What is Laminated Glass?
Laminated glass consists of a tough protective interlayer made of
polyvinyl butyral (PVB) bonded together between two panes of glass
under heat and pressure. Once sealed together, the glass "sandwich"
behaves as a single unit and looks like normal glass. Annealed, heat
strengthened or tempered glass can be used to produce laminated
glass. Similar to the glass in car windshields, laminated glass may
crack upon impact, but the glass fragments tend to adhere to the
protective interlayer rather than falling free and potentially
Laminated glass is the only glass to provide durability, high-performance
and multi-functional benefits while at the same time preserving the
aesthetic appearance of the glass. Laminated glass furnishes
solutions to many architectural design problems and offers increased
protection from the effects of disasters such as hurricane,
earthquake and bomb blast. Benefits of laminated glass include:
is just the start
In every glazing design, minimizing the risk of injury from accidental glass
impact, breakage and/or fallout is everything!
Ordinary glass windows are fragile and when broken can cause serious
injuries - sometimes even fatal. When laminated glass made with Saflex
protective interlayer is used in a glazing design, the risk of
injury as a result of broken glass is considerably reduced. On
impact, the glass itself may crack, but the fragments tend to
adhere to the Saflex plastic interlayer. By keeping the glass in its place,
the Saflex protective interlayer provides added protection from dangerous flying
or falling glass fragments. Laminated architectural glass is
commonly used for its safety applications in residential and
commercial applications and meets the tests for the following
the Consumer Product Safety Commission (CPSC) and the architectural glazing
safety sections of the major model building codes (Basic National Building Code;
Standard Building Code; Uniform Building Code) all set uniform
requirements for the performance of glazing materials used in
applications which present a potential hazard to the public. These
applications include entrance doors, storm doors, patio-type sliding
doors, shower and bath enclosures, sidelights and fixed glazed
panels. Performance requirements are determined by the
application and the size of the glazing area. Laminated glass with Saflex meets all
of these established building codes.
the use of glass in sloped and overhead
glazing presents a design and safety challenge. If the glass should break for
any reason, the glazing system specified needs to be able to provide
protection from glass fallout. With adhesion of the glass to the
plastic interlayer and its ability to remain integral if broken,
laminated glass with Saflex has passed the
requirements set of all the major model building codes in the United States and
the Glazing Industry Code Committee for sloped and overhead glazing.
The astonishing strength of laminated
glass is perhaps most dramatically illustrated in safety and security
applications. Glazing systems using
Saflex laminated glass can improve the design of facilities to reduce
physical damage and human injury resulting from accidental, criminal and
terrorist attacks. Security glazing can generally be used anywhere
ordinary glass is required, providing an effective substitute for
other construction materials while furnishing the added benefits of
light and visibility.
Current United States building codes do not require glass to meet
performance stipulations which relate specifically to security
concerns. Glass is not required by code to deter forced entry, to
deflect projectiles such as bullets, or to remain intact after
exposure to the shock wave and fragment impacts resulting from an
Security glazing can be
used to counter threats from the following general areas:
Burglaries are frequently directed towards targets of easy opportunity
and low perceived risk by the burglar. A simple deterrent, security
glazing, may be enough to
send the intruder to the next easier target. The ability of a
laminated glazing product to protect against forced entry is
measured by Underwriter's Laboratories Inc. Test UL972 (12). Glazing
materials which meet these test requirements are generally strong
enough to deter a "smash and grab" burglary, and is often specified
for residences, shop fronts and display cases in stores, museums and
Security glazing with laminated glass of appropriate thickness and
configuration can reduce death and injury from bullets in high-risk
locations, while still providing the aesthetic and visions benefits
of glass. Bullet-resistant glass is made by bonding alternate layers
of glass with Saflex to form a single, multiple-ply
laminate. Bullet-resistant glazing is tested under Underwriter's
Laboratories Inc. Test UL752 (13). Laminated glass between 1" and 2"
inches thick can generally resist bullets from weapons ranging from
a .38 super automatic to a high power .30-06 rifle.
Bomb Blast Resistance
Unfortunately, bomb attacks and threats are on the rise all over the
world. The fear generated by a bomb's instant holocaust of property
damage, injury, flame and noise can be more powerful than
conventional armed attacks. Bomb blasts propagate blast energy in
all directions, making buildings nearby the intended target
candidates for destruction as well. Experts report that
approximately 75 percent of all damage and injury from bomb blasts
can be attributed to flying and falling glass following the
Laminated glass can substantially reduce injury resulting from
explosions, and even reduce the cost to repair a bombed facility by
reducing the extent of damage and opportunity for looting. Since the
tragic Oklahoma City Bombing in April, 1995, the United States
Government is exploring the role of glazing as a deterrent to
explosions, but no federal standards currently exist.
With high technology playing an increasing role in corporate and
government security operations, electronic eavesdropping to obtain
classified or proprietary information can result in staggering
losses. Interference with computer networks from electromagnetic
noise generators (such as heavy machinery operating outside the
facility) can also be the source of loss.
glazing uses Saflex metalized fabric mesh and glass. When
the glass is manufactured, the fabric mesh is extended an inch or
more from the edge of the glass on all four sides and then connected
to the metal frame. The frame members are connected to each other,
and then to an effective ground. The result is a facility that is
isolated from external electro-magnetic signals and occupants are
capable of communicating without interception from the outside. The
specification frequently used to describe performance requirements
for computer and communications security is NSA 65-8, National
Security Specifications for RF Shielded Enclosures for
Communications: General Specifications(19).
Sound solutions for noise
Skylights can be the weak link in the transmission of unwanted sound
into a building. Just as a window lets in light, it also can
transmit irritating noise from airplanes, traffic, and heavy
machinery to name a few. Laminated glass made with Saflex
plastic interlayer is highly effective in reducing unwanted sound
transmission and can also be used in standard skylights design.
Whether in single or double glazing, the presence of one or two laminated
components in a window or door can improve the acoustic performance
of the glazing surface by dampening resonance effects. In
comparison, solid or monolithic glazing systems do not effectively
control sound because of their inadequate ability to screen high
frequency noises. Double glazed systems may offer an improvement
over the monolithic systems, but the span of air space required to
provide acceptable acoustical control introduces architectural
design restraints as well as higher costs. Only laminated glass made
provides significantly better sound insulation performance in a
single unit system. With laminated glass made with Saflex,
the protective interlayer dampens the vibration of the glass thus
reducing transmitted sound.
For example, a ¼" laminate (two lights of 1/8" glass bonded with 0.0300"
Saflex) has sound transmission loss performance nearly
equal to that of monolithic glass having almost twice its surface
weight (slightly less the ½" monolithic glass). Additionally, the
sound isolation provided by two pieces of glass ¼" thick separated
by ½" air space can also be achieved by laminating two pieces of
1/8" glass with only 0.030"
Glazing solar control is accomplished in laminated glass by the
interlayer's ability to reflect and/or absorb and re-radiate much of
the solar UV radiation. Laminated glass made with Saflex
screens out more than 99% of damaging UV light. The Saflex
protective interlayer prevents the degrading of dyes, pigments and
polymers which causes color fading and deterioration of natural and
synthetic materials of the interiors in a building.
While protecting buildings from harmful and damaging solar UV radiation,
laminated glass made with Saflex has no adverse affect on
the health of indoor plants. In fact, laminated glass is commonly
used in greenhouses and atriums to help protect flower color and
reproductive development from the damaging effects of UV radiation.
Photoreceptors in plants are still able to absorb sunlight the
Saflex interlayer allows to be transmitted.
Laminated glass has been used to protect some of the world's most
valuable treasures from harmful UV damage, including the Mona Lisa
and the Declaration of Independence.
Achieving Color with Laminated Glass Saflex color can be
added to enhance any project while taking advantage of the
protective benefits of laminated glass. The pigmented interlayer
offers true, long-lasting earth tones and sky tones to help you
create a lasting impression. Saflex has the ability to
match colors of standard glass types while providing all the
functional benefits of Saflex clear laminates. The
architect can achieve varying light transmissions without having to
vary glass thickness or sacrifice structural performance.
Vanceva™ Design Studio, at
www.saflex.com/en/TechnicalLibrary.aspx?pt=ARCH, is an
interactive online tool designed to allow architects to experience
the creative possibilities of Solutia's color and design products.
Saflex is available in
many colors for small or large projects and for interior or exterior
Conventional Laminated Glass Construction
Laminated Glass Designation ("nominal" thickness)
Unit Construction Glass-
Vanceva™ Design and Vanceva™ Color are trademarks of Solutia, Inc.
laminated safety glass
safety glass for commercial, industrial and residential
applications. Glass that is heat-treated offers increased bending
strength and significantly higher compressive stress than annealed
laminated glass of the same thickness. This results in increased
resistance to impact breakage, improved ability to withstand uniform
loads and decreased chance of thermal stress breakage.
Heat-treated laminated safety glass is available as
heat-strengthened. Heat-treated glass is fabricated by heating
annealed glass to a temperature of approximately 1150 degrees F (621
degrees C), then rapidly cooling it by blowing air (quenching)
uniformly on to all glass surfaces simultaneously.
The color, clarity, chemical composition and light transmission
characteristics of the glass remain unchanged during/after the
heat-treating process. The physical properties of the glass such as
compressive strength, hardness, specific gravi ty, expansion
coefficient, softening point, and it thermal
conductivity, solar transmittance and stiffness also remain
unchanged. All fabrication such as cutting, drilling, edge grinding
and sandblasting must be completed prior to heat-treating.
Standard Silk Screened
Dot- 40% coverage:
1/8" dots staggered on 1/4" centers
1/8" lines on 1/4" centers
1/8" holes staggered 1/4"oncenters
Silk-screened decorative products allow building designers to create
different looks for exterior vision and non-vision areas
using patterns and colors. Silk-screened products help control light
transmittance, reduce solar heat gain by lowering the shading
coefficient and provide a desired level of privacy.
The silk-screened decorative products are fabricated using the same
technology as spandrel glass, except the ceramic frit is applied to
the glass using a silk-screened process. More durable than
acid-etched or sandblasted surfaces, silk-screened glass is always
heat-treated to prevent breakage and withstand thermal stress in
The ceramic frit is silk-screened onto the glass substrate in one of
three standard patterns - dots, lines, holes or a full flood
application. In addition, custom patterns can be easily duplicated
on the glass. Depending on the pattern, the glass lite can be made
transparent, translucent or opaque. With a wide range of substrate
and frit color options, the silk-screen process gives designers
exceptional creative flexibility.
Bent glass for creative design applications in architectural,
commercial and residential installations. A creative alternative for
building designers and engineers,
Bent glass is glass that is bent or curved to create unique profiles for
installations in architectural, commercial and
When using bent glass you are limited in the types of Low
| Insulating Glass
Insulating glass (IG) units enhance thermal performance and keep
interior spaces more comfortable. IG units also help minimize interior
condensation and moisture-related problems and reduce drafts near
windows to maximize usable interior living/working space.
IG units are hermetically sealed combinations of two or more lites
of glass separated by a dehydrated airspace that can be used in a
variety of applications ranging from residential to commercial
installations. South Coast Skylights Manufacture can offer IG unit options to satisfy a wide range of application requirements.
The glass of an IG unit can be fully tempered over annealed laminated or
heat-strengthened laminated on and can be of equal or unequal
By combining low-e coatings, tinted glass, reflective coatings,
silk-screened patterns with laminated glass, a wide array of
insulating glass configurations are available to meet specific
design, security, performance and code requirements.
units Tempered over Laminated
| Low-E Glass is one of the most
popular and versatile building materials used today. One reason is
because of its constantly improving solar anthermal performance. And
one way this performance is achieved is through the use of passive
and solar control low-e coatings. So, what is low-e
glass? In this section, we provide you
with an in-depth overview of coatings.
In order to understand coatings, it’s important to understand the
solar energy spectrum or energy from the sun. Ultraviolet (UV)
light, visible light and infrared (IR) light all occupy
different parts of the solar spectrum – the differences between the
three are determined by their wavelengths.
- Ultraviolet light, which is what causes
interior materials such as fabrics and wall coverings to fade,
has wavelengths of 310-380 nanometers when reporting glass
- Visible light occupies the part of the spectrum between wavelengths
from about 380-780 nanometers.
- Infrared light or heat energy, is transmitted as heat into a
building, and begins at wavelengths of 780 nanometers. Solar
infrared is commonly referred to as short-wave infrared energy, while heat radiating
off of warm objects has higher wavelengths than the sun and referred to
as long-wave infrared.
Low-e coatings have been developed to minimize the amount of ultraviolet and
infrared light that can pass through glass without compromising the
amount of visible light that is transmitted.
When heat or light
energy is absorbed by glass it is either shifted away by moving air
or reradiated by the glass surface. The ability of a material to
radiate energy is known as emissivity. In general, highly reflective
materials have a low emissivity and dull darker colored materials
have a high emissivity. All materials, including windows, radiate
heat in the form of long-wave, infrared energy depending on the
emissivity and temperature of their surfaces. Radiant energy is one
of the important ways heat transfer occurs with windows. Reducing
the emissivity of one or more of the window glass surfaces improves
a window’s insulating properties. For example,
uncoated glass has an emissivity of .84, while PPG’s solar control Solarban
70XL glass has an emissivity of .02.
This is where low emissivity or low-e glass coatings come into play.
Low-e glass has a microscopically thin, transparent coating – it is
much thinner than a human hair – that reflects long-wave infrared energy (or heat). Some
low-e’s also reflect significant amounts of short-wave solar infrared
energy. When the interior heat energy tries to escape to the colder
outside during the winter, the low-e coating reflects the heat back
to the inside, reducing the radiant heat loss through the
glass. The reverse happens during the summer time.. To use a simple
analogy, low-e glass works the same way a thermos does. A thermos
has a silver lining, which reflects the temperature of the drink it
contains back in. The temperature is maintained because of the
constant reflection that occurs, as well as the insulating benefits
that the air space provides between the inner and outer shells of
the thermos … similar to an insulating glass unit. Since low-e glass
is comprised of extremely thin layers of silver or other low
emissivity materials, the same theory applies. The silver low-e
coating reflects the interior temperatures
back inside, keeping the room warm or cold.
There are actually two different types of low-e coatings: passive
low-e coatings and solar control low-e coatings. Most passive low-e
coatings, a remanufactured using the pyrolytic process – the coating
is applied to the glass ribbon while it is being produced on the
float line, the coating then “fuses” to the hot glass surface,
creating a strong bond, or “hard-coat” that is very durable during
fabrication. Finally, the glass is cut into stock sheets of various
sizes for shipment to fabricators. Passive low-e coatings are good
for very cold climates because they allow some of the sun’s
short-wave infrared energy to pass through and help heat the building
during the winter, but still reflect the interior long-wave heat energy back
Most solar control low-e coatings, such as what are used for Solarban 70XL
solar control glass, are manufactured using the MSVD process – the coating
is applied off-line to pre-cut glass in a vacuum chamber at room
temperature. This coating, sometimes referred to as a “soft-coat,”
needs to be sealed in an IG or laminated unit and has lower emissivity and superior
solar control performance. That being said, the best performing solar
control coatings are MSVD and are ideal for mild to hot climates that are
more dominated by air conditioning use in commercial buildings.
Low-E coatings are applied to the various surfaces of insulating glass
units. In a standard double panel IG there are four potential
coating surfaces to which they can be applied: the first (#1)
surface faces outdoors, the second (#2) and third (#3) surfaces face
each other inside the insulating glass unit and are separated by an airspace and an insulating
spacer, and the fourth (#4) surface faces directly indoors.
Whether a low-e coating is considered passive or solar control, they offer
improvements in performance numbers. The following are used to measure the
effectiveness of glass with low-e coatings:
the rating given to a window based on how much heat loss it allows.
Visible Light Transmittance is
a measure of how much light passes through a window.
Solar Heat Gain Coefficient is
the fraction of incident solar radiation admitted through a window, both
directly transmitted and that is absorbed and re-radiated inward. The
lower a window's solar heat gain coefficient, the less solar heat it
Light to Solar Gain is
the ratio between the window's Solar Heat Gain Coefficient (SHGC) and
its visible light transmittance (VLT) rating.
| Here’s how the coatings measure up by
minimizing the amount of ultra-violet and infrared light that can
pass through glass without compromising the amount of visible light that is transmitted.
As a general rule, pyrolytic coatings work well in heating dominated
climates, while MSVD is a good fit for cooling dominated climates.
When thinking of windows, size, tint and other aesthetic qualities
come to mind, but low-e coatings play an important role in the
overall performance of
a window and can significantly affect the overall heating, lighting, and
cooling costs of a building.