Glassary - A

AA
see reaction to fire

Absorptance
the proportion of incident solar radiation absorbed by the glass, expressed as a fraction (see solar properties).

Absorption
an alternative word for absorptance, expressed as a percentage.

Acid etching
a process whereby the polished surface of glass is etched by exposure to hydrofluoric acid to produce patterns, designs or obscuration – see Information on Pilkington Acid Etched Decorative Glass for Decoration Brochure and Product Data Sheet on Pilkington Oriel™ Collection.

Acoustic laminate
a laminated glass with special interlayers with better acoustic performance than ordinary laminated glass. See Product Data sheet on Pilkington Acoustic Laminate and Technical Bulletin Glass and Noise Control.

Acoustic performance
simply how much noise does a product stop. It is the properties of a glass or glazing product which describe its airborne sound insulation, as measured by the reduction or attenuation of sound, at specific pitches or frequencies, in decibels (dB), or by sound reduction indexes, such as the mean sound reduction index (Rm), the weighted sound reduction index (Rw) or the road traffic sound reduction index (R TRA).

Activ™
Pilkington Activ™ is the brand name for the world’s first self-cleaning glass. Its unique dual action uses the forces of nature to help keep the glass free from organic dirt, giving you not only the practical benefit of less cleaning, but also
clearer, better-looking windows.


A Frame
a rack or stillage that is A shaped in profile.

Air Mass 1
a particular definition of the solar spectrum. See also relative spectral distribution.

Air Mass 1.5
a particular definition of the solar spectrum. See also relative spectral distribution.

Air Mass 2
a particular definition of the solar spectrum. See also relative spectral distribution.

Airborne sound insulation
the correct term for the type of sound insulation given by glass. See also acoustic performance. See Technical Bulletin Glass and Noise Control.

Air Gap
an alternative term for cavity in an insulating glass unit. See also Product Data Sheet on Pilkington Insulight™.


Airspace
an alternative term for the cavity in an insulating glass unit. See also Product Data Sheet on Pilkington Insulight™.

Annealed glass
another term for "ordinary" glass, most commonly used for float glass but Pilkington Texture Glass™ and Pilkington Pyroshield™ are also annealed glass. Glass that immediately after it has solidified into the required form, while still at a high temperature, is slowly cooled in order to minimise the internal stresses in the glass. The resulting glass can be cut by scoring and snapping and worked. It is, in fact "ordinary" glass as taken from the production line and stored in stock plates. Annealed glass, when broken, gives large fragments with sharp edges and so is not usually classifiable as a safety glass.

Anti-bandit glazing
a form of security glazing resistant to manual attack. See Product Data Sheet Pilkington Security Glass and Technical Bulletin Glass and Security.

Antisun ™
An old brand name for Pilkington Optifloat™ Tinted, our tinted float range of solar control glass.

Applied Bevel
a bevelled piece of glass that is stuck on to another piece of glass or insulating glass unit with a UV curing resin.

Applied Film
an organic (plastic) film stuck onto glass to give it additional properties, e.g. safety film. See Technical Bulletin Glass and Safety.

Applied Leading
strips of lead adhered to both surfaces of a pane of glass to give the appearance of a leaded light. See also Product Data sheet Pilkington Leaded Decorative Glass.

Arctic™
Arctic™ is a design of one of the glasses in the Pilkington Texture Glass range (see customer leaflet The Pilkington Texture Glass Range) of patterned glass.  Arctic™ has an obscuration level of 4.

Arctic Blue™


Armed attack

an attack using firearms. See Technical Bulletin Glass and Security.

Armourclad™
Pilkington Armourclad™ was an old brand name used for spandrel panels. We now refer to these products as Pilkington Sprandrel Glass (see Product Data Sheet).

Armourfloat™
an old brand name used for Pilkington Toughened Safety Glass (See Product Data Sheet) see also toughened glass.

Armourlight™
an old brand name for Pilkington Heat Strengthened Glass. See heat strengthened glass and Technical Bulletin Glass and Safety.

Armourplate™
an old brand name used for Pilkington Toughened Safety Glass (see Product Data Sheet) see also toughened glass.

Armourscreen™
an old brand name for Pilkington Design Glass (see Product Data Sheet). See also screen printed glass.

Arrissed edge
an edge finish to the glass where the sharp corners of the edge have been removed.

Arrissing
a process of edge finishing where the sharp edges of a piece of glass are removed.

Aspect ratio
the ratio of the long edge of a pane to the short edge.

Attenuation
the reduction of either sound (see acoustic performance) or electromagnetic radiation (see electromagnetic shielding).

Audioscreen™
Pilkington Audioscreen™ was an old brand name for Pilkington Acoustic Laminate (see Product Data Sheet) see acoustic laminate.

Autoclave
a large pressure vessel that Polyvinylbutyral PVB laminated glass is heated in, to bond the layers of glass and PVB together.

Autumn™
Pilkington Autumn™ is the brand name for one of the Pilkington Texture Glass™ range (see consumer leaflet Pilkington Texture Glass™) of patterned glass. Pilkington Autumn™ has an obscuration level of 3.