The standard GB/T 9264-2012 "Paints and varnishes, sag resistance assessment" is a method for evaluating the Sag resistance performance of Coatings (including Paints, varnishes and similar coating materials). This article will understand and explain the standard.
1. Background and origin of the standard
The formulation of the standard follows the rules of GB/T 1.1-2009 and replaces GB/T 9264-1988 "Determination of Paints sagability". Compared with the previous version, this standard has been updated in terms of editorial revisions and technical changes. The formulation of the standard was proposed by the CHINA Petroleum and Chemical Industry Federation and centralized by the National Coating and Pigment Standardization Technical Committee (SAC/TC 5). The drafting units include CNOOC Changzhou Coating Chemical Research Institute, Carlberry Chemical Group joint stock company, and Shandong Lehua Paint Industry joint stock company.
2. Scope of application and main content of the standard
The scope of application of this standard has been adjusted from the previous application only to Paints to apply to all liquid Coatings. The standard details two methods for assessing Sag resistance performance: using a scaled sag Coating Applicator and applying with a Spray Gun. The standard specifies the procedure, test conditions, instrument requirements and presentation of results for each method.
3. Methods for assessing Sag resistance
There are two main sag resistance assessment methods described in the standard:
Method of using a scaled sag Coating Applicator: In this method, the Coating is scraped on the test plate, and then the test plate is placed vertically to record the maximum wet film thickness without sag. This method is suitable for situations where you wish to apply Coating by scraping, such as brushing or roller painting.
Method of applying with Spray Gun: This method involves spraying the Coating evenly on the test plate, and then observing whether sagging occurs after a certain period of time. This method is suitable for applying Coatings with Spray Gun, such as high voltage compression airspraying, airless spray with or without air support.
4. Presentation of test conditions and results
The standard specifies conditions such as temperature, Humidity, etc. at the time of testing. For methods using scaled sag Coating Applicators, reported results include no observed maximum gap depth of sag and corresponding actual wet film thickness. For methods applied with Spray Guns, reported results are no observed wet film thickness of sag.
5. Accuracy and test reports
Accuracy data is provided in the standard, as well as the requirements for the test report. The test report should include details of the tested product, test method, temperature and Humidity during the test, viscosity of the Coating and other information to ensure the Reliability and conformity of the test.
Through the standard GB/T 9264-2012, we can accurately evaluate the Sag resistance performance of Coatings, so as to ensure that Coatings can achieve the expected effect and mass requirements in practical applications.
