One Way Bullet Proof Glass • Engr45 Materials • Instructor: Younes Ataiiyan • December 1, 2004 • By: Chris Rogers • Bryan Clifton • Nick Petrucci
The Concept One-way bulletproof glass Advances in bulletproof glass have lead to the invention of one-way bulletproof glass, such as used in some bank armored cars. This glass will resist incoming small arms fire striking the outside of the glass, but will allow those on the other side of the glass, such as guards firing from inside the armored car, to fire through the glass at the exterior threat. One-way bulletproof glass is usually made up of two layers, a brittle layer on the outside and a flexible one on the inside. When a bullet is fired from the outside it hits the brittle layer first, shattering an area of it. This shattering absorbs some of the bullet's kinetic energy, and spreads it on a larger area. When the slowed bullet hits the flexible layer, it is stopped. However, when a bullet is fired from the inside, it hits the flexible layer first. The bullet penetrates the flexible layer because its energy is focused on a smaller area, the brittle layer then shatters outward due to the flexing of the inner layer and doesn't hinder the bullet's progress.
Testing • Multiple Shot Integrity • Spall Quantity • Exiting Velocity • Resin • Acrylic • Plastic • Radius of Dispersion Energy • Weight • Different Bullet/Jackets
No Spall or penetration of the 9mm rounds Inside surface (opposite threat side) 9mm 124 FMJ and .357 Magnum JSP http://www.firstdefense.com/html/default_faqs.htm
BBC Presents: http://www.labock.com/english/bpq_oneway.htm
Original Bullet Proof Glass • Bullet proof glass in general • Typical composite glazing cross-section • Glass to polycarbonate • OmniLite • OmniArmor • Spall • Ballistic Standards
Bulletproof glass is usually transparent material, such as polycarbonatethermoplastic (i.e.Lexan but also called Tuffak and Cyrolon), that provides the appearance and light-transmitting behavior of standard glass but offers varying degrees of protection from small arms fire. • Bulletproof glass usually consists of a polycarbonate layer sandwiched between layers of regular glass. A bullet pierces the exterior glass layer with ease, but the strong polycarbonate layer stops the bullets motion before it can pierce the inner layer of glass. Bulletproof glass is usually 7-75mm thick.
Level IV Glass http://www.firstdefense.com/html/default_faqs.htm
Applications • USES & APPLICATIONS • Armored Vehicles • Prison security doors and guard gates/posts • Riot shields, Clip boards and Helmet visors/shields • Residential homes • Banks, bank doors and teller glass • Aircraft, helicopters, water craft • VIP personal protection vehicles • Airport security & parking booths • Transit booths • Government buildings, Embassies and lobbies • Malls, shops, stores/bomb blasts • Corporate offices and Executive offices • Military bases and guard points • Courthouses • Police stations Offset Baffle Design with ADA Station
History Channel http://www.labock.com/english/bpq_oneway.htm
One Way Test http://www.labock.com/english/bpq_oneway.htm