ISO 15184:2012 download.Paints and varnishes – Determination of film hardness by pencil test.
ISO 15184 specifies a method for deterniwiing the fibii hardness by pushing pencils of known hardness over the film
The test can be perfonned on a single coating of a paint, varnish or related product, or on the upper layer of a multi-coal system,
The rapid lest has not been found to be useful in companng the pencil hardness of different coatings. It is more useful in providing relative ratings fora series of coaled panels exhibiting sl’iificant differences In pencil hardness.
The method is applicable only 1 smooth surfaces.
2 NormatIve references
The following referenced documents are indispensable for the applcabon of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (Including any amendments) applies.
Iso 1513. PaInts and varnishes — Examination and preparation of test santes
ISO 1514. Paints and varnishes — Standard panels for testing
ISO 2808. Paints and varnishes — Determination of ITim thickness
ISO 15528, Paints, varnishes and maw materlats for pain rs and varnishes — Sampling
3 Terms and definitions
For the purposes of ISO 15184, the folowing lemis and definitions apply
3.1
pencil hardn.ss
resistance of the surface of a paint lien to marking, or the formation of some other defect, as a result of the action of a pencil, with a lead of specified dimensions, shape and hardness, whoh is pushed aaoss the surface
4 Principle
A pencil lead with a defined geometry is pushed over the paint surface at an angle of 45. exerting a force of
7.5 N on the surface The hardness of the pencil lead is increased in steps until the surface of the coating is
macIced by visible defects. The test result is the highest hardness at which no marking occurs.
7.4 DryIng and conditioning
Dry (or stove) and age. if applicable, each coated lest panel for the specified time under the specified conditions. Before testing, condition the coated panels at (23 2) C and a relative humity of (50 ± 5) %. unless otherwise agreed, for a minimum period of 16 h.
7.5 Thickness of coating
The thickness of the coating shall be as specified or as agreed between the interested partIes. Determine the thickness of the coating by on. of the procedures sp.cifl.d m ISO 2808.
8 Procedure
8.1 Caiy out the test at a leniperaturo of (23 ± 2) C and a relative humidity of (50 5) %. unless othaiwise agreed.
8.2 Remove approximately 5 mm to 6mm of wood Iron, the point of each pencil using the special mechanical sharpener (5.3). beIng careful to leave an undisturbed. unmarked, smooth cylinder of pencil lead.
8.3 Flatten the tip of the teed by holding the pencil In a vertical position and moving the pencil back and forth over abrasive paper (5.4), maintaining an angle of 90. Continue until a flat, smooth, circular cross-section i obtained, free from chçs or nicks in the edges.
Repeat this procedure each time a pencil is used.
8.4 Place the coated panel on a level. firm, horizontal surface.
Insert a pencil in the test instrument (5.1) and damp it In position so that the instrument is horizontal, with the tip of the pencil resting on the sistace of the paint film (see Figure 1).
8.5 ImmedIately after the tip of the pencil has come to rest on the coating, push the pencil in the direction away from the operator at a uniform speed.
8.6 Unless otherwise agreed. .nsped the coating after 30s. using normal corrected vision, for marking of the kind defined in Clause 9.
The damage can be assessed more easily after cleanIng all fragments of pencil lead from the pn( surface. using a soft cloth or swab of cotton wool (5.5) and an inert solvent. If this is done, take care that the solvent does not affect the hardness of the coating in the test area
By agreement, a magnifying lens (magnification 6 to 10) may be used to assess the damage. If a magnifying lens is used, this sha8 be reported In the test report.
If no marking has occurred, repeat the test (8 3 to 8.6) without overlap of the lest areas, moving up the hardness scale until marking occurs over a distance of at least 3mm.
If marking has occurred, repeal the test (8.3 to 8.6) down the hardness scale until marking no longer occurs.
Determine wtnch of the defects of the kinds defined in Clause 9 has been produced.
The hardness of the hardest pencil which does not mark the coaling is the so-called pencil hardness.
By agreement, the test may also be carried out to determine the minimum pencIl hardness which does not cause a cohesive fracture (the so-called ‘gouge hardness as defined In ASTM D3363). If the test Is done this way, this shaU be reported In the test report.
8.7 Carry out the test In duplicate. If the Iwo results differ by more than one unit of pencil hardness, discard them and repeat the test
9 Types of defect
Marking by pencil leads covers a range of defects in the surface of the paint film.
These defects are defined as foIIow:
a) Plastic deformation: a permanent Indentation in the pa Wit surface wthout cohesive fracture.
b) Cohesive fracture: the presence of a visible scratch or rupture in the surface of the paint film, material having been removed from the paint 51m
c) Combinations of the above
These defects can occur slmultanously.
10 Precision
No precision data are available.
NOTE The applicability of the method is decussed In Annex A
11 Test report
The tes* report shall contain at least the following information:
a) .11 details necessary to identity the product tested:
b) a reference to this International Standard (ISO 15184):
c) details of the preparation at the test panels, including
1) the material and surface preparation of the substrate (see 7.1 and 7,2),
2) the method of appbcation of the test coating to the substrate, including the duration arid conditions of drying between coats in the case of a multi-coat system (see 7.3).
3) the duration and conditions of drying (or stoving) of the coating, and the conditions of agewig, if applicable, before testing (see 7.4).
4) the thickness. In m.crometres, of the dry coating and the method of measurement used from ISO 2808 (see 7.5). and whether it Is a single coating or a multi-coat system:
d) the temperature and relative humidity of the test. If different from those specified In 8.1;
e) the make and manufacturer of the pencils used:
f) the result of the test, inclung. if agreed between the interested parties, a description of the kinds of defect defined In Clause 9 which actually occurred;
g) the magnification ci the magnifying lens, if used:
h) any deviation from the test method specified:
i) any i.musual features (anomalies) observed during the test:
j) thedateotthetest.