Molding pellets

Plexiglas Molding Pellets, PE-926a, Rohm and Haas Co., Philadelphia, Pa. 

The product of a successful suspension polymerization is small, uniform polymer spheres. For certain applications, they are used directly, eg, as the precursors for ion-exchange resins or bead foams. For others, they may be extruded and chopped to form larger, more easily handled molding pellets. 

F.B. Wells, S-Trinitrobenzene as a Binder in Compression-Molded Explosive Compositions , PATR 4783 (1975) [It was found that the ideal HMX/TNB ratios required to provide compression-molded pellets that come close to the theoretical max d are 95/5 to 94/6 with no TNB loss at SOOOpsi compression press. It was also noted that the HMX used need not be of a very fine particle size to be successfully molded in the mixt] 54) J.R. Hendrickson F.B. Wells, Castable Composite Explosive Compositions Containing a Mixture of Trinitrobenzene (TNB) and Trinitroxylene , USP 3994756 (1976) CA 86, 75497 (1977) [A castable composite expl which meets Mil Specs is claimed which contains TNB 26.25, Trinitroxylene 3.75, and HMX 70 wt %] 55) F.B. Wells, High-... 

For mold pellets and other suspended particles with densities close to that of the continuous phase, the agitation in a stirred mixing vessel creates the dominant force for relative fluid motion between the two phases. The intrinsic gas-liquid mass-transfer coefficient under these conditions is given by Calderbank (1967) as... 

Compression molding is not widely utilized for thermoplastic materials and information on commercial blends is scarce. As mentioned above, PP/EPDM blends (Santoprene , Sar-link ) exhibit high melt viscosity. For compression molding, pellets or preformed slabs should be heated for 20 min at 190-215°C to generate a melt that is then compression molded at 120-190°C under pressure of 1.5-3 MPa. For large parts, preformed slabs should be used to avoid air entrapment. In order to fill the mold cavity, a slight excess (5-10%) of melt is recom-... 

Phillips (1966) measured oxygen diffusion in pellets of PeniciIlium chrysogenum by first assuming that diffusion is the mechanism that supplies oxygen to the interior of the microbial pellet and that the mass transfer resistance outside the pellet is comparatively small. Yano et. al. (1961) and Koyayashi et al. (1973 b) did the same with Aspergillus nicer pellets. By taking into account the effect of intraparticle diffusion. Kobayashi and Suzuki (1976) were able to characterize the kinetic behavior of the enzyme galactosidase within mold pellets of Mortierella vinacea. 

Figure 4. Oxygen transjer in mold pellets. Comparison between theoretical curves...

Radio frequency preheating can also be used to dry molding pellets or other molding materials before molding or incorporating into a mixture. It has also been... 

Sheet material is more costly than molding pellets. 

Common thermoplastic molding pellets are derived from fossil fuels and suffer the price fluctuations present in this market. However, thermoset molding compounds contain a high percentage of filler the filler is usually inorganic and made of some inexpensive, plentiful material. Thus the thermoset molding compounds are not as sensitive to market crude oil and natural gas pricing. Currently, in response to... 

Commercial grades of unfilled Nylon 6,6 and polycarbonate resins were used. For preparation of Nylon test coupons, the samples were molded and remolded up to 10 consecutive molding cycles in an injection molder to simulate resin re-use. For the polycarbonate resins, molded pellets from a commercial resin reprocessor were used and compared to virgin. 

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