Machine conditions

BE-740S The development of a PC artificial intelligence system for the diagnosis and oroanosis of machine condition usina acoustic emission and acceleration Mr. A. Aurrecoechea gBKWS ... 

The viscosity of an adhesive directly influences its penetration into a substrate as the viscosity increases, the penetrating power decreases. It also determines the amount of mileage or spread that can be obtained. An optimum viscosity exists for each substrate and each set of machine conditions and must be achieved in order to manufacture an efficient adhesive. Poly(vinyl acetate) emulsions are frequently too low in viscosity to be metered efficiently or to perform well as adhesives by themselves. They must be bodied to working viscosities, eg, by adding thickeners. 

As previously mentioned in Chapter 5, one of the most severe disturbances for the power recovery train (PRT) is a generator breaker opening. This event often causes the PRT to trip on overspeed or other process or machine conditions. A control solution has been developed to keep the PRT and the process under control during breaker opening. 

Work scheduled to monitor machine condition, predict pending failure, and make repairs on an as-needed basis e.g. monitoring machine vibration. 

The useful frequency range for displacement probes is from 10 to 1000 Hz, or 600 to 60,000 rpm. Frequency components above or below this range are distorted and therefore unreliable for determining machine condition. 

Comparative analysis directly compares two or more data sets in order to detect changes in the operating condition of mechanical or process systems. This type of analysis is limited to the direct comparison of the time-domain or frequency-domain signature generated by a machine. The method does not determine the actual dynamics of the system. Typically, the following data are used for this purpose (1) baseline data, (2) known machine condition, or (3) industrial reference data. 

This method provides the means to quickly monitor the mechanical condition of critical machine components, not just the overall machine condition. This technique provides the ability to monitor the condition of gear sets, bearings and other machine components without manual analysis of vibration signatures. 

In order to understand potential problems and solutions of design, it is helpful to consider the relationships of machine capabilities, plastics processing variables, and product performance (Fig. 1-10). A distinction has to be made here between machine conditions and processing variables. For example, machine conditions include the operating temperature and pressure, mold and die temperature, machine output rate, and so on. Processing variables are more specific, such as the melt condition in the mold or die, the flow rate vs. temperature, and so on (Chapter 8). 

The speed of closure to the form is a function of machine condition and sheet thickness, with the thicker sheets being more difficult to move rapidly. The designer should indicate this to the sheet former when form stability at elevated temperatures is critical and the process must be tailored to improve this condition. One should also select a material which is intrinsically more stable and easily formed to minimize the possibility of unmolding. These factors must be considered in conjunction with the design of the product to minimize sheet stretching differentials in the part. 

A distinction should be made between machine conditions and processing variables. Machine conditions are basically temperature, pressure, and processing time (such as screw rotation/rpm, and so on) in the case of a screw plasticator, die and mold temperature and pressure, machine output rate (lb./hr), and the like. Processing variables are more specific such as the melt temperature in the die or mold, melt flow rate, and pressure used. 

The distinction between machine conditions and fabricating variables is a necessary one to avoid mistakes in using problem-and-solution or cause-and-effect relationships to advantage. If the processing variables are properly defined and measured, not necessarily the machine settings, they can be directly... 

Speed of die rotation and gelatin ribbon thickness are two important machine conditions that are included in Table 5. The rationale of their selection is... 

Wear resistance of such tools strongly depends on the tool composition, the machined material, and the machining conditions, which makes this topic very complex [270-272],... 

Because of the strong temperature dependence of exhaustion and the poor migration properties, dye absorption must be as level as possible from the start. Correspondingly, attention should be paid to uniform packaging, package density, liquor flow or movement of textile material, and controlled machine conditions. 

A better understanding of and advanced mathematical formulation of all the basic mechanisms under realistic machine conditions with a single polymeric feed or a mixture of them, with the goal of simulating the process as a whole ... 

Prior to startup one must check certain machine conditions and process control that should be listed on some kind of worksheet from the machine manufacturer, plastic supplier, and/or the more important plant setup person with experience (Chapter 3). Checkup includes the... 

In conclusion, for smooth and perfect machine runs, product properties and machine conditions have to be tightly controlled. 

In lapped and abraded surfaces, on the other hand, they appear to be compressive in nature (58, 59,61). The magnitude of the stresses and the depth to which they extend vary considerably, depending upon the exact machining conditions (56-60). 

When solving the direct and inverse ECM problems, it is necessary to take into account the peculiarities of the shaping scheme used and the machining conditions. In most cases of ECM, the WP surface is formed under steady-state or nonsteady-state conditions according to one of the following schemes. 

For the chosen machining conditions, the distribution of gap width over the machining zone is calculated using Eq. (24). 

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