Processing impregnation

The presulfided catalyst used in this study was industrially prepared of a commercial CoMo type HDS catalyst by the Sulficat Process, impregnation with an organic polysulfide compound followed by fixation at an elevated temperature. The amount of sulfur introduced on the catalyst has been calculated from the theoretical stoechiometry necessary to convert all the molybdenum and cobalt into M0S2 and CoqSg. 

The thermoplastic semifinished part production can be divided into the following processes impregnating, consolidating, and transitioning to the solid state. During processing, the input materials (fiber and matrix) depend on the process-required control variables Temperature T, time t, and pressure p, which will then determine the resulting properties of the semifinished parts [2]. 

On standing, gelatinous aluminium hydroxide, which may initially have even more water occluded than indicated above, is converted into a form insoluble in both acids and alkalis, which is probably a hydrated form of the oxide AI2O3. Both forms, however, have strong adsorptive power and will adsorb dyes, a property long used by the textile trade to dye rayon. The cloth is first impregnated with an aluminium salt (for example sulphate or acetate) when addition of a little alkali, such as sodium carbonate, causes aluminium hydroxide to deposit in the pores of the material. The presence of this aluminium hydroxide in the cloth helps the dye to bite by ad sorbing it—hence the name mordant (Latin mordere = to bite) dye process. 

Two processes may be used in the manufacture of combustible cases the original post-impregnation process and the more recently and more widely employed beater additive process. The processes differ primarily in the point at which the required resin is added to the composition. A schematic of the beater additive process is shown in Figure 11. 

Two processes precede the affixing of the heads for wooden matches. The first one is glow-proofing of the splint by impregnation with ammonium phosphate or a mixture of it with boric acid. In paper matches, the impregnation is conveniently done during the fabrication of the paper. This suppresses... 

Fig. 15. Schematic of the interfacial polymerization process. The microporous film is first impregnated with an aqueous amine solution. The film is then treated with a multivalent cross-linking agent dissolved in a water-immiscible organic fluid, such as hexane or Freon-113. An extremely thin polymer film...

The chemical materials requited for this process iaclude the cormgatiag adhesive, 1—1.2 MPa (150—175 psi) process steam to provide heat to set the cormgator adhesive, possible coatings appHed to the surface of the linerboard facings, possible chemicals impregnated into the linerboard and/or medium, the manufacturer s (glue) joint adhesive, and the printing ink (see Inks). 

Manufacture of friction elements includes the impregnation of fabrics and subsequent lamination, the wet-dough process, and the dry-mix process. Elements from the last two are prepared by compression-molding the formulation for up to an hour at 150—175°C. Thick brake elements require a carefully controUed heating-and-cooHng cycle to minimize stresses created by expansion and contraction (see Brake linings and clutch facings Fillers). 

Fig. 7. Schematic of a self-contained plasma processing unit designed to continuously plasma-treat and impregnate with resin, reinforcing fibers for enhanced composite strength. The unit can also be used to plasma-treat wires to be coated or treated for improved adhesion. Throughput speeds of over...

Diphenylamine can also be produced by passing the vapors of aniline over a catalyst such as alumina, or alumina impregnated with ammonium fluoride (17). The reaction is carried out at 480°C and about 700 kPa (7 atm). Conversion per pass, expressed as parts diphenylamine per 100 parts of reactor effluent, is low (18—22%), and the unconverted aniline must be recycled. Other catalysts disclosed for the vapor-phase process are alumina modified with boron trifluoride (18), and alumina activated with boric acid or boric anhydride (19). 

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