Fusing presses

The adhesive coating materials, applied to the base cloth to form the fusible interlining, are thermoplastic materials, which melt and flow in the fusing press and so form the bond between interlining and face fabric. The materials most commonly used as adhesives have already been described (under Hot melt adhesives), that is polyethylene, copolyamide, copolyester, plasticized PVC, cellulose acetate and polyvinyl acetate. 

The fusing process is performed by special fusing presses. They can be divided into two groups according to the way they perform the work process discontinuous work process (flat) fusing presses and continuous work process fusing presses. 

The discontinuous fusing press is generally flat bed, which has a heating zone with two work surfaces. The other arts are handle, head and buck. Depending upon the... 

Figure 9.20 The schema of a continuous fusing presses 1, loading and feed (lower) conveyer belt 2, upper conveyer belt 3, upper heating zone 4, lower heating zone 5 and 6, pressure rolls 7, exit conveyer.

The fusing presses are produced by companies Meyer (Germany), VEIT-Group " (Germany), Reliant Machinery (UK), The Martin Group (Italy), Macpi (Italy),... 

Pellets of such oxides are usually prepared by mixing 5—10 wt % of the oxide with KBr and pressing a pellet that is several mm thick. Although the preparation of such systems is not difficult, often the pellet must be pressed for long periods of time to allow the KBr to fuse around the oxide particulates. Once prepared, in spectra of these pellets can be acquired in standard KBr pellet holders. 

Laminates. Laminate manufacture involves the impregnation of a web with a Hquid phenoHc resin in a dip-coating operation. Solvent type, resin concentration, and viscosity determine the degree of fiber penetration. The treated web is dried in an oven and the resin cures, sometimes to the B-stage (semicured). Final resin content is between 30 and 70%. The dry sheet is cut and stacked, ready for lamination. In the curing step, multilayers of laminate are stacked or laid up in a press and cured at 150—175°C for several hours. The resins are generally low molecular weight resoles, which have been neutralized with the salt removed. Common carrier solvents for the varnish include acetone, alcohol, and toluene. Alkylated phenols such as cresols improve flexibiUty and moisture resistance in the fused products. 

To make a decorated plate, the mold is opened shortly after the main charge of molding compound has been pressed iato shape, the decorative foil is laid ia the mold on top of the partially cured plate, ptinted side down, and the mold closed again to complete the curing process. The melamiae-treated foil is thus fused to the molded plate and, as with the decorative lamiaate, the overlay becomes transparent so that the ptinted design shows through yet is protected by the film of cured resia. 

Group 2 Nitrate/metal/sulphur compositions Compositions with >65% chlorate Black powder Nitrate/boron compositions Burn violently Large firework shells Fuse unprotected signal flares Non-pressed report bullets (bird scarers) Report cartridges (unpacked) Black matches (uncovered) Accelerating single-item explosions... 

Group 3 Nitrate/metal compositions without sulphur Compositions with <35-65% chlorate Compositions with black powder Lead oxide/silicon with >60% lead oxides Perchlorate/metal Burn fast Large firework shells Fuse protected signal flares Pressed report cartridges in primary packagings Quickmatches in transport packagings Waterfalls Silver wheels Volcanoes Black powder delays Burn very violently with single-item explosions... 

Mullins, L.J. Christensen, D.C. Babcock, B.R. "Fused Salt Processing of Impure Plutonium Dioxide to High Purity Metal", Los Alamos Nat. Lab. Report LA-9154-MS also Symposium on Actinide Recovery from Waste and Low Grade Sources, ACS, New York City August 23-28, 1981 (in press). 

For books on this subject, see Gutman, I. Cyvin, S.J. Introduction to the Theory of Benzenoid Hydrocarbons, Springer NY, 1989, Dias, J.R. Handbook of Polycyclic Hydrocarbons, Part A Benzenoid Hydrocarbons, Elsevier NY, 1987, Clar, E. Polycyclic Hydrocarbons, 2 vols. Academic Press NY, 1964. For a periodic table that systematizes fused aromatic hydrocarbons, see Dias, J.R. Acc. Chem. Res., 1985, 18, 241 Top. Curr. Chem., 1990, 253, 123 J. Phys. Org. Chem., 1990, 3, 765. 

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