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ISO (Organizația Internațională pentru Standardizare) este federația globală a organismelor naționale de standardizare (organismele membre ISO). Elaborarea standardelor internaționale se realizează de obicei prin intermediul comitetelor tehnice ISO. Each member group interested in a subject on which a technical committee has been established has the right to be represented on the Committee. International, governmental and non-governmental organizations in liaison with ISO are also involved in this work. ISO lucrează îndeaproape cu Comisia Electrotehnică Internațională (IEC) în toate problemele de standardizare electrică.

The draft international standards adopted by the Technical Committee will be circulated to member bodies for voting. Publicarea ca standard internațional necesită aprobarea cu un vot de cel puțin 75% of the member body.

Standardul internațional ISO 8780-6 was developed by the ISO/TC 35 Technical Committee on Paints and Varnishes.

ISO 8780 consists of the following sections under the general heading Pigments and Increments – Dispersion Methods for assessing dispersion properties:

— Parte 1: Introducere

— Parte 2: Dispersion using oscillating motors

— Parte 3: Dispersion using high speed impeller mill

— Parte 4: Dispersion using a bead mill

— Parte 5: Using an automatic grinder for dispersion

— Parte 6: Dispersion using a three-roll grinder

Appendix A forms an integral part of this part of ISO 8780.

ISO 8780-6-1990 “Metode de dispersie pentru evaluarea proprietăților de dispersie ale pigmenților și materialelor de umplutură — Parte 6: Dispersion using a three-roll mill”

1 Scope of application
Această parte a ISO 8780 specifies a method for dispersing pigments and increments using a three-roll grinder. The results allow conclusions to be drawn about the behavior of the test product when dispersed using the corresponding production machine. Această parte a ISO 8780 is used in conjunction with the evaluation methods described in ISO 8781, using an agreed upon high viscosity adhesive system that does not contain volatile substances. It should be read in conjunction with ISO 8780-1.

This method is limited to high viscosity abrasives. In order to improve the precision of the method, it is suggested that the dispersion procedure of the test pigment and the agreed reference pigment should be carried out at the same temperature.

The results obtained are not suitable for comparison with the dispersion results obtained using other dispersion methods.

Notă 1 The advantages of the three-high mill described in this section of ISO 8780 are ease of handling the equipment, the ability to prepare sufficient quantities of abrasive for extensive evaluation procedures, ease of cleaning and associated probable results with the results of the production machinery. Unlike dispersion devices used for low-viscosity abrasive formulations, three-roll grinders such as those described in this part of ISO 8780 allow processing of a variety of high-viscosity abrasive formulations. Because of this greater flexibility, it is not necessary to precisely specify the appropriate color paste formula.

2 Normative reference files
The following standards contain provisions which, by reference, constitute the provisions of this part of ISO 8780. At the time of publication, the version shown is valid. All standards are subject to revision and parties to an agreement based on this part of ISO 8780 are encouraged to investigate the possibility of applying the latest versions of the following standards. IEC and ISO members maintain a register of international standards currently in force.

ISO 787-24:1985, General methods of test for pigments and increments – Parte 24: Determination of the relative tinting force of coloured pigments and the relative scattering force of white pigments – photometric method.

ISO 842:1984, Raw Materials for paints and varnishes – Prelevarea de probe.

ISO 1524:1983 Vopsele și lacuri – Determination of grinding fineness.

ISO 8780-1:1990, pigments and increments — Dispersion methods for the evaluation of dispersion properties — Parte 1: Introducere.

ISO 8781-1:1990, pigments and increments – Methods for assessing dispersion properties – Parte 1: Assessment against changes in the tint strength of coloured pigments.

ISO 8781-2:1990, pigments and increments – Method for assessing dispersion properties – Parte 2: Assessment against changes in grinding fineness.

ISO 8781-3:1990, pigments and increments – Methods for assessing dispersion properties – Parte 3: Assessment from changes in gloss.

Doar secțiunea de informații standard este publică. Pentru a vedea conținutul complet, trebuie să achiziționați standardul prin canalele oficiale.