In January 2011, DuPont Glass Lamination Solutions conducted a comprehensive technical testing program to characterize the impact strength and post-break performance of glass balustrades (railings) made with commonly specified types of safety glass.

TEST METHODS AND MATERIALS

2011 GLASS RAILING SYSTEM POST-BREAK PERFORMANCE TESTING

“Swing Bag” Impact Tests Were Conducted on A Wide Range of Safety Glass Types Used in Glass Railings Beginning in January 2011, DuPont Glass Lamination Solutions conducted a comprehensive technical testing program to characterize the breakage characteristics and post-break behavior of glass balustrades (railings) made with commonly specified types of safety glass. An industry recognized “swing bag” test was conducted under controlled lab conditions, based on the protocol outlined in ANSI Standard Z97.1-2004. This protocol considers the impact loading created by a 100-lb (45.4 kg) shot bag, dropped from various heights. Because the intent of the test was to EXCEED the force needed to break the glass, a shot bag height of 5 ft was chosen for most of the tests, resulting in an impact in excess of 500 ft-lbs (69 kg-m). Dozens of 42-in. x 48-in. (107-cm x 122-cm) panels were tested for deflection strength and breakage behavior in line-supported and 3-side-supported configurations. The cantilevered panels were mounted and dry-glazed in the channel of an R.B. Wagner PanelGrip™ railing system. For the swing bag portion of the test, care was taken to impact each glass panel at exactly the same location, in the middle of the panel at a consistent height above the floor.

DUPONT GLASS LAMINATING SOLUTIONS

The swing bag testing protocol involves controlled acceleration (by gravity) of a 100-lb (45.4-kg) shot bag, resulting in repeatable delivery of a chosen impact force on glass panels intended for applications such as railings, requiring barrier performance.

2011 GLASS RAILING SYSTEM POST-BREAK TESTING -- METHODS AND MATERIALS

A Variety of “Safety Glass” Types are Used in Balustrades

Safety glass panels tested in the railing system were typical for U.S. railing applications, and included:

Non-Laminated Glass Panels:½-in. (12.7-mm) Fully Tempered (FT) monolithic glass

½-in. (12.7-mm) FT monolithic glass with 0.008-in. (0.2-mm) applied PET film

Laminated Glass Panels:¼-in. FT | 0.060-in. PVB | ¼-in. FT (6.35-mm. FT | 1.52-mm PVB | 6.35-mm FT)

¼-in. FT | 0.035-in. SentryGlas® | ¼-in. FT (6.35-mm. FT | 0.89-mm SentryGlas® | 6.35-mm FT)

3/16-in. FT | 0.060-in. SentryGlas® | 3/16-in. FT(4.76-mm. FT | 1.52-mm SentryGlas® | 4.76-mm FT)

Conventional and high-speed video cameras recorded the swing bag impacts, as well as the resulting post-break behavior of the panels, from multiple viewing angles.

Conclusions for Cantilevered Glass Balustrades

1. Standard impact testing simulates potential human loading

2. Tempered glass provides no residual barrier on impact break-age

3. Applied PET film does not retain glass in place on breakage

4. PVB laminates remain attached to the railing system after impact breakage ... but

5. PVB laminates display no residual barrier after glass breakage

6. Laminates made with SentryGlas® ionoplast interlayer display residual barrier after glass breakage

7. Laminates made with 35-mil (0.89-mm) SentryGlas® demonstrate considerable post-glass breakage integrity

8. Laminates made with 60-mil (1.52-mm) SentryGlas® allow reduction in glass thickness while retaining good barrier performance.

What does “safety glass” mean in a balustrade or railing system?

Tempered glass (see right) is often used in railings, but retains no barrier properties after breakage.

DuPont tested tempered glass, applied-films, and laminated glass panels to compare and record post-break performance.

DUPONT™ SENTRYGLAS® POST-BREAK STRENGTH

The strength and stiffness of DuPont™ SentryGlas® interlayer results in balustrade glass panels that retain barrier properties (see left-most panel, above) even after a 500-ft-lb (69-kg-m) swing bag impact.

REGIONAL CONTACT CENTERSDuPont Glass Laminating Solutions, Wilmington, Delaware U.S.A.Telephone +1 302 992 4557, Toll-free (USA) 800 438 7225

DuPont do Brasil, S.A., Barueri, Sao Paulo BrasilTelephone +55 11 4166 8000

DuPont China Holding Co., Ltd., Pudong New District, ShanghaiTelephone +86 21 3862 2888

DuPont de Nemours Int’l. S.A., Geneva, SwitzerlandTelephone +41 22 717 51 11

The information contained herein involves the use of DuPont materials in end-use applications designed by others. The proper design, manufacture and acceptance of laminated glass meeting a user’s project requirements is the responsibility of the user. Glass and glazing system performance criteria, testing requirements, manufacturing methods and processing conditions vary by project and location. Information about specific applications is given and accepted at the user’s risk and confirmation of its validity and suitability in particular cases should be obtained independently. The DuPont Company makes no guarantees of results and assumes no obligations or liability in connection with its advice. This publication is not to be taken as a license to operate under, or recommendation to infringe, any patents.

The DuPont Oval, DuPont™, The miracles of science™ and SentryGlas® are trademarks or registered trademarks of DuPont or its affiliates. Copyright © 2011 E.I. du Pont de Nemours and Company. All rights reserved.

K-25330_1 (05/2011)

Make glass safer.Build lighter, stronger.

www.sentryglas.com

DuPont has assembled “moment-of-impact” technical video footage into several educational clips that can be viewed online at safetyglass.dupont.com.