Two polyethylene（PE） resins（samples A and B） are synthesized as high-speed extrusion coatings with similar minimum coating thickness and neck-in performance but different maximum coating speeds. Both samples are s...Two polyethylene（PE） resins（samples A and B） are synthesized as high-speed extrusion coatings with similar minimum coating thickness and neck-in performance but different maximum coating speeds. Both samples are separated into seven fractions using preparative temperature rising elution fractionation. The microstructures of the original samples and their fractions are studied by high-temperature gel permeation chromatography, Fourier transform infrared spectroscopy, 13 C nuclear magnetic resonance spectroscopy, differential scanning calorimetry, and successive self-nucleation/annealing thermal fractionation. Compared with sample B, sample A has a broader MWD, more LCB contents, and less SCB contents. Moreover, sample A contains slightly more 30 ℃ and 50 ℃ fractions with lower molecular weights, and more fractions at 75 ℃ and 85 ℃ with higher molecular weight. The chain structure and its distribution in the two PE resins are studied in detail, and the relationship between the chain structure and resin properties is also discussed.展开更多
The extrusion ratio is one of the key parameters for manufacturing the lead-glass fiber(Pb-GF)composite wire by coating extrusion.The effect of extrusion ratio on coating extrusion of Pb-GF composite wire was studied ...The extrusion ratio is one of the key parameters for manufacturing the lead-glass fiber(Pb-GF)composite wire by coating extrusion.The effect of extrusion ratio on coating extrusion of Pb-GF composite wire was studied by finite element numerical simulation with the use of the DEFOEM simulation software.The simulation result shows that the higher the extrusion ratio,the higher the effective stress that the glass fiber bears during extrusion.It is also observed that the extrusion force increases with the increase of the extrusion ratio.The extrusion experiment of Pb-GF composite wire reveals that extrusion ratio is changed by changing the quantity of glass fiber and composite diameter.The rule that increasing the extrusion ratio enhances the coating speed limit suggests that the load on the glass fiber increases with increasing extrusion ratio.Both the simulation and the extrusion experiments show that the extrusion force increases with increasing extrusion ratio.展开更多
基金financially supported by the National Basic Research Program of China(No.2005CB623806)the National Natural Science Foundation of China(Nos.20734006 and 50921062)
文摘Two polyethylene（PE） resins（samples A and B） are synthesized as high-speed extrusion coatings with similar minimum coating thickness and neck-in performance but different maximum coating speeds. Both samples are separated into seven fractions using preparative temperature rising elution fractionation. The microstructures of the original samples and their fractions are studied by high-temperature gel permeation chromatography, Fourier transform infrared spectroscopy, 13 C nuclear magnetic resonance spectroscopy, differential scanning calorimetry, and successive self-nucleation/annealing thermal fractionation. Compared with sample B, sample A has a broader MWD, more LCB contents, and less SCB contents. Moreover, sample A contains slightly more 30 ℃ and 50 ℃ fractions with lower molecular weights, and more fractions at 75 ℃ and 85 ℃ with higher molecular weight. The chain structure and its distribution in the two PE resins are studied in detail, and the relationship between the chain structure and resin properties is also discussed.
文摘The extrusion ratio is one of the key parameters for manufacturing the lead-glass fiber(Pb-GF)composite wire by coating extrusion.The effect of extrusion ratio on coating extrusion of Pb-GF composite wire was studied by finite element numerical simulation with the use of the DEFOEM simulation software.The simulation result shows that the higher the extrusion ratio,the higher the effective stress that the glass fiber bears during extrusion.It is also observed that the extrusion force increases with the increase of the extrusion ratio.The extrusion experiment of Pb-GF composite wire reveals that extrusion ratio is changed by changing the quantity of glass fiber and composite diameter.The rule that increasing the extrusion ratio enhances the coating speed limit suggests that the load on the glass fiber increases with increasing extrusion ratio.Both the simulation and the extrusion experiments show that the extrusion force increases with increasing extrusion ratio.
