Laboratory Glassware Terminology: User's Guide
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- Anneal: To prevent or remove objectionable stresses in glassware by controlled cooling.
- Binder (Fibrous Glass): Substances employed to bond or hold the fibers together.
- Blister: An imperfection a relatively large bubble or gaseous inclusion.
- Check: an imperfection; a surface crack in a glass article.
- Chill Mark: A wrinkled surface condition on glassware, resulting from uneven contact in the mold prior to forming.
- Chip: An imperfection due to breakage of a small fragment from an otherwise regular surface.
- Cord: An unattenuated glassy inclusion, possessing optical and other properties differing from those of the surrounding glass.
- Cullet: waste or broken glass, usually suitable as an addition to raw batch.
- Devitrification: Crystallization in glass.
- Dice: The more or less cubical fracture of tempered glass.
- Fiber: An individual filament made by attenuating molten glass. A continuous filament is a glass fiber of great or indefinite length. A staple fiber is a glass fiber or relatively short length (generally less than 44cm).
- Fusion: Joining by heating.
- Glass Ceramic: A material melted and formed as a glass, then converted largely to a crystalline form by processes of controlled devitrification.
- I.D.: Inside diameter.
- Lampworking: Forming glass articles from tubing and rod by heating in a glass flame.
- Lap: (1) An imperfection; a fold in the surface of a glass article caused by incorrect flow during forming. (2) A process used for mating ground surfaces.
- Liquidus Temperature: The maximum temperature at which equilibrium exists between molten glass and its primary crystalline phase.
- Mat (Fibrous Glass): A layer of intertwined fibers bonded with some resinous material or other adhesive.
- O.D.: Outside diameter.
- Out-of-Round: Asymmetry in round glass articles.
- Sealing: Joining by heating.
- Seed: An extremely small gaseous inclusion in glass.
- Softening Point: the temperature at which a uniform fiber, 0.5 to 1.0mm in diameter and 22.9 cm in length, elongates under its own weight at a rate of 1 mm per minute when the upper 10cm of its length is heated in a prescribed furnace at the rate of approximately 5ºC per minutes. For a glass of density near 2.5, this temperature corresponds to viscosity of 10 • 7.6 poises.
- Standard Taper: A two part number, 24/40, wtih 24 being the approximate diameter in millimeters at the large end of the taper and 40 the axial length of taper, also in millimeters.
- Stone: An imperfection; crystalline contamination in glass.
- Stria: A cord of low intensity generally of interest only in optical glass.
- Tempered Glass: Glass that has been rapidly cooled under rigorous control from near its softening point to increase its mechanical and stermal strength.
- Thermal Endurance: The relative ability of glassware to withstand thermal shock.
- Weathering: Attack of a glass surface by atmospheric elements.
- Working Range: The range of surface temperature in which glass is formed into ware in a specific process. The "upper end: refers to the temperature at which the glass is ready for working (generally corresponding to a viscosity of 10 •3 to 10 •4 poises), while the "lower end" refers to the temperature at which it is sufficiently viscous to hold its formed shape (generally corresponding to a viscosity greater than 10 •6 poises). For compartive purposes, when no specific process is considered, the working range of glass is assumed to correspond to a viscosity range from 10 •4 to 10 • 7.6 poises.
Working in a laboratory implies working with glassware. Use the following list of terms to help you understand the nature and characteristics of the glass pieces that are a part of your laboratory’s inventory and how those characteristics affect the processing and applications taking place in your lab.
Glass Terminology
Anneal (v.)
to prevent or remove objectionable stresses in glassware by controlled cooling.
Binder (Fibrous Glass) (n.)
substances employed to bond or hold the fibers together.
Blister (n.)
an imperfection, a relatively large bubble, or gaseous inclusion.
Check (n.)
an imperfection, a surface crack in a glass article.
Chill Mark (n.)
a wrinkled surface condition on glassware resulting from uneven contact in the mold prior to forming.
Chip (n.)
an imperfection due to the breakage of a small fragment from an otherwise regular surface.
Cord (n.)
an unattenuated glassy inclusion possessing optical and other properties differing from those of the surrounding glass.
Cullet (n.)
waste or broken glass, usually suitable as an addition to raw batch.
Devitrification (n.)
crystallization in glass.
Dice (n.)
the more or less cubical fracture of tempered glass.
Fiber (n.)
an individual filament made by attenuating molten glass. A continuous filament is a glass fiber of great or indefinite length. A staple fiber is a glass fiber of relatively short length (generally less than 44cm).
Fuse (v.)
to join by heating.
Glass Ceramic (n.)
a material melted and formed as glass, then converted largely to a crystalline form by processes of controlled devitrification.
I.D. (n.)
inside diameter.
Dice (n.)
forming glass articles from tubing and rod by heating in a glass flame.
Lampworking (n.)
an imperfection, a fold in the surface of a glass article caused by incorrect flow during forming; (2) a process used for mating ground surfaces.
Lap (n.)
the maximum temperature at which equilibrium exists between molten glass and its primary crystalline phase.
Liquidus Temperature (n.)
the maximum temperature at which equilibrium exists between molten glass and its primary crystalline phase.
Mat (Fibrous Glass) (n.)
a layer of intertwined fibers bonded with some resinous material or other adhesive.
O.D. (n.)
outside diameter.
Out-of-Round (adj.)
asymmetry in round glass articles.
Sealing
to close/join by heating.
Seed (n.)
an extremely small gaseous inclusion in glass.
Softening Point (n.)
the temperature at which a uniform fiber, 0.5 to 1.0mm in diameter and 22.9 cm in length, elongates under its own weight at a rate of 1 mm per minute when the upper 10cm of its length is heated in a prescribed furnace at the rate of approximately 5ºC per minutes. For a glass of density near 2.5, this temperature corresponds to viscosity of 10 • 7.6 poises.
Standard Taper (n.)
a two-part number, 24/40, with 24 being the approximate diameter in millimeters at the large end of the taper and 40 the axial length of the taper, also in millimeters.
Stone (n.)
an imperfection; crystalline contamination in glass.
Stria (n.)
a cord of low intensity generally of interest only in optical glass.
Tempered Glass (n.)
glass that has been rapidly cooled under rigorous control from near its softening point to increase its mechanical and thermal strength.
Thermal Endurance (n.)
the relative ability of glassware to withstand thermal shock.
Weathering (v.)
degrading of a glass surface by atmospheric elements.
Working Range (n.)
the range of surface temperature in which glass is formed into ware in a specific process. The "upper end: refers to the temperature at which the glass is ready for working (generally corresponding to a viscosity of 10 •3 to 10 •4 poises), while the "lower end" refers to the temperature at which it is sufficiently viscous to hold its formed shape (generally corresponding to a viscosity greater than 10 •6 poises).
For comparative purposes, when no specific process is considered, the working range of glass is assumed to correspond to a viscosity range from 10 •4 to 10 • 7.6 poises.
Please note n. = noun; v. = verb; adj. = adjective.