Heat Treated Glass
At PFG Glass, we understand that architectural and commercial projects demand glass products that deliver exceptional strength without compromising safety or aesthetic quality. Our heat-treated glass manufacturing capabilities combine precision engineering with decades of expertise to produce glass solutions that meet the most demanding specifications across Western Canada and beyond.
Advanced Manufacturing for Superior Results
Our automated heat-treating system represents a significant investment in quality and consistency. By minimizing manual handling throughout the process, we reduce the risk of surface damage and ensure each panel meets our exacting standards. The system incorporates an automated gantry, automatic laser logos, automatic seamers, and automated batching, all designed to deliver lean manufacturing efficiency while maintaining the highest quality output.
Our state-of-the-art washer uses treated water to ensure pristine surfaces before thermal processing begins. Two Mappi convection tempering furnaces provide the flexibility to handle glass ranging from 3mm to 19mm in thickness, with capabilities extending from minimum dimensions of 8″ x 10″ to maximum sizes reaching 98″ x 198″. This range allows us to serve everything from custom residential installations to large-scale commercial projects requiring oversized panels.
Quality verification happens in real time through our Osprey Distortion Measurement System, which measures optical distortion in flat glass during production. This technology allows us to maintain superior optical clarity across our product range, ensuring that architectural vision remains uncompromised by manufacturing processes.
All of our heat-treated glass products carry SGCC (Safety Glazing Certification Council) certification, providing architects, contractors, and building professionals with confidence that our products meet rigorous safety standards for specified applications.
Understanding Heat Treatment Technology
Heat treatment transforms standard annealed glass through controlled thermal processing, creating products with dramatically enhanced performance characteristics. The process begins after all fabrication work has been completed on the annealed glass. Cutting, drilling, edge finishing, and any surface treatments must happen before thermal processing because heat-treated glass cannot be modified afterward without causing immediate failure.
During heat treatment, glass panels enter our furnaces where they are uniformly heated to approximately 1,150°F to 1,200°F. The duration and precise temperature depend on glass thickness, colour, and the desired final properties. Once the glass reaches optimal temperature throughout its entire cross-section, it moves immediately into the quench zone.
In the quench zone, high-pressure air streams rapidly cool both glass surfaces simultaneously. This accelerated cooling creates distinct stress zones within the glass structure. The outer surfaces develop significant compression stress, while the core maintains compensating tension stress. This internal stress distribution is what gives heat-treated glass its enhanced strength and unique safety characteristics.
Two Distinct Products for Different Requirements
Fully Tempered Glass
Fully tempered glass undergoes the complete quenching cycle, producing maximum stress differentiation within the glass structure. The result is a product approximately four times stronger than annealed glass of equivalent thickness. This exceptional strength makes tempered glass ideal for applications where mechanical impact resistance is essential.
The most distinctive characteristic of fully tempered glass appears during breakage. Rather than fracturing into large, dangerous shards like annealed glass, tempered glass breaks into small, relatively harmless cube-shaped pieces. This safety performance has made fully tempered glass the specified choice for applications where building codes mandate safety glazing.
Heat-Strengthened Glass
Heat-strengthened glass represents a middle ground between annealed and fully tempered glass. The modified quenching process produces lower internal stress levels than full tempering, resulting in glass that is approximately twice as strong as annealed glass. While this does not qualify heat-strengthened glass as safety glazing under building codes, it offers distinct advantages for specific applications.
The breakage pattern of heat-strengthened glass falls between that of annealed and fully tempered glass. Fragments are larger than tempered glass particles but smaller than annealed glass shards. More importantly, heat-strengthened glass is far less prone to spontaneous breakage and offers superior resistance to thermal stress and edge damage compared to annealed glass.
Compliance and Performance Standards
Our heat-treated glass products meet rigorous industry standards that specify performance requirements, testing methods, and safety criteria. ASTM C1048 provides the primary specification framework for heat-treated flat glass, covering both heat-strengthened and fully tempered varieties. ANSI Z97.1 defines safety glazing material performance specifications, while CPSC 16 CFR 1201 establishes federal safety standards for architectural glazing materials.
For projects requiring Canadian compliance, our products meet CAN/CGSB 12.1 standards for tempered and laminated safety glass. Engineers specifying glass for structural applications reference ASTM E1300 for determining load resistance, and we work closely with design teams to ensure our products meet calculated requirements for specific installations.
Our SGCC certification provides independent verification that our heat-treated glass products consistently meet safety performance standards, giving architects and contractors confidence in specifying our products for code-compliant installations.
Frequently Asked Questions About Heat-Treated Glass Products
What is Heat-Treated Glass?
Heat-treated glass is annealed glass that has undergone a thermal tempering process to increase its durability, enhance resistance to mechanical stresses, and improve safety through specific breakage characteristics. After cutting the annealed glass panel to required dimensions and completing all fabrication work, each panel is transferred to a furnace where it is heated to high temperature and then cooled by blowing air onto both sides simultaneously. The cooling rate determines whether the glass becomes heat-strengthened or fully tempered.
Where is Heat-Treated Glass Used?
Heat-treated glass serves applications requiring enhanced durability and safety. Fully tempered glass qualifies for safety glazing applications including sliding glass doors, shower enclosures, all-glass entrance systems, railings, and partitions. Heat-strengthened glass is specified for large architectural installations where superior thermal stability and reduced distortion are priorities. Curtain wall systems benefit from heat-strengthened glass, as do skylights when combined with lamination for safety.
How Can You Tell if Glass Has Been Heat-Treated?
Heat-treated glass displays certain characteristics that distinguish it from annealed glass. Some degree of bow or warp occurs during the thermal process. This is an inherent result of heating glass to near its softening point and rapidly cooling it. While our high-quality equipment and controlled processes minimize distortion, architects and installers should understand that heat-treated glass will not be as perfectly flat as annealed glass.
Strain patterns, sometimes called quench marks, may appear under certain lighting conditions as geometric patterns of iridescence or subtle shadowing. These patterns result from the stress distribution that gives heat-treated glass its strength characteristics. Industry standards recognize strain patterns as normal and inherent to heat-treated glass, not as defects affecting performance or structural integrity.
What are the Benefits of Heat-Treated Glass?
Heat-treated glass offers significantly enhanced strength and durability compared to annealed glass. Heat-strengthened glass is twice as strong as annealed glass, while fully tempered glass is four times as strong. Fully tempered glass features a distinctive safety breakage pattern. Instead of breaking into large, sharp shards, it fractures into small cube-shaped pieces that are far less likely to cause injury. This safety performance is why building codes specify fully tempered glass for applications where human contact with glass is likely. Heat-treated glass also provides superior resistance to thermal stress, making it suitable for applications exposed to temperature fluctuations.
Architects Area
Find out why architects and designers continue to trust PFG Glass for their glass product needs.