Bimodal grades

Some polyethylenes are supplied as so-called bimodal grades a mix of high- and low-molecular weight components in similar concentrations. They often show quite different processing characteristics compared to normal, monomodal (unmodified) polyethylenes. Bimodal grades PE often have higher die swell. 

Atofina Finacene BM 359SG, Finathene B 593 MDPE and bimodal grades with hexene monomers. 

Table I also Illustrates the effect of adding 0.60% of Milube N-32 to a low grade, low micronaire and high trash content cotton. The histograms and cumulative distribution curves of the control and treated cottons are shown in Figures 7 and 8. The results are similar to those found for the other cottons containing additives in that there is a drop of 74.7% in particle count and of 90.8% in dust concentration. The presence of the additive lowers d from 1.62 to 1.09 un (based on the cumulative plots). The cumulative distribution of the stock cotton is linear (except for the lowest dicuneter cell) over a ramge including 99.95% of the particles and that of the additive-treated cotton is bimodal. The smaller...

Abstract Nash creek is the largest Zn-Pb deposit in the Tobique-Chaleurs Zone, and contains indicated and inferred resources of 7.8 Mt grading 2.72% Zn, 0.55% Pb and 18.26 g/t Ag and 1.2 Mt grading 2.66% Zn, 0.52% Pb and 18 g/t Ag, respectively. The deposit is hosted by Early Devonian bimodal volcanic and minor interlayered sedimentary rocks that were deposited in a trans-pressional rift. The host rocks sequence includes the Archibald Settlement Formation (rhyolite flows domes and related rocks), and the Sunnyside Formation (mafic lava flows and interlayered volcaniclastic and sedimentary rocks). 

The characteristics of the presolar diamonds also change with the metamorphic grade of the host meteorite. F igure 5.15 shows the typical bimodal release of heavy noble gases (here illustrated by xenon) in Orgueil, an unheated chondrite. This pattern is compared to the xenon-release patterns of two ordinary chondrites that have experienced different degrees of mild metamorphism. The amount of low-temperature gas, labeled P3 for historical reasons, is a sensitive function of temperature. Its abundance correlates well with other indicators of... 

Traditionally, bimodal polyethylene resins are produced with a Ziegler-Natta (Z-N) type catalyst, but for specialty grades (e.g. bimodal LLDPE) the... 

Fig. 10.2. The bimodal curve represents the probable distribution of a geochemically scarce metal in the earth s crust. The large peak is the distribution in common rocks, where scarce metals occur not as separate minerals but as atomic substitutes for abundant metals the small peak represents deposits produced by ore-forming processes such as those resulting from the circulation of brines in the crust. Current mining has already reached the point where the distribution curve for easily accessible scarce minerals turns downward. Further reductions in the grade of ore mined will produce declining tonnages of ore and will eventually bring us to a mineralogical barrier — which lies somewhere in the area between the two humps.

In the past, several ABS grades were produced with a broad or bimodal particle-diameter distribution. Particles of different sizes can contribute to crazing in different ways. Figure 7 shows such a material and clearly reveals the greater capability of the largest particles to initiate crazes. Beside these large particles, the smaller ones show only a small effect on craze initiation. 

In reality, both of these cases are unlikely but not impossible. Our group could have been two classes of fifth- and eleventh-grade students that would have been a bimodal population very similar to that described above. In most cases, the magnitude of the variability is intermediate between these extremes for most normally distributed populations. Just as we can use weight as a descriptor, we can use other measurements to describe disease or toxicity induced by drugs or pesticides. The statistical principles are the same for all. 

HDPE HDPE ( reactor blends ) Bimodal molar mass distributions provide rmique properties that cannot he achieved by mixing the two PE grades... 

This effect is used in some commercial latexes to provide maximum solids at viscosities that are easily handled in pumping and mixing. Some grades have bimodal particle size distributions, while others utilize a broad particle size distribution to obtain a similar effecL... 

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