Improved solvent resistance. LIM technology improves thechemical resistance and environmental stress crack resistance ofmolded products. Tests show that, with nylon (polycaprolactam)loadings of only 5%, HDPE-nylon-6 articles fabricated with LIMexhibit a reduction in hydrocarbon permeability of more than 200-fold compared with HDPE (see Fig. 6-44).Molded articles produced with LIM technology can exhibitnearly double the critical crazing strain and are more resistant tocatastrophic failure when exposed to aggressive chemicals. Forexample, up to a 14-fold increase in time to fail under load can beachieved through LIM with PC-PBT blends.Figure 6-45 illustrates the potential of using LIM to capture apreferred balance of optical and barrier properties not otherwiseobtainable by traditional injection molding. This figure shows thatbarrier structures made by LIM, based on polystyrene copolymersand aromatic nylon, can offer clarity comparable to PS or PET,with a 5–1000-fold improvement in oxygen barrier.Higher heat distortion temperature. Compared with conventionalblends, LIM technology can provide an increased heat distortiontemperature. In PC-PBT structures, the heat distortion temperatureis increased by over 50° F (28° C) (see Table 6-12).LIM is repeatable. LIM technology results in consistentlymolded parts. Repeatability was evaluated during a 50-cycle run
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