Theoretical Calculation and Simulation of Polymer

A special issue of Polymers (ISSN 2073-4360). This special issue belongs to the section "Polymer Physics and Theory".

Deadline for manuscript submissions: closed (10 December 2022) | Viewed by 13182

Special Issue Editors


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Guest Editor
Institute of Polymer Extrusion and Compounding, Johannes Kepler Universitat Linz, Linz, Austria
Interests: modeling and simulation; polymer processing; extrusion; digitalization; screw design

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Guest Editor
Institute of Polymer Extrusion and Compounding, Johannes Kepler University Linz, Linz, Austria
Interests: injection molding; polymer processing; surfaces; digitalization

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Guest Editor
Institute of Polymer Extrusion and Compounding, Johannes Kepler University Linz, Linz, Austria
Interests: modeling and simulation; polymer processing; extrusion

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Guest Editor
Institute of Polymer Injection Moulding and Process Automation, Johannes Kepler University Linz, Linz, Austria
Interests: injection molding; polymer processing

Special Issue Information

Dear Colleagues,

Modeling and simulation have been an important discipline in the field of polymer science. In order to understand the material structure–property–processing–performance relationship of polymers in various applications, numerous mathematical models have been developed, attempting to represent the physical reality with equations. While for many decades, the setup and solution of these models was limited by the computational power available, these characteristics have changed with the recent advent of more powerful computers. It is now increasingly possible to relax traditional modeling assumptions and solve more realistic mathematical models, thereby providing insights into the complex behavior of polymers.

The aim of this Special Issue is to highlight progress in the theoretical calculation and simulation of polymers in a broad field of applications ranging from material science over processing to product design. Submissions are welcomed based on any modeling approach and can be either original research or reviews.

Dr. Christian Marschik
Prof. Dr. Berger-Weber Gerald Roman
Dr. Wolfgang Roland
Prof. Dr. Georg Steinbichler
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Polymers is an international peer-reviewed open access semimonthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2700 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

 

Keywords

  • modeling and simulation
  • theory
  • polymer science
  • material science
  • polymer processing
  • polymer product design

Published Papers (5 papers)

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Research

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12 pages, 2829 KiB  
Article
Web Wrinkle Defects due to Temperature Profile in Roll-to-Roll Manufacturing Systems
by Jaehyun Noh, Minho Jo, Hojin Jeon, Minjae Kim, Jeongdai Jo and Changwoo Lee
Polymers 2023, 15(2), 457; https://doi.org/10.3390/polym15020457 - 15 Jan 2023
Cited by 2 | Viewed by 2787
Abstract
The roll-to-roll manufacturing system is extensively used for mass producing products made of plastic, paper, and fabric in several traditional industries. When flexible substrates, also known as webs, are heated and transported inside the dryer, an inconsistent temperature distribution occurs on the material [...] Read more.
The roll-to-roll manufacturing system is extensively used for mass producing products made of plastic, paper, and fabric in several traditional industries. When flexible substrates, also known as webs, are heated and transported inside the dryer, an inconsistent temperature distribution occurs on the material in the machine direction (MD) and cross-machine direction (CMD). If rollers are not aligned in parallel on the same plane in the roll-to-roll web handling process, or if roller misalignment exists, strain deviation occurs in the web, resulting in lateral displacement and web wrinkles. Therefore, this study examined a wrinkle, which is a thermal deformation that occurs when an inconsistent web temperature distribution is formed on the material inside a dryer. The changes in the elastic modulus and thermal expansion of the web were also examined. Experiments were conducted using a PET film, and its elastic modulus and thermal expansion were examined. The results showed that the presence of a web wrinkle defect can cause a thickness deviation in the functional layer manufactured on the web. Moreover, an appropriate operating speed should be set to reduce the CMD temperature deviation, thereby reducing instances of wrinkle defects. Full article
(This article belongs to the Special Issue Theoretical Calculation and Simulation of Polymer)
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24 pages, 11143 KiB  
Article
Multi-Dimensional Regression Models for Predicting the Wall Thickness Distribution of Corrugated Pipes
by Hanny Albrecht, Wolfgang Roland, Christian Fiebig and Gerald Roman Berger-Weber
Polymers 2022, 14(17), 3455; https://doi.org/10.3390/polym14173455 - 24 Aug 2022
Cited by 3 | Viewed by 1355
Abstract
Corrugated pipes offer both higher stiffness and higher flexibility while simultaneously requiring less material than rigid pipes. Production rates of corrugated pipes have therefore increased significantly in recent years. Due to rising commodity prices, pipe manufacturers have been driven to produce corrugated pipes [...] Read more.
Corrugated pipes offer both higher stiffness and higher flexibility while simultaneously requiring less material than rigid pipes. Production rates of corrugated pipes have therefore increased significantly in recent years. Due to rising commodity prices, pipe manufacturers have been driven to produce corrugated pipes of high quality with reduced material input. To the best of our knowledge, corrugated pipe geometry and wall thickness distribution significantly influence pipe properties. Essential factors in optimizing wall thickness distribution include adaptation of the mold block geometry and structure optimization. To achieve these goals, a conventional approach would typically require numerous iterations over various pipe geometries, several mold block geometries, and then fabrication of pipes to be tested experimentally—an approach which is very time-consuming and costly. To address this issue, we developed multi-dimensional mathematical models that predict the wall thickness distribution in corrugated pipes as functions of the mold geometry by using symbolic regression based on genetic programming (GP). First, the blow molding problem was transformed into a dimensionless representation. Then, a screening study was performed to identify the most significant influencing parameters, which were subsequently varied within wide ranges as a basis for a comprehensive, numerically driven parametric design study. The data set obtained was used as input for data-driven modeling to derive novel regression models for predicting wall thickness distribution. Finally, model accuracy was confirmed by means of an error analysis that evaluated various statistical metrics. With our models, wall thickness distribution can now be predicted and subsequently used for structural analysis, thus enabling digital mold block design and optimizing the wall thickness distribution. Full article
(This article belongs to the Special Issue Theoretical Calculation and Simulation of Polymer)
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19 pages, 4907 KiB  
Article
Application of Mixing Rules for Adjusting the Flowability of Virgin and Post-Consumer Polypropylene as an Approach for Design from Recycling
by Ines Traxler, Christian Marschik, Manuel Farthofer, Stephan Laske and Joerg Fischer
Polymers 2022, 14(13), 2699; https://doi.org/10.3390/polym14132699 - 30 Jun 2022
Cited by 9 | Viewed by 2269
Abstract
To enable the use of recyclates in thermoformed polypropylene products with acceptable optical appearance and good mechanical stability, a multilayer structure of virgin and recycled material can be used. When producing multilayer films with more than two layers, the used materials should have [...] Read more.
To enable the use of recyclates in thermoformed polypropylene products with acceptable optical appearance and good mechanical stability, a multilayer structure of virgin and recycled material can be used. When producing multilayer films with more than two layers, the used materials should have similar melt flow properties to prevent processing instabilities. In the case of a three-layer film, post-consumer recyclates are often hidden in the core layer. Due to the inconsistent melt flow properties of post-consumer recyclates, the adjustment of the melt flow properties of the core layer to those of the outer layers has to be realized by blending with virgin materials. In order to understand the effect of mixing with a virgin material with a certain pre-defined melt flow rate (MFR), material mixtures with different mixing partners from various sources were realized in this study. Hence, the pre-defined virgin material was mixed with (i) virgin materials, (ii) artificial recyclates out of a mixture of different virgin materials, and (iii) commercially available recyclates. These blends with mixing partner contents ranging from 0–100% in 10% increments were prepared by compounding and the MFR of each mixture was determined. For a mathematical description of the mixing behavior and furthermore for a proper MFR prediction of the material mix, existing mixing rules were tested on the three pre-defined sample groups. Therefore, this paper shows the applicability of different mixing rules for the prediction of the MFR of material blends. Furthermore, a new mixing rule was developed using symbolic regression based on genetic programming, which proved to be the most accurate predictive model. Full article
(This article belongs to the Special Issue Theoretical Calculation and Simulation of Polymer)
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15 pages, 10336 KiB  
Article
Strain Optimization of Tensioned Web through Computational Fluid Dynamics in the Roll-to-Roll Drying Process
by Minho Jo, Jaehyun Noh, Gyoujin Cho, Taik-min Lee, Bukuk Oh, Sanghoon Nam and Changwoo Lee
Polymers 2022, 14(12), 2515; https://doi.org/10.3390/polym14122515 - 20 Jun 2022
Cited by 3 | Viewed by 2190
Abstract
Unpredictable web temperature distributions in the dryer and strain deviations in the cross-machine (CMD) and machine (MD) directions could hamper the manufacture of smooth functional layers on polymer-based webs through the roll-to-roll (R2R) continuous process system. However, research on this topic is limited. [...] Read more.
Unpredictable web temperature distributions in the dryer and strain deviations in the cross-machine (CMD) and machine (MD) directions could hamper the manufacture of smooth functional layers on polymer-based webs through the roll-to-roll (R2R) continuous process system. However, research on this topic is limited. In this study, we developed a structural analysis model using the temperature distribution of the web as a boundary condition to analyze the drying mechanism of the dryer used in an R2R system. Based on the results of this model, we then applied structural modifications to the flow channel and hole density of the aluminum plate of the dryer. The model successfully predicted the temperature and strain distributions of the web inside the dryer in the CMD and MD by forming a tension according to the speed difference of the driven rolls at both ends of the span. Our structural improvements significantly reduced the temperature deviation of the moving web inside the dryer by up to 74% and decreased the strain deviation by up to 46%. The findings can help prevent web unevenness during the drying process of the R2R system, which is essential to minimize the formation of defects on functional layers built over polymer-based webs. Full article
(This article belongs to the Special Issue Theoretical Calculation and Simulation of Polymer)
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Review

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32 pages, 6117 KiB  
Review
Melt Conveying in Single-Screw Extruders: Modeling and Simulation
by Christian Marschik, Wolfgang Roland and Tim A. Osswald
Polymers 2022, 14(5), 875; https://doi.org/10.3390/polym14050875 - 23 Feb 2022
Cited by 5 | Viewed by 3438
Abstract
Numerous analyses have modeled the flow of polymer melts in the melt-conveying zones of single-screw extruders. While initial studies mainly provided exact analytical results for combined drag and pressure flows of Newtonian fluids, more recently developed, numerical methods seek to deepen the understanding [...] Read more.
Numerous analyses have modeled the flow of polymer melts in the melt-conveying zones of single-screw extruders. While initial studies mainly provided exact analytical results for combined drag and pressure flows of Newtonian fluids, more recently developed, numerical methods seek to deepen the understanding of more realistic flow situations that include shear-thinning and non-isothermal effects. With the advent of more powerful computers, considerable progress has been made in the modeling and simulation of polymer melt flows in single-screw extruders. This work reviews the historical developments from a methodological point of view, including (1) exact analytical, (2) numerical, and (3) approximate methods. Special attention is paid to the mathematical models used in each case, including both governing flow equations and boundary conditions. In addition, the literature on leakage flow and curved-channel systems is revisited. Full article
(This article belongs to the Special Issue Theoretical Calculation and Simulation of Polymer)
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