Due to the increasing complexity of modern engineering products, the sophistication of requirements for accuracy and reliability, with the improvement of production technology significantly increased demands on the quality of cleaning. Perfection of applied technological processes of cleaning and surface preparation depends essentially on quality cleaning products in various industries. Modern methods of surface cleaning products provide a complete mechanical, chemical and physico-chemical interaction between the active cleaning environment pollution and the surface being cleaned.
High-quality cleaning of parts is a quite complicated and time consuming process. It is carried out with the help of special detergents that have the ability to soften and dissolve dirt to remove it from the surface. Aqueous solutions are known to be the widely used medium for removing contaminants. They are effective, non-toxic, non-flammable and allowing using ultrasonic activation, greatly accelerating the cleaning process and improving its efficiency. Under the influence of ultrasonic the washing liquid acquires the ability to penetrate into the deep pores, tight holes, channels and nodes of complex configuration, portions of which under normal circumstances, the impact of cleaning media will hardly be achieved. Despite the wide variety of processes for the preparation of the surface details before subsequent operations, cleaning process in general is reduced to two aspects:
- Cleaning in an aqueous solution of technical detergent (TD);
- Washing residues from TD in running water.
One of the most promising applications of ultrasound in various industries, which meets modern requirements of technological processes, is the cleaning of parts, components and assemblies of technological and operational pollution. The specialised equipment is supplied by the brands producing ultrasonic cleaning systems. Hilsonic Company, a prominent ultrasonic cleaner equipment manufacturer offers a range of 20+ models with deep customisation capabilities, and this is just a single brand.
The process of contamination occurs on the surfaces mostly during the production process. Preclassification pollution assessment of the cleaning surface allows to choose the right detergent and cleaning technology. Taking into account the features of ultrasonic cleaning all the dirt is classified into three main features:
- the ability to withstand loads microshock;
- the nature and strength of the connection with the surface to be cleaned;
- the nature of the chemical interaction with the cleaning fluid.
The most common for most industries are oil pollution and oil-based polishing paste, inorganic pollution in the form of mechanical particles and dust, corrosion products, oxides, oxide film. When machining chips, dust, burrs and etc. are produced. When welding and scale, flux residues, resins, salts are formed.
It is relatively easy to remove inorganic contaminants in the form of particles and dust mechanically weakly coupled with the surface details. But when it comes to polishing, grinding and lapping pastes consisting of abrasive powders and binders – the removal will hardly be a walk in the park. They are based on stubborn substance – oleic acid, stearin, paraffin, etc. and abrasives do not dissolve neither in water nor in organic solvents. With ultrasonic cleaning such contamination is removed due to emulsification and saponification of fatty pollution and dispersion of solid particles.