Electrostatic clinging

Electrostatic clinging of fabrics Fabric to metal test Quantitative... 

Only "tortuous-pore" membrane discs may be used in such a stack. The reason is that the polycarbonate or polyester "capillary-pore" membranes currently available are very thin (typically 10 ju thick) and easily pick up an electrostatic charge. It is almost impossible to load 293 mm discs of these membranes onto the plates. They cling to hands and wrinkles cannot be totally eliminated. It is possible to buy (in Japan) a heat sealed "sandwich" with polyester screens on both sides of the "capillary-pore" membrane (see Figure 2.46) which facilitates handling. The "sandwich" is sealed around the periphery to prevent lateral leakage. 

Immobilization of whole microbial cells for industrial purposes eliminates the need for the isolation, purification and attachment of enzymes and provides the enzymes with a microenvironment maintained at optimal conditions by cellular metabolic and transport activities. Adhesion of microbial cells to inert substrata often occurs in nature and greater understanding of these natural processes may lead to advances in the technology of whole cell immobilization. Mechanisms of attachment in natural systems involve adhesive microexudates produced by the cells, electrostatic attraction, and anatomical projections which cling to the support surface. The chemical methods which have been used for whole cell immobilization have recently been reviewed by Jack and Zajic (1 ). 

In addition to the ability to dispose of the used material by dissolving it, an interesting advantage of starch-based loose fill cushioning materials is they do not tend to build up electrostatic charges, so they do not cling the way packaging peanuts made of expanded polystyrene tend to do. 

Some materials are sticky or have electrostatic properties that cause clinging to duct surfaces. Velocity will not overcome these problems. 

Scrubbers. These are tanks where the waste gets sprayed by jets of water, before it reaches the chimneys. The water washes away smoke and dust, and dissolves some of the harmful gases. Electrostatic precipitators. In some factories, the waste is led into a chamber called an electrostatic predpitator, where an electric current is passed through it. The smoke and dust partides get charged, and cling to electrodes. In time, they fall to the bottom of the predpitator and are removed. 

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