ISO 8130-3:1992 pdf download – oating powders -Part 3: Determination of density by liquid displacement pyknometer.
This part of lSO 8130 specifies a liquid displacementpyknometer method for the determination of thedensity of coating powders. The method is based ona determination of the mass and the volume of a testportion.
The apparatus specified is relatively inexpensive,but the liquid displacement pyknometer method isliable to give erroneous results,particularly if thepowder swells in contact with the displacement llq-uid used or the displacement liquid does not totallydisplace the air botwoen the powder particles.Thcliquid displacement method is much slower in exe-cution and less accurate than the gas comparisonpyknometer method specified in isO 8130-2and isonly to be used if it can be shown that the same re-sults will be obtained as for the gas comparisonpyknometer method.
2Normative references
The following standards contain provisions which,through reference in this text,constitute provisionsof this part of ISO 8130.At the time of publication,the editions indicatedi were valid.All standards aresubject to revision,and parties to agreements basedon this part of lSO 8130 are encouraged to investi-gate the possibility of applying the most recent edi-tions of the standards indicated below. Members ofEc and 1sO malntain registers of currently valldlnternational Standards.
IsO 787-10:1981.General methods _of test for pig-ments and extenders Part 10: Determination ofdensity – Pyknometer mefhod.
ISO 842:19B4,Raw materials for paints and varnishesSampling.
ISO 3696:1987,Wafer for analytical laborafory use –Specification and test methods.
ISO 8130-2:1992.Coating powders – Part 2: Deter-mination of densify by gas comparison pyknometer(referee method).
The density of the coating powder is determined ina liquid displacement pyknometer in accordancewith lsO 787-10.using a liquid that completely wetsthe product under test without swelling or dissolvingit.
4.1water,of at least grade 3 purity as defined iniso 3696, freshly boiled and cooled.
4.2Displacementliquid: any suitable aliphatichydrocarbon or mixture of aliphatic hydrocarbons,free from aromatic compounds, with a boiling pointwithin the range 8OC to 140 “C.
n-Heplane has been found to be suitable in manyinstances for the determination of the density ofthermosetting coating powders.However. if there isan interaction between n-heptane and the productunder test or its components,a suitable alternativeliquid shall be used.
4.3Acetone, analytical grade.
7.2Determination of the density of the coatingpowder
Empty the pyknometer, wash it with three separateportions of acetone and dry it under vacuum. Intro-duce a test portion of the sample of between 3 g and4ginto thc pykinometer and reweigh.Add sufficlentdisplacement liquid to wet the test portion and just cover it. Attach the opening of the pyknometer to thepreooure tubc conncctod to tho vacuum pump (5.2y.Reduce the pressure in the pyknometer to amaxi-mum of 1,2 kPa and shake until there is no furtheremission of air from the powder/liquid mixture.carefully allow the pressure in the pyknometer torise toatmospheric pressure. Then fi thepyknometer to the mark” with displacement liquid,taking care not to disturb the sedimented powder.Take care also on filling in order to avoid powderremaining in the neck of the pyknometer. Reweighthe filled pyknometer.