What Is A Laminated Glass? Is Toughened Glass Or Laminated Glass Better?
What Is A Laminated Glass?
Laminated glass (LG) is a type of safety glass that contains a thin polymer interlayer between multiple layers of glass, which holds the glass together when shattered. This interlayer is typically made of materials such as PVB, EVA, TPU etc.
When the glass breaks it forms a “spider web” cracking pattern and is held in place by the interlayer preventing it from breaking into large, sharp pieces. Laminated glass is commonly used in architecture, automobiles, UV protection, and for increased sound insulation.
It is also frequently used in areas requiring hurricane-resistant construction for exterior storefronts, curtain walls and windows.
History Of Laminated Glass
In 1902, the French Le Carbone corporation patented a method for coating glass objects with celluloid to make them more resistant to cracking or breaking. In 1903, French chemist Édouard Bénédictus was inspired by a laboratory accident involving a coated glass flask to invent laminated glass.
He filed a patent for the invention in 1909 after learning of a car accident where two women were injured by glass debris.
In 1911, he formed the Société du Verre Triplex to produce a glass-plastic composite to reduce injuries in car accidents, but it was expensive and not widely adopted by car manufacturers at the time.
In 1912, the process was licensed to the English Triplex Safety Glass Company, and later to companies in the United States.
In 1905, John Crewe Wood in England patented a laminated glass using Canada balsam to bond the layers of glass, and founded the Safety Motor Screen Company to produce and sell it.
In 1927, Canadian chemists Howard W. Matheson and Frederick W. Skirrow invented the plastic polyvinyl butyral (PVB), which was discovered by U.S. companies to not discolor and be more resistant to penetration during accidents.
By 1939, “Indestructo” safety glass made from PVB was being used in vehicles produced by the Ford Motor Company in Dagenham, England.
Benefits Of Laminated Glass
Laminated glass, due to its robust nature and thickness, offers a variety of benefits including increased security, reduced emissions, reduced noise pollution, increased safety, protection from natural disasters, and more design options.
Its strength makes it difficult to break and interlayers hold the structure together in case of breakage. Low-emissivity glass can reduce heat gain and emissions.
Its thickness disrupts noise waves and reduces pollution. It does not shatter when broken, reducing the risk of injury.
It also remains in its frame during natural disasters and is available in various colors, tints, and can be curved for design versatility.
Specifications Of Laminated Glass
Laminated glass is typically made up of two layers of 2.5 mm glass with a 0.38 mm interlayer in between, resulting in a final thickness of 5.38 mm. Increasing the number of layers and using thicker glass can increase its strength.
Bullet-resistant glass is a type of laminated glass that uses materials such as polycarbonate, thermoplastic, and EVA to increase its strength. Automotive laminated glass is typically 6.5 mm thick, while airplane glass is much thicker at around 18 mm.
In airplanes, the front and side cockpit windows often have three layers of 4 mm toughened glass with 2.6 mm PVB interlayers. The Concorde’s windshield had 7 layers, 4 glass and 3 PVB, with a total thickness of 38 mm.
To increase sound attenuation in extreme environments, a combination of glass thicknesses such as 3 mm, 4 mm, 5 mm, and 6 mm may be used in laminated glass.
Types Of Laminated Glass
Laminated glass is a type of safety glass composed of two or more layers of glass bonded together with a special plastic interlayer. The most common types are PVB (Polyvinyl Butyral), SGP (SentryGlas Plus) and EVA (Ethylene Vinyl Acetate).
Depending on the application and purpose, there are several types of laminated glass available ranging from bulletproof to acoustic laminated glasses.
Whether it’s for protection against forced entry, wind-borne debris, UV radiation or sound insulation, laminated glass will provide the desired level of security required for the utmost safety.
Producing Laminated Glass
Laminated glass is made by sandwiching a plastic interlayer, such as polyvinyl butyral (PVB), thermoplastic polyurethane (TPU), or ethylene-vinyl acetate (EVA), between two or more layers of ordinary glass.
The interlayer improves the mechanical properties of the glass, such as impact strength and fracture toughness. The assembly is heated under pressure in an autoclave to create a fully bonded product. Tinted or colored interlayers can also be added to the laminated glass.
This process is used in architectural, interior design, and signage industries, as well as for making bulletproof and penetration-proof glass.
What Is A Toughened Laminated Glass
Toughened laminated glass is a combination of two pieces of toughened/tempered glass bonded together with a special interlayer. The layer gives the glass increased strength and safety, while also reducing noise pollution.
It can also be used to give extra insulation properties, as well as providing an aesthetically pleasing design due to its translucent nature.
Toughened laminated glass is ideal for applications such as window glazing, partitions or balustrades where longevity and safety are essential requirements.
Is Toughened Glass Or Laminated Glass Better?
Toughened glass is an ideal option when safety and strength are paramount, as it is five times stronger than annealed and laminated glass of the same size and thickness.
It is created through a process known as tempering which is where the glass is strengthened using heat and then cooled rapidly to increase its tensile strength making it far more durable than traditional glass.
Compared to laminated glass, toughened has superior break resistance and does not require additional framing for structural support. This makes it a good option for places where security or impact resistance needs to be high such as public transportation or display windows.
However, compared to laminated, toughened glass can be prone to shattering if hit by an object with sufficient force and there are times when a combination of both types of glazing may be necessary depending on the application.
Toughened glass is a far superior choice to laminated glass due to its increased strength, safety features and ease of installation. It is made by heating annealed glass in a furnace to around 650-700 degrees Celsius which causes the surface of the glass to compress and creates tension on the inside.
This increases strength and makes it five times more resistant to breakage than plain annealed or laminated glass of the same size and thickness. Additionally, when broken, toughened glass breaks into small pieces with blunt edges that are relatively less likely to cause serious injury.
It is also easier for installers as it comes pre-cut and does not require any additional bonding making it quicker, simpler and cheaper process overall.
What is Acoustic Laminated Glass?
Acoustic glass is a specially designed laminated glass that reduces the amount of sound intrusion. It consists of two panes of glass with resin-based plastic, polyvinyl butyral (PVB) sandwiched between them which helps in increasing their strength and sound proofing ability.
The acoustic glass has been designed to reduce noise from outside sources such as traffic and other industrial noises, making it an ideal solution for residences or commercial buildings situated close to noisy areas.
It is also used in conference rooms and recording studios for soundproofing purposes and provides great insulation against exterior noise pollution.
