Molding grades

Cjcolac Brand ABS—General Purpose Blow Molding Grades, Technical PubHcation SR-616, GE Plastics, Pittsfield, Mass., 1989. 

Table 7. Comparison of Injection Molding Grades of LLDPE and LDPE ...

Fig. 12. Viscosity at different temperatures measured by a capillary viscometer injection-molding grade of poly(methyl methacrylate) (43). To convert N/m to psi, multiply by 145 to convert (N-s)/m to (dyn-s)/cm (P), multiply by 10.

Articles made from polyacetals vary from door handles to gears and bushings, carburetor parts to aerosol containers. The major use of polyacetals is for molded grades. 

Injection molding grades of polyethylene terephthalate and polybutylene terephthalate have low melt viscosities. Because of this, they can be used to manufacture intricate parts within... 

The present N orth American market is dominated by Du Pont, no doubt by virtue of their eady lead other suppliers are AlliedSignal with Petra and Hoechst Celanese Corporation with Impet. Eastman also markets PET injection molding grades under the trade name Thermo In Europe the situation... 

HDPE is alinear polymer with the chemical composition ofpolymethylene, (CII2V Depending on application, HDPE molecules either have no branches at all. as in certain injection molding and blow molding grades, or contain a small number of branches which are introduced by copolymerizing ethylene with o-olefins, e g., ethyl branches in the case of 1-butene and -butyl branches in the case of 1-hexene. The number of branches in HDPE resins is low, at most 5 to 10 branches per 1000 carbon atoms in the chain. 

For example, Figs. 2.43 and 2.44 present the measured [55] viscosity and first normal stress difference data, respectively, for three blow molding grade high density polyethylenes along with a fit obtained from the Papanastasiou-Scriven-Macosko [59] form of the K-BKZ equation. A memory function with a relaxation spectrum of 8 relaxation times was used. 

Narrow molecular-weight HDPE provides superior injection molding grades. Broad molecular-weight HDPE is used for blow molding, pipe, film and other extrusion applications. 

Figure 12.14 Effect of process conditions on the Izod impact strength of an article molded in an injection molding-grade HIPS...

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