Oriented balanced

Property Cast polymer Monoaxially oriented Balanced oriented... 

S. Blenk, W. Muschik. Orientational balances for nematic liquid crystals. J Non-Equilib Thermodyn 7(5 67-87, 1991. 

The concept of] structure—or rather the structurality of structure. . . has always been neutralized or reduced, and this by a process of giving it a center or referring it to a point of presence, a fixed origin. The function of this center was not only to orient, balance, and organize the structure. . . but above all to make sure that the organizing principle of the structure would limit what we might call the freeplay of the structure.. . . The center of a... 

The most common manufacturing method for BOPP is the fiat tenter stretching process where a thick sheet is first cast, then conditioned for subsequent drawing. Machine and transverse direction stretching are performed on-line and can be adjusted to secure the required orientation balance. ... 

Tubular-Blown Film Process. This process is more flexible with regard to the permissible polymer viscosity mismatch, control of film orientation balance in the transverse and machine directions through blow-up ratio, and easy randomization of film-thickness variations. Production rates are limited by flow rates per circumferential length of die (pressure drop) and cooling rates (heat transfer). 

Seiko offers the EXSTAR6000 TGA/DTA series with dual-beam, horizontally oriented balance configuration. The TG/DTA6200 has an ambient-1100 °C range, and the TG/DTA6300 has an ambient-1500 °C range. Both systems have a maximum sample capacity of 200 mg, can heat from 0.01 to 100°C/min, and will cool from 1000 °C to 50 °C in less than 15 min. A 30-pan autosampler is optional. For more information, see wvw.sii.co.jp or the North American distributor RT Instruments at vww.rtinstruments.com. RT Instruments also sells previously owned, refurbished thermal analysis systems. 

Orientation, balance It is the result where stretch in the machine and transverse directions are uniform. 

Biaxial Orientation. Many polymer films require orientation to achieve commercially acceptable performance (10). Orientation may be uniaxial (generally in the machine direction [MD]) or biaxial where the web is stretched or oriented in the two perpendicular planar axes. The biaxial orientation may be balanced or unbalanced depending on use, but most preferably is balanced. Further, this balance of properties may relate particularly to tensile properties, tear properties, optical birefringence, thermal shrinkage, or a combination of properties. A balanced film should be anisotropic, although this is difficult to achieve across the web of a flat oriented film. 

Plant layout and noise suppression material are two general noise abatement methods. Plant layout does not affect noise levels at any given point however, noise can be abated by screening off a section of the plant. An example of this is to orient cooling towers with their closed faces toward the critical location. This method must also consider wind direction to balance air draft. Tankage can be located to act as a noise screen. 

Effects of Surfactants on Solutions. A surfactant changes the properties of a solvent ia which it is dissolved to a much greater extent than is expected from its concentration effects. This marked effect is the result of adsorption at the solution s iaterfaces, orientation of the adsorbed surfactant ions or molecules, micelle formation ia the bulk of the solution, and orientation of the surfactant ions or molecules ia the micelles, which are caused by the amphipathic stmcture of a surfactant molecule. The magnitude of these effects depends to a large extent on the solubiUty balance of the molecule. An efficient surfactant is usually relatively iasoluble as iadividual ions or molecules ia the bulk of a solution, eg, 10 to mol/L. 

Equations-Oriented Simulators. In contrast to the sequential-modular simulators that handle the calculations of each unit operation as an iaput—output module, the equations-oriented simulators treat all the material and energy balance equations that arise ia all the unit operations of the process dow sheet as one set of simultaneous equations. In some cases, the physical properties estimation equations also are iacluded as additional equations ia this set of simultaneous equations. 

The essential differences between sequential-modular and equation-oriented simulators are ia the stmcture of the computer programs (5) and ia the computer time that is required ia getting the solution to a problem. In sequential-modular simulators, at the top level, the executive program accepts iaput data, determines the dow-sheet topology, and derives and controls the calculation sequence for the unit operations ia the dow sheet. The executive then passes control to the unit operations level for the execution of each module. Here, specialized procedures for the unit operations Hbrary calculate mass and energy balances for a particular unit. FiaaHy, the executive and the unit operations level make frequent calls to the physical properties Hbrary level for the routine tasks, enthalpy calculations, and calculations of phase equiHbria and other stream properties. The bottom layer is usually transparent to the user, although it may take 60 to 80% of the calculation efforts. 

In the equation-oriented approach, the executive organizes the equations and controls a general-purpose equation solver. The equations for material and energy balances may be grouped separately from those for the calculation of physical properties or phase equiHbria, or as ia the design of some simulators, the distinction between these groups of equations may disappear completely. 

A positively charged heteroatom can be balanced by a negatively charged substituent, and if they are oriented favourably relative to each other the charges may formally cancel. Thus, the 2- and 4-pyridone structures (26, 27 X = NH) and the corresponding pyrones... 

There are other differences between cast, monoaxially oriented, and balanced biaxially oriented film. Typical figures illustrating these effects are given in Table 11.5. 

Further improvements in the properties of PAN-based carbon fibers are likely to emerge through improved stabilization, that is, by creating the ideally cross-linked fiber. On the other hand, as purer pitch precursors become available, further improvements in mesophase pitch-based carbon fibers are likely to arise from optimized spinnerette designs and enhanced understanding of the relationship between pitch chemistry and its flow/orientation behavior. Of course, the development of new precursors offers the potential to form carbon fibers with a balance of properties ideal for a given application. 

Composites fabricated with the smaller floating catalyst fiber are most likely to be used for applications where near-isotropic orientation is favored. Such isotropic properties would be acceptable in carbon/carbon composites for pistons, brake pads, and heat sink applications, and the low cost of fiber synthesis could permit these price-sensitive apphcations to be developed economically. A random orientation of fibers will give a balance of thermal properties in all axes, which can be important in brake and electronic heat sink applications. 

There are, of course, many more aspects of composite hardware design that differ from metallic bonded structure but do not necessarily involve adhesive bonding. For instance there are many types of reinforcement tape and fabric to choose from, the orientation of the plies must be chosen, the ply stackups must be balanced to avoid part warping after cure, a minimum number of plies must be used to prevent non-visible impact damage that significantly affects the load carrying capability of the part, etc. 

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