Viscosity requirements

The heavy fuel should be heated systematically before use to improve its operation and atomization in the burner. The change in kinematic viscosity with temperature is indispensable information for calculating pressure drop and setting tbe preheating temperature. Table 5.20 gives examples of viscosity required for burners as a function of their technical design. 

Average kinematic viscosity required for the atomization of heavy fuels. 

For dehydration of very high viscosity crudes, heaters can be used in combination with dehydration tanks. The temperature to which the crude is heated is a function of the viscosity required for effective separation. 

Glass is usually melted and fined at viscosities between 5 and 50 Pa-s (50—500 P) but forming and final viscosity requirements vary gready. The ranges of viscosity for various forming methods ate compared in Figure 7. 

The stabihty of the emulsions further permits them to be compounded in simple Hquid-blending vessels by means of agitators, eg, marine-type propellers, paddles, or turbines. The adhesives can be adapted to any type of machine appHcation, ie, from spray guns to rollers to extmder-type devices. Different appHcators are fairly specific in their viscosity requirements, as are the various substrates receiving the adhesive. 

AH these mechanisms except high bulk viscosity require a stabilizer in the surface layers of foam films. Accordingly, most theories of antifoaming are based on the replacement or modification of these surface-active stabilizers. This requires defoamers to be yet more surface active most antifoam oils have surface tensions in the 20 to 30 mN/m range whereas most organic surfactant solutions and other aqueous foaming media have surface tensions between 30 and 50 mN/m(= dyn/cm). This is illustrated in Table 3. 

The viscosity of a substance measures its resistance to flow. The melt viscosity of a polymer increases as the molecular weight of the polymer rises. Polymers with high melt viscosities require higher temperatures for processing. 

In addition to analytical requirements for the above constituents, the Spec contains a moisture requirement of 0.25% max, an insol particles requirement, and a viscosity requirement Refs 1) Beil 2, 545 2) C.S. Davis, Develop-... 

Pharmaceutical scientists have developed improved suspension dosage forms to overcome problems of poor physical stability and patient-perceived discomfort attributed to some active ingredients. An important development aspect of any suspension is the ability to resuspend easily any settled particles prior to instillation in the eye and ensure that a uniform dose is delivered. It would be ideal to formulate a suspension that does not settle since the patient may not always follow the labeled instructions to shake well before using. However, this is usually not feasible or desirable since the viscosity required to retard settling of the insoluble particles completely would likely be excessive for a liquid eyedrop. The opposite extreme, of allowing complete settling between doses, usually leads to a dense layer of agglomerated particles that are difficult to resuspend. 

After the precursor stock solution is prepared, various techniques can be used to coat the substrate, depending on the solution viscosity, required film thickness and coverage. The most common methods in the semiconductor industry are spin- and dip-coating. Other processes that are used for deposition include spray coating and stamping. A summary of the uses, limitations, and advantages of the various thin film deposition methods is reported in Table 2.2. 

Solid-state polycondensation (SSP) is thus a technique applied to thermoplastic polyesters to raise their molecular weight or IV. During solid-state polycondensation, the polymer is heated above the glass transition temperature and below the melt temperature of the polymer either under an inert gas or under vacuum. Increasing the intrinsic viscosity requires a residence time of up to 12 h under vacuum or under inert gas, at temperatures from 180 to 240 °C. 

Let us now consider the effect of solvent viscosity on the cavitation threshold. According to Tab. 2.1, an increase in the solvent viscosity required the application of a... 

The ideal diester for use in a partial synthetic lubricant, i.e. blend of diester, petroleum basestock and additives, should have the lowest viscosity at both high and low temperatures, and also be the least volatile. Of course, it would also need to be resistant to oxidation and corrosion and provide lubrication and wear protection when compounded into a finished lubricant. The low viscosity requirement of the synthetic portion of the partial synthetic lubricant is for economic reasons. The synthetic portion is substantially more expensive than the petroleum portion and the lower the amount required to achieve the low viscosity of the final oil, the better the final economics. As mentioned earlier, the low volatility is desirable to prevent carrying the... 

As a matter of fact, the viscosity is a very dominant property for the processing technology. A fluid polymer mass with a high viscosity requires high pressures to be transported in processing machines. How strongly the processability prevails, has already been discussed in 2.2.3 for some thermoplasts like PE, PP and ABS,... 

The primary use of Nd-BR is in tires. This application of Nd-BR accounts for only 15% of the total amount of BR used in this field. Minor amounts of Nd-BR are used in technical rubber goods and in golf ball cores. To date, only special Nd-BR grades meet the viscosity requirements for rubber modification of HIPS. Mainly due to high solution viscosities Nd-BR is not yet used as the rubber component in ABS. 

Composite manufacture process (resin viscosity requirements)... 

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