ASTM D4226-19e1

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: D4226 − 19 An American National Standard
Standard Test Methods for
Impact Resistance of Rigid Poly(Vinyl Chloride) (PVC)
Building Products
This standard is issued under the fixed designation D4226; 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.
ε NOTE—Eq 4 was editorially corrected in August 2020.
1. Scope* mendations issued by the World Trade Organization Technical
Barriers to Trade (TBT) Committee.
1.1 These test methods cover the determination of the
energy required to crack or break rigid poly(vinyl chloride)
2. Referenced Documents
(PVC)plasticsheetingandprofileflatsectionsusedinbuilding
2.1 ASTM Standards:
products, as well as extruded or molded test samples, under
D618Practice for Conditioning Plastics for Testing
specified conditions of impact from a freefalling standard
D883Terminology Relating to Plastics
weightstrikinganimpactorwitheitheroftwoconfigurationsin
D5947Test Methods for Physical Dimensions of Solid
contact with the specimen.
Plastics Specimens
1.2 Two test procedures are included:
E178Practice for Dealing With Outlying Observations
1.2.1 Procedure A, used to determine minimum impact
E456Terminology Relating to Quality and Statistics
energy required to cause failure (hole, crack, split, shatter, or
E691Practice for Conducting an Interlaboratory Study to
tear).
Determine the Precision of a Test Method
1.2.2 Procedure B, used to determine minimum impact
E2935Practice for Conducting Equivalence Tests for Com-
energy required to cause brittle failure.
paring Testing Processes
1.3 Thevaluesstatedininch-poundunitsaretoberegarded
3. Terminology
as standard. The values given in parentheses are mathematical
3.1 Definitions—Definitions are in accordance with Termi-
conversions to SI units that are provided for information only
nology D883, unless otherwise specified. For terms relating to
and are not considered standard.
precision and bias and associated issues, the terms used in this
NOTE 1—There is no known ISO equivalent to this standard.
standard are defined in accordance with E456.
1.4 The text of this standard references notes and footnotes
3.2 Definitions of Terms Specific to This Standard:
whichprovideexplanatorymaterial.Thesenotesandfootnotes
3.2.1 failure (of test specimen, as related to impact
(excluding,thoseintablesinfigures)shallnotbeconsideredas
resistance)—signified by the presence of a punched hole,
requirements of this standard.
crack,split,shatter,ortearthatwascreatedinthetargetareaby
1.5 This standard does not purport to address all of the
the impact of the falling weight (see Fig. 1).
safety concerns, if any, associated with its use. It is the
3.2.2 ductile failure (ductile break, as related to impact
responsibility of the user of this standard to establish appro-
resistance)—a tear or split having an angle greater than 0° at
priate safety, health, and environmental practices and deter-
the tip and extending through the entire thickness of the
mine the applicability of regulatory limitations prior to use.
specimen such that light is directly visible through the tear or
Specific precautionary statements are given in Section 8.
split (see Fig. 1).
1.6 This international standard was developed in accor-
3.2.3 brittle failure (brittle break, as related to impact
dance with internationally recognized principles on standard-
resistance)—a punched hole, split, or shatter where a piece of
ization established in the Decision on Principles for the
the specimen separates from the main part of the specimen or
Development of International Standards, Guides and Recom-
acrackthathasa0°angleatthetipasviewedbythenakedeye
(see Fig. 1).
These test methods are under the jurisdiction of ASTM Committee D20 on
Plastics and are the direct responsibility of Subcommittee D20.24 on Plastic
Building Products. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved Nov. 1, 2019. Published December 2019. Originally contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
approved in 1983. Last previous edition approved in 2016 as D4226-16. DOI: Standards volume information, refer to the standard’s Document Summary page on
10.1520/D4226-19E01. 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
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D4226 − 19
FIG. 1 Types of Failures of the Specimen
3.2.4 mean failure height (Procedure A)—the height from 3.2.9 normalized mean brittle failure energy (normalized
which the falling weight will cause 50% of the specimens to mean energy of ductile-to-brittle transition), (Procedure B)—
fail. the mean brittle failure energy per unit (average) specimen
thickness.
3.2.5 mean failure energy (mean impact resistance), ( Pro-
cedure A)—energy required to produce 50% failures; the 3.2.10 outlier—anobservationthatappearstodeviatemark-
product of the weight and mean failure height. edly from other members of the sample in which it occurs.
3.2.6 normalized mean failure energy (normalized mean
4. Summary of Test Method
impact resistance)—the mean failure energy per unit (average)
specimen thickness (Procedure A).
4.1 Flat sections of a PVC building profile are tested by
means of an impactor driven by a falling weight to determine
3.2.7 mean brittle failure height—theheightfromwhichthe
impactresistanceoftheprofile.Ifnecessary,cuttheprofileinto
falling weight will cause 50% brittle failures in specimens
smaller sections or coupons in order to properly position the
(Procedure B).
profile on the tester support plate.
3.2.8 mean brittle failure energy (mean energy of ductile-
to-brittle transition), (Procedure B)—energy required to pro- 4.2 Procedure A establishes the height from which a stan-
duce 50 % brittle failures; the product of the weight and mean dard falling 8-lb (3.6-kg) weight will cause 50% of the
brittle failure height. specimens to fail.
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D4226 − 19
FIG. 2 Impact Tester
4.3 Procedure B establishes the height from which a stan- quality control, environmental and weatherability research and
dard falling 8-lb (3.6-kg) weight will cause 50% of the development studies, and fabrication tolerance prediction con-
specimens to fail in a brittle mode. stitute useful applications.
4.4 Both procedures employ either of two configurations of 5.4 Choice of the specific impactor head configuration used
impactorheadsrestingonthespecimen.Thespecimenlaysflat is related to a variety of product attributes, such as specimen
on a stand that has a 0.64-in. (16.3-mm) hole. The falling thickness and product toughness as well as abstract factors,
suchastheanticipatedmodeoffailureinaspecificapplication.
weightimpactsontheimpactorheadtendingtodriveitthrough
the specimen into the hole of the stand. The geometric uniqueness of the impactor head configurations
prevents any comparison or correlation of testing results on
4.5 The technique used to find 50% failure level in both
samples tested with differing impactor head configurations. In
procedures is commonly called the Bruceton Staircase Method
general, the conical impactor, C.125, is useful to ensure failure
or Up-and-Down Method. Testing is concentrated near the
of thicker specimens where the H.25 impactor caused no
mean, reducing the number of specimens required to obtain a
failure.
reasonably precise estimate.
NOTE 2—Equivalent surface conditions are more likely to occur when
specimens are prepared by compression molding or extrusion than by
5. Significance and Use
injection molding.
5.1 The impact strength values obtained on the flat sections
5.5 When comparing different samples tested with the same
ofabuildingproductprofilearerelevantonlytotheflatsection
impactorheadconfiguration,impactresistanceshallbepermit-
thathasbeentestedandthesevaluesdonotnecessarilyindicate
ted to be normalized for average specimen thickness over a
theimpactresistanceofthewholeproduct,whichisaffectedby
reasonably broad range (for example, 1 to 3 mm). However,
the configuration of the profile (that is, corners, ribs, etc).
this should only be done when the surface conditions listed in
6.1 are essentially equivalent.
5.2 Constant weight and variable height, employed in these
test methods, allow the velocity of impact to vary and,
6. Interferences
therefore, by Procedure B, can determine the energy of
6.1 The results obtained are greatly influenced by the
ductile-to-brittle transition, which cannot be determined if a
qualityofthetestspecimens.Cracksusuallystartatthesurface
variable weight is dropped from a constant height.
5.3 These test procedures have been found to be useful
O.R. Weaver, “Using Attributes to Measure a Continuous Variable in Impact
elements in rigid poly(vinyl chloride) (PVC) building product
Testing Plastic Bottles,” Materials Research & Standards, MR & S, Vol. 6, No. 6,
characterization. Compound qualification, finished product June, 1996, pp. 285-291.
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D4226 − 19
FIG. 3 Impactor Head Configuration H.25 Specimen Support Detail
in tension; the surface opposite the one that is struck by the steel.Itshouldhaveaconical(40°)configurationand0.125-in.
impactor head. The composition of this surface layer and the (3.18-mm) radius hemispherical tip.
degree of orientation introduced during the formation of the 7.1.2.2 Impactor H.25 shall be constructed, as is shown in
specimen are very important variables. Flaws in this surface Fig. 3, of tough, hardened (Rockwell C50-55) scratch resistant
will also affect results. Because of these factors, sometimes steel.Itshouldhavea0.25-in.(6.35-mm)radiushemispherical
additional information about the sample is achieved by testing tip (see Fig. 3 and Fig. 4).
the sample from a variety of locations in a product or testing 7.1.2.3 The surface of the impactor head shall be polished
from both sides of a flat section. free of nicks, scratches, or other surface irregularities.
7.2 Supporting Base—In order to minimize the energy
6.2 Samplesmustnotcollapseintotheholeinthespecimen
absorption, compression, and deflection of the support the
support plate when driven by the impactor. Sample collapse
tester shall be firmly fixed to a dense, solid, block or base.
into the hole during the impact test affects impact results.
7.2.1 The main body of said block or base shall have
6.3 When resting on the support plate and in contact with
maximum dimensions of 16 in. (40 cm) (h) × 30 in. (75 cm)
the impactor the specimen must lie flat. Bowed samples will
(w) × 30 in. (75 cm) (d) and shall have a minimum weight of
affect test results.
375 lb (171 kg). This block shall be placed at a height that
facilitatesequipmentusage.Itisnotnecessarytoboltblocksor
7. Apparatus
bases of this weight to the floor.
7.1 Testing Machine—The apparatus shall be constructed
NOTE 3—The required block weight and dimensions conform to
essentiallyasshowninFig.2andFig.3andshallconsistofthe
commercially available butcher block type tables.
following: suitable base to withstand the impact shock; steel-
7.2.2 Alternative supporting bases or those lighter than 375
rod impact weight weighing 8 6 0.2 lb (3.6 6 0.1 kg);
lb (171 kg) should be bolted to a concrete floor. Mean failure
hardened steel impactors as specified in 7.1.2; a slotted guide
energy comparisons shall be made between these alternative
tube40in.(1.0m)inlengthinwhichtheimpactweightsslide,
supports and one where the tester is bolted directly to the
having an internal diameter sufficient so that friction does not
concrete floor. If mean failure energy differences between the
reduce the weight velocity, and having graduations in inch-
concretefloorandthealternativesupportarefoundstatistically
pound (newton-meter) increments, or multiples thereof. A
nonsignificant, use of the lighter support shall be allowed.
bracket is used to hold the tube in a vertical position by
7.2.3 If the weight of the butcher block that was originally
attaching it to the base and also to hold the hand knob, which
375 lb (171 kg) or greater decreases with time to less than 375
is a pivot-arm alignment for the impactor, about 2 in. (50 mm)
lb (171 kg), increase the block weight to a minimum of 375 lb
under the tube. The top edge of the opening in the specimen
(171 kg) by adding a suitable amount of weight to the bottom
supportplateshouldberoundedtoa0.031-in.(0.8-mm)radius.
of the table. The weight shall be tightly affixed and in direct
Fig. 3 shows the specimen support configuration for this test.
contact with the bottom of the table and not cause any
7.1.1 Thetestershallbemountedsothattheaxisofthetube
vibrations during the impact test.
is plumb when measured with a spirit level at least 1 ft (300
mm) in length. NOTE 4—The weight of the butcher block can decrease over time, for
instance, due to drying.
7.1.2 Impactor Configurations:
7.1.2.1 Impactor C.125 shall be constructed, as is shown in 7.2.4 Use of rubber mats either under the tester or the
Fig.4,oftough,hardened(RockwellC50-55),scratchresistant supporting base is prohibited.
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D4226 − 19
FIG. 4 Impactor Head Configuration C.125
plateisrelatedtosamplethicknessandforthickersamplesit’spossibleto
7.3 Micrometer, for measurement of specimen thickness. It
use smaller samples.
should be accurate to1%ofthe average thickness of
specimens used. See Test Method D5947 for suitable microm- 10.2 When the approximate mean failure height for a given
eters. sample is known, 20 specimens usually yield sufficiently
precise results. If the mean failure height cannot be
8. Safety Precautions
approximated,
...