ASTM D4508-10

Standard Test Method for Chip Impact Strength of Plastics (Withdrawn 2016)

SIGNIFICANCE AND USE
The chip-impact test is a variation of the Izod impact test described in Test Methods D256.  
The specimen geometry has been chosen to fit three basic criteria as follows:  
The specimen is relatively thin and is struck on the broad surface so that the test result is sensitive to the condition of the surface,  
The specimen is relatively small for efficient utilization of space in accelerated testing media or devices and to minimize amounts of material needed for testing, and  
The specimen can be tested using a standard Izod pendulum tester.  
It has been found that a 12.7-mm (0.500-in.) wide strip with a thickness in the range from 1.02 to 3.18 mm (0.040 to 0.125 in.) meets the above criteria. Much experimental work on 1.78-mm (0.070-in.) strips has demonstrated the utility of the chip-impact test to track weather aging of a variety of materials.  
The distance (L) between clamping and impact points (striker height) will affect test results. Extensive experimental work has established that a ratio of L = 2.182 h (where L is the distance between clamping and impact points and h is the thickness of the specimen) will provide accurate and sensitive chip-impact values. Increasing this ratio (that is, raising the striker height for a given thickness) lowers chip-impact values and reduces sensitivity of the test. Decreasing the above ratio (that is, lowering the striker height for a given thickness) results in a shearing of the specimen rather than the desired bending and breaking.  
In general, the chip-impact value during weathering varies according to specimen thickness, even after adjusting striker heights for constant deflection, as given in Table 1. Report the thickness of the specimen, along with the test values, making comparisons only between samples with similar thickness.
The standard Izod Methods A, C, D, and E require that the type of failure for each specimen be recorded as one of the four coded categories defined as follows:
SCOPE
1.1 The purpose of this test method is to provide an impact test that can be performed on small specimens of plastics of different thicknesses. This test method is especially suited for observing the effects of microcracks caused by weathering, or by exposure to solvents or other hostile environments, on the surface of plastic materials. It is not meant to be used as a replacement for any existing impact test, but can be used to measure impact on coupons machined from finished parts that cannot be tested by the drop-weight, Izod, or Charpy method because of shape or thickness limitations.  
1.2 The chip-impact test is run on small, flat, unnotched specimens using a standard pendulum-impact device. The test places the impacted surface in tension and, for notch-sensitive materials, is extremely sensitive to the presence of surface microcracks. Thus, for plastics that develop surface cracks when exposed outdoors, the chip-impact test is a severe test of the weathered impact strength.  
1.3 Round-robin testing has indicated that materials that break at total energy values of less than 0.17 joules (1.5 in.-lbf) have within-laboratory coefficients of variation of approximately 30 %. Therefore, such values are considered out of the normal testing range for this test.  
1.4 The values stated in SI units are to be regarded as standard. The values given in parentheses are for information only.
1.5 There is no known ISO equivalent to this test method.
1.6 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 and health practices and determine the applicability of regulatory limitations prior to use.
WITHDRAWN RATIONALE
The purpose of this test method is to provide an impact test that can be performed on small specimens of plastics of different thicknesses. This test method is especially suited for observing the e...

General Information

• Status: Withdrawn
• Publication Date: 31-Mar-2010
• Withdrawal Date: 17-May-2016
• ICS: 83.080.01 - Plastics in general
• Technical Committee: D20 - Plastics
• Drafting Committee: D20.10 - Mechanical Properties

Relations

• Referred By: ASTM G178-16(2023) - Standard Practice for Determining the Activation Spectrum of a Material (Wavelength Sensitivity to an Exposure Source) Using the Sharp Cut-On Filter or Spectrographic Technique
• Effective Date: 01-Apr-2010

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation:D4508 −10
StandardTest Method for
1
Chip Impact Strength of Plastics
This standard is issued under the fixed designation D4508; 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* 2. Referenced Documents
2
1.1 The purpose of this test method is to provide an impact 2.1 ASTM Standards:
test that can be performed on small specimens of plastics of D256Test Methods for Determining the Izod Pendulum
different thicknesses. This test method is especially suited for Impact Resistance of Plastics
observing the effects of microcracks caused by weathering, or D618Practice for Conditioning Plastics for Testing
by exposure to solvents or other hostile environments, on the D883Terminology Relating to Plastics
surface of plastic materials. It is not meant to be used as a D1600TerminologyforAbbreviatedTermsRelatingtoPlas-
replacement for any existing impact test, but can be used to tics
measure impact on coupons machined from finished parts that D4066Classification System for Nylon Injection and Extru-
cannot be tested by the drop-weight, Izod, or Charpy method sion Materials (PA)
because of shape or thickness limitations. D5947Test Methods for Physical Dimensions of Solid
Plastics Specimens
1.2 The chip-impact test is run on small, flat, unnotched
E691Practice for Conducting an Interlaboratory Study to
specimens using a standard pendulum-impact device. The test
Determine the Precision of a Test Method
places the impacted surface in tension and, for notch-sensitive
materials, is extremely sensitive to the presence of surface
3. Terminology
microcracks. Thus, for plastics that develop surface cracks
3.1 Definitions—For definitions of plastic terms see Termi-
when exposed outdoors, the chip-impact test is a severe test of
nology D883 and for abbreviations see Terminology D1600.
the weathered impact strength.
There re no terms in this test method that require new or
1.3 Round-robin testing has indicated that materials that
other-than-dictionary definitions.
breakattotalenergyvaluesoflessthan0.17joules(1.5in.-lbf)
have within-laboratory coefficients of variation of approxi-
4. Significance and Use
mately 30%. Therefore, such values are considered out of the
4.1 The chip-impact test is a variation of the Izod impact
normal testing range for this test.
test described in Test Methods D256.
1.4 The values stated in SI units are to be regarded as
4.2 The specimen geometry has been chosen to fit three
standard. The values given in parentheses are for information
basic criteria as follows:
only.
4.2.1 The specimen is relatively thin and is struck on the
1.5 There is no known ISO equivalent to this test method.
broad surface so that the test result is sensitive to the condition
of the surface,
1.6 This standard does not purport to address all of the
4.2.2 The specimen is relatively small for efficient utiliza-
safety concerns, if any, associated with its use. It is the
tion of space in accelerated testing media or devices and to
responsibility of the user of this standard to establish appro-
minimize amounts of material needed for testing, and
priate safety and health practices and determine the applica-
4.2.3 The specimen can be tested using a standard Izod
bility of regulatory limitations prior to use.
pendulum tester.
1
ThistestmethodisunderthejurisdictionofASTMCommitteeD20onPlastics
2
and is the direct responsibility of Subcommittee D20.10 on Mechanical Properties. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved April 1, 2010. Published June 2010. Originally contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
approved in 1985. Last previous edition approved in 2006 as D4508-06. DOI: Standards volume information, refer to the standard’s Document Summary page on
10.1520/D4508-10. the ASTM website.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

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D4508−10
4.3 It has been found that a 12.7-mm (0.500-in.) wide strip
with a thickness in the range from 1.02 to 3.18 mm (0.040 to
4.6.1 Impact values cannot be directly compared for any
0.125 in.) meets the above criteria. Much experimental work
two materials that experience different types of failure as
on 1.78-mm (0.070-in.) strips has demonstrated the utility of
defined in the method for this code.
the chip-impact test to track weather aging of a variety of
materials.
4.7 Beforeproceedingwiththistestmethod,makeref
...