flat sheet.

The MCM fabricator is responsible for cutting, routing, folding, and otherwise processing the MCM to fabricate panels to be installed on the building. These fabricators can either have a proprietary installation system using aluminum extrusions or use a third party’s extrusion system.

In the manufacturing, fabrication, and installation process, there are many testing requirements that must be met along the way. Some pertain to the manufacturer, some to the fabricator, and certain tests can only be accomplished by a cooperation and coordination of the two. The manufacturer is responsible for anything related directly to the MCM sheet, including surface finishes and material fire performance. Testing pertaining to wind loads and water penetration generally applies to the fabricator, as the MCM is simply a transfer component moving wind load from one location to another. Some of the more extensive fire testing is a combination of manufacturer and fabricator performance since the MCM is a primary combustible element. The installation system allows the panel to maintain its position and has an impact on the direction of the flames.

Securing a Quality MCM Sheet Manufacturer

There are many MCM manufacturers across the globe, offering varying levels of quality and pricing options. When specifying MCM products, it is important to choose a quality manufacturer to ensure the health, safety, and welfare of occupants while also providing a long life for the building.

As previously discussed, the typical MCM manufacturing process is to extrude or place a core material between two skins of metal with some type of continuous bonding technology to keep the components together. These components are run through a series of heated rolls under a considerable amount of pressure, then each panel is cut to length. Various manufacturers have tried to create composite panels in a batch process; however, consistent visual appearance and bond strength between the core and the skins has generally been a limiting factor in production. Continuous panel production in a controlled factory environment has proven to be the most common practice to ensure a high-quality, consistent panel product. For the best results when specifying a manufacturer, ensure that the materials produced are manufactured using a continuous production process. Manufacturers should provide warranties on the finish quality, bond integrity, and appearance (flatness). Warranties will be discussed in more detail later in this article.

TOWER HOSPITAL AT RUSH UNIVERSITY HOSPITAL

Photo: Robert R. Gigliotti; courtesy of Metal Construction Association

Rush University Medical Center's Tower Hospital in Chicago features an MCM exterior.

Project: Tower Hospital at Rush University Medical Center
Location: Chicago
Contractor: Powers/Jacob Joint Venture
Architect: Perkins+Will
Metal Installer: ASI Ltd.
Manufacturer and Fabricator: 3A Composites USA and Sobotec Ltd.
Materials: Alucobond
Completion Date: January 2012

Chicago is renowned for its skyscraper architecture, and the city’s new Tower Hospital at Rush University Medical Center stands tall among the best. More than just a pretty building, it was designed by and for its occupants—the doctors, nurses, staff, and patients who use it.

The unique butterfly-shaped design is awe-inspiring to outsiders, but the design serves an important purpose as well. The floor plan, essentially a triangle, brings the patient rooms closer together, a specific concern for the nurses seeking more efficient access to patients.

“We used an inside-out approach to design Tower Hospital,” says John Moorhead, senior project designer at Perkins+Will, the Chicago-based architecture firm that designed the building.

The architects collaborated with Rush University Medical Center staff to find out how they worked and designed the shape of the building to fit their operational model. “We let that impact what the design needed to be,” Moorhead says. “The nurses talked about the number of miles they walk per shift. They were particularly interested in creating a plan that pushed together the patient rooms.”

Once the butterfly shape was conceptualized, the challenge became how to make it fly—functionally, aesthetically, and monetarily. A composite panel consisting of two aluminum cover sheets and a mineral-filled polymer core provided the solution. About 250,000 square feet of composite panel consisting of two aluminum cover sheets and a mineral-filled polymer core in a custom bone-white color was installed as exterior wall cladding on the Tower Hospital.

At one point in the planning, the idea of the butterfly shape was nearly scrapped for a more standard rectangular shape to stay within budget, but the Rush team was determined to achieve its vision.

Because it is durable, can be bent into any shape, and will not warp, the ACM used to clad the tower helped Rush realize its goals. “The Rush Tower has a lot of bends and curves,” Moorhead says. “The cladding material provided the vehicle for architects to do that.”