Meaning and use
4.1 Indoor paint films often become dirty, especially near doorways, Windows and play areas, and often need to be cleaned by scrubbing. This test method covers the determination of the relative resistance of paint to erosion during scrubbing.

4.2 At absolute physical values (e.g. cycle to failure for test method D2486 or microrise per 100 cycles for this test method), the accuracy of the scrub resistance measurement is poor due to the relatively large influence of subtle and difficult to control variables under the test conditions. The test method described herein minimizes this problem by using a standard calibration panel as an integral part of each scrubbing operation and correlating its weight loss to the weight loss of the film under test to determine the scrubbing resistance of the latter.

Note 1: The value of scrub resistance obtained through this test method is only relevant to the specific calibration panel type for which the value was obtained. Thus, for example, a scrub resistance value of 83 for an X-type calibration panel would be reported as 83X.

4.3 The results obtained by this test method are not necessarily representative of the scrubbing resistance that may be determined if the test film is allowed to dry before the test is significantly longer than the seven-day period specified here.

4.4 The results obtained by this test method are not necessarily related to the ease of dirt or stain removal (also known as “cleanability” or “cleanability”). To test these characteristics, use test methods D3450 and D4828.

STM D4213-2016 “Standard test Method for Determining Scrubbing Resistance of Coatings by wear weight Loss”

Radius
1.1 This test method covers an accelerated procedure for determining the resistance of paint to erosion caused by scrubbing. (Note: The term wet wear is sometimes used for scrubbing, and wet wear or scrubbability is used for scrubbing resistance. While scrubbing resistance tests are primarily used for internal coatings, they are sometimes used in conjunction with external coatings as an additional measure of film performance.

1.2 Values expressed in SI units shall be considered standard. The values given in parentheses are for reference only.

1.3 This standard is not intended to address all safety concerns, if any, associated with its use. It is the responsibility of users of this standard to establish appropriate safety and health practices and to determine the applicability of regulatory restrictions prior to use.