ASTM F484-08(2019)

Standard Test Method for Stress Crazing of Acrylic Plastics in Contact with Liquid or Semi-Liquid Compounds

ABSTRACT
This test method covers the procedure for determining the crazing effect caused by a liquid or semi-liquid on transparent three types of acrylic plastic materials under bending stress. Cast acrylic materials from Types A and B should be annealed according to specifications while the stretched acrylic materials of Type C should not be annealed. All test specimens should be machined from polished acrylic plastic sheets and should have smooth machined surfaces.
SCOPE
1.1 This test method covers determination of the crazing effect that a liquid or semi-liquid test compound will have on transparent acrylic plastic material that is under bending stress.  
1.2 Three types of acrylic material are covered. One, two, or all of the materials shall be used in the test, as specified by the procuring agency. When not specified otherwise, all three types of acrylic shall be used in the test.  
1.3 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.  
1.4 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.  
1.5 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-Apr-2019
• ICS: 83.080.10 - Thermosetting materials
• Technical Committee: F07 - Aerospace and Aircraft
• Drafting Committee: F07.07 - Qualification Testing of Aircraft Cleaning Materials

Relations

• Refers: ASTM D1193-06 - Standard Specification for Reagent Water
• Effective Date: 01-Mar-2006
• Refers: ASTM D1193-99e1 - Standard Specification for Reagent Water
• Effective Date: 10-Feb-1999
• Refers: ASTM D1193-99 - Standard Specification for Reagent Water
• Effective Date: 10-Feb-1999

Overview

ASTM F484-08(2019), titled “Standard Test Method for Stress Crazing of Acrylic Plastics in Contact with Liquid or Semi-Liquid Compounds,” provides a standardized procedure to assess the susceptibility of transparent acrylic plastics to stress crazing. Stress crazing is the formation of fine cracks or craze lines when an acrylic material is exposed to liquids or semi-liquids under bending stress. Developed and maintained by ASTM International, this test method is crucial for manufacturers, suppliers, and users of acrylic materials in industries requiring high transparency and durability, such as aerospace, transportation, and electronics.

Key Topics

• Stress Crazing Definition: Minute, often hairline, surface cracks that develop due to simultaneous mechanical stress and chemical exposure.
• Material Types Covered:
  • Type A: Cast acrylic conforming to relevant military specifications
  • Type B: Modified cast acrylic
  • Type C: Stretched acrylic (not annealed before testing)
• Test Specimen Preparation:
  • Machined from polished acrylic sheet with a smooth surface
  • Standardized dimensions and surface quality to ensure reliability
• Conditioning and Annealing:
  • Types A and B require annealing after machining
  • Type C is tested as-machined
• Testing Procedure:
  • Specimens are subjected to specific bending stresses
  • Application and maintenance of test compounds on the specimen surface
  • Visual inspection for crazing at multiple intervals up to 8 hours
  • Stresses are specific to each type of acrylic (e.g., 3000–4500 psi)
• Reporting Requirements:
  • Must include compound tested, acrylic type, observed effects, and time to failure or evidence of crazing

Applications

ASTM F484-08(2019) is widely used in multiple industries to ensure the long-term performance and safety of acrylic plastic components, particularly where exposure to liquids, cleaning agents, and operational stresses is common:

• Aerospace: Testing aircraft windows, canopies, and light covers for chemical resistance and fracture safety under stress
• Automotive and Transportation: Assessment of transparent panels and displays exposed to cleaning fluids or environmental contaminants
• Electronics and Display Manufacturing: Evaluating acrylic sheets used in protective covers, touch panels, and lighting equipment
• Architectural Glazing: Verifying the durability of acrylic panels in locations subject to both stress and possible liquid exposure
• Quality Control: Adoption by manufacturers to qualify new acrylic materials or formulations against regulatory and customer specifications

Implementing this standard helps reduce the risk of premature failure or aesthetic degradation, improving product reliability and maintaining compliance with industry requirements, especially in regulated sectors like defense and aviation.

Related Standards

The following standards complement or are referenced within ASTM F484-08(2019):

• MIL-PRF-5425: Plastic Sheet, Acrylic, Heat Resistant
• MIL-PRF-8184: Plastic Sheet, Acrylic, Modified
• MIL-PRF-25690: Plastic Sheets and Formed Parts, Modified Acrylic
• ASTM D1193: Standard Specification for Reagent Water

These standards form an integrated framework for selecting, testing, and qualifying acrylic plastic materials against stress crazing and related phenomena. For users seeking robust chemical resistance and stress performance in acrylic plastics, referencing these standards ensures best practices and aligns with international quality and safety requirements.

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: F484 − 08 (Reapproved 2019)
Standard Test Method for
Stress Crazing of Acrylic Plastics in Contact with Liquid or
Semi-Liquid Compounds
ThisstandardisissuedunderthefixeddesignationF484;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginal
adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.Asuperscript
epsilon (´) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the U.S. Department of Defense.
1. Scope MIL-PRF-25690 Plastic, Sheets and Formed Parts, Modified
Acrylic-Basic, Monolithic, Crack Propagation Resistant
1.1 This test method covers determination of the crazing
effect that a liquid or semi-liquid test compound will have on
3. Terminology
transparent acrylic plastic material that is under bending stress.
3.1 Definitions:
1.2 Threetypesofacrylicmaterialarecovered.One,two,or
3.1.1 craze—a minute surface crack, sometimes hairline in
all of the materials shall be used in the test, as specified by the
size.
procuringagency.Whennotspecifiedotherwise,allthreetypes
of acrylic shall be used in the test.
NOTE 1—Hairline craze cracks are very difficult to see except with
careful inspection under properly oriented light.
1.3 The values stated in inch-pound units are to be regarded
3.1.2 crack—a fracture or tear.
as standard. The values given in parentheses are mathematical
conversions to SI units that are provided for information only
4. Types
and are not considered standard.
1.4 This standard does not purport to address all of the 4.1 Type A, cast acrylic material shall conform to MIL-PRF-
5425, Finish A.
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro-
4.2 Type B,castacrylicmaterialshallconformtoMIL-PRF-
priate safety, health, and environmental practices and deter-
8184, Finish B.
mine the applicability of regulatory limitations prior to use.
4.3 Type C, stretched acrylic material shall conform to
1.5 This international standard was developed in accor-
MIL-PRF-25690.
dance with internationally recognized principles on standard-
ization established in the Decision on Principles for the
5. Apparatus
Development of International Standards, Guides and Recom-
mendations issued by the World Trade Organization Technical 5.1 Stress Apparatus—The means of stressing the acrylic
Barriers to Trade (TBT) Committee. plastic test specimen bars shall be as shown in Fig. 1.
2. Referenced Documents
6. Test Specimens
2.1 ASTM Standards:
6.1 The test specimens shall be machined from 0.25 6
D1193 Specification for Reagent Water
0.025 in. (6.4 6 0.64 mm) thick polished acrylic plastic sheet
2.2 Military Standards:
conforming to the applicable specification.
MIL-PRF-5425 Plastic Sheet, Acrylic, Heat Resistant
6.2 The test specimens shall be 1 6 0.03 in. (25.4 6
MIL-PRF-8184 Plastic Sheet, Acrylic, Modified
0.8 mm) wide by 7 6 0.05 in. (177.8 6 1.27 mm) long by 0.25
6 0.025 in. (6.4 6 0.64 mm) thick. Edges shall be a smooth
This test method is under the jurisdiction of ASTM Committee F07 on
Aerospace and Aircraft and is the direct responsibility of Subcommittee F07.07 on
machined surface without cracks.
Qualification Testing of Aircraft Cleaning Materials.
Current edition approved May 1, 2019. Published June 2019. Originally
7. Conditioning
approvedin1977.Lastpreviouseditionapprovedin2013asF484 – 08(2013).DOI:
10.1520/F0484-08R19.
7.1 Do not anneal Type C acrylic specimens.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
7.2 Anneal Type A and Type B acrylic test specimens after
Standards volume information, refer to the standard’s Document Summary page on
machining by heating in a circulating air oven at 195 65°F
the ASTM website.
3 (91 6 3 °C) for 5 ⁄2 h. Cool the specimens to room temperature
AvailablefromStandardizationDocumentsOrderDesk,Bldg.4SectionD,700
Robbins Ave., Philadelphia, PA 19111-5098, Attn: NPODS. in the oven using a uniform cooling rate of 50 °F (28 °C)⁄h.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
F484 − 08 (2019)
Load: outer fiber stress 3000 psi (20 685 kPa) Type A acrylic
outer fiber stress 3500 psi (24 132 kPa) Type B acrylic
outer fiber stress 4500 psi (31 027 kPa) Type C acrylic
stress in psi
Formula:
load, lb5w3t 3
stress in kPa
load, g5w3t 3
where:
w = width of specimen in inches or millimetres to nearest 0.001 in. or 0.025 mm, respectively, and
t = thickness of specimen in inches or millimetres to nearest 0.001 in. or 0.025 mm, respectively. Width and thickness shall be measured
at the stress area.
Note: The fulcrum radius shall be ⁄4 in. (6.4 mm) where it bears on the acrylic specimen.
FIG. 1 Description of Stressing Procedure
7.3 Condition all specimens at 75 6 10 °F and 50 6 5% 8.6 Completely soak the cotton o
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