Injection molding of engineering plastics

Wagner, Alan H.; Yu, Jeong S.; Kalyon, Dilhan M.

doi:10.1002/adv.1989.060090103

Cited by 19 publications

(11 citation statements)

References 38 publications

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“…The melt density versus pressure and temperature data of ULTEM 1000 is available from the study of Yu et al . Kalyon and coworkers have shown that the glass transition temperature of PEI is affected by both the cooling rate and pressure during solidification and comprehensive studies focusing on the rheology, injection molding, microstructural distributions and ultimate properties of ULTEM 1000 and its compounds with nanoinclusions are available . The CO 2 gas, 99.9% percent purity was obtained from Welco‐CGI Gas Technologies, NJ.…”

Section: Methodsmentioning

confidence: 99%

Extrusion of poly(ether imide) foams using pressurized CO₂: Effects of imposition of supercritical conditions and nanosilica modifiers

Aktaş

Gevgilili

Küçük

et al. 2013

Polymer Engineering & Sci

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Foams of an engineering plastic, poly(ether imide), were extruded using a single screw extruder employing pressurized CO 2 as the blowing agent. The porosity, pore size distributions, and the density of the foams were especially affected by the pressure drop, the pressure loss rate, and temperature at the die. Significant increases in porosity and pore size and corresponding decreases in density were observed when the pressure imposed on CO 2 became greater than the critical pressure values of CO 2 (i.e., the temperature was always greater than the critical temperature of the CO 2 in the extruder and the die). The viscoelastic material functions of the extruded foams depended especially on the density of the foam, with the elastic modulus increasing with density. The incorporation of nanosilica particles in the 0.08-0.6% by weight range increased only the density of the foam and did not provide any benefits in controlling of the nucleation rate and the pore size distribution, presumably due to their poor dispersibility and agglomerated state in the single screw extruder. POLYM. ENG. SCI., 54:2064-2074, 2014

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Section: Methodsmentioning

confidence: 99%

Extrusion of poly(ether imide) foams using pressurized CO₂: Effects of imposition of supercritical conditions and nanosilica modifiers

Aktaş

Gevgilili

Küçük

et al. 2013

Polymer Engineering & Sci

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“…After about 500 nm thick material was removed from the top of the specimens, slices about 60 nm thick were sectioned with a diamond knife on Ultracut R microtome at 1.0 mm/sec and ambient temperature. The ultrathin sections were mounted on 300 mesh copper grids and dried in a desiccator for at least 4 hrs, and then were stained for about 30 min in ruthenium tetroxide vapor generated in situ 21, 22. The transmission electron microscopy (TEM) examination of the slices was performed on JEOL JEM‐100CX II TEM; an accelerating voltage of 80 kV was adopted.…”

Section: Methodsmentioning

confidence: 99%

Phase structure and mechanical properties of modified poly(phenylene oxide) with high fluidity

Jian-xiong

Chan

2011

Polymers for Advanced Techs

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Polyphenylene oxide (PPO) possesses excellent mechanical properties and heat resistance but extremely high viscosity. Virgin PPO has to be blended with polystyrene (PS) to reduce the viscosity. However, PS is miscible with PPO; it reduces not only the viscosity but also the heat distortion temperature and, consequently, narrows the applications. This paper is an attempt to develop crystalline additives that will dissolve in PPO at processing temperature but precipitate and recrystallize after molding. Thereby, the additives are able to reduce the viscosity of PPO melts but will not reduce the heat distortion temperature of PPO materials. In the present work, a PPO was compounded with bisphenol-A and bisphenol-S as well as PS separately on Haake Rheometer and the mixing torque was recorded. The dynamic properties of the modified PPO were analyzed with DMA and the mechanical properties were tested at ambient and elevated temperatures. The phase structures were examined with DSC and TEM. The effect of the additives on the fluidity, mechanical properties, and heat distortion temperature of the PPO compounds was investigated. All three additives dissolved in the PPO during mixing and reduced the mixing torque. But bisphenol-S precipitated after molding and is present as 40 nm crystalline phases in the molded materials; it did not affect the glass transition nor did it deteriorate the performance at elevated temperature. While bisphenol-A did not recrystallize after molding; it reduced the T g and heat distortion temperature as does PS. General principles about such plasticizers with phase transition for PPO were proposed.

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“…They were molded using a 40t Van Dorn reciprocating screw type injection molding machine. Details of the procedure and operating conditions can be found elsewhere (13,14). For the density study, the specimens injection molded in Runs 10, 11, 14, and 15 of our previous reports (13,14) were used.…”

Section: S a M P L E Preparationmentioning

confidence: 99%

“…Details of the procedure and operating conditions can be found elsewhere (13,14). For the density study, the specimens injection molded in Runs 10, 11, 14, and 15 of our previous reports (13,14) were used. Processing conditions for these runs are given in Table 1.…”

Section: S a M P L E Preparationmentioning

confidence: 99%

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Development of density distributions in injection molded amorphous engineering plastics. Part I

Lim

Kalyon

1991

Polymer Engineering & Sci

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The gapwise density distributions of the injection molded specimens of two engineering thermoplastics, i.e., poly(pheny1ene ether) and poly(ether imide), were characterized employing the density gradient column technique. The samples were molded using a 40t Van Dorn injection molding machine. The effects of the thermal history on the density distribution of unconstrained quenched specimens were also investigated. In addition, various material properties, such as pressure-volume-temperature, isothermal contraction, and pressure induced densification behavior were characterized for the two resins employed in this study. The moldings of the two resins exhibited different trends in their density distributions. These findings were explained in terms of the competing effects of cooling rate and the pressure history experienced by the engineering plastic resins during the molding cycle. The data collected were also used as input to mathematical modeling of density distributions in injection molded articles, which is reported in Part I1 of this article.

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Injection molding of engineering plastics

Cited by 19 publications

References 38 publications

Extrusion of poly(ether imide) foams using pressurized CO₂: Effects of imposition of supercritical conditions and nanosilica modifiers

Extrusion of poly(ether imide) foams using pressurized CO₂: Effects of imposition of supercritical conditions and nanosilica modifiers

Phase structure and mechanical properties of modified poly(phenylene oxide) with high fluidity

Development of density distributions in injection molded amorphous engineering plastics. Part I

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Injection molding of engineering plastics

Cited by 19 publications

References 38 publications

Extrusion of poly(ether imide) foams using pressurized CO2: Effects of imposition of supercritical conditions and nanosilica modifiers

Extrusion of poly(ether imide) foams using pressurized CO2: Effects of imposition of supercritical conditions and nanosilica modifiers

Phase structure and mechanical properties of modified poly(phenylene oxide) with high fluidity

Development of density distributions in injection molded amorphous engineering plastics. Part I

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Product

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Extrusion of poly(ether imide) foams using pressurized CO₂: Effects of imposition of supercritical conditions and nanosilica modifiers

Extrusion of poly(ether imide) foams using pressurized CO₂: Effects of imposition of supercritical conditions and nanosilica modifiers