Related Experiment Video
Updated: Jun 25, 2026
08:05
Localized Bathless Metal-Composite Plating via Electrostamping
Published on: September 22, 2020
Effect of relative humidity on coating efficiency in nonelectrostatic and electrostatic coating
1Dept. of Food Science and Technology, The Ohio State Univ., 2015 Fyffe Road, Columbus, OH 43210, USA.
Journal of Food Science
|February 26, 2009
Summary
Relative humidity (RH) impacts food powder coating efficiency. High RH increases coating loss for larger particles in nonelectrostatic coating and affects electrostatic coating of salts, while 20%-60% RH is recommended.
Area of Science:
- Food science and technology
- Materials science
- Surface engineering
Background:
- Optimizing powder coating processes is crucial for food product quality and manufacturing efficiency.
- Understanding the influence of environmental factors like relative humidity (RH) on coating performance is essential for industrial applications.
Purpose of the Study:
- To investigate the effect of relative humidity (RH) on coating efficiency of food powders using both nonelectrostatic and electrostatic corona coating methods.
- To determine the impact of RH on targeting loss, coating loss, and transportation loss for various food powders.
Main Methods:
- Fifteen food powders were coated onto aluminum targets under varying RH (20%-80%) and electrostatic potentials (0, +25, -25 kV).
- Coating efficiency was assessed by measuring targeting loss, coating loss, and transportation loss.
- Powder properties such as particle size and resistivity were analyzed in relation to RH.
Main Results:
- RH did not affect targeting loss in either coating method.
- Increasing RH increased coating loss for larger particles (>297 microm) in nonelectrostatic coating.
- Electrostatic charging efficiency and powder resistivity decreased with increasing RH, impacting electrostatic coating loss, particularly for salts.
Conclusions:
- A relative humidity range of 20% to 60% is recommended for optimal food powder coating, balancing efficiency and minimizing losses.
- Particle size and powder type significantly influence the effect of RH on coating performance.
- While electrostatic coating showed some RH sensitivity, especially for salts, overall efficiency can be maintained within the recommended RH range.
More Related Videos
06:49In situ Grazing Incidence Small Angle X-ray Scattering on Roll-To-Roll Coating of Organic Solar Cells with Laboratory X-ray Instrumentation
Published on: March 2, 2021
07:47Experimental Protocol to Investigate Particle Aerosolization of a Product Under Abrasion and Under Environmental Weathering
Published on: September 16, 2016
Related Concept Videos
01:17Factors Affecting Activity Coefficient
The extended Debye-Hückel equation indicates that the activity coefficient of an ion in an aqueous solution at 25°C depends on three partially interdependent properties: the ionic strength of the solution, the charge of the ion, and the ion size.
The activity coefficient value for an ion is close to one when the solution has almost zero ionic strength, i.e., when the solution shows close to ideal behavior. As the ionic strength of the solution increases from 0 to 0.1 mol/L, a decrease in the...
The activity coefficient value for an ion is close to one when the solution has almost zero ionic strength, i.e., when the solution shows close to ideal behavior. As the ionic strength of the solution increases from 0 to 0.1 mol/L, a decrease in the...
01:27The Debye–Hückel Theory of Electrolyte Solutions
The Debye–Hückel theory, established by Peter Debye and Erich Hückel in 1923, is a fundamental concept in physical chemistry. It provides an understanding of the behavior of strong electrolytes in solution, particularly explaining their deviations from ideal behavior.The theory is based on Coulombic interactions (the attraction or repulsion between charged particles) between ions in solution. In an ionic solution, oppositely charged ions tend to attract each other. This means that cations...
01:09Colloidal precipitates
The high insolubility of some precipitates can result in an unfavorable relative supersaturation. This can lead to colloidal particles with a large surface-to-mass ratio, where adsorption is promoted. For instance, in the precipitation of silver chloride, silver ions are adsorbed on the surface of the colloidal particles, forming a primary layer. This layer attracts ions of opposite charge (such as nitrate ions), forming a diffuse secondary layer of adsorbed ions. This electric double layer...
01:20Preparation of Samples for Electron Microscopy
To be visualized by an electron microscope, either transmission or scanning, biological samples need to be fixed (stabilized) so the electron beam does not destroy them and dried thoroughly (desiccated/dehydrated) so the vacuum does not affect them. Fixation needs to be done as quickly as possible because the sample properties will start changing as soon as it is removed from its natural environment. For example, in a tissue sample, the oxygen levels begin decreasing, causing an altered...
01:23Theory of Strong Electrolytes
The interionic forces of the strong electrolytes depend on the solvent's dielectric constant, which is the ability of a solvent to store electrical energy, based on its polarizability. and the solution's concentration. In high-dielectric solvents and in dilute solutions, weak electrostatic forces keep ions apart. However, in low-dielectric solvents or concentrated solutions, stronger interionic forces may cause ions to pair up as ionic doublets despite being fully ionized. The theory of strong...
01:30The Electrical Double Layer
In the region where two bulk phases meet, an intricate electric charge distribution arises due to charge transfer, ion adsorption, molecular orientation, and charge distortion. This complex distribution is commonly referred to as the electrical double layer.When a solid electrode interfaces with ions in an electrolyte solution, the speed of electron transfer dictates the rates of oxidation and reduction. The electrode acquires a charge through the escape of atoms into the solution as cations or...