Coating thickness is a critical variable when it comes to process control, product quality, and cost control. The measuring film thickness is a routine process for coaters as it can have a big impact on quality and cost of work. There are many different types of instruments that can be used to determine this value and the proper gauge to use usually depends on the shape and type of the substrate, the thickness range of the coating, the cost of the gauge, and the criticality of a precise measurement. These factors are among the most important things you should pay attention to when selecting the right coating thickness meter to use for any type of project.

Understanding the equipment you are using as well as how efficient it is for the coating operation at hand is important to ensure the quality of the new coating being applied. Some commonly used measuring techniques and methodologies used for measuring the thickness of cured organic films include non-destructive methods like eddy current, magnetic gauges, ultrasonic pulse echo, and micrometer measurement. Destructive dry film methods are also used like gravimetric or mass measurement and cross-sectioning measurement. Methods for liquid and powder coatings are also used to measure film thicknesses before it is cured.ral 9005 powder coating

Magnetic film thickness gages are commonly used for non-destructive measurement of non-magnetic coating on ferrous substrates. Coatings on ferrous metals like iron and steel are typically measured this way. Magnetic gages use one of two operational principles, namely, magnetic pull-of or electromagnetic induction.

Eddy current techniques also promote non-destructive measurement. Instruments that use Eddy current often use a coil of fine wire that conducts high-frequency alternating current to set up an alternating magnetic field at the probe's surface. When the instrument is brought near the conductive surface, the magnetic field triggers eddy currents or an opposing magnetic field, which is then sensed by the exciting coil or by an adjacent coil. Gages that use Eddy current resemble and are operated like electromagnetic gages, although they are commonly used to measure coating thickness on non-ferrous metals.

Ultrasonic pulse-echo gages, on the other hand, are used to measure coating thickness on non-metal substrates like wood and plastic. Like the previous types of gages, ultrasonic instruments won't damage coating in the process of measurement. Micrometers are another type of non-destructive coating thickness meter that allow for the measurement of different coating and substrate combinations. However, they may not be sensitive enough to detect thin coatings.

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Knowing the definite characteristics, behavior and Powder flow properties are of the utmost importance in various industries such as the pharmaceutical industry. This information is vital because it helps us to know the exact result, we will obtain in doing certain operations. For example, the complete and definite knowledge of powder flow properties helps us in different operations such as compression, transportation etc.

These powder flow properties can further be measured using various metrics. Some of the most popular and most useful properties which are used to predict the behavior of flow of powders are powder cohesion, the dynamic angle of repose, powder compressibility, Carr's index and Hausner ratio. Various instruments are used to measure and predict these properties accurately such as Powder Rheometer, Bulk density testers, powder flow testers and much more. Let us dive deep and get an overview of each of these properties.ral 9005 powder coating

Powder Cohesion
Cohesion is defined as sticking together of particles of the same substance. The particles tend to collect together or attract each other. They exert attractive forces towards each other called the Wander Waal’s forces. This is an important factor that determines the powder flow. Another type of attractive force that the particles can exert is an electrostatic force. This property signifies how the powder will flow through hoppers. Too much attractive forces inhibit the flow.

The Dynamic Angle of Repose
There are two kinds of angles of repose that affect powder flow properties, static and dynamic angle of repose. Here we will consider the dynamic angle of repose.

Dynamic angle of repose is the angle observed when the powder particles are moving continuously downwards on an inclined slope. Different angles of repose exert different effects on the powder flow properties. Different angles are associated with the size of the particles present in the powder.

Powder Compressibility
This is yet again an important factor which determines the powder flow. The powder compressibility is the ability of particles present in the sample of powder to shrink or compress in volume when pressure is applied. In other words, a material’s compressibility is its bulk density/pressure relationship.

Wall friction
The flowability of powder is also largely dependant on external factors such as the friction between the walls of the container they are flowing through and the particles of the powder. Wall friction affects the angle of the hopper and it is required to be designed keeping the wall friction in mind. Taking account of this property, the shape of the hopper is decided whether it will be shaped as a cone or a wedge because wall friction dictates the mass flow.

Powder Rheometers
These instruments are capable of measuring the shear, bulk and various above mentioned dynamic properties of a powder. The powder samples are analyzed for various different conditions like consolidated, conditioned or even in the fluidic state leading to a full exploration of various properties.

With the advent of sensitive instruments like Powder Rheometer, measuring the powder flow properties has become accurate. The knowledge of powder flow properties is very vital if we want our system to run at maximum efficiency

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When the powder is poured or passively filled into a container, the density is then termed as bulk density. This causes smaller particles to occupy the spaces between larger ones, and also changes the angles of the particles so that a more compact fit is achieved. Tapped DensityWhen it's required to assess the geometrical space occupied within the container, or envelope of a solid material, the true density of the powder is measured.

These features Specialty powder coatings for sale can broadly be classified into:primary or fundamental characteristics regarding basic materials, particulate size, shape, surface area etc. Read also about tap test tool. This includes any cracks, pores, fissures etc. A comparison between true density and tapped density is useful and powder handling equipments can then calculate the rate of flow, compressibility and powder-behavior under flow-conditions. Why It is ImportantThe difference between bulk and tapped densities is in the way the powder is handled.

Tapped density is obtained when the container is then lifted and dropped a certain number of times and the powder settles down more towards the bottom of the container. Accurate powder measurement is important from the point of view of estimating packaging requirements and storage needs. This is known as tapped density.Properties of Powders All powders have certain features in common. It is achieved without the application of any pressure and allows the powder to retain its flowability and consistency.

However, powder consists of particles with individual shapes and though the powder bulk density remains the same after grinding or processing, it's possible to increase the space occupied by the entire content by tapping or vibrating the container. This is also called bulk density.derived characteristics or behavioral properties like flow, bulk, tapped density, compactibility, lubricity etc

 

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