| KAISER PERMANENTE SAN DIEGO MEDICAL CENTER |
 The Leadership in Energy and Environmental Design (LEED) Platinum-certified Kaiser Permanente San Diego Medical Center, California, features an exterior aluminum panel system with mica and metallic color finishes. Clean, modern, soothing—the visual impact of mica and metallic color finishes on the exterior of the Kaiser Permanente San Diego Medical Center in California reflects the hospital’s philosophy of high-tech healing in a patient-centered, sustainable environment. Opened in April 2017, it is one of few healthcare facilities in the world to achieve Leadership in Energy and Environmental Design (LEED) Platinum certification through the U.S. Green Building Council (USGBC). Kaiser Permanente worked had closely with the design team of CO Architects and general contractor (GC) Hensel Phelps to create a medical center focusing on innovative care. The interior and exterior designs of the 57,321-m2 (617,000-sf), seven-story building is reminiscent of San Diego’s coastal colors and climate. Bringing the design from concept to reality, the glazing contractor Architectural Glass & Aluminum selected products with durable metallic and mica coatings. For Level 1, the 3-mm (1/8-in.) aluminum plate panel system, balcony plate panels, interior curtain wall closer panels, and column covers were painted in a platinum mica sunstorm color. For all the other levels on the medical center, the curtain wall panels were finished in a light blue metallic color. These finishes add shimmer and sparkle under the California sun. The color can seem to change with the way the visible light is reflected off the surface, depending on the intensity and angle of the light. Protecting against ultraviolet (UV) damage and unwanted color change, both of the paint color formulations use 70 percent fluoropolymer resin-based coatings. These offer the highest performance finish for architectural aluminum products, providing outstanding resistance to humidity, chalk, gloss loss, chemicals, and salt spray. Supporting environmentally sound practices, the high-performance painted coatings were applied in a controlled facility, contributing to enhanced durability for long-lasting materials and improved indoor air quality (IAQ) for healthier buildings. |
It is recommended that a professional finisher apply the metallic paints under climate-controlled conditions where the process and quality is closely monitored. There are two main application methods used: coil coating and spray coating.
Coil coating is used for painting high quantities of aluminum in coil form that can be later cut into sheet form. With this process, continuous rolls of sheet are passed through a rolled application of paint. The uniform geometry of the flat sheets and the spray distance of the paint remain constant, so there is very little opportunity for variation in the coating application.
Spray coating either by hand or by automatically controlled equipment is used for painting almost all aluminum parts other than rolled coil aluminum. The differing sizes and geometries of brake metal, extrusion profiles, and flat sheet parts are just some of the numerous variables that make it more difficult to apply a perfectly random flake orientation.
Other aspects that affect flake orientation include the following.
Paint lines
Different types of paint lines used by the applicator will affect the outcome of the painted finish. Paint application lines can be automated or manual, horizontal or vertical, continuous or batch. Any variance in the application can greatly affect the positioning of the metallic flakes.
Shapes of parts
Different shapes of parts mean different painting distances from a part’s surface. Most spray-applied, architectural aluminum does not have a totally flat surface.
Application equipment
Different application equipment will cause various types of flake distortion. A cup gun will minimally affect the flakes whereas a mini bell at a high rotation will cause the greatest distortion. The distorted or bent flakes will reflect light in a scattered ray for an inconsistent appearance.
Pressures, atomization, and human elements
Different pressures, atomization, and human elements of supplemental hand-spraying with manual guns often will produce finishes that look different than an area sprayed with the accuracy of automated equipment. Some amount of hand-spraying almost always is required to reach recessed or angled areas on extrusions or formed metal.
Electrostatic attraction
Different levels of electrostatic attraction within or between parts can occur. Even without electrostatic painting equipment, electrostatic/grounding effects are present.
Solvent types
Different solvent types are used by different applicators to blend the paint. Faster evaporating solvents orient flakes differently than slower evaporating ones.
Coverage
Different coverage should be anticipated for overlapping spray areas because these have twice the flake content as other areas. The initial layer of flakes will be disturbed and re-oriented by the re-application of paint on the overlapped area.
