Designation: C972 − 00 (Reapproved 2011)

Standard Test Method for

Compression-Recovery of Tape Sealant1
This standard is issued under the fixed designation C972; 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 5.2 Steel Panels, two, cold-rolled, each 0.762 by 76.2 by

1.1 This test method describes a laboratory procedure for 76.2 mm (0.03 by 3 by 3 in.).
determining compression-recovery characteristics of tape seal- NOTE 2—Substitutes such as aluminum, acrylic, acrylonitrile-
ant. butadiene-styrene (ABS), may be substituted for the plates (5.1) and
panels (5.2).
1.2 The values stated in SI units are to be regarded as the
standard. The values given in parentheses are for information 5.3 Compression Testing Machine, with a cross-head speed
only. of 50 mm (2 in.)/min and capable of stopping at specified
settings.
1.3 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the NOTE 3—Load values may differ when determined on screw-type
responsibility of the user of this standard to establish appro- versus spring-type test machines due to a drift past the desired stop in the
priate safety and health practices and determine the applica- spring-type machine. It may be necessary to use shims to obtain the
desired stop.
bility of regulatory limitations prior to use.
5.4 Recorder, for recording compression loads in newtons
NOTE 1—There are no ISO standards similar or equivalent to this
ASTM standard. (or pounds-force).
5.5 Stop Watch, measuring in minutes and seconds.
2. Referenced Documents
5.6 Gage or Rule, capable of measuring tape thickness to
2.1 ASTM Standards:2
0.025 mm or 0.001 in.
C717 Terminology of Building Seals and Sealants

3. Terminology 6. Test Specimen and Sample

3.1 Definitions—For definitions of terms used in this test 6.1 Conditioning:
method, refer to Terminology C717. 6.1.1 Condition the specimens for 24 h at 23 6 2°C (73.4 6
3.6°F) and 506 10 % relative humidity.
4. Significance and Use 6.1.2 Other conditioning parameters may be included as
4.1 Tape sealants are tacky, deformable solids used under desired.
compression between two or more surfaces of similar or 6.2 Samples to be tested shall be taken from a roll or tape
dissimilar materials in a variety of sealing applications. This sealant after first removing and discarding approximately the
procedure presents an indication of the compression recovery first 0.6 m (2 ft) of the roll.
characteristics of preformed tapes.
6.3 Tape sealant configuration should be approximately 9.53
5. Apparatus by 9.53 by 76.2 mm (0.375 by 0.375 by 3 in.). The sample
5.1 Glass Plates, two, each 6.35 by 76.2 by 76.2 mm (0.25 should be re-extruded rather than plied to conform to the
by 3 by 3 in.). specified size if the sample does not approximate these
dimensions.

1
6.4 Total tape volume (V) should be calculated (width by
This test method is under the jurisdiction of ASTM Committee C24 on Building
Seals and Sealants and is the direct responsibility of Subcommittee C24.20 on
length by thickness) for determination of tape sealant compres-
General Test Methods. sion index.
Current edition approved June 1, 2011. Published August 2011. Originally
approved in 1982. Last previous edition approved in 2006 as C972 – 00 (2006). 6.5 Prepare two test specimens for each sample as follows:
DOI: 10.1520/C0972-00R11. 6.5.1 Do not clean or unnecessarily handle the surfaces of
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or surface-treated or painted plate or panels.
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on 6.5.2 Clean plates or panels with detergent or solvent, or
the ASTM website. both.

Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States

1
 C972 − 00 (2011)
6.5.3 Place two 76.2 by 9.53 by 9.53-mm (3 by 0.375 by where:
0.375-in.) lengths of tape sealant on one of the plates or panels, Pc = tape compression index, N/mm3 (lbf/in.3),
as shown in Fig. 1, and remove the release paper. Place the P = maximum compression load, N (lbf), and
second plate or panel over the tape sealant to complete the test V = total tape sealant volume, mm3 (in.3 ).
specimen in accordance with Fig. 1.
9. Report
7. Procedure 9.1 The report shall include the following:
7.1 Place the specimen in a laboratory press or equivalent 9.1.1 Average recovery height after 5 min and after 2 h to
equipment, and compress the specimen at 51 mm (2 in.)/min the nearest 5.1 mm (0.001 in.),
until the sealant tape thickness is 5.1 mm (0.20 in.). Maintain 9.1.2 Average tape sealant compression index in newtons
the compression mode for exactly 1 min, recording maximum per cubic millimetre (or pounds-force per cubic inch), and
compressive load in newtons or pounds force. At the end of 1 9.1.3 Type of compression equipment used.
min, raise the press crosshead and remove the specimen, taking
care not to disturb the specimen. 10. Precision and Bias3

7.2 After removing the specimen from the press, measure 10.1 Three laboratories were used in the force to compress
and record the tape sealant thickness after 5 min and after testing and four laboratories were used for both recovery tests
2 h. (5 min and 2 h).
10.2 Repeatability I(r)—The repeatability interval (within a
8. Calculations given laboratory) for four materials tested by three (or four)
8.1 Calculate the compression load and recovery height for laboratories is listed in Table 1 for each of the calculated values
each specimen as follows: defined in Section 8.
R 1 5 T 1 2 5.1 mm ~ 0.200 in.! (1) 10.3 Reproducibility I(R)—The reproducibility interval (be-
tween given laboratories) for four materials tested by three (or
where: four) laboratories is listed in Table 1 for each of the calculated
R1 = free recovery height after 5 min, and values defined in Section 8.
T1 = tape thickness after 5 min.
11. Keywords
R 2 5 T 2 2 5.1 mm ~ 0.200 in.! (2)
11.1 compression; recovery; tape sealant
where:
R2 = free recovery height after 2 h, and
T2 = tape thickness after 2 h. 3
Supporting data have been filed at ASTM International Headquarters and may
P c 5 P/V (3) be obtained by requesting Research Report RR:C24-1008.

FIG. 1 Compression Recovery Test Sample

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 C972 − 00 (2011)
TABLE 1 Indexes of Precision
Source of Variability Symbol Force to Compress, N (lbf) Recovery, 5 min, mm (in.) Recovery, 2 h, mm (in.)
Repeatability (within laboratory) I(r) 50.5 (11.34) 0.43 (0.017) 0.30 (0.012)
Reproducibility (between laboratories) I(R) 443.0 (99.56) 0.76 (0.030) 0.76 (0.030)

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