ASTM D2134 - 93(27)
Standard Test Method for Determining the Hardness of Organic Coatings with a Sward-Type Hardness Rocker 有机涂层斯华德硬度测试方法
Significance and Use
Sward-type hardness rocker instruments have been used by the coatings industry for more than a half a century as a nondestructive test instrument to measure cure and ultimate surface hardness of organic coatings (see Refs. (1) through (11)). An accepted standard test method for the use of such an instrument is long overdue.
In previous task group work designed to establish an ASTM method for measuring hardness of organic coatings with Sward-type hardness rocker instruments, round-robin test results continually showed poor interlaboratory reproducibility. This lack of interlaboratory agreement could have resulted from dimensional variations among instruments, with the contact rocker rings as the most likely offender in that regard. There are several producers of Sward-type hardness rockers making instruments that differ among themselves in net weight and ring radius. Some of them exceed the measurements and net weight called for in this test method.
This test method, however, is useful within laboratories to quickly screen and measure the surface hardness of candidate coatings.
1. Scope
1.1 This test method covers the determination of the relative degree of surface hardness of organic coatings using a specific apparatus widely used in the coatings industry.
1.2 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.
1.3 This test method does not purport to address all of the safety problems, 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.
2. Referenced Documents
ASTM Standards
D823 Practices for Producing Films of Uniform Thickness of Paint, Varnish, and Related Products on Test Panels
D15 Test Method for Measurement of Dry-Film Thickness of Organic Coatings Using Micrometers
D3924 Specification for Environment for Conditioning and Testing Paint, Varnish, Lacquer, and Related Materials
D4138 Practices for Measurement of Dry Film Thickness of Protective Coating Systems by Destructive, Cross-Sectioning Means
D823 Practices for Producing Films of Uniform Thickness of Paint, Varnish, and Related Products on Test Panels
D15 Test Method for Measurement of Dry-Film Thickness of Organic Coatings Using Micrometers
D3924 Specification for Environment for Conditioning and Testing Paint, Varnish, Lacquer, and Related Materials
D4138 Practices for Measurement of Dry Film Thickness of Protective Coating Systems by Destructive, Cross-Sectioning Means
Index Terms
hardness; hardness tests—Sward hardness; surface hardness; Hardness tests--organic coatings; Organic coatings; Surface hardening/hardness; Sward hardness rocker; ICS Number Code 25.22. (Organic coatings)
有机涂层的Sward hardness (斯华德硬度测试)是以水平测试板上的滑轮震荡次数作为基准,以玻璃板的震荡次数作为1%，其他结果以百分比的形式表示，具体测试详情如下：
METHOD OF USE
The levelling table with the test plates is levelled carefully and the surface of the glass test plate thoroughly cleaned. The underside rings of the rocker should be examined critically and cleaned with a suitable solvent to remove any sticky deposits.
1. Place the rocker carefully into the test surface, roll the instrument to the right until
bubbles are in view.
IMPORTANT: ensure that NO undue pressure is applied to the rocker.
2. Release the rocker START counting the number of ‘rocks’ (complete oscillations)
when the LEFT-HAND bubbles just disappears.
3. STOP the count when the right-hand bubble just disappears.
The rocker is set before despatch to make 5 oscillations on a standard glass plate with the period of oscillation being set at +.5 seconds by means of the adjustable knurled nuts. A frequent check should be made on the number of oscillations the apparatus makes on the standard glass plate.
It is usual to express the results obtained from the test piece as a percentage of the number of rocks made on the plate glass standard representing 1%.
The change of state for rocker hardness can be monitored against time provided that the coating is smooth, free from blemishes, and its thickness controlled.
Sample Requirement :*inches ,4PCS.
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