AIA: School Bus Learns Adhesives Lesson
Thomas Built Buses Inc. (High Point, NC) has been building school buses for over 60 years. Today it is the largest school bus manufacturer in the United States, and its Saf-T-Liner C2 one of the most advanced buses in the world.
Going into full production in late 2004, the bus is manufactured in a new 275,000-square-foot facility with a 3/4-mile-long assembly line. It was designed with extensive input from hundreds of industry professionals, including everyone from school transportation directors to drivers and mechanics. Specific innovations include a low, sloping hood for better driver visibility and recessed warning lights that are less prone to damage when the bus is in use. An ergonomic driver cockpit reduces operator fatigue, and specialized floor and interior panels resist both corrosion and graffiti.
To cut down on manufacturing costs and increase durability, Thomas Built Buses assembles the bus bodies using a combination of self-piercing rivets and Loctite structural adhesives from Henkel Technologies (Madison Heights, MI), in a technique similar to that used in the aerospace industry. According to Henkel, this represents the first major use of structural adhesive as a primary fastening method for school bus assembly.
"The combination of adhesives and rivets results in fewer fasteners, for a sleek look, fewer potential leak points and substantially stronger joints," says Thomas Built Buses president John O'Leary.
According to Thomas Built Buses, during testing, sample joints demonstrated nearly twice the strength of conventional riveted joints when subjected to the U.S. Department of Transportation's standardized FMVSS 221 compliance testing. A framework comprised of a welded floor, rafters and stringers forms a solid structure that when bonded with adhesive to the side panels, creates a single, strong unitized body, providing both stability and durability.
Specific parts being bonded with adhesive include side sheet assemblies, interior headers, roof sheets, interior side sheets and roof caps.
According to Thomas Built Buses, adhesive joints maintain their integrity better over time than rivet-only joints, which will help cut down on operators' maintenance costs. "The ride to school is no longer a history lesson," says O'Leary. "We have designed a bus with proven technology for improved performance, life cycle cost and safety."
For more information on structural adhesives, visit www.loctite.com/industrial, call 800-562-8483 or eInquiry 1.