Spindle speed

Slurry Viscosity. Viscosities of magnesium hydroxide slurries are determined by the Brookfield Viscometer in which viscosity is measured using various combinations of spindles and spindle speeds, or other common methods of viscometry. Viscosity decreases with increasing rate of shear. Fluids, such as magnesium hydroxide slurry, that exhibit this type of rheological behavior are termed pseudoplastic. The viscosities obtained can be correlated with product or process parameters. Details of viscosity deterrnination for slurries are well covered in the Hterature (85,86). 

Both washed and unwashed cottons were processed through a blender feeder, a No. 12 horizontal opener, and a two-beater picker and made into picker laps. The carding was conducted in our model cardroom at 18,2 kg/h, and dust levels were determined by use of vertical elutriators. The cottons were spun into 19.7 mg/ m yarn of 38.2 twist factor at 13000 rpm spindle speed in a 4536 spindle-hour test. 

All cottons were carded at 13,6 kg/hr. The Mississippi and California cottons were processed into both 14.8 mg/m yarn of 37.2 twist factor and 19.7 mg/m yam of 38.3 twist factor at several spindle speeds. The Texas cotton was made into 19.7 mg/m yarn of 38.3 twist factor at 12500 rpm spindle speed. 

The only significant difficulty in processing occured at carding where static electricity caused the web to behave erratically. The static was controlled by carding the cotton with a static bar in place under the web just as it exited the crush rolls. Processing and yarn quality results for the 3 cottons made into 19.7 mg/m yarns at 13000 rpm spindle speed are shown in Table X. Spinning quality results for the Mississippi and California cottons that were made into 14.8 mg/m yarn are shown in Table XI. 

Cotton Spindle speed (rpm) EDMSRa Yarn Break Factor Units Yarn Neps per 914.4 m Yarn CV (%)... 

This cotton was carded at 13.6 kg/hr and processed into 1A.8 mg/m yarn of 37.2 twist factor at 10000 rpm spindle speed. Ends down per thousand spindle hours was AO as compared to 56 for the same cotton washed on the rayon line. Yarn appearance characteristics were also slightly better for the wool scoured cotton. 

High polishing speeds are essential in todays economy, and the latest equipment employs much higher spindle speeds and pressures than those used just a few years ago. Cerium oxide is ideal under these more modern conditions, A spherical lens that required 8 minutes to polish 15 years ago is now polished in less than one minute, A toric (cylinder) lens that previously took 15 minutes to polish, now requires 4-1/2 minutes. 

Viscosities of liquid epoxy systems are usually measured with a rotating spindle instrument, such as a Brookfield viscometer. Solid resins are usually dissolved in solvent for viscosity measurement by these instruments. Temperature and spindle speed are important... 

Epoxy resin emulsions are commercially available from several sources. As a group, the typical particle size of the dispersion is in the 0.5- to 3.0-pm range. Solids typically range from 50 to 65 percent, and viscosity from 10,000 to 12,000 cP. The dispersions, in general, are thixotropic as supplied. There is also a dramatic decrease in viscosity of the system with the addition of water. Table 4.7 shows the effect of dilution and Brookfield viscosity spindle speed (thixotropy) on a typical epoxy emulsion. 

Viscosity Transfer a 4-g sample, finely powdered, into the container of a stirring apparatus equipped with blades capable of being adjusted to about 1000 rpm. Add 10 mL of alcohol to the sample, swirl to wet it uniformly, and then add 390 mL of water, avoiding the formation of lumps. Stir the mixture for 7 min, pour the resulting dispersion into a 500-mL bottle, insert a stopper, and allow to stand for about 12 h in a water bath at 25°. Determine the apparent viscosity at this temperature with a model LVF Brookfield, or equivalent, viscometer (see Viscosity of Cellulose Gum, Appendix IIB) using a suitable spindle, speed, and factor. 

Melt Viscosity Equation of Sulfui>-DCP Solutions. An assumption is made that the sulfur-DCP solution is a Newtonian fluid, i.e., the viscosity measured by the Brookfield viscometer is independent of the spindle speed, which is related to shear rate. The linear plots of log (viscosity) vs. time as in Figures 8, 9, and 10 give the following equation for a given sulfur-DCP composition at a given temperature ... 

Viscosity of epoxy resins ASTM D2393-86 Measure pre-cure viscosity of filled and unfilled epoxy liquids Viscosity versus spindle speed at desired temperature... 

Viscosity measurements used to describe polymer solubility are based on the Brookfield model LVF, at 60 rpm after 1 min spindle revolution. This is a rotational type viscometer which can vary its shear rate by spindle speed changes. Only one-point (shear rate) measurements were made however. This type of reporting puts it on a par with the efflux type viscometers used in the coating industry in that only one shear rate is used. 

Figure 18-14. Grease consistency and the running temperature of a rolling element bearing. i Grease with initial worked penetration 200. II Grease with initial worked penetration 260. Spindle speed 10,000 rpm. Data by Horth, Norton and Pattenden [36].

Figure 5.34 illustrates hardness as a function of spindle speed and distance from the weld center for the top, center, and weld root. These are the similar W -shaped hardness profiles reported for other friction stir welded aluminum alloys. Each profile consists of a central uniform plateau that corresponds to the width of the nugget zone. Moving outward from the center, the profile then falls through the TMAZ, reaches a minimum (-110 HV) in the HAZ, and then gradually recovers to the level of the parent plate (-170 HV). Overall, the hardness of the plateau region is lower than the parent alloy and... 

Alloy 600 plates ( 6 mm thick) were butt welded using a PCBN tool. Spindle speed was 450 rpm, and travel rate was 56 mm/min (2.2 in./min). Substantial grain refinement was observed in the stir zone. Mechanical properties were excellent. Yield strength and ultimate strength were 370 and 720 MPa (54 and 104 ksi), respectively, compared with 265 and 630 MPa (38 and 92 ksi) for the base metal. Elongation was reduced from 50% in the base metal to 27% in the transverse weld specimen. However, it is important to recognize that the non-... 

Alloy 718 sheets (3.2 mm thick) were butt welded using a tool with a 16 mm diameter shoulder. Spindle speed was 500 rpm, and travel speed was 50 mm/min (2.0 in./min). The weld was fully consolidated and exhibited substantial grain refinement as compared with the base material. Yield and ultimate strengths of the transverse weld specimens were 670 and 985 MPa (97 and 143 ksi), respectively. There was not enough material available to make a base-metal measurement. However, for comparison purposes, typical yield and tensile strengths are 460 and 895 MPa (67 and 130 ksi) for alloy 718 in the annealed condition and 1170 and 1390 MPa (170 and 202 ksi) in the precipitation-hardened condition. 

Table 6 Intrinsic Dissolution Rates (IDR) for the Various Polymorphs of Aprazolam at Two Different Spindle Speeds IDR, 50 RPM (p/min IDR, 75 RPM ...

Since the wafer- and die-level sources are deeply confounded, it is difficult to characterize the tool dependencies until these sources are decomposed. After application of variation decomposition techniques, the die-level variation can be analyzed for its pattern dependencies. Divecha et al. (1996) have shown that for similar polishing pad and processing conditions (e.g., platen speed, back/head pressure, and spindle speed) between the two tools, the die-level variation is similar and is... 

Material machined Cutter diameter No. of teeth Spindle speed Cutting speed Feed rate Feed per tooth... 

Machine capabilities, such as spindle power, spindle speed, and rigidity Type of material to be machined Tooling cost and tool rehabUity Factors that positively affect performance of a tool material are ... 

Within Fig. 6b, a sharp increase of the force level emerges, which corresponds to the stability limit shown in Fig. 6a. For stable regions, the FTP force is constant regardless of the spindle speed. 

However, both radii must not exceed the smallest (concave) radius of curvature on the surface to be machined. The spindle speed is usually kept below 4,000 min for easier balancing and for avoiding centrifugal distortions. 

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