ISO 4624:2002 pdf download
ISO 4624:2002 pdf download.Paints and varnishes -Pull-off test for adhesion.
These test methods have been found useful in comparing the adhesion behaviour of different coatmgs. It is most useful in providing relative ratings tot a series of coaled panels exhiting significant ditterences in adhesion.
The test may be applied using a wide range of sutstrates. Different procedures are given according to whether the substrate is deforrnable, for example ttn metal, plastics and wood. or rigid, for example thick concrete and metal plates. For special purposes, the coating may be applied directly to the face of a test dolly.
2 Normative references
The following normative documents contam provisions which, through reference in this text, constitute provisions of this International Standard, For dated references, subsequent amendments to, or revisions of. any of these publications do not apply, However, parties to agreements based on this International Standard are encouraged to investigate the possibdity of applying the most recent editions of the normative documents indicated below. For undated references, the latest edition of the normative document referred to applies. Members of ISO and IEC maintain registers of currently valid International Standards.
ISO 1513:1992, Paints and varniSheS — Examination and preparation of samples for testing
ISO 151 4:_lI. Paints and varnishes — Standa,rJ panels for testing
ISO 2806:1997. Paints and varnishes — Deter’mination of fin thickness
ISO 3270:1984. Paints and varnishes and their raw materials — Temperatures and humidities for conditioning and testing
ISO 15528:2000, Paints, varrwshes arid raw materials for paints and varnishes— Sampling
3 PrInciple
The product or system under test Is applied at uniform thickness to flat panels of uniform surface texture.
After drying/curing the coating system, dollies are bonded directly to the surface of the coated, cured panel using an aiesive.
After curing of the adhesive, the bonded dolly assemblies are placed in a suitable tensile tester. The bonded assemblies are subØcted to a controlled tensile test (pulI.ofl test), and the force required to break the coating/substrate bond is measured.
The test result is the tensile stress necessary to break the weakest wilerface (adhesive failure) or the weakest component (cohesive failure) of the test assembly. Mixed adhesive/cohesive failures may also occur.
1) To be published. (Revision of ISO 1514:1993)
5.2 Test doilies, each consisting of a steel- or aluminium-faced cylinder, specifically designed to be used with the tensile tester. Each dolly has a rigid, flat face for bonding the adhesive/coating at one end and a facility for connecting the pull-oft tester at the other. Each dolly has a nominal diameter of 20 mm (see however following paragraph) and sufficient thickness to ensure freedom from distortion during me test. It is recommended that the length of each dolly is not less man half its diameter. The faces of each dolly shall be machined perpendicular to its axis before use.
Dollies with a diameter 017 mm may be used when the method for testing adhesion from one side only is used (see 9.4.2), If dollies of 7mm in diameter are used. 10 measurements shall be made to improve the precision. The diameter of the dollies shall be reported in the test repot.
5.3 Centering device, for ensuring proper coaxial alignment of the test assemty during the adhesion process described in 9.4.1 and 9.4.3. A suitable design Is shown In Figure 3.
5.4 Cutting device. such as a sharp knife, for cutting through cured adhesive and the paint coating to the substrate, round the circumlerence of the dolly.
Depending on the mechanical proper lies of the paint system (e.g. brittleness), cutting through the cured adhesive and the paint film to the substrate can have a big Influence on the adhesion ol the paint system. It Is permitted. if specified or agreed between the interested parties. not to cut when the paint systems are less man i 50 pin in layer thickness. If cuts around the dolly have been made, this shall be mentioned in the test report and the type of cutting tool also mentioned.
