Granule adhesives

EN 543 1995 Adhesives. Determination of apparent density of powder and granule adhesives. (Norme Frangaise T76-091). 

Starch is insoluble in cold water, but in hot water the granules gelatinize to form an opalescent dispersion. It is made from corn, wheat, potatoes, rice and other cereals by various physical processes such as steeping, milling and sedimentation. It is used as an adhesive, for sizing paper and cloth, as an inert diluent in foods and drugs, and for many other purposes. 

Amino Resins. Amino resins (qv) include both urea- and melamine—formaldehyde condensation products. They are thermosets prepared similarly by the reaction of the amino groups in urea [57-13-6] or melamine [108-78-1] with formaldehyde to form the corresponding methylol derivatives, which are soluble in water or ethanol. To form plywood, particle board, and other wood products for adhesive or bonding purposes, a Hquid resin is mixed with some acid catalyst and sprayed on the boards or granules, then cured and cross-linked under heat and pressure. 

In terms of processing there is no need for pre-drying PCHE granules, a standard extruder screw as used for polycarbonate may be used and discs are said to release well from the mould. Question marks remain on the oxidative stability of the polymer and on the quality of adhesion of the reflective layer but Dow claim that metallising is possible. 

Solid bed dehydration systems work on the principle of adsorption. Adsorption involves a form of adhesion between the surface of the solid desiccant and the water vapor in the gas. The water forms an extremely thin film that is held to the desiccant surface by forces of attraction, but there is no chemical reaction. The desiccant is a solid, granulated drying or dehydrating medium with an extremely large effective surface area per unit weight because of a multitude of microscopic pores and capillary... 

Figure 2. (1) Neutrophils circulating passively in blood capillary. (2) Chemoattractants may be detected by the circulating neutrophils, by the endothelial cells lining the lumen, or both in order that the neutrophils become adhesive. This adhesion is mediated by selectins, a group of cell surface proteins. Neutrophils roll on the surface of the endothelial cells and then actively locomote seeking out spaces between the endothelial cells. (3) The adhesive neutrophils begin to squeeze between endothelial cells. (4) Cells move through the extracellular matrix towards the site of infection. Here adhesion is low and may not be necessary for locomotion. (5) At the site of infection, neutrophils become trapped by increased adhesion where they phagocytose bacteria and liberate the contents of their granules. After Lackie (1982,1986).

Granulated fly ash [6] can substitute for Portland cement to an extent of 40% to 60%. Fly ash is used in granulated form and has a moisture content around 10% to 20%. The formulation can be used for cementing oil and gas wells within a temperature range of 20° to 250° C. The solution has reduced water absorption and increased sedimentation stability. A formulation [1388] is shown in Table 18-2. Hydrosil (Aerosil) is used to increase the adhesion of the produced cement rock to the casing string. It also reduces the density and water absorption. 

CD62P or P-selectin, which is a component of the platelet a granule membrane of resting platelets. It is expressed on the platelet surface membrane only after a granule secretion. P-selectin mediates the adhesion of activated platelets to neutrophils and monocytes. 

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