AATCC 22-2010 Water Repellency: Spray Test

Developed in 1941 by AATCC Committee
RA63; revised 1952, 1996, 2001, 2005;
reaffirmed 1943, 1961, 1964, 1967,
1971, 1974, 1977, 1980, 1985, 1989,
2010; editorially revised 1987, 2008.
Technically equivalent to ISO 4920.
1. Purpose and Scope
1.1This test method is applicable to
any textile fabric, which may or may not
have been given a water-repellent finish.
It measures the resistance of fabrics to
wetting by water. It is especially suitable
for measuring the water-repellent effi-
cacy of finishes applied to fabrics.
1.2 The results obtained with this test
method depend on the resistance to wet-
ting or water repellency of the fibers,
yarns and finishes on the fabric, and upon
the construction of the fabric.
2. Principle
2.1 Water sprayed against the taut sur-
face of a test specimen under controlled
conditions produces a wetted pattern
whose size depends on the repellency of
the fabric. Evaluation is accomplished by
comparing the wetted pattern with pic-
tures on a standard chart.
3. Terminology
3.1 water repellency, n.—in textiles,
the characteristic of a fiber, yarn or fabric
to resist wetting.
3.2  face, n.—in textiles, the side of a
fabric that is intended to be the outer visi-
ble surface in an end product.
4. Safety Precautions
NOTE:These safety precautions are
screening finishes. It is not intended,
however, for use in predicting the proba-
ble rain penetration resistance of fabrics,
since it does not measure penetration of
water through the fabric. For testing rain
penetration, AATCC Method 35, Water
Resistance: Rain Test, should be used.
6. Apparatus and Materials (see 11.1)
6.1 AATCC Spray Tester (see 11.2,
Figs. 1, 2, 2A and 3).
6.2 Graduated cylinder, 250 mL.
6.3 Water, distilled.
6.4 Stopwatch (see 8.3)
7. Test Specimens
7.1 Three test specimens 180.0 × 180.0
mm (7.0 × 7.0 in.) are needed and should
be conditioned at 65 ± 2% relative hu-
midity and 21 ± 1°C (70 ± 2°F) for a min-
imum of 4 h before testing.
7.2 Where possible, each specimen
should contain different groups of length-
wise and widthwise yarns.
8. Procedure
8.1 Calibrate the apparatus by pouring
250 mL of distilled water at 27 ± 1°C (80
± 2°F) into the funnel of the tester and
measure the time required for the funnel
to empty.
8.1.1 The spray time must be between
25-30 s, otherwise the nozzle should be
checked to see if the holes are enlarged or
blocked.
8.2 Fasten the test specimen securely
in the 152.4 mm (6.0 in.) diameter hoop
so that the face of the fabric specimen
will be exposed to the water spray. The
surface of the specimen should be smooth
and without wrinkles.
Water Repellency: Spray Test3556