Glass fabrication is a broad and complex industry that relies on expert skill and precision. In so many ways it is an industry that is filled with mystery and for good reason. Because often its products and properties are invisible to us. Glass is most beautiful when it forms shimmering lines and natural walls of light that allow expanses of the outside in while controlling our environment. But there is so much more to this amazing substance.
Many Common Items You Use Every Day Rely On Glass Fabrication
In fact, look around you. Chances are several products in your vicinity now rely on glass components to function properly. These items could include security cameras, heat and fire detection, gas detection, smartphones, binoculars, labware, microwaves, and ovens. Can you think of other common items that you use every day? How about the insulated cabin on an airplane, automobiles, computers, watches, night vision, x-ray, lasers, kitchen tools, medical applications, and fiber optics?
Therein deepens the mystery of glass. Since many people do not understand the unique properties of glass, it is enough to know that glass is an excellent insulator and was originally an important part of the telegraph and electrical industry. This is why, so often today, glass components are still hard at work inside our technology. If you are lucky enough to find some of these old glass components, such as glass insulators from old telephone poles or glass floats from old fishing nets, be sure to hold onto them. They could become collector items!
Understanding Why the Unique Properties of Glass Make it Work So Well
Different types of glass possess different qualities depending upon their chemical makeup and how they have been produced. Choosing the right type of glass for a particular application also means understanding the different physical properties each different type of glass possesses.
There are five main properties of glass to be considered:
- Thermal Properties: plasticity but no defined melting point, thermal conductor.
- Optical Properties: reflects, bends, transmits and absorbs light.
- Chemical Properties: corrosion resistance and inertness.
- Electrical Properties: efficient electrical insulator.
- Mechanical Properties: hard, elastic surface that is scratch and abrasion-resistant.
Glass Fabrication Based on Thermal Properties
Glass is measured by a variety of factors that greatly affect your choice of glass. For example, the Coefficient of Thermal Expansion (CTE) is the expansion measurement of glass as the temperature is raised. This is an important factor to consider when making glass-to-glass and glass-to-metal seals since each type of glass and metal has different CTE and sealing materials with a big difference in CTE will cause the glass to break.
Thermal conductivity is the ability to conduct heat through the glass or away from the heat or light source. This is important when considering glass as a viewport exposed to high temperatures or for high infrared applications. Each type of glass has a maximum operating temperature and thermal shock rating. These guide the choice of glass. It depends on the amount of heat you expose the glass to and how it cools after a rapid change in temperature.
Heat strengthening, heat tempering, or chemically strengthening alter glass to change these thermal properties.
Optical Properties for Consideration in Glass Fabrication
There are several important measurements that determine the amount of light that passes through glass. The refractive index determines how much a light wave bends when entering or leaving the surface of the glass. This is important in producing certain optical devices or effects. The dispersion measures the separation of light into component colors, similar to a prism dispersing white light into the color band or rainbow effect. Transmission measures the amount of light passing through glass material, and its opposite is reflectivity which measures the return of light from the surface. The absorption property is the amount of light energy converted to heat within the glass. This energy is not transmitted or reflected. Tinted materials absorb more light than clear materials.
Using the Chemical Properties of Glass
All soda-lime type glasses and some borosilicate glasses contain sodium or alkali metal ions. As a result of their composition, prolonged exposure to liquids or vapor, such as water, cause the sodium or alkali ions to migrate to the surface of the glass. This is sodium or alkali leaching and causes cloudiness or haze on the surface of the glass. Porous coatings may also incur this sensation due to a disruption of the bond between the coating and glass surface. This is an important consideration with high humidity or critical surface applications. A barrier coating such as silicon dioxide will help limit the amount of reaction.
Conductivity and other Electrical Properties of Glass
When choosing glass for electrical or electronic applications, there are several characteristics to consider. The volume resistivity is the resistance in ohms between opposite faces of a centimeter cube of the test glass. This is important when the glass is an electrical insulator, such as with x-ray components used as insulators in food, luggage and other types of inspection.
The dielectric constant of glass is the ratio of energy in a condenser with the glass as the dielectric. Simply put, this measures the ability of a glass to store electrical energy and varies with the frequency of the voltage applied to the condenser. This is important when the glass is a substrate for electrical or electronic devices.
Surface resistivity is the ratio of the potential gradient parallel to the current along its surface, to the current per unit width of the surface. This method measures the conductivity of coated glass.
Mechanical Properties Determine the Strength for Glass Fabrication
The mechanical properties of glass determine the amount of stress glass can withstand. Stress is the perpendicular force per unit area on an object. This pressure is defined as the way that compresses (compressive stress) or stretches (tensile stress) the object.
Strength is the ability of glass to withstand these stresses. Non-strengthened glass materials have relatively low tensile strength yet high compressive strength. Therefore, most glass breakage is due to tensile stress failure.
Mechanical properties are measured in a variety of ways: Modulus of Rupture (MOR) test measures the bending or flexural strength; shear modulus measures the amount of shearing or twisting forces a glass can withstand; Knoop Hardness Number (KHN) measures the hardness of glass; density is the mass value per unit of volume-specific gravity is the ratio of the density of the glass to the density of water.
Glass Fabrication and Sustainability
Few materials are more desirable than glass from a sustainability standpoint. This fully recyclable material provides many environmental benefits. It mitigates climate change and saves precious natural resources. It is also valuable in many applications for its inert nature and it contributes to safeguarding people’s health and well-being. In many of its applications, glass helps save energy. For example, it lightens the weight of vehicles through the use of glass fibers in automotive, aviation, and other transport modes to reduce fuel consumption. It also helps generate renewable energy through solar-thermal and photovoltaic applications as well as wind turbines.
Since glass is a fully recyclable material, it saves significant amounts of raw materials and natural resources. Glass recycling also helps in saving energy as cullets melt at a lower temperature than raw materials. Consequently, less energy is required for the melting process.
Also, since glass is inert, it preserves taste and vitamins so it is healthier for humans and animals. It is also common in the pharmaceutical industry to preserve the properties of medicines. And we all recognize the benefits of natural light in our buildings to enhance living and working conditions.
The Future of Glass Fabrication
Glass fabrication is unlimited in possibilities. And the number of applications evolves constantly, especially used in combination with other materials for high-tech applications such as the work we do at Precision Electronic Glass. The achievements with glass are extensive. Because of this incredible material, we continue to progress in space exploration, medical research, optics, and networking.
Other areas of research and development for the future of glass include special coatings for buildings that are photosensitive and electrochromic glazing. Researchers are also working on glass with anti-reflective technologies for clean energy generation. Work is also underway to come up with glass that is up to 50 times the current strength, allowing it to be ultrathin and therefore ultralight. This will open up many opportunities for using glass that don’t exist today due to breakage.
Another research project currently underway is the functional integration in glass that can then become an ideal substrate for OLED lighting, touch screens, audiovisual displays, and more. Finally, new glass will also be bendable, more scratch-resistant, capable of transmitting audio, thinner, and with many more features. More research on the structure of glass surface, chemical reactions, and how these interact with molecules to further increase glass properties will help achieve these goals.
Imagining Future Glass Products
The outcome of research in all different fields could open up tremendous opportunities for the development of future glass products and the way we currently use glass in various applications. Just imagine:
- Color-changing smart glass bottles and containers to indicate temperature or chemical compounds.
- Interactive drinking glass linked to your smartwatch or phone to assess contents before you drink them.
- Photovoltaic sunroof to provide electricity to hybrid and electric vehicles.
- LED light and energy sources for jewelry and clothing to provide music, warmth, color, etc.
- Mirrors that assess your health condition when you stand in front of them.
- More complex glass shapes and improved insulation properties free architects from constraints.
- Better alternative energy equipment.
- Walls that synthesize the outdoor environment of your choice allow better utilization of urban areas that might not be attractive as a living or working space.
About PEG
PEG’s mission is to provide customized glass and quartz products and related services to OEMs and distributors. We work globally in all countries where our customers operate. Our objective is to fabricate the finest precision glass and quartz components and assemblies to customers’ specifications. Working together with customers, PEG manufactures prototypes; handles small to large production runs; performs value-added assembly, and provides cleanroom processing when specifications dictate the need for it.
Utilizing standard or computer-controlled glass lathe fabrication; glass-to-glass and glass-to-metal graded seals; cutting and end finishing; and precision grinding/polishing. PEG produces components and value-added assemblies, including medical, dental, or industrial glass X-ray tubes, CO2 or HeNe lasers. We produce all glass and quartz fabrications in facilities certified to ISO 9001:2015 standards of quality. Our commitment to quality and integrity in everything we do is reflected in our mission statement, corporate values, and quality policy.