ISO 1524:2020 pdf download Paints, varnishes and printing inks — Determination of fineness of grind
1 Scope
This document specifies a method for determining the fineness of grind of paints, inks and relatedproducts by use of a suitable gauge, graduated in micrometres.
lt is applicable to all types of liquid paints and related products, except products containing pigments inflake form (e.g.glass flakes, micaceous iron oxides, zinc flakes).
2Normative references
The following documents are referred to in the text in such a way that some or all of their contentconstitutes requirements of this document. For dated references,only the edition cited applies. Forundated references, the latest edition of the referenced document (including any amendments) applies.ISO 1513, Paints and varnishes — Examination and preparation of test samples
ISO 4618, Paints and varnishes — Terms and definitions
ISO 15528,Paints, varnishes and raw materials for paints and varnishes —Sampling
3Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 4618 and the following apply.ISO and lEC maintain terminological databases for use in standardization at the following addresses:-ISo online browsing platform: available at https://www.iso.org/obp
—IEC Electropedia: available at http://www.electropedia.org/
3.1
fineness of grind
reading obtained on a standard gauge under specified conditions of test, indicating the depth of thegroove(s)of the gauge at which discrete solid particles in the product are readily discernible
4 Apparatus
4.1 Gauge, consisting of a block of a hardened steel or other suitable material, e.g. 175 mm long,65 mm wide and 13 mm thick.
At least for use with water-dilutable paints, a block of stainless steel should be used.
The top surface of the block shall be both plane and ground smooth and shall contain one, two or threegrooves approximately 140 mm long and 12,5 mm wide parallel to the longer sides of the block. Thedepth of each groove shall be uniformly tapered along its length from a suitable depth (for example25 um, 50 um or 100 um) at one end to zero at the other end and shall be graduated as specified inTable 1.A diagram showing two typical gauges is given in Figure 1.
The depth of the groove at any position along its length shall not depart from its nominal value at any position across the groove depth by more than 2,5 µm. The top surface of the block shall be finished by fine grinding or lapping; it shall be flat so that all points lie between two parallel planes 12 µm apart and, in addition, at every position along the surface, the transverse generator shall be straight so that all points along it lie between two parallel straight lines 1 µm apart. The top and bottom surfaces of the block shall be parallel within 25 µm. Steel gauges of the approximate dimensions stated are suitable for the test, but other gauges giving similar results may be used. The precision of the fineness-of-grind determination depends in part on which gauge is used (see Clause 6). The 100 µm gauge is suitable for general use, but the 50 µm and especially the 25 µm gauge will only provide reliable results in the hands of skilled laboratory personnel. Particular caution is necessary in interpreting readings of less than 10 µm. Therefore, it is essential to identify the gauge (100 µm, 50 µm or 25 µm) when reporting results or specifying requirements.
4.2 Scraper, consisting of a single- or double-edged steel blade. The length of the scraper should be at least 10 mm more than the width of the gauge. The edge(s) on the long side(s) shall be straight and rounded to a radius of approximately 0,25 mm. A drawing of a suitable scraper is shown in Figure 2. The scraper shall be periodically checked for wear, damage or warpage. Reject the scraper if inspection reveals damage. The top surface of the gauge may be used for routine checking of the scraper, provided it itself is not worn or warped. The scraper shall be handled and stored with particular care.ISO 1524:2020 pdf download