Cleaning and surface treatments

Adhesive users should not assume that meticulous cleaning and costly surface treatments will always be needed to ensure reliable adhesive bonding however, as in all adhesive applications, the better the user imderstands what the adhesive must do, the more readily the need for cleaning and surface treatments can be assessed. Cleaning and surface treatment of substrates is not always economically feasible nor is it necessarily environmentally desirable. There have been considerable advances with respect to pressure-sensitive and structural adhesives which form strong durable bonds on oily metals and untreated plastics. 

Surface Modification. Plasma surface modification can include surface cleaning, surface activation, heat treatments, and plasma polymerization. Surface cleaning and surface activation are usually performed for enhanced joining of materials (see Metal SURFACE TREATMENTS). Plasma heat treatments are not, however, limited to high temperature equiUbrium plasmas on metals. Heat treatments of organic materials are also possible. Plasma polymerization crosses the boundaries between surface modification and materials production by producing materials often not available by any other method. In many cases these new materials can be appHed directly to a substrate, thus modifying the substrate in a novel way. 

On the other hand, many metals have characteristic bright, reflective surfaces that may be enhanced by polishing and surface treatments such as electroplating. The natural appearance of plastics is quite acceptable for many applications but sometimes there is need to make components with reflective surfaces similar to those in metals this may be no more than a question of appearance—the designer or manufacturer feeling that an item will look better—while in other circumstances a metallic finish may be functional. One instance of the second would be fittings for bathrooms, where a bright surface not only is attractive but also resistant to wear and easy to keep clean. 

Most conventional coal cleaning operations utilize gravity methods for the coarser size fractions and surface treatment methods for the finest particle sizes (Riley and Firth, 1993). The selection of equipment, especially for the finer sizes, depends on the mining method, coal hardness, and size distribution and amounts thereof. Typical of these is a dense-media cleaning process (Fourie, 1980) which use dense-media vessels or jigs for the coarsest size usually +3/8 in., dense-media cyclones, concentrating tables or jigs for the 3/8 in. x 28-mesh size, water-only cyclones or spirals, and sometimes flotation for the 28 x 100-mesh size and flotation for the -100 mesh. 

Most conventional coal cleaning facilities utilize gravity methods for the coarser size fractions and surface treatment methods for the finest particle sizes (Riley and Firth, 1993). The selection of equipment, especially for the finer sizes, depends on the mining method, coal hardness, and size distribution and amounts thereof. 

As in the case of other stuface analytic methods, in order to examine well-defined stufaces, the sample surface must be prepared by cleaning and subsequent treatments such as adsorption and/or annealing processes in an ultrahigh vacuum (UHV). After that, the surface species must be desorbed from the surface by a specific excitation method and are analyzed by a specific detector. To induce desorption of the adsorbed species or the surface atoms, the surface is thermally excited by increasing the temperature (as in most cases) or electronically excited by irradiation... 

The quality of the coating (e.g. crystal size, porosity, smoothness, thickness, adhesion to base metal) is influenced mainly by bath composition, pH and temperature, although initial metal surface structure, cleaning and pre-treatment can also be important. In addition to accelerators, other additives may be included in bath formulations to control crystal nucleation, wetting of the metal surface and the metal ion concentration. 

J.C. Harris, Hard surface cleaning and water treatment in (3). 

J.C. Harris, Hard surface cleaning and water treatment, in Phosphorus and Its Compounds, Vol. 2, Wdey, New York, 1960. 

Stone, (iv) Metal alloys and (v) Surface modifications induced by cleaning and protective treatments. 

Surface Modifications Induced by Cleaning AND Protective Treatments... 

Abrasive Developments have, in conjunction with their Japanese licensee, developed a wet blast phosphating plant that raises the quality standard within the industry. The solution achieved delivers high quality components from an automatic machine that combines both the cleaning and phosphating processes. The cleaning section benefits from the unique degreasing and surface treatment properties of the VAQUA process. 

Other laser applications include marking (e.g. product codes), drilling (e.g. where extremely small holes are required) and surface treatment (e.g. annealing, hardening, spraying, coating and cleaning). 

Spray ponds have enormous potential for promoting microbiological growth. In a ventilation system, all surfaces which are in contact with water must be kept clean, and chemical treatments must not be added to spray ponds. 

Once inside the analytical system there are many types of preparation or treatment of the specimen that might need to be carried out in the course of any one problem-solving procedure. They fall into the approximate categories of cleaning, depth profiling, interface exposure, and surface treatment. 

Surfactants are as important to the metal processing as to the mining industry. In order to perform as needed, metal surfaces must be cleaned and freed from deposits of oxides, oils, and other contaminants. Welding, painting, and other machining and surface treatments require a well-prepared surface. Even before that stage of... 

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