ASTM C912-17
(Practice)Standard Practice for Designing a Process for Cleaning Technical Glasses
Standard Practice for Designing a Process for Cleaning Technical Glasses
SIGNIFICANCE AND USE
3.1 Many of the low-silica technical glasses which contain soluble or reactive oxides require processing or involve applications that require cleaning. Very often these cleaning procedures have evolved over several decades and are considered an art. They usually contain numerous steps, some of questionable validity. It is the premise of this practice that cleaning glass can be more scientific. Design of a cleaning procedure should involve (1) a definition of the soil to be removed, (2) an awareness of the constraints imposed by the glass composition, and (3) a rational selection of alternative methods that will remove the soil and leave the glass in a condition suitable for its intended application. This practice provides information to assist in step (3). General references on glass cleaning and on various methods of evaluating cleanliness and associated information has been published.2
SCOPE
1.1 This practice covers information that will permit design of a rational cleaning procedure that can be used with a glass that is somewhat soluble in many aqueous chemical solutions. Typically, this type of glass is used in applications such as optical ware, glass-to-metal seals, low dielectric loss products, glass fibers, infrared transmitting products, and products resistant to metallic vapors.
1.2 In most cases, this type of glass contains high concentrations of oxides that tend to react with a number of aqueous chemicals. Such oxides include B2O3, Al2O3, R2O, RO, La2O3, ZnO, PbO, P2O5, and Fe2O3. The more conventional high-silica glasses are usually more chemically resistant, but the cleaning principles outlined here also apply to them.
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. Specific hazard statements are given in Section 4 and Table 1. (A) s = relatively soluble, i = relatively insoluble.(B) hot
1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
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Designation: C912 − 17
Standard Practice for
1
Designing a Process for Cleaning Technical Glasses
This standard is issued under the fixed designation C912; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope dures have evolved over several decades and are considered an
art.Theyusuallycontainnumeroussteps,someofquestionable
1.1 This practice covers information that will permit design
validity.Itisthepremiseofthispracticethatcleaningglasscan
of a rational cleaning procedure that can be used with a glass
be more scientific. Design of a cleaning procedure should
that is somewhat soluble in many aqueous chemical solutions.
involve (1) a definition of the soil to be removed, (2)an
Typically, this type of glass is used in applications such as
awareness of the constraints imposed by the glass composition,
optical ware, glass-to-metal seals, low dielectric loss products,
and (3) a rational selection of alternative methods that will
glass fibers, infrared transmitting products, and products resis-
remove the soil and leave the glass in a condition suitable for
tant to metallic vapors.
its intended application. This practice provides information to
1.2 In most cases, this type of glass contains high concen-
assist in step (3). General references on glass cleaning and on
trations of oxides that tend to react with a number of aqueous
various methods of evaluating cleanliness and associated
2
chemicals. Such oxides include B O ,Al O ,R O, RO, La O ,
2 3 2 3 2 2 3
information has been published.
ZnO, PbO, P O , and Fe O . The more conventional high-
2 5 2 3
silica glasses are usually more chemically resistant, but the 4. Hazards
cleaning principles outlined here also apply to them.
4.1 Manyofthechemicalsthatcanbeusedincleaningglass
1.3 This standard does not purport to address all of the
are hazardous. This is true of most of the aqueous chemicals
safety concerns, if any, associated with its use. It is the
discussed in Section 5 and shown in Table 1 as well as the
responsibility of the user of this standard to establish appro-
organic chemicals discussed in Section 6.
priate safety, health, and environmental practices and deter-
4.2 Specialcareshouldbeusedwithhydrofluoricacid(HF),
mine the applicability of regulatory limitations prior to use.
which will react with glass generating heat. HF destroys
Specific hazard statements are given in Section 4 and Table 1.
dermal tissue and exposure of the skin to the liquid or
1.4 This international standard was developed in accor-
inhalation of the vapors can be fatal.
dance with internationally recognized principles on standard-
4.3 Concentrated acids can react violently if water is added
ization established in the Decision on Principles for the
into them. When it is necessary to dilute acid, add the acid to
Development of International Standards, Guides and Recom-
the water slowly and with constant stirring so that heat is never
mendations issued by the World Trade Organization Technical
allowed to concentrate locally in the solution.
Barriers to Trade (TBT) Committee.
4.4 Organic solvents may be flammable or toxic, or both.
2. Terminology
Thresholdlimitvaluesforsomecommonsolventsareshownin
2.1 Definitions of Terms Specific to This Standard:
Table 2. Note that the fluorocarbons are most likely to exhibit
2.1.1 technical glass, n—glasses designed with some spe-
toxic effects as a result of inhalation or skin absorption.
cificpropertyessentialforamechanical,industrial,orscientific
Benzene is not recommended as a solvent since it is a known
device.
carcinogen.
3. Significance and Use
5. Aqueous Solvents
3.1 Many of the low-silica technical glasses which contain
5.1 Selection—In using aqueous solvents for cleaning, gen-
soluble or reactive oxides require processing or involve appli-
erally two extreme choices are available. One is to select an
cations that require cleaning. Very often these cleaning proce-
aqueous system that dissolves the soil to be removed, but has
little effect on the glass. The other is to select a system that
dissolves the glass uniformly, thus undercutting the soil and
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This practice is under the jurisdiction of ASTM Committee C14 on Glass and
GlassProductsandisthedirectresponsibilityofSubcommitteeC14.02onChemical leaving a chemically polished glass surface. It is best to avoid
Properties and Analysis.
Current edition approved Nov. 1, 2017. Published November 2017. Originally
2
approved in 1979. Last previous edition approved in 2013 as C912 – 93 (2013). Campbell, D. E., andAdams, P. B., “Bibliography on Clean Glass: Supplement
DOI: 10.1520/C912-17. 1,” Journ
...
This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: C912 − 93 (Reapproved 2013) C912 − 17
Standard Practice for
1
Designing a Process for Cleaning Technical Glasses
This standard is issued under the fixed designation C912; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope
1.1 This practice covers information that will permit design of a rational cleaning procedure that can be used with a glass that
is somewhat soluble in many aqueous chemical solutions. Typically, this type of glass is used in applications such as optical ware,
glass-to-metal seals, low dielectric loss products, glass fibers, infrared transmitting products, and products resistant to metallic
vapors.
1.2 In most cases, this type of glass contains high concentrations of oxides that tend to react with a number of aqueous
chemicals. Such oxides include B O , Al O , R O, RO, La O , ZnO, PbO, P O , and Fe O . The more conventional high-silica
2 3 2 3 2 2 3 2 5 2 3
glasses are usually more chemically resistant, but the cleaning principles outlined here also apply to them.
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility
of the user of this standard to establish appropriate safety safety, health, and healthenvironmental practices and determine the
applicability of regulatory limitations prior to use. Specific hazard statements are given in Section 4 and Table 1.
1.4 This international standard was developed in accordance with internationally recognized principles on standardization
established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued
by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
2. Terminology
2.1 Definitions of Terms Specific to This Standard:
2.1.1 technical glass—glass, n—glasses designed with some specific property essential for a mechanical, industrial, or scientific
device.
3. Significance and Use
3.1 Many of the low-silica technical glasses which contain soluble or reactive oxides require processing or involve applications
that require cleaning. Very often these cleaning procedures have evolved over several decades and are considered an art. They
usually contain numerous steps, some of questionable validity. It is the premise of this practice that cleaning glass can be more
scientific. Design of a cleaning procedure should involve (1) a definition of the soil to be removed, (2) an awareness of the
constraints imposed by the glass composition, and (3) a rational selection of alternative methods that will remove the soil and leave
the glass in a condition suitable for its intended application. This practice provides information to assist in step (3). General
2
references on glass cleaning and on various methods of evaluating cleanliness and associated information has been published.
4. Hazards
4.1 Many of the chemicals that can be used in cleaning glass are hazardous. This is true of most of the aqueous chemicals
discussed in Section 5 and shown in Table 1 as well as the organic chemicals discussed in Section 6.
4.2 Special care should be used with hydrofluoric acid (HF), which will react with glass generating heat. The vapors as well
as the liquid destroy HF destroys dermal tissue and can be fatal if inhaled.exposure of the skin to the liquid or inhalation of the
vapors can be fatal.
4.3 Concentrated acids can react violently if water is added into them. When it is necessary to dilute acid, add the acid to the
water slowly and with constant stirring so that heat is never allowed to concentrate locally in the solution.
1
This practice is under the jurisdiction of ASTM Committee C14 on Glass and Glass Products and is the direct responsibility of Subcommittee C14.02 on Chemical
Properties and Analysis.
Current edition approved Oct. 1, 2013Nov. 1, 2017. Published October 2013November 2017. Originally approved in 1979. Last previous edition approved in 20082013
ε1
as C912–93(2008)C912 – 93 (2013). . DOI: 10.1520/C912–93R13.10.1520/C912-17.
2
Campbell, D. E., and Adams, P. B., “Bibliography on Clean Glass: Supplement 1,” Journal of Testing and Evaluation, Vol 14, No. 5, September 1986, pp. 260–265.
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