Correlation between polyethylene topology and melt flow instabilities by determining in-situ pressure fluctuations and applying advanced data analysis

Palza, Humberto; Filipe, S.; Naue, Ingo F. C.; Wilhelm, Manfred

doi:10.1016/j.polymer.2009.11.050

Cited by 25 publications

(58 citation statements)

References 56 publications

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“…Hence, only the signal at the frequency with the highest magnitude (in the frequency domain) needs to be considered. For the Fourier transform employed on the time dependent pressure data please refer to the following publications, where the method is described in detail …”

Section: Optical Analysis Methodsmentioning

confidence: 99%

“…If two layers of the extrudate need to be glued together they might not adhere properly due to sharkskin. The precise origins of sharkskin instability are still unclear . Although many publications suggest that its origin is related to phenomenon at the die exit, Palza and Filipe showed that it can be measured throughout the whole die by using an in situ measurement technique based on piezoelectric pressure transducers.…”

Section: Introductionmentioning

confidence: 99%

“…The precise origins of sharkskin instability are still unclear . Although many publications suggest that its origin is related to phenomenon at the die exit, Palza and Filipe showed that it can be measured throughout the whole die by using an in situ measurement technique based on piezoelectric pressure transducers. The stick‐slip instability, referred to as just stick‐slip henceforth, is characterized by alternating smooth and rough regions at the extrudates surface.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Investigation of the Sharkskin melt instability using optical Fourier analysis

Gansen

Řehoř

Sill

et al. 2019

J of Applied Polymer Sci

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An optical method allowing the characterization of melt flow instabilities typically occurring during an extrusion process of polymers and polymer compounds is presented. It is based on a camera‐acquired image of the extruded compound with a reference length scale. Application of image processing and transformation of the calibrated image to the frequency domain yields the magnitude spectrum of the instability. The effectiveness of the before mentioned approach is shown on Styrene‐butadiene rubber (SBR) compounds, covering a wide range of silica filler content, extruded through a Göttfert capillary rheometer. The results of the image‐based analysis are compared with the results from the sharkskin option, a series of highly sensitive pressure transducers installed inside the rheometer. A simplified version of the code used to produce the optical analysis results is included as supplementary material. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48806.

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Section: Optical Analysis Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Investigation of the Sharkskin melt instability using optical Fourier analysis

Gansen

Řehoř

Sill

et al. 2019

J of Applied Polymer Sci

View full text Add to dashboard Cite

show abstract

“…Recently, chaotic regimes were also observed in similar experimental fixtures [13]. It should be remarked that other authors, with a different approach, have focused their attention on these flow instabilities and they have already demonstrated that their characterization could give useful insights on the material properties [14].…”

Section: Introductionmentioning

confidence: 98%

Flow instabilities in rheotens experiments: Analysis of the impacts of the process conditions through neural network modeling

Tronci

Coppola²,

Bacchelli³

et al. 2012

Polymer Engineering & Sci

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Fiber spinning experiments are conducted with a capillary rheometer and a Rheotens tester on linear styrene‐isoprene‐styrene copolymer samples by varying extrusion temperature and drawdown velocity in a wide range of values, also covering the occurrence of instability phenomena. Tensile stress is measured during the experiences, and the experimental time series are then analyzed by means of a new methodology. The proposed approach is based on Neural Network modeling of the time series, coupled with Principal Component Analysis postprocessing of the results. The methodology is able to identify and quantify the effects of process condition on the dynamical behavior of the system. POLYM. ENG. SCI., 2013. © 2012 Society of Plastics Engineers

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“…[1][2][3][4] In particular, the effect of lateral chains on the main properties of either polyethylenes or poly(propylene)s has been deeply studied allowing the relation between polymer topology and its final properties. [5][6][7][8][9] During the last 25 years the development of metallocene catalysts has improved this microstructural control allowing the synthesis of both polyolefins with tailored tacticities and new olefin copolymers with a random/uniform intermolecular comonomer incorporation and a narrow molecular weight distribution. [2,5,10] The effect of either lateral chains or short chain branching, on the main properties of polyolefins has been largely studied.…”

Section: Introductionmentioning

confidence: 99%

Effect of Comonomer Content on the Behavior of Propylene Copolymer/Compatibilizer/Clay Nanocomposites

Palza

2010

Macro Materials & Eng

Self Cite

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A set of isotactic propylene copolymers with either 1‐hexene or 1‐octadecene were synthesized using a metallocene catalyst, and their nanocomposites with 5 wt.‐% of clay and 15 wt.‐% of compatibilizer were prepared and characterized. Clay intercalation and dispertion depend on the comonomer content in the matrix which improves at high short‐chain‐branching levels. The presence of both clay and compatibilizer increased the crystallization temperature of the matrix. A strong correlation between the elastic modulus of the matrix and its relative increase in the nanocomposite was observed. By adding clay and compatibilizer to the copolymer, the modulus can be increased by a factor of two. The results open new perspectives in the understanding of the effect of polyolefin topology on nanocomposites properties.

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Correlation between polyethylene topology and melt flow instabilities by determining in-situ pressure fluctuations and applying advanced data analysis

Cited by 25 publications

References 56 publications

Investigation of the Sharkskin melt instability using optical Fourier analysis

Investigation of the Sharkskin melt instability using optical Fourier analysis

Flow instabilities in rheotens experiments: Analysis of the impacts of the process conditions through neural network modeling

Effect of Comonomer Content on the Behavior of Propylene Copolymer/Compatibilizer/Clay Nanocomposites

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