Casting Study: Traffic Light Housing

Together, these two parts form a protective casing for the internal components of traffic lights. The material properties provide protection against vandalism and have much longer lifetimes than polymer materials. Due to thinner sections, they are also lighter than the previous generation which was cast in aluminum. The parts’ design simplifies maintenance of traffic lights, requiring only one screw to open the housing.  Part 1 weighs 1364g and has dimensions of 427 x113 x 65 mm, while part 2 weighs 560g and has dimensions of 441 x 118 x 43 mm, both are finished with a polyester powder coating. ZP5 was chosen over other materials for its lower cost, closer dimensional tolerances and better surface finish. The weather tight seal requires flatness, solidity and a high quality surface. There was also a large reduction in production cost due to their ability to be hot chamber die cast with a reasonable machine size (250 tons).

• Part 1 weight: 1364g
• Dimension: 427 x113 x 65 mm
• Part 2 weight:  560g
• Dimension: 441 x 118 x 43 mm
• Alloy: ZP5
• Finishing: Manual picking off, manual deburring, polyeser powder coating

Reasons for choosing zinc alloy:
ZP5 was chosen over other materials for is lower cost, closer dimensional tolerances, and good surface finish. The seal requires flatness, solidity and high quality surface. No further machining required. Important reduction of production cost due to hot chamber zinc die casting with a reasonable machine size (250tons).