Polycarbonate is a thermoplastic polymer that can be easily molded, and thermoformed. This glazing material is commonly known by various manufacturer brand names such as Lexan, Makrolon and Tuffak. With an impact resistance 250 times greater than glass and a weight reduction of approximately 50%, polycarbonate is the ideal choice for transit bus windows.
This virtually unbreakable product is an excellent candidate for heavy-duty vehicle window glazing applications. Potential product benefits for using polycarbonate in transit bus windows include:
- Half the weight of glass: resulting in an approximate 300 lb weight reduction per 40 ft. bus, which improves fuel efficiency and battery life, increases passenger capacity, and enables easier window handling during installation and maintenance.
- Impact resistance 250 times greater than glass: the high strength of polycarbonate results in a huge reduction in window damage and the associated cost for repair and replacement.
- Available custom colors and tints: customizable color and visible light transmittance permit the user to optimize passenger comfort and achieve a desired aesthetic.
AROW offers polycarbonate glazing for both their Storm-Tite Flush Window Series and Evolution Framed Window Series. All transit bus windows made with polycarbonate glazing are built and tested in accordance with FMVSS 217 guidelines and conform to all applicable ANSI Z26.1 requirements. Polycarbonate has a very low scratch resistance and is typically specified with an additional scratch protection in the form of an interior/exterior hard coating. Although Polycarbonate has a higher cost when compared to glass, significant annual savings are realized due to the reduced need to purchase replacement glass for damaged and broken windows.
Click on the videos below to watch how polycarbonate glazing stands up against a brick and sledgehammer.
AROW windows with polycarbonate glazing offer great durability and reliability throughout the life cycle of the bus. Review of 3-4 year old window systems in the field show outstanding performance with respect to clarity and color consistency, mar and scratch resistance, dimensional stability and overall in-service performance. A major transit authority in the U.S. has implemented the Storm-Tite Flush Window Systems with polycarbonate glazing since 2012 within their fleet. A representative of the transit authority has stated:
- Increase in passenger safety when compared to glass options.
- Window replacement incidents reduced to near zero. Incidents of window damage requiring replacement have been reduced from approximately 60 per month to near zero and window optical clarity has remained intact.
- No more idle buses. Buses equipped with polycarbonate glazed windows remain in service versus sitting idle for several weeks awaiting glass or glass window system replacement.
- Significant man-hours saved in window maintenance.