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Mackley, M. R.; Moggridge, Geoff D.; Saquet, O.

doi:10.1023/a:1004824924912

Cited by 18 publications

(11 citation statements)

References 12 publications

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“…Only the melt spinning and the MPR experiments can approach industrial processing conditions. Spinning speeds up to 8.3 m/s, Schultz et al [3], and shear rates up to 2225 s -1 , Mackley et al [24], were reported.…”

Section: Measurement Of Flow-induced Crystallizationmentioning

confidence: 97%

“…The peaks grew rapidly until 100 s, after which they saturate and grow relatively slowly. Mackley et al [24] observed, after 10 s shearing of HDPE in the MPR at 135°C and 225 s -1 , an increase in pressure and formation of fibers. Typically, these oriented structures were not observed at a higher shear rate of 2250 s -1 .…”

Section: Measurement Of Flow-induced Crystallizationmentioning

confidence: 99%

“…Duplay et al [31] showed that the growth rate increased during shear and correlated with molecular weight. The largest deviation (ten times higher than in quiescent conditions) was found for a high molecular weight with a broad molecular weight distribution (M w = 375 kg/mol [13] FB; D four roll mill HDPE Doufas et al [55] PB melt spinning PA Duplay et al [31] OM fiber pull out iPP Göschel et al [56] WAXS contraction cell iPP Jerschow and Janeschitz-Kriegl [26,27] PB; TEM; OM slit flow cell iPP Kumaraswamy et al [57] PB; OM slit flow cell iPP Kumaraswamy et al [30] WAXS; TEM; OM slit flow cell iPP Liedauer et al [25] PB; TEM; OM slit flow cell iPP Mackley et al [24] WAXS; FB MPR HDPE Masubuchi et al [58] SAOS/DTA SFTR iPP Monasse [28] OM fiber pull out iPP Monasse [59] OM parallel plate LMDPE Pogodina et al [60] SAOS; DSC cone plate rheometry iPP Ryan et al [61] WAXS + SAXS melt spinning iPP; PET; HDPE Samon et al [4] WAXS + SAXS melt spinning PB1 Samon et al [62] WAXS + SAXS melt spinning HDPE; PVDF Schultz et al [3] WAXS + SAXS melt spinning HDPE; PVDF; PA6 Somani et al [63] SAXS; TEM parallel plate iPP Tribout et al [23] OM parallel plate; fiber pull out EPBC Vleeshouwers and Meijer [29] SAOS cone plate rheometry iPP and MWD = 3.2). Also Tribout et al [23] showed a shear dependent growth rate.…”

Section: Measurement Of Flow-induced Crystallizationmentioning

confidence: 99%

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Stress Induced Crystallization in Elongational Flow

Swartjes

Peters

Rastogi

et al. 2003

International Polymer Processing

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Stress-induced crystallization is studied in an extensional flow device (a cross-slot flow cell) for an isotactic Polypropylene (iPP) by measuring the micro-structure that develops after flow. Birefringence and Wide Angle X-ray experiments were performed. The birefringence experiments with flow below the melting temperature showed the occurrence of a fiber-like structure around the outflow centerline and, later in time, of 'streamlines'. The latter are explained by the influence of shear gradients close to the optical windows. The WAXS experiments also showed the fiber-like structure around the outflow centerline, having orientations in the (110), (040) and (130) reflections, with a width of about 80 lm. This dominance of the elongational flow around the stagnation line could not be observed in experiments with flow above and subsequent crystallization below the melting temperature. Structure development in this cell was numerically predicted using the Leonov and the extended Pompom (XPP) model. The oriented structures can be predicted. Moreover, process conditions are found with less influence of the (unwanted) shear gradients. Finally, it was concluded that the strain hardening behavior in the Leonov model over-estimates the first component of the Finger tensor, and thus the number of flow-induced nuclei. Therefore it is recommended to use the extended Pompom model as a more realistic basis for a quantitative flow-induced crystallization model. IPP_ipp1719 -2.4.03/druckhaus köthen FIBER AND FILM Intern. Polymer Processing XVIII (2003) 1  Hanser Publishers, Munich 53

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Section: Measurement Of Flow-induced Crystallizationmentioning

confidence: 97%

Section: Measurement Of Flow-induced Crystallizationmentioning

confidence: 99%

Section: Measurement Of Flow-induced Crystallizationmentioning

confidence: 99%

See 1 more Smart Citation

Stress Induced Crystallization in Elongational Flow

Swartjes

Peters

Rastogi

et al. 2003

International Polymer Processing

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“…Flow‐induced crystallization was studied by numerous groups using rheo‐optical methods and some selected references are discussed in the following. Pioneering works were carried out by Keller and Mackley who developed a multipass rheometer with in situ microstructural characterization and studied crystallizing polymers under process‐like conditions . Winter et al.…”

Section: Hyphenated Rheology Techniquesmentioning

confidence: 99%

“…Pioneering works were carried out by Keller and Mackley who developed a multipass rheometer with in situ microstructural characterization and studied crystallizing polymers under process-like conditions. [11,[129][130][131][132][133] Winter et al investigated the molecularweight dependence of flow-induced crystallization. [134,135] More recently, Pantani et al studied the kinetics of crystallizing polymers under flow conditions using Rheo-Microscopy.…”

Section: Rheo-microscopymentioning

confidence: 99%

Polymer Crystallization Studied by Hyphenated Rheology Techniques: Rheo‐NMR, Rheo‐SAXS, and Rheo‐Microscopy

Räntzsch

Özen

Ratzsch

et al. 2018

Macro Materials & Eng

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Rheological set‐ups with in situ analytical sensors, combine information on the flow and deformation behavior of soft matter, with simultaneous insights into structural and dynamic features. Furthermore, they permit the study of soft matter under well‐defined flow conditions. Herein are presented hyphenations of rheology and nuclear magnetic resonance (NMR), small angle X‐ray scattering (SAXS), and optical microscopy. They are employed to unravel relationships between the molecular dynamics, morphology, and rheology of crystallizing polymers. The results confirm a physical gelation process during polymer crystallization, mediated by the interaction of growing superstructures at volume fractions of 10–15%. The buildup of row‐nucleated structures during flow‐induced crystallization is found to reduce the time of gelation as detected by the rheological response. These investigations help to clarify the crystallization mechanism, structure–property relationships, and the hardening behavior of crystallizing polymers.

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Residual orientation in injection‐moulded plaques of atactic‐polystyrene I: The effect of processing conditions

Healy

Knott

Edward

2017

Polymer Engineering & Sci

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Injection moulded polymer articles often have residual macromolecular or crystalline orientation which can have a significant impact on the optical and mechanical properties of the moulded article. Small angle neutron scattering (SANS) was used to measure the molecular shape and orientation of deuterated blends of injection moulded polystyrene. For ∼1‐mm‐thick mouldings of uniform rectangular cross‐section, the eccentricity in the SANS pattern gave a direct measure of the residual molecular orientation over the length scale ∼100–1,500 Å. The residual orientation was found to vary significantly with injection moulding conditions with comparative residual orientation decreasing with decreasing mould fill‐time, and increasing with mould thickness and moulding temperatures. The orientation was found to be a minimum in the centre of the mould and highest near the surface and the average orientation at a particular position in the mould was found to be strongly correlated with the volume of material deposited as a solid skin layer during injection moulding. POLYM. ENG. SCI., 58:1322–1331, 2018. © 2017 Society of Plastics Engineers

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Untitled

Cited by 18 publications

References 12 publications

Stress Induced Crystallization in Elongational Flow

Stress Induced Crystallization in Elongational Flow

Polymer Crystallization Studied by Hyphenated Rheology Techniques: Rheo‐NMR, Rheo‐SAXS, and Rheo‐Microscopy

Residual orientation in injection‐moulded plaques of atactic‐polystyrene I: The effect of processing conditions

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