Melt strength, local velocity, and elongational viscosity profiles of low-density polyethylene filaments affected by the die design and process conditions

บทความในวารสาร

ผู้เขียน/บรรณาธิการ

กลุ่มสาขาการวิจัยเชิงกลยุทธ์

ไม่พบข้อมูลที่เกี่ยวข้อง

รายละเอียดสำหรับงานพิมพ์

รายชื่อผู้แต่ง: Sitticharoen W., Harnnarongchai W., Intawong N., Sombatsompop N.

ผู้เผยแพร่: Wiley

ปีที่เผยแพร่ (ค.ศ.): 2012

วารสาร: Journal of Applied Polymer Science (0021-8995)

Volume number: 124

Issue number: 5

หน้าแรก: 3751

หน้าสุดท้าย: 3764

จำนวนหน้า: 14

นอก: 0021-8995

eISSN: 1097-4628

URL: https://www.scopus.com/inward/record.uri?eid=2-s2.0-84857997160&doi=10.1002%2fapp.35378&partnerID=40&md5=d867e0caf8747976fb8df4f63fa37f42

ภาษา: English-Great Britain (EN-GB)

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บทคัดย่อ

An experimental arrangement to simultaneously measure the melt strength, velocity profiles, and elongational viscosity profiles across the cross section of a molten filament that emerged from either a circular or slit die for low-density polyethylene (LDPE) under nonisothermal and isothermal conditions is proposed. The proposed experimental rig was based on a parallel coextrusion technique of colored LDPE melt layers into an uncolored melt flowing from the barrel into and out of a die to form a continuous filament before they were pulled down by mechanical rollers until the filament failed. The experimental rig was also equipped with a high-speed data-logging system and a personal computer for real-time measurements. The results suggest that the draw-down forces changed continuously with changing roller speed, and the velocity profiles of the melt were not uniform across the LDPE filament during the stretching of the melt. Greater draw-down forces and local melt velocities were obtained in the slit die or under the nonisothermal condition. The draw-down forces and velocity profiles in both dies were affected by the volumetric flow rates from the extruder and the roller speeds used, with the effect being more pronounced for the circular die. The elongational viscosity profiles of the LDPE filament were not uniform across the filament cross section and corresponded well to the obtained velocity profiles. The elongational viscosities of the LDPE filament were relatively higher when the filament was extruded and stretched in the circular die and under the nonisothermal condition. The changes in the elongational viscosity profiles were more sensitive to changes in the volumetric flow rate and roller speed in the circular die. ฉ 2011 Wiley Periodicals, Inc.

คำสำคัญ

Polyolefins