NEIEP Mechanics Practice Exam

Which type of material is required for vision panels on swing doors?

1. Polycarbonate

2. Tempered glass

3. Laminated glass

4. Acrylic sheet

The correct answer is: Laminated glass

Vision panels on swing doors are primarily required to enhance visibility while maintaining safety and durability. Laminated glass is the preferred material for these applications because it consists of two or more layers of glass bonded together with an interlayer, usually made of polyvinyl butyral (PVB). This construction offers several advantages. Laminated glass is designed to hold together if shattered, making it much safer than regular glass. In the event of impact, the interlayer keeps the glass pieces bonded, reducing the risk of injury from sharp shards. This property is especially important in areas with high foot traffic, where safety is paramount. Additionally, laminated glass provides sound insulation, which can help in environments where noise reduction is desired. It also offers UV protection, reducing the fade of interior materials from sunlight exposure. While other materials like tempered glass and polycarbonate may be used in specific situations, they do not possess the same combination of safety features and visibility as laminated glass. Tempered glass is stronger than regular glass and does shatter into small pieces, reducing injuries, but does not have the same bonding properties as laminated glass. Polycarbonate is known for its impact resistance but may not provide the same level of clarity and safety as laminated glass in terms of preventing shards from