Wetting and cleaning

It is easily understood that a good adhesive must wet and clean the adherend, have a high Dupre energy of adhesion, a high viscosity, and no residual stress. To wet... 

The surface of the workpiece is wetted and cleaned as it passes through the flux into the molten bath. The dry process produces a lower quality of dross and a cleaner environment can be maintained in the plant. Less space is required for the wet process and a better surface for galvanizing is produced as the workpiece passes through the flux blanket. 

Uses Emulsifier, wetting and cleaning agent, penetrant, detergent, stabilizer, dispersant, coemulsifier... 

The top of the bench should always be kept clean and dry this can easily be done if a wet and a dry rag are kept at hand. Apparatus not immediately required (a) should be kept as far as possible in a cupboard beneath the bench if it must be placed on the bench, it should be arranged in a neat and orderly manner. All apparatus should be washed immediately after use and placed in a position to drain at the first opportunity, the apparatus should be dried. It must be emphasised that as a general rule a deposit of dirt or tar is more easily removed when it is freshly formed a suitable cleaning agent can usually be found while one still remembers the nature of the material or the circumstances attending its formation. It is hardly necessary to add that sohd waste and filter papers must not be thrown into the sink, and that all operations requiring the handhng of unpleasant and noxious materials sliould be carried out in the fume cupboard ( hood ). 

The gas, along with entrained ash and char particles, which are subjected to further gasification in the large space above the fluid bed, exit the gasifier at 954—1010°C. The hot gas is passed through a waste-heat boiler to recover the sensible heat, and then through a dry cyclone. SoHd particles are removed in both units. The gas is further cooled and cleaned by wet scmbbing, and if required, an electrostatic precipitator is included in the gas-treatment stream. 

It is generally unacceptable to emit sulfur dioxide, thus the scmbber effluent must be treated for sulfur dioxide removal. If the plant aheady possesses faciUties for the production of sulfuric acid, this rather concentrated sulfur dioxide stream can be easily fed into the wet gas cleaning circuit and disposed of in the sulfuric acid plant. The quantity is so small that it does not put any additional burden on the sulfuric acid plant. Because no tellurium is carried over with the selenium dioxide during roasting, it is possible to produce a selenium product which can be purified to commercial grade (99.5-99.7%). 

Molten tin wets and adheres readily to clean iron, steel, copper, and copper-base alloys, and the coating is bright. It provides protection against oxidation of the coated metal and aids in subsequent fabrication because it is ductile and solderable. Tin coatings can be appHed to most metals by electro deposition (see Electroplating). 

Adhesion to Metals. For interaction between coating and substrate to occur, it is necessary for the coating to wet the substrate (107). Somewhat oversimplified, the surface tension of the coating must be lower than the surface tension of the substrate. In the case of metal substrates, clean metal surfaces have very high surface tensions and any coating wets a clean metal substrate. 

Our Electronic Chemicals group is an industry leader in most basic manufacturing of Wet Process Chemistries, from UHP Straights (100 ppt qualities). Custom formulated Wet Etch, Solvents and Solvent Blends, and Cleaning Products. 

During prolonged outages, remove wet packing and clean gasketed surfaces thoroughly. 

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