EN ISO 8130 Coating Powders

The “EN ISO 8130 Coating Powders” standard, developed by the International Organization for Standardization (ISO) and later published as a European standard within the scope of harmonization efforts, consists of the following sub-sections published under the same title:

The standard “EN ISO 8130-1 Part 1: Determination of particle size distribution by sieving” describes a method for determining the particle size distribution of coating powders by sieve analysis. Particle size distributions smaller than 100 µm are determined by laser diffraction (EN ISO 8130-13). This method is particularly used to identify large-sized material or the presence of contaminants and can be used as a quality control procedure (pass/fail test) by checking the amount retained on a single sieve.

The following particle sizes are typical for coating powders, but particle size may vary depending on the application:

Thin film technology: 1 µm to 63 µm
Electrostatic coating: 10 µm to 200 µm
Fluidized bed method: 100 µm and above

Sieves with a mesh size smaller than 32 µm are impractical and are prone to clogging during use.

In principle, a weighed quantity of coating powder is separated into fractions using one or more sieves, and the mass of the fraction remaining on the sieve is determined. Sieve analysis can be performed manually or with a machine, using individual sieves or a set of sieves. The passage of coating powder particles through the sieve mesh is due to gravity, shear, or flow forces.

The standard “EN ISO 8130-2 Part 2: Determination of density by gas comparative pycnometry (referee method)” describes a method for determining the density of all types of coating powders using gas comparative pycnometry.

In principle, density is calculated from the mass and volume of the test sample. The volume of the weighed test sample is determined by measuring the volume of gas displaced within the container when the test sample is placed inside. This is accomplished by measuring the pressure difference caused by the displacement of the gas.

The standard “EN ISO 8130-3 Part 3: Determination of density by liquid displacement pycnometry” describes the liquid displacement pycnometry method for determining the density of coating powders. This method is based on determining the mass and volume of a test sample. Coating powders with a density of up to 1 g/cm³ can be measured by agreement according to the ISO 1183-1 standard and the appropriate method.

In principle, the density of the coating powder is determined in a liquid displacement pycnometer using a liquid that completely wets the tested product without swelling or dissolving it.

The standard “EN ISO 8130-4 Part 4: Calculation of the lower explosion limit” describes a method for calculating the lower explosion limit of coating powder, i.e., the minimum concentration of coating powder that will form an explosive mixture in air. This method is based on measuring the gross calorific value of the product, as determined by the method described in the ISO 1928 standard.

In principle, the lower explosion limit of coating powder is calculated by measuring the gross calorific value through the heat of combustion of 1 g of product using the formula given in the standard. Alternatively, starting from another formula, the lower explosion limit can be estimated by multiplying the gross calorific value of each combustible component by the mass present in 1 g of product.

The standard “EN ISO 8130-5 Part 5: Determination of flow properties of powder/air mixture” describes the method for predicting the flow properties of a coating powder and air mixture. The results obtained are influenced by the composition, density, particle size distribution, and particle shape of the coating powder, as well as the tendency of the particles to aggregate and accept charge.

In principle, a certain amount of coating powder is placed in a container and fluidized with clean, dry air under known temperature, humidity, and atmospheric pressure conditions. The height of the powder is measured during and after fluidization, and the mass of fluidized powder flowing through a specific orifice in a given time interval is determined. These measurements are used to calculate the fluidization factor and powder flow rate, which together define the powder's transport and spraying properties.

The standard “EN ISO 8130-6 Part 6: Determination of the gel time of thermoset coating powders at a specific temperature” describes a method for determining the gel time of a thermoset coating powder at a specific temperature. It defines a method for controlling batch variation and ensuring quality control of a specific coating powder. This method is not applicable to coating powders with ultra-short gel times (less than 15 seconds).

In principle, a sample of coating powder is heated to a specific temperature in the cavity of a heating block. The time is determined when no more yarn can be drawn from the molten product.

The standard “EN ISO 8130-7 Part 7: Determination of mass loss during baking” describes a method for determining the mass loss of coating powders applied by electrostatic spraying, flock spraying, or fluidized bed methods during baking (heating). This method is a simple and practical test that provides sufficiently accurate results for coating powders that lose approximately 2 percent (by mass) during baking (heating). Above 2 percent, accuracy decreases as mass loss increases. This method determines the amount of all volatile substances, including water. The thermogravimetric test described in the ISO 11358 series of standards can be used as a comparative method.

In principle, a test sample of the powder is placed on a plate and then baked (heated). The mass loss that occurs during baking is calculated from weighings taken before and after baking.

The standard “EN ISO 8130-8 Part 8: Assessment of storage stability of thermoset powders” describes a method for estimating the storage stability of thermoset coating powders. This standard includes procedures for determining changes in both the physical state and chemical reactivity of the thermoset coating powder, as well as its capacity to form a satisfactory final coating.

In principle, thermoset coating powder is subjected to artificial storage conditions at a defined temperature for a specific period of time. Then, any changes in the fluidity of the powder and its tendency to clump or cake are recorded. Subsequently, any changes in the powder's ability to chemically react and form a satisfactory final coating are evaluated. The conditions at the bottom of the container can be simulated by placing a weight piece in the test portion to simulate compression.

The standard “EN ISO 8130-9 Part 9: Sampling” describes methods for sampling coating powders from shipments and dividing the sample into appropriate quantities to apply the appropriate test methods specified in other parts of this standard. It is assumed that this standard will be used and applied by persons with appropriate qualifications and experience. The procedures are intended to be performed by appropriately trained or supervised personnel.
The standard “EN ISO 8130-10 Part 10: Determination of deposition efficiency” describes a method for determining the percentage mass ratio of spray coating powder deposited on a test object under known spray gun and environmental conditions. This method is applicable to powders applied with corona or tribo charging and can be used to compare the deposition efficiency of the same powder with the same or different guns. This method is only used for comparison when powders or guns are evaluated sequentially, as the effect of the environment and equipment can vary significantly over time and location.

In principle, this method consists of spraying a charged powder at a known flow rate and under known temperature and humidity conditions. The powder is sprayed onto five identical steel pieces, each wrapped in aluminum foil. The mass of powder that settles on the central piece is determined, and from this, the deposition efficiency is calculated. The process is carried out in an air-evacuation chamber. The results depend on the following properties of the powder:

Chemical composition
Density
Particle size distribution
Particle shape
The air flow properties of the mixture
Moisture content
The standard “EN ISO 8130-11 Part 11: Inclined plane flow test” describes a comparative method for determining the flow characteristics of molten thermoset coating powder on a plane inclined at a specific angle to the horizontal plane. The purpose of this test method is to provide an indication of the degree of melt flow that may occur during the curing of the coating powder. This characteristic contributes to the surface appearance and the degree of coating on sharp edges. The test is a comparative method for checking batch-based variation in the behavior of a particular coating powder. No correlation is expected between results obtained from coating powders of different compositions. This method is not suitable for coating powders with a gel time of less than 1 minute at the test temperature when characterized according to the ISO 8130-6 standard. This method is also not suitable for textured powders.

In principle, heat-curing coating powder is formed into a standard-sized pellet and melted on a heated inclined plate, allowing it to flow downwards. The flow rate is measured over a specific period of time from the pellet's starting position.

The standard “EN ISO 8130-12 Part 12: Determination of Conformity” describes a visual method for determining the deterioration in the surface quality of the final coating when two different coating powders are mixed. The surface quality depends on the following properties of the coating powders:
Chemical reactivity
Chemical composition
Melting properties.

The onset, nature, and extent of visual discrepancy depend largely on the mixing ratio of the powders. The nature of the surface appearance discrepancy can manifest itself in the various ways described here.

This test is useful for predicting the possibility of incompatibility arising from mixing different powders, both during the production process and during the application of the coating powder.

This standard only addresses changes in the visual aspects of the coating. The mixture series can also be used to test properties such as mechanical properties, chemical properties, corrosion properties, and resistance to UV radiation. Further properties can be agreed upon between the relevant parties.

In principle, coating powders are mixed in various ratios, and each mixture is applied to standard test panels, baked, and examined for signs of surface incompatibility.

The standard “EN ISO 8130-13 Part 13: Particle size analysis by laser diffraction” describes a method for determining the equivalent spherical particle size distribution of coating powders by laser diffraction for particles ranging in size from 1 µm to 300 µm. A different optical model may be required for particle sizes larger than 300 µm. This standard is specific to the measurement of coating powders and also refers to the ISO 13320 standard, which provides guidance on instrument suitability and particle size distribution. Laser diffraction is not suitable for determining large-sized materials, which can be verified by sieve analysis as described in ISO 8130-1 or dynamic image analysis as described in ISO 13322-2.

In principle, the coating powder sample is analyzed by dynamic light scattering. The powder particles scatter light, and their intensities are measured from various angles using a multi-array detector to obtain the scattering pattern. This pattern is then converted into numerical values using an appropriate optical model and mathematical procedure, and the ratio of the total particle volume for a specific number of size classes that constitute the volumetric particle size distribution is obtained.

The standard “EN ISO 8130-14 Part 14: Terminology” describes the specific terminology used in the field of coating powders. Other terms and definitions related to paints and varnishes are given in the ISO 4618 standard.
The standard “EN ISO 8130-15 Part 15: Rheology” describes methods for determining the rheological behavior of coating powder in both its particulate and molten states.

In principle, different fluidization properties are determined using a rheometer. In addition to rotational speed and torque, the airflow velocity through the powder bed can be precisely controlled, and the pressure drop can be determined. This allows for a complete analysis of all fluidization parameters affecting the powder coating process. To characterize the powder in its molten state, a rheometer conforming to the ISO 3219-2 standard should be used to determine its melting and polymerization properties.

The standard “EN ISO 8130-16 Part 16: Determination of density by liquid displacement method in a measuring cylinder” describes a method for determining the density of coating powders by liquid displacement in a measuring cylinder. The method is based on determining the mass and volume of a test sample. It can be used for all types of coating powders.

If the powder does not swell upon contact with the displacement fluid used, and the displacement fluid replaces the air between the powder particles, then this method can be used and is comparable to the method described in ISO 8130-3.

In principle, the density of the coating powder is determined by the liquid displacement method in a measuring cylinder. The measurement uses a liquid that completely wets the product being tested without swelling or dissolving it.

For many years, our organization, with its competent and experienced staff, has been understanding the needs of its clients, providing the advanced testing services they require, and assisting them in the establishment, implementation, and improvement of management systems. Within this framework, we also provide testing services in accordance with the EN ISO 8130 standard.