ASTM C1914-21

Standard Test Method for Bake and Boil Testing of Laminated Glass

SIGNIFICANCE AND USE
5.1 It is generally recognized that excess moisture and air within an interlayer will cause bubble formation in a laminate when exposed to heat or UV radiation, or both. These may be caused by initial moisture and air in the interlayer and be generated by thermal exposure. The purpose of this test method is to measure quantitatively the laminate stability under controlled conditions, specifically in relation to the formation of bubbles in the body of the laminate.  
5.2 Subjecting the laminated glazing to extended heat at a controlled temperature and time provides the excess moisture and air which are forced into the interlayer during processing to surface as bubbles. This occurs only if there are excess moisture and air trapped in between the glass. Therefore, making these thermal tests efficient to determine proper de-airing of laminated glass products.  
5.3 This test method provides a means to visually determine if discoloration has or is occurring and serves as a pass/fail test for some aspects of lamination quality.  
5.4 This test method can be performed after natural or accelerated exposure to determine if there are changes to the polymer such as the stability with high temperature which is useful for understanding the visual stability of installed glazing.  
5.5 This test method does not provide an indication of laminated glass capability for impact resistance, glass shard retention on breakage or edge stability of laminated glass.
SCOPE
1.1 The purpose of this test method is to measure quantitatively the laminate stability under controlled conditions, specifically in relation to the formation of bubbles in a laminate with heat exposure.  
1.2 This test method can be performed on laminates which have been exposed to weathering or as manufactured samples to determine the amount of excess air dissolved in the interlayer.  
1.3 This test method determines the stability of laminated glass when subjected to high heat environments.  
1.4 This test method outlines a procedure to be used on laminated glass with two or more layers of glass bonded by an interlayer.  
1.5 This test method covers visual rating of tested specimens.  
1.6 The values stated in SI units are to be regarded as standard. The values given in parentheses after SI units are provided for information only and are not considered standard.  
1.7 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.  
1.8 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.

General Information

• Status: Published
• Publication Date: 30-Jun-2021
• ICS: 81.040.30 - Glass products
• Technical Committee: C14 - Glass and Glass Products
• Drafting Committee: C14.08 - Flat Glass

Relations

• Refers: ASTM C1172-14 - Standard Specification for Laminated Architectural Flat Glass
• Effective Date: 15-Sep-2014
• Refers: ASTM C1172-09e1 - Standard Specification for Laminated Architectural Flat Glass
• Effective Date: 01-May-2009
• Refers: ASTM C1172-09 - Standard Specification for Laminated Architectural Flat Glass
• Effective Date: 01-May-2009
• Refers: ASTM C1172-03 - Standard Specification for Laminated Architectural Flat Glass
• Effective Date: 10-Jul-2003
• Refers: ASTM C1172-96e1 - Standard Specification for Laminated Architectural Flat Glass
• Effective Date: 29-Aug-1996

Overview

ASTM C1914-21: Standard Test Method for Bake and Boil Testing of Laminated Glass is an international standard developed by ASTM International for assessing the laminate stability of laminated glass. This standard specifies controlled procedures-bake and boil tests-to quantitatively measure the formation of bubbles and visually identify any discoloration within laminated glass. The test method serves as a valuable quality control tool to determine the effectiveness of the lamination process, specifically the removal of excess air and moisture from the interlayer, which are critical for long-term durability and optical performance in architectural and safety glazing applications.

Key Topics

• Laminate Stability Testing: Describes procedures to evaluate the stability of laminated glass, focusing on bubble formation due to trapped moisture or air when exposed to heat.
• Bake and Boil Test Methods: Outlines conditioning, bake testing in ovens, and boil testing in water baths at controlled temperatures, along with sample handling for accurate results.
• Visual Assessment: Provides guidance for visually inspecting glass specimens for bubbles and discoloration, ensuring clear pass/fail criteria for lamination quality.
• Sample Preparation and Reporting: Stipulates minimum sample sizes, numbers of test specimens, and comprehensive data to be reported, supporting traceability and repeatability.
• Limitations: Clarifies that this method is designed for assessing visual and durability-related attributes and does not evaluate impact resistance, glass shard retention, or edge stability.

Applications

ASTM C1914-21 is widely applied within industry sectors concerned with the quality and durability of laminated glass, including:

• Architectural Glass Manufacturing: Used as a production quality control measure to ensure glass laminates meet durability requirements before installation in buildings, facades, or transportation infrastructure.
• Product Certification and Compliance: Assists manufacturers and third-party certifiers in determining adherence to safety and durability standards for laminated glass products.
• Research and Development: Supports R&D efforts to improve lamination processes and materials, particularly in assessing the performance of new interlayer formulations under thermal stress.
• Post-Exposure Evaluation: Enables evaluation of in-service or weathered glazing units to identify potential degradation, providing insight into the long-term optical stability of installed glass.

By employing this standard, organizations can more effectively mitigate the risk of bubble formation and discoloration, which not only affect aesthetics but could also compromise the integrity and lifetime of laminated safety glass in various environments.

Related Standards

Understanding ASTM C1914-21 within the broader context of glass testing standards can enhance compliance and product performance:

• ASTM C1172: Specification for Laminated Architectural Flat Glass, which complements C1914-21 by defining requirements for laminated glass used in buildings.
• ISO and Other ASTM Glass Standards: Includes standards for impact resistance, durability, and weathering that may be used alongside this test method for comprehensive quality assessments.

Implementing ASTM C1914-21 ensures the visual and functional quality of laminated glass, promoting higher safety and aesthetic standards across architectural and engineered glazing applications. For further reference and to access more glass standards, visit the official ASTM International website.

Standards Content (Sample)

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.
Designation: C1914 − 21
Standard Test Method for
Bake and Boil Testing of Laminated Glass
This standard is issued under the fixed designation C1914; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 3. Terminology
1.1 The purpose of this test method is to measure quantita-
3.1 Definitions:
tively the laminate stability under controlled conditions, spe-
3.1.1 boil tank, n—a vessel capable of holding laminated
cifically in relation to the formation of bubbles in a laminate
glass specimens submerged in water at a set temperature for a
with heat exposure.
specified amount of time.
1.2 This test method can be performed on laminates which
have been exposed to weathering or as manufactured samples 4. Summary of Test Method
to determine the amount of excess air dissolved in the
4.1 This test method involves engulfing the laminate in heat
interlayer.
for a predetermined amount of time, removing the laminates
1.3 This test method determines the stability of laminated
from the heat source, allowing the specimen to cool and rating
glass when subjected to high heat environments.
the number and location of any bubbles or other anomalies
1.4 This test method outlines a procedure to be used on formed in the laminated glass.
laminated glass with two or more layers of glass bonded by an
interlayer. 5. Significance and Use
1.5 This test method covers visual rating of tested speci-
5.1 It is generally recognized that excess moisture and air
mens.
within an interlayer will cause bubble formation in a laminate
when exposed to heat or UV radiation, or both. These may be
1.6 The values stated in SI units are to be regarded as
caused by initial moisture and air in the interlayer and be
standard. The values given in parentheses after SI units are
provided for information only and are not considered standard. generatedbythermalexposure.Thepurposeofthistestmethod
is to measure quantitatively the laminate stability under con-
1.7 This standard does not purport to address all of the
trolled conditions, specifically in relation to the formation of
safety concerns, if any, associated with its use. It is the
bubbles in the body of the laminate.
responsibility of the user of this standard to establish appro-
priate safety, health, and environmental practices and deter-
5.2 Subjecting the laminated glazing to extended heat at a
mine the applicability of regulatory limitations prior to use.
controlled temperature and time provides the excess moisture
1.8 This international standard was developed in accor-
and air which are forced into the interlayer during processing
dance with internationally recognized principles on standard-
to surface as bubbles. This occurs only if there are excess
ization established in the Decision on Principles for the
moisture and air trapped in between the glass. Therefore,
Development of International Standards, Guides and Recom-
making these thermal tests efficient to determine proper de-
mendations issued by the World Trade Organization Technical
airing of laminated glass products.
Barriers to Trade (TBT) Committee.
5.3 Thistestmethodprovidesameanstovisuallydetermine
2. Referenced Documents
ifdiscolorationhasorisoccurringandservesasapass/failtest
2.1 ASTM Standards:
for some aspects of lamination quality.
C1172Specification for Laminated Architectural Flat Glass
5.4 This test method can be performed after natural or
accelerated exposure to determine if there are changes to the
This test method is under the jurisdiction of ASTM Committee C14 on Glass
polymer such as the stability with high temperature which is
and Glass Products and is the direct responsibility of Subcommittee C14.08 on Flat
Glass.
useful for understanding the visual stability of installed glaz-
Current edition approved July 1, 2021. Published August 2021. DOI: 10.1520/
ing.
C1914-21.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
5.5 This test method does not provide an indication of
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
laminated glass capability for impact resistance, glass shard
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. retention on breakage or edge stability of laminated glass.
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C1914 − 21
6. Apparatus 11.2.2 Samples are placed in the water bath ensuring
samples are not contacting the walls or floor of the boil tank
6.1 Safety Equipment (Minimum):
except for the racking mechanism while allowing free flow of
6.1.1 Heat and cut-resistant gloves.
water around each specimen.
6.1.2 Eye protection.
11.2.3 The boil tank is allowed to regain set temperature
6.2 Tools:
prior to the beginning of the duration timing
...