Machinery, availability

Figure 86 summarizes the features of the processes, in terms of machinery available, types of plate, composition of inks, methods of drying, and applications, and Figures 87 to 95 show the basic elements of each process. 

The semiclassical treatment of inelastic scattering processes is well developed (see, e.g., Refs. (12) and (23). It is therefore obvious to attempt to use the machinery available... 

Obviously, the equipment that a supplier has available will affect the type of materials offered. Decisions should be based on the needs of the product and the packaging machinery available. Once one has set these goals, compromises because of business issues, such as limited supplier base, economics, etc., maybe necessary. 

The construction engineers who have to decide how the job is to be bu and for how much, also have the information of the above four categori available to them. However, they have extra considerations and constrain They have to plan the job within their company s resources. They need to knc the men and machinery available within the company, what can be hired, wli can reasonably be done and how much it will cost. This sort of information is crucial importance in deciding on a tender price. A company will only expect win, say about one in six of the contracts it tenders for. The tender price w depend on many things but one of the most important considerations will be t simple attractiveness of the job to the contractor. Is it an easy profit or is risky Does the company need another job on the books to keep its work for busy, or are they already over-committed ... 

Coating is a basic and important form of finishing for nonwoven bonded fabrics. The way in which the coating is carried out depends on the substrate, the machinery available, the substance that is to be applied, and also the effect desired. Crushed foam coatings can modify the porosity of filter fabrics from zero upwards, depending on the add-on of resin and the severity of cmshing. Foam collapsed into the fabric will present the least resistance and is more suitable for high airflow requirements. 

Dry powder mixers should be selecfed or designed for a particular operation, firstly by analyzing and giving careful examinations to the applicable areas discussed above. Mixer selection should also involve consideration of the place of the mixer within the overall process. Possible integration of many steps within the overall processing of solids in a particular application deserves scrutiny at this time. If there is no machinery available including all the necessary requirements, consideration should be given to modifications in order to obtain the most desirable features combination of the equipment. 

Screens are used in many different applications to separate solids according to particle size. As is true of other highly empirical operations, there are many different approaches to screening. Ihe wide variety of machinery available is described in standard texts and vendors literature. 

The spin finish properties (wetting time, special adhesive content) must be correlated with the customer s machinery availability to guarantee optimum application. The preparations for softening and antistatic protection of the PP staple fibers must be compatible with the stabilizers, and should be preferably liquid and have suitable fogging and ecological behavior [115]. The most important properties of nondurable antistats include low volatility, low toxicity, heat resistance, oil solubility, nonyellowing characteristics, and low flammability they should also be noncorrosive, especially if the treated material will come into contact with metallic processing equipment. 

Insect Cells. In this system the cDNA is inserted into the genome of an insect vims, baculovims. Insect cells, or Hve insect larvae, are then infected with the vims. In this way advantage is taken of the vims s natural machinery for repHcation utilizing the insect cell. This is one of the best systems available for high level production of native protein having post-translational modifications similar to those seen in mammalian cells. Disadvantages of this system include lytic—batch variations, comparatively slow growth, and cosdy scale-up. 

D. R. Smith, ed., Rjcbber WorldMaga ne s 1995 Blue Book, Lippincott Peto, Akron, Ohio, 1995. An annual compilation of materials, compounding ingredients, machinery, and services for the mbber industry. Available on CD-ROM in combination with R. E. Ohm, ed.. The Vanderbilt RjibberHandbook, 14th ed.,1995. 

Monitoring should include the usual parameters worthy of surveillance in high-speed turbo machinery the temperature of journal bearings, vibration and axial position of the pinions, inlet and discharge temperatures combined with discharge pressure from the individual compressor stages, and various lube oil system devices. Competent manufacturers make sure all measurement locations are completely prewired on the machine and made available at predefined interfaces or in terminal boxes for connection at the plant site. 

Too little maintenance results in unexpected failures and consequential major losses of production and/or customers (Figure 7-1). This impractical approach is termed reactive strategy and should be avoided on all important machinery. Optimum maintenance strategy balances reasonable costs with maximum possible availability and reliability. The two main maintenance strategies employed by companies today are labelled predictive strategy and preventive strategy. These are part of a balanced approach as shown in Figure 7-2. 

These unbalance forces increase as a function of making the design and operation of high-speed machinery a complex and exacting task. Balancing is the only method available to tame these excitation forces. 

Diagnosis This includes several levels of machinery diagnosis assistance available via expert systems. These systems must integrate both mechanical and aerothermal diagnostics. 

Charts are available to convert from one type of measurement to another as shown in Figure 19-13. Many of these charts also show approximate vibration limits. The charts demonstrate the independence of velocity measurements relative to frequency, except at very low and very high frequencies where the amplitude limits are constant throughout the operating speed range. These limits are approximate—the type of machinery, casing, foundation, and bearings must be considered to determine final vibration limits. 

A practical solution is to digitize the drawings and place them on CD s available to the maintenance and operation department. A good digital file reduces search time and helps the departments do a better job of keeping the machinery operating at their peak efficiency with minimal downtime. 

As with any power equipment, gas turbines require a program of planned inspections with repair or replacement of damaged components. A properly designed and conducted inspection and preventive maintenance program can do much to increase the availability of gas turbines and reduce unscheduled maintenance. Inspections and preventive maintenance can be expensive, but not as costly as forced shutdowns. Nearly all manufacturers emphasize and describe preventive maintenance procedures to ensure the reliability of their machinery, and any maintenance program should be based on manufacturer s recommendations. Inspection and preventive maintenance procedures can be tailored to individual equipment application with references such as the manufacturer s instruction book, the operator s manual, and the preventive maintenance checklist. 

Flow rate changes are sometimes used in the design of local exhaust systems. An example of this is the use of dampers, blastgates, or valves that are interlocked with the machinery of interest. When the tool is on, the damper is opened and air is exhausted from that hood. When the tool is off, the damper is closed and more exhaust air is available to other parts of the system. These kinds of systems diminish the cost for running the system but increase the cost for installation as well as periodic preventive maintenance. The supply system... 

The well-documented case of the United States serves as an illustration. During the period 1870 to 1900 the farm population was increased through a rapid expansion of the agricultural area. The agricultural labor force increased by 60 percent, but there was a replacement of labor by nonland capital in the form of horses and mules. New and more efficient types of horse-drawn machinery including plows, cultivars, seed drills, grain harvesters, and mowers became available. 

---