This paper presents the results of an emission study on plasma spraying equipment and processes. Various measurements and samples were taken outside the spraying booth, at the operator level, and in the suction ducts upstream and downstream of the filtration equipment, creating a detailed profile of the aerosol emitted by the injection of NiAl powder in the plasma jet. The results show the existence of two families of particles, one ranging in size from 0.5 to 20 µm, the other of nanometric proportions. Concentrations of the larger particles were in the range of 600 cm-3 in the booth. As for submicron particles, concentrations of up to 107 cm-3 were observed but decreased significantly at the outlet of the filter system. The aerosol samples examined were dominated by a nanometric background of aggregates made up of oxidized nickel particles. Aggregates up to 100 nm in size, consisting of finer particles in the 5-20 nm size range, were found in high concentrations upstream of the filtration system. Great vigilance is thus required to protect equipment operators, an important part of which is placing dust collectors as close as possible to spraying booths connected by short, straight pipe runs.

This paper addresses a need for information on nanoparticle emissions and related issues such as worker exposure, filtration efficiency, and dustiness. A survey has been conducted on the working conditions and safety measures used in thermal spray companies and the results compared to scientific literature and previous surveys. Responses to questions on matters of health and safety reveal a lack of information and awareness of the risks posed by the emissions of ultrafine particles generated by thermal spraying processes.

Due to its easy handling and low operating costs, wire arc spraying has become one of the most established processes for applying protective coatings to components used in waste incineration plants. This paper discusses the development of relatively low-cost Fe-Cr-Si coating materials for incinerator applications and the corrosion and wear properties that have been achieved using conventional arc spraying methods.

Thermal spray particulate presents unique challenges for in-plant dust collection. Regulations about particulate level emissions are becoming increasingly stringent. This paper will discuss the thermal spray environment and technologies that can be useful in the mitigation of airborne particulate. First, a discussion of basic filtration concepts - The many methods that are used to collect particulate (diffusion, inertial impaction, interception, and sieving) and an explanation of each with an understanding of when each methodology is used. We will also explore the properties of the typical thermal spray particulate - particle size analysis of typical resultant thermal overspray process dust including actual test data and scanning electron microscope photos. The structure of the filter media is vital to achieve superior filtration performance. A unique filter media technology for this application will be discussed, including media construction and characteristics of its use. Finally, the filter media must function within a system. A brief discussion of dust collection technology and the dust collection system will describe a solution to the problems of thermal spray particulate.

This paper provides an overview of the equipment used in cold gas spraying. It discusses the general design and operation of key components, including the nozzle, the control system, the gas heater, and powder feeder. It also describes a typical gas supply system, the recycling of helium, and the provisions for health and safety that are necessary in a spray booth. Paper includes a German-language abstract.

The paper discusses the testing methodology and identifies the analytical protocols, with proper validation, in order to evaluate the compatibility of thermal spray coatings in the food production technology, according to EU and FDA applicable standards. A brief state-of-the-art analysis of the international standards on food additives and human health is given, namely on indirect food additives (as defined in 21 CFR 170.3(e)), that can migrate into the food during the process. An outline of the test protocols, based on contact between coating and food simulating solvents in a set time/temperature conditions, are presented, and the main phases for the proposed testing methodology, as the choice of the simulating solvent, the migration cell design and the time/temperature conditions, are discussed. Finally the proposed methodology and protocols are validated through a thermal spray coating for food process application test case.

Coating shops are under increasing pressure by stringent legislation to demonstrate sound environmental performance. This paper describes how one can combine the environmental requirements according to ISO 14000 with existing Quality Management Systems according to ISO 9000. The Environmental Management System requires that a company establishes and maintains an environmental policy with a strong commitment to continual improvement and prevention of pollution. The company has to establish environmental targets with a timeframe by which they are to be achieved. In this paper, some practical aspects of prevention of pollution by using new processes, practices and materials will be described. Some important aspects like recycling of waste from dust collectors or sand blasting units will be discussed.