Drying methods hardware

This chapter does not deal with the electronic soft- and hardware to document the data, to calculate the desired results, and to monitor failures. The hardware is available in different configurations and the software can be bought or developed to fit into the software used in production. The prerequisites discussed are those for the methods of measurements and the plant layout to permit automation. The general prerequisite is the use of the same freeze-drying methods from product development through pilot plant studies to production for example, the same principle of temperature and pressure measurements, identical definitions of tolerances, and similar criteria for statistical evaluations. If this prerequisite is not observed, the development steps may have to be repeated to permit later automation. 

The General Electric SPE (17) consists of two porous particulate electrodes which are bondecTcohesively with polytetrafluoro-ethylene dispersion particles and connected electrically to the outside of the cell hardware by means of metallic current collectors which are pressed against the SPE by mechanical methods. Such an SPE can be prepared via perfluoroionomer solution techniques. One method is to apply a paste consisting of the electrolyte powder and the perfluoroionomer solution to the membrane and evaporate the solvent. Alternately, the paste can be applied to a sacrificial substrate such as aluminum foil, dried, and subsequently pressed into the membrane as a decal. 

Accelerated testing of the protective ability of the preservation of hardware by inhibited plastics is carried out by standard methods at the branch, state or international level. The real conditions of storage and transportation of preserved articles are simulated during these tests. With this aim, the system is subjected to a cyclic loading with a salt mist in dry or wet conditions with [87-89] and without moisture condensation [86]. Aside from this, certain simplified non-standardized procedures take into account the type and purpose of preserved hardware as well as the required conditions, aims and terms of preservation [49-51,90-92]. 

Dry samples are placed in the crystallization vessels, dissolved, crystallized, and sampled. The polymer concentration is measured by an FT-IR at increasing T. The instrument may be converted into a CRYSTAF-TREF system capable of running both types of measurements in the same hardware. Each method provides complementary information on the CCD in some complex resins. 

Walter and Bryant [414] described a method for freeze drying latex specimens in a home made vacuum system rather than a commercially available device (as was typical of the state of the art at that time). Later, a freeze drying/image analysis method using commercially available equipment was described [413]. Important details of that method included specimen preparation, placement onto a TEM (or SEM) grid, the hardware for the experiment and the metal coating. 

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