In a world that seems to be becoming more and more violent, there is an increased demand for protection from ballistic and even environmental threats in the building and construction industry. Performance plastic materials are playing an important role in filling this need. From Federal buildings to local police stations, from corporate headquarters to customer service centers, from college campuses to your local elementary schools, security is becoming an increasingly important part of the design of these buildings.
The Rundown on Ballistic Protection
That design will typically include some areas, if not the entire building, that require protection from ballistic attack. To meet these requirements, windows, doors, storefronts, and transaction windows are being designed and tested to meet UL 752 levels of ballistic protection (see sidebar). In order to pass these tests, absolute protection is required, meaning not only can the bullet not penetrate the glass but there can be no spall (flakes of material that are broken off a larger solid body) or glass shards of any kind that penetrate craft paper on the safe side.
For higher levels of ballistic protection with an all-glass product, you could be looking at glass as thick as 3″ to 4″ and weighing 35-40 pounds per square foot. This is where performance plastics shine: By adding layers of polycarbonate and urethanes together with glass layers and, in some cases, adding polycarbonate or PET to the safe side of the glazing you can meet these same levels of protection with glazing make-ups that are 2″ or less, which now allow it to be glazed into framing and are less than half the weight, which makes for a much easier installation and a much lower carbon footprint when transporting the material.
For lower levels of protection, typically UL752 levels 1-3, you can use all polycarbonate laminated products or even monolithic acrylics. These products are much lighter than glass products and provide much better clarity along with ease of fabrication. These all-plastic products can be cut-to-size, routered, and polished to a water-like clarity, providing an aesthetically pleasing solution to protecting employees from the threat of gun violence.
How Performance Plastics Protects From Natural Disasters
Performance plastics also play a vital role in protecting lives against natural disasters in the building and construction industry. The International Building Code 2015 requires that all new critical emergency facilities (emergency operations centers, 911 call centers, police, fire, and rescue stations) and K-12 schools built in the 250 mph wind zone must include a tornado-safe room and the safe room must house all occupants of the school.
An Overview of Performance Plastics Protection Levels
Insulgard’s BULLETBLOCK UL 752 Level 3 storefront, doors, and glass-clad polycarbonate cre-
ates a secure entrance for a school. Insulgard’s SAFECHANGE Counter line system uses UL 752 Level 2 Acrylic to secure the bank teller area.
These requirements present a dilemma for designers: Do they design a safe room that is a concrete bunker with no natural light that is used once or twice a year or do they incorporate the safe room into the rest of the building so it can be used 365 days a year? If choosing the latter option, windows allowing natural light into the space are required to meet pressure and debris impact testing requirements for impact protective systems.
This testing consists of a 15-pound 2 x 4 being launched out of a cannon at 100 mph impacting multiple locations on the glass. As with ballistic testing, the result must be complete protection. Not only can the 2 x 4 not penetrate the glass but there can be no spall or fragmenting coming into the interior. Nothing can penetrate the craft paper.
The only way to achieve this type of absolute protection with over 5,000 ft-lb of energy at impact is by including polycarbonate in the glazing makeup. This must be done not only within the interior makeup but also as the innermost surface of the safe side. This polycarbonate layer acts as a diaphragm and prevents any type of spall from penetrating the safe side. Through the use of plastics in these glazing makeups, designers are able to use spaces such as classrooms, gymnasiums, and cafeterias which require natural light to double as safe rooms in the event of a tornado.
The benefits of performance plastics can be found in all aspects of our lives so it should come as no surprise they also play a major role in our security and well-being. From monolithic and laminated acrylic and polycarbonate sheeting providing protection from low-level ballistic threats to combination glass/polycarbonate glazing makeups used in windows that protect us from higher-level ballistic threats and EF-5 tornados, plastic continues to stretch
the boundaries. In an insecure world, performance plastics help to provide windows and doors that can keep us safe.
UL 752 Protection Standards for Bullet Resistant Products
In order to understand what bullet-resistant material is right for your building or structure, you first need to understand the different ballistic standards that are used to measure the level of protection each product provides. The UL 752 ratings offer a system for understanding ballistic protection in bullet-resistant glazing. Here’s some more information to help you understand what the UL 752 levels mean.
UL 752 requires absolute protection
There is no such thing as a “low spall” UL 752 product. All products that have been tested and certified to meet the standards of a particular level must offer absolute protection from that type of ballistic threat. So if there is any spall created by an impact, that particular product would not qualify for UL 752 standards at that level.
Not all UL 752 ratings are linear
When you think of a rating system, you normally assume that the numbers correspond to the level of protection or benefit that is offered. Level 1 would be the lowest, level 2 would be the next in line, and so on. But that’s not the case for all UL 752 ratings. In this specific instance, only levels 1 through 3 are linear. So if something is tested to UL level 3, it would automatically meet the standards set for UL levels 1 and 2; however, once you get to level 4 the standards vary. For example, if something is tested for level 8 that doesn’t mean that it automatically meets the standards for level 7.
So rather than being an ordered ranking system, each level is meant to describe a particular product so that you can more easily find the type of ballistic protection that is most relevant to your needs.
UL 752 Levels 1-8 Explained
Each level requires the material to withstand impact from a specific type of
ballistic impact. Here are the testing requirements for each level.
Level 1: Provides protection against three shots of a 124-grain 9 mm full metal copper jacket with lead core at an fps between 1175 and 1293.
Level 2: Provides protection against three shots of a 158-grain .357 magnum jacketed lead soft point at an fps between 1250 and 1375.
Level 3: Provides protection against three shots of a 240-grain 44 magnum lead semi-wadcutter gas checked at an fps between 1350 and 1485.
Level 4: Provides protection against one shot of a 180-grain .30 caliber rifle lead core soft point at an fps between 2540 and 2794.
Level 5: Provides protection against one shot of a 150-grain 7.62 mm rifle lead core full metal copper jacket military ball (.308 caliber) at an fps between 2750 and 3025.
Level 6: Provides protection against five shots of a 124-grain 9 mm full metal copper jacket with lead core at an fps between 1400 and 1540.
Level 7: Provides protection against five shots of a 55-grain 5.56 mm rifle full metal copper jacket with lead core (.223 caliber) at an fps between 3080 and 3383.
Level 8: Provides protection against five shots of a 150-grain 7.62mm rifle lead core full metal copper jacket military ball (.308 caliber) at an fps between 2750 and 3025.
Shotgun: Provides protection against three shots of a 12-gauge rifled lead slug at an fps between 1585 and 1744 and three shots of a 12-gauge 00 buckshot (12 pellets) at an fps between 1200 and 1320.
— Source: www.insulgard.com/ul-752-protection-standards
Gerry Sagerman is the business development manager for Insulgard Security Products, a division of Polymershapes. For more information, contact Polymershapes at 10130 Perimeter Parkway, Suite 500, Charlotte, NC 28216- 2442 USA; phone (704) 948-5000 or (866) 437-7427, fax (704) 948-5082, info@polymershapes.com or www.polymershapes.com.
