Význam a použití
5.1 Aby nátěr plnil svou funkci ochrany nebo zdobení podkladu, the coating needs to remain adhered to the substrate. Because the substrate and its surface treatment (or lack thereof) have a huge impact on the adhesion of the coating, methods for evaluating the adhesion of the coating to different substrates or surface treatments, or the adhesion of different coatings to the same substrate, are very useful in industry.

5.2 This test method is limited to assessing low adhesion levels (vidět 1.3). The laboratory and interlaboratory accuracy of this test method is similar to other test methods for coated substrates (např., test method D2370 and test method D4060) and is insensitive to all methods except for the significant difference in adhesion. The limitation of the ranking range to 0 na 5 reflects the inability of this test method to make fine distinctions in adhesion levels. Users may not use the median value to rank adhesion tests in this method.

5.3 Extreme temperature or relative humidity may affect the adhesion of the tape or coating.

5.4 Due to a variety of factors, including differences in coating composition and topology, a given tape may not adhere equally well to different coatings. Proto, no single tape is likely to be suitable for testing all coatings. Navíc, these test methods do not give an absolute value of the force required for bond breaking, but only as an indicator of reaching or exceeding some minimum value of bond strength (1,2).

ASTM D3359-2022 Standardní zkušební metoda pro hodnocení adhezivní síly testováním pásky

5.5 Operators performing these test methods need to be trained and practiced to achieve consistent results. The accuracy and precision of the test results obtained using these methods depends largely on the operator’s skill and the operator’s ability to perform the tests in a consistent manner. Key steps that directly reflect the importance of operator skill include the Angle and rate of tape removal and the visual evaluation of the test sample. It’s not surprising that different operators might get different results (1,2).

5.6 The standard requires rapid removal of the free end of the tape at as close to a 180° Angle as possible. When the peel Angle and peel rate change, the force required to remove the tape can change dramatically due to the rheological properties of the backing and adhesive. Variations in pull rate and peel Angle can affect large differences in test values, which need to be minimized to ensure repeatability (3).

Poznámka 1: These test methods are reportedly used to measure the adhesion of organic coatings on non-metallic substrates such as wood and plastics, but lack relevant accuracy and deviation data. If the coating is tested on A non-metallic substrate, test method A or test method B may be more appropriate, and the method used should be discussed by interested parties. Problems with plastic substrates are noted in Appendix X1. A similar test method, ISO 2409, allows testing of non-metallic substrates such as wood and gypsum. Accuracy and deviation data on the latter are lacking. The test method D3359 was developed on a metal base and is very limited without supporting accuracy and bias data.

ASTM D3359-2022 Standardní zkušební metoda pro hodnocení adhezivní síly testováním pásky

Poloměr
1.1 These test methods cover procedures to assess the adhesion of a relatively ductile coated film to a metal substrate by applying and removing pressure-sensitive tape over cuts in the film.

1.2 Test Method A is mainly used in the field, while test method B is more suitable for use in a laboratory or workshop environment. Navíc, test method B is not considered suitable for films thicker than 125μm (5 mil) unless a wider interval cut is used and there is an explicit agreement between buyer and seller.

1.3 These test methods are used to assess whether the adhesion of the coating to the substrate is sufficient for the user’s application. They do not distinguish between higher adhesion levels that require more sophisticated measurement methods.

1.4 This test method is similar in content to ISO 2409 (but not technically equivalent).

1.5 In multilayer coating systems, adhesion failures between coatings may occur, so the adhesion of the coating system to the substrate cannot be determined.

1.6 Hodnoty vyjádřené v jednotkách SI se považují za standardní. Hodnoty uvedené v závorkách jsou pouze orientační.

ASTM D3359-2022 Standardní zkušební metoda pro hodnocení adhezivní síly testováním pásky

1.7 Tato norma není určena k řešení všech bezpečnostních problémů, jestli nějaký, spojené s jeho užíváním. Je odpovědností uživatelů této normy zajistit odpovídající bezpečnost, zdravotní a environmentální postupy a určit použitelnost regulačních omezení před použitím.

1.8 Tato mezinárodní norma je založena na mezinárodně uznávaných zásadách normalizace stanovených v Rozhodnutí o zásadách pro vývoj mezinárodních norem, Směrnice a doporučení vydané Výborem WTO pro technické překážky obchodu.