Designation: D – 01Standard Test Method for Evaluating Adhesion by Knife1 This standard is issued under the fixed desig. From ASTM D Standard Test Method for Evaluating Adhesion by Knife. Section 3 | Summary of Test Method. Adhesion is determined by making an “ X”. Buy ASTM D Standard Test Method for Evaluating Adhesion by Knife from SAI Global.
|Published (Last):||24 January 2012|
|PDF File Size:||3.98 Mb|
|ePub File Size:||16.87 Mb|
|Price:||Free* [*Free Regsitration Required]|
Summary of Test Method tions. Adhesion is rated on an even number scale between 0 and 10, with 10 having the best adhesion and 0 d6677 worst.
Coating Adhesion Testing using Knife/Tape Methods
Eugen, The following comes from the author: In addition, the method aastm not to be used on overly thick coatings that cannot be cut to the substrate with a utility knife blade in one stroke. This is primarily due to the directional forces applied to the coating system during the tests. Adhesion is rated based on the scale provided in the ASTM standard. August 7, at 8: It is correct this affirmation?
The test has also been used successfully on softer substrates e. However, the subsequent delamination is a result of shear forces.
Adhesion is evaluated qualitatively on a 0 to 10 scale. After removal of the tape, the amount of coating removed from the substrate or underlying coating is rated. Table 1 provides the evaluation criteria for Method A; Table 2 provides the evaluation criteria for Method B. Further, the results of any knife adhesion tests performed on these coatings must be carefully considered. The shear tests are oftentimes more definitive because they better replicate the way in which coatings fail.
Standard Test Method for Evaluating Adhesion by Knife
While tape and knife adhesion tests are generally regarded as more subjective than their tensile pull-off adhesion test counter parts, the tape and knife adhesion tests can be much more revealing of the true adhesion properties of a coating system. Simply stated, the ASTM standard test procedures have limitations that need to be considered when making judgements or decisions based on the test results.
When the coating is greater than 5-mils thick an X-cut with each leg approximately 1.
Inspection Instruments Pipeline Coatings — Volume 2: S6677, adhesion ratings of 8 and 10 are considered good, adhesion values of 4 and 6 are considered marginal, and adhesion values of 2 and 0 are considered poor. If the tape adhesion test is required, the chalking should be removed from the area prior to performing the test. Aztm are included regarding the use of the test on coatings with a high cohesive strength that may appear to have worse adhesion than one that is brittle and fractures easily.
When the coating is less than 5-mils thick, a cross-cut lattice pattern is created with either asstm or eleven cuts in each direction. Your comments are invited either for revision of this standard or for additional standards and should be addressed to ASTM Headquarters.
April 7, at 6: That is a correct statement. Apparatus and Materials only.
ASTM D – 18 Standard Test Method for Evaluating Adhesion by Knife
Report Current edition approved May 10, March 3, at August 8, at 8: If you feel that your comments have not received a fair hearing you should make your views known to the ASTM Committee on Standards, at the address shown below. Leave a Reply Cancel reply Your email address will not be published. Undercutting and peeling can occur as a result of shear forces.
The adhesion by knife test may provide a more accurate picture of the actual adhesion characteristics. The test was developed for assessing the adhesion of coating to steel, but can be used on other hard substrates. Tape and knife adhesion exert a prying type of force. The tip of a knife blade is then inserted into the intersect of the two incisions and used to attempt to lift the coating from the substrate or an underlying coating.