Borosilicate glass
Borosilicate glass is sold under various trade names, including Borosil, Duran, Pyrex, Glassco, Supertek, Suprax, Simax, Bellco, Marinex (Brazil), BSA 60, BSC 51 (by NIPRO), Heatex, Endural, Schott, Refmex, Kimax, Gemstone Well, United Scientific, and MG (India).
Most common today is borosilicate 3.3 or 5.0x glass such as Duran, Corning33, Corning51-V (clear), Corning51-L (amber), International Cookware's NIPRO BSA 60, and BSC 51.
Borosilicate glass is created by combining and melting boric oxide, silica sand, soda ash,[6] and alumina.
In addition to quartz, sodium carbonate, and aluminium oxide traditionally used in glassmaking, boron is used in the manufacture of borosilicate glass.
The manufacturing process depends on the product geometry and can be differentiated between different methods like floating, tube drawing, or molding.
This reduces material stresses caused by temperature gradients, which makes borosilicate a more suitable type of glass for certain applications (see below).
Among the characteristic properties of this glass family are: The softening point (temperature at which viscosity is approximately 107.6 poise) of type 7740 Pyrex is 820 °C (1,510 °F).
For the purposes of classification, borosilicate glass can be roughly arranged in the following groups, according to their oxide composition (in mass fractions).
High-grade borosilicate flat glasses are used in a wide variety of industries, mainly for technical applications that require either good thermal resistance, excellent chemical durability, or high light transmission in combination with a pristine surface quality.
Sealability to metals in the expansion range of tungsten and molybdenum and high electrical insulation are their most important features.
Fused quartz is also found in some laboratory equipment when its higher melting point and transmission of UV are required (e.g. for tube furnace liners and UV cuvettes), but the cost and manufacturing difficulties associated with fused quartz make it an impractical investment for the majority of laboratory equipment.
Additionally, borosilicate tubing is used as the feedstock for the production of parenteral drug packaging, such as vials and pre-filled syringes, as well as ampoules and dental cartridges.
This type of glass is typically referred to as USP / EP JP Type I. Borosilicate is widely used in implantable medical devices such as prosthetic eyes, artificial hip joints, bone cements, dental composite materials (white fillings)[13] and even in breast implants.
[14] During the mid-20th century, borosilicate glass tubing was used to pipe coolants (often distilled water) through high-power vacuum-tube–based electronic equipment, such as commercial broadcast transmitters.
Items made of borosilicate glass can be thin yet durable, or thicker for extra strength, and are microwave- and dishwasher-safe.
[citation needed] Organic light-emitting diodes (OLED) (for display and lighting purposes) also use borosilicate glass (BK7).
[citation needed] Borosilicate is also a material of choice for evacuated-tube solar thermal technology because of its high strength and heat resistance.
[citation needed] Borosilicate glass is offered in slightly different compositions under different trade names: It was initially thought that borosilicate glass could not be formed into nanoparticles, since an unstable boron oxide precursor would prevent successful forming of these shapes.
However, in 2008 a team of researchers from the Swiss Federal Institute of Technology at Lausanne were successful in forming borosilicate nanoparticles of 100 to 500 nanometers in diameter.
[22] Borosilicate (or "boro", as it is often called) is used extensively in the glassblowing process lampworking; the glassworker uses a burner torch to melt and form glass, using a variety of metal and graphite tools to shape it.
Lampworking is also done as art, and common items made include goblets, paper weights, pipes, pendants, compositions and figurines.
In 1968, English metallurgist John Burton brought his hobby of hand-mixing metallic oxides into borosilicate glass to Los Angeles.
A few of the students in the classes, including Suellen Fowler, discovered that a specific combination of oxides made a glass that would shift from amber to purples and blues, depending on the heat and flame atmosphere.
He then founded Northstar Glassworks in the mid-1980s, the first factory devoted solely to producing colored borosilicate glass rods and tubes for use by artists in the flame.
The metals used to color borosilicate glass, particularly silver, often create strikingly beautiful and unpredictable results when melted in an oxygen-gas torch flame.
Because it is more shock-resistant and stronger than soft glass, borosilicate is particularly suited for pipe making, as well as sculpting figures and creating large beads.
