Study on extrudate swell of polypropylene in double-lumen micro profile extrusion

Tian, Hua; Zhao, Danyang; Wang, Minjie; Jin, Guobao; Jin, Yifei

doi:10.1016/j.jmatprotec.2015.06.015

Cited by 32 publications

(32 citation statements)

References 29 publications

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“…[16,[36][37][38][39] Originally one confronted the difficulty that numerical simulations for extrudate swell were only implemented considering the basic Maxwell constitutive model, due to limitations of numerical solution methods or schemes. [36,40] In the last decades of the previous century, extending the Maxwell-type models for solving extrudate swell problems at high shear rates paved a way of important contributions to the modeling with more realistic constitutive models, such as the nonlinear differential Phan-Thien-Tanner model (PTT model), [16,34,41,42] the molecular-based Double-Convected POM-POM model (DCPP model), [43][44][45][46] and the integral Kaye-Bernstein-Kearsley-Zapas model (K-BKZ model). [47][48][49] These constitutive models seem more promising in capturing the extrudate swell at high Weissenberg (Wi) number, thus for a large product of (overall) relaxation time and shear rate, accompanied by a suited die design for industrial applications.…”

Section: Introductionmentioning

confidence: 99%

“…Specific focus has although been on the more general no strain-hardening extensional behavior for linear polymers such as high-density polyethylene (HDPE), linear low-density polyethylene (LLDPE), and polypropylene (PP) melts [51,52] with reasonable rheological parameters. [46,53,54] In addition, it should be pointed out that currently the numerical calculation divergence for non-Newtonian flow at high Wi numbers still limits the development of numerical modeling. [55,56] Hence, experimental as well as modeling research has been conducted to capture extrudate swell, as also highlighted in Table 1, listing important references for both types of research making a distinction between polymer types and ranges of processing temperatures.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

State of the‐Art for Extrudate Swell of Molten Polymers: From Fundamental Understanding at Molecular Scale toward Optimal Die Design at Final Product Scale

Tang

Marchesini

Cardon

et al. 2020

Macro Materials & Eng

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Exit velocity profiles for parallel die and die optimized using conical widening or narrowing. Reproduced permission. [164] Copyright 2010, Elsevier Ltd. c) Average velocity of each outflow subsection of the slit die (width = 100 mm and height = 1.5 mm), Reproduced with permission. [173] Copyright 2012, Elsevier Ltd. d,e) The geometry profiles of the Catheter cross section covered as case study. f) The velocity distribution at the die outflow for different trials-T0: the original die profile; T1: r 2 varies from 0.9 to 0.95 mm; T2: r 2 varies from 0.95 to 0.9 mm, θ 2 varies from 45° to 43°; T3: r 2 varies from 0.9 to 0.95 mm; T4: θ 2 varies from 43° to 40°; T5: r 3 varies from 0.7 to 0.65 mm. Reproduced with permission. [166] Copyright 2013, Elsevier. g) The corresponding objective function evolution in consecutive trials. Reproduced with permission. [166] Copyright 2013, Elsevier Ltd.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

State of the‐Art for Extrudate Swell of Molten Polymers: From Fundamental Understanding at Molecular Scale toward Optimal Die Design at Final Product Scale

Tang

Marchesini

Cardon

et al. 2020

Macro Materials & Eng

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“…Small amplitude oscillatory measurements were carried out using 25 mm parallel plates on a stress-controlled rotational rheometer (Anton Paar, MCR 301) at 160 C. The linear viscoelastic parameters, including i and G i , were obtained by tting the experimental data, using MATLAB's tting toolbox, to the Maxwell model [24,25]: …”

Section: Rheological Parameters Of the Dopementioning

confidence: 99%

Study on the Viscoelastic Fluid Behavior in Hollow Fiber Membrane Fabrication Process Using Giesekus’ Model

2017

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Abstract. In the present study, attempts are made to study the behavior of a viscoelastic uid in the hollow ber membrane production process. For this purpose, the uid is considered to obey the Giesekus' model and ow is taken as steady, two-dimensional and isothermal one. The ow eld is obtained using DEVSS/SUPG scheme combined with a free surface tracking method. The obtained results are compared to the case of Newtonian uid. It is shown that the extrudate swell is 20% more in the case of viscoelastic uid. Moreover, the elastic behavior of the viscoelastic uid signi cantly a ects the velocity eld in the extrudate outside the die. It causes the uid ow to become reversed in the middle part of the extrudate as the direct result of the stress relaxation process, whereas such a behavior is not seen for Newtonian uid. Also, the First Normal Stress Di erence (FNSD) distribution in the extrudate is obtained and its variation is discussed. Furthermore, the e ects of operational parameters, including die back pressure and take-up velocity, are investigated. Finally, the predicted extrudate swell for various operation conditions is compared to experimental results showing good agreement between experimental and simulated data.

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“…Catheter manufacturing techniques have advanced over time, although more precise catheter manufacturing techniques are still required. In addition, microextrusion techniques are being actively studied to produce steerable or smart catheters [18][19][20][21]. Column strength, flexibility, and buckling are important mechanical properties for sheath catheters used for stent delivery and electrophysiology catheters for intervention of arrhythmia and atrial fibrillation.…”

Section: Introductionmentioning

confidence: 99%

Extrusion Characteristics of Thin Walled Tubes for Catheters Using Thermoplastic Elastomer

Cho

Lee

et al. 2020

Polymers

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As the market for minimally invasive surgery has grown, the demand for high-precision and high-performance catheters has increased. Catheters for the diagnosis and treatment of cardiovascular or cerebrovascular disease mainly use a braided wire tube with a polymer inner liner and outer jacket to improve the pushability and trackability. The outer jacket should have an accurate inner and outer diameter and while maintaining a wall thickness of 150 µm or less. In this study, we designed and manufactured a tip and die capable of extruding an outer jacket with a wall thickness of 150 µm or less using a medical thermoplastic elastomer for manufacturing 8Fr (2.64 mm diameter) thin-walled tubes. The ovality and inner/outer diameters of the tube were studied according to changes in the screw speed (mass flow rate), puller speed, air pressure applied to the lumen, and distance between the quench and head, which are the main variables of microextrusion processes. The screw speed (mass flow rate), puller speed, and air pressure affected the inner/outer diameter of the tube, with screw speed and puller speed having the largest influence on diameter. The air pressure and distance between quench and head had the greatest influence on ovality. The results show the effect of different processing parameters on the characteristics of the extruded tube, which will help to establish a stable extrusion process for the manufacture of outer jackets for braided catheter shafts.

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Study on extrudate swell of polypropylene in double-lumen micro profile extrusion

Cited by 32 publications

References 29 publications

State of the‐Art for Extrudate Swell of Molten Polymers: From Fundamental Understanding at Molecular Scale toward Optimal Die Design at Final Product Scale

State of the‐Art for Extrudate Swell of Molten Polymers: From Fundamental Understanding at Molecular Scale toward Optimal Die Design at Final Product Scale

Study on the Viscoelastic Fluid Behavior in Hollow Fiber Membrane Fabrication Process Using Giesekus’ Model

Extrusion Characteristics of Thin Walled Tubes for Catheters Using Thermoplastic Elastomer

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