Study of a novel co-rotating non-twin screw extruder in processing flame retardant polymer materials

2017 ◽  
Vol 37 (8) ◽  
pp. 827-835
Author(s):  
Song Zhao ◽  
Baiping Xu ◽  
Liang He ◽  
Huiwen Yu ◽  
Shouzai Tan
Keyword(s):  
Flame Retardant ◽  
Mechanical Performance ◽  
Acrylonitrile Butadiene Styrene ◽  
Operating Conditions ◽  
Polymer Materials ◽  
Twin Screw Extruder ◽  
Screw Extruder ◽  
Limiting Oxygen Index ◽  
Twin Screw ◽  
Halogen Free

Abstract A thorough study was carried out to investigate the priority of a novel co-rotating non-twin screw extruder (NTSE) over a traditional twin screw extruder (TSE) in the mixing process of halogen-free intumescent flame-retardant acrylonitrile-butadiene-styrene (ABS) composites. The homogeneity of the flame-retardant additives of the composites processed by NTSE and TSE under the same operating conditions was characterized by using mechanical performance properties, limiting oxygen index values, UL-94 tests, and thermogravimetric analysis. All the results suggested that NTSE could achieve better mixing of the flame-retardant additives in the polymer matrix than TSE, which was further clarified by the scanning electron microscope pictures.

scholarly journals Effects of a Twin-Screw Extruder Equipped with a Molten Resin Reservoir on the Mechanical Properties and Microstructure of Recycled Waste Plastic Polyethylene Pellet Moldings

Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1058
Author(s):  
Hikaru Okubo ◽  
Haruka Kaneyasu ◽  
Tetsuya Kimura ◽  
Patchiya Phanthong ◽  
Shigeru Yao
Keyword(s):  
Mechanical Properties ◽  
Mechanical Performance ◽  
Value Added ◽  
Industrial Applications ◽  
Twin Screw Extruder ◽  
Screw Extruder ◽  
Polymer Properties ◽  
Wide Range ◽  
Twin Screw ◽  
Recycled Plastics

Each year, increasing amounts of plastic waste are generated, causing environmental pollution and resource loss. Recycling is a solution, but recycled plastics often have inferior mechanical properties to virgin plastics. However, studies have shown that holding polymers in the melt state before extrusion can restore the mechanical properties; thus, we propose a twin-screw extruder with a molten resin reservoir (MSR), a cavity between the screw zone and twin-screw extruder discharge, which retains molten polymer after mixing in the twin-screw zone, thus influencing the polymer properties. Re-extruded recycled polyethylene (RPE) pellets were produced, and the tensile properties and microstructure of virgin polyethylene (PE), unextruded RPE, and re-extruded RPE moldings prepared with and without the MSR were evaluated. Crucially, the elongation at break of the MSR-extruded RPE molding was seven times higher than that of the original RPE molding, and the Young’s modulus of the MSR-extruded RPE molding was comparable to that of the virgin PE molding. Both the MSR-extruded RPE and virgin PE moldings contained similar striped lamellae. Thus, MSR re-extrusion improved the mechanical performance of recycled polymers by optimizing the microstructure. The use of MSRs will facilitate the reuse of waste plastics as value-added materials having a wide range of industrial applications.

CFD Simulation of a Co-rotating Twin-screw Extruder: Validation of a Rheological Model for a Starch-Based Dough for Snack Food

2017 ◽  
Vol 14 (2) ◽  
Author(s):  
Giorgia Tagliavini ◽  
Federico Solari ◽  
Roberto Montanari
Keyword(s):  
Cfd Simulation ◽  
Fluid Dynamic ◽  
Operating Conditions ◽  
Second Phase ◽  
Snack Food ◽  
Suitable Model ◽  
Twin Screw Extruder ◽  
Parallel Plates ◽  
Screw Extruder ◽  
Twin Screw

AbstractThe extrusion of starch-based products has been a matter of interest, especially for the pasta and the snack food production. In recent years, twin-screw extruders for snack food have been studied from both structural and fluid dynamics viewpoints. This project started from the rheological characterization of a starch-based dough (corn 34 wt%, tapioca 32 wt%), comparing viscosity values acquired in laboratory with different theoretical models found in literature. A computational fluid dynamic (CFD) simulation recreating the simple case of a fluid flow between two parallel plates was carried out to validate the former comparison. After the rheological validation was completed, the second phase of this work covered a 3D CFD simulation of the first part of the twin-screw extruder (feeding zone). The objective was to find a suitable model for describing the dough rheological behavior and the operating conditions of a co-rotating intermeshing twin-screw extruder. Once the model would be defined, it would allow to investigate several working conditions and different screws geometries of the machine, predicting the evolution of the product rheological properties.

Extraction of coriander oil by twin-screw extruder: Screw configuration and operating conditions effect

2012 ◽  
Vol 40 ◽  
pp. 355-360 ◽  
Author(s):  
Jazia Sriti ◽  
Kamel Msaada ◽  
Thierry Talou ◽  
Mamadou Faye ◽  
Ika Amalia Kartika ◽  
...  
Keyword(s):  
Operating Conditions ◽  
Twin Screw Extruder ◽  
Screw Extruder ◽  
Extruder Screw ◽  
Twin Screw

Research on Flame Retardant and Insulation of Plastic Alloys of PEEK/PEI/PES

2014 ◽  
Vol 584-586 ◽  
pp. 1523-1526
Author(s):  
Jian Bing Chen ◽  
Zhun Zhun Li ◽  
Jiang Jie Wang ◽  
Jin Ming Qian
Keyword(s):  
Flame Retardant ◽  
Oxygen Index ◽  
Volume Resistivity ◽  
Twin Screw Extruder ◽  
Screw Extruder ◽  
Mass Ratios ◽  
Twin Screw ◽  
Insulation Performance

The PEEK/PEI/PES plastic alloys were processed by twin-screw extruder at 370°C separately with five mass ratios of 70/30, 70/25/5, 65/30/5, 60/30/10. The flame retardant of plastic alloys were investigated by experiments, their results showed that, the oxygen index declines when PES was added, the oxygen index of plastic alloy with mass ratios of 70/30 is higher than that of pure PEEK or PES, lower than that of pure PEI, which the oxygen index is 37.1%. The volume resistivity plastic alloy with mass ratios of 60/30/10 is 3.72×1017Ω·cm, which is higher than that of pure PEEK and PES for two orders of magnitude, and the insulation performance of PEEK is improved significantly by alloying.

Synthesis and characterisation of the halogen-free flame retardant and mechanical performance of the retardant epoxies resin

2017 ◽  
Vol 46 (3) ◽  
pp. 172-180 ◽  
Author(s):  
Bing Liang ◽  
Jiao Lv ◽  
Gang Wang ◽  
Tsubaki Noritatsu
Keyword(s):  
Flame Retardant ◽  
Mechanical Performance ◽  
Cyanuric Chloride ◽  
Proton Nuclear Magnetic Resonance ◽  
Flame Resistance ◽  
Limiting Oxygen Index ◽  
Content Type ◽  
Ul 94 ◽  
Halogen Free ◽  
The Impact

Purpose The purpose of this paper is to prepare a novel halogen-free intumescent flame retardant (IFR) BHPPODC (benzene hydroquinone phosphorous oxy dichloride cyanuric chloride) for application to epoxy resin (EP) and study their mechanical and flame-retardant performance. Design/methodology/approach The IFR was synthesised by phenylphosphonic dichloride, hydroquinone and cyanuric chloride via solvent reaction, and the structure was fully characterised by proton nuclear magnetic resonance (1H-NMR), mass spectrometry (MS) and Fourier transform infrared (FT-IR) spectroscopy. The thermal stability, mechanical and flame properties and morphology of the char layer of the flame-retardant EP was investigated by using thermogravimetric analysis (TGA), tensile and Charpy impact tests, limiting oxygen index (LOI) and vertical burning test (UL-94) and scanning electron microscopy (SEM). Findings Results of the LOI indicated that the halogen-free flame retardant as an additive exhibits very good flame-retardant effects. The results showed that the addition of IFR improved the flame resistance properties of epoxies resin composites, and the residual char ratio at 800°C significantly increased. Research limitations/implications The IFR can be prepared successfully and can improve the flame-retardant performance. Practical implications This contribution can provide a high flame retardant performance and has minimal impact on the mechanical performance of the BHPPODC/EP composition. Originality/value This study showed that flame-retardant BHPPODC has an effective flame effect under optimal conditions. When the 12 Wt.% IFR was added to the EP, the LOI was 29.1 and the UL-94 rank can reach V-0 rank, the tensile strength was 83.86 MPa and the impact strength was 8.82 kJ/m2.

scholarly journals Restoring mechanism of mechanical properties of recycled polyethylene pellet moldings by a repelletizing treatment using a twin-screw extruder

2021 ◽  
Vol 23 (3) ◽  
pp. 1152-1176
Author(s):  
H. Okubo ◽  
S. Yao
Keyword(s):  
Mechanical Properties ◽  
Value Added ◽  
Polymer Materials ◽  
Twin Screw Extruder ◽  
Screw Extruder ◽  
Material Recycling ◽  
Tensile Performance ◽  
Recycled Polyethylene ◽  
Twin Screw ◽  
Plastic Products

AbstractTo develop material-recycling processes for used plastic products, it is necessary to design new material-recycling techniques to optimize the mechanical properties of the recycled plastics since the mechanical properties of recycled plastic products are normally deteriorated. In this study, we suggest one of the approaches that is a repelletizing treatment for improving the mechanical properties of recycled-polyethylene moldings using a twin-screw extruder. The results of the tensile test revealed the significant effect of the repelletizing treatment on the tensile performance of the recycled-polyethylene moldings. The tensile performance of the repelletized recycled-polyethylene moldings was significantly higher than that of the original recycled-polyethylene moldings under specific repelletizing conditions. The analysis of the polymeric structures revealed the significant effect of the repelletizing treatment on the secondary and higher-order structures such as the lamellar shape, aggregation of the crystal domains, amorphousness, and polyethylene chain conformation in the recycled-polyethylene moldings. The repelletizing treatment increased the tensile performances by optimizing the internal structure of the recycled-polyethylene moldings. The results confirmed the efficacy of the repelletizing treatment to optimize the mechanical performance of the recycled-polymer materials, thereby facilitating the reuse of waste plastics as value-added materials for various industrial applications.

Steady and Transient Flow of a Non-Newtonian Chemically Reactive Fluid in a Twin-Screw Extruder

2001 ◽  
Author(s):  
W. Zhu ◽  
Y. Jaluria
Keyword(s):  
Steady State ◽  
Response Time ◽  
Transient Flow ◽  
Transient Behavior ◽  
Operating Conditions ◽  
Twin Screw Extruder ◽  
Screw Extruder ◽  
Twin Screw ◽  
Calculated Velocity ◽  
Screw Extruders

Abstract The flow of chemically reactive non-Newtonian materials, such as bio-polymers and aciylates, in a fully intermeshing, co-rotating twin-screw extruder is numerically investigated. A detailed study of the system transient behavior is carried out. The main transient aspects, including response time, variation of system variables, and instability of operation, are studied for both single- and twin-screw extruders. The effect of a time-dependent variation in the boundary conditions is studied. The coupling due to conduction heat transfer in the screw barrel is found to be very important and is taken into account for single-screw extruders. In the absence of this conjugate coupling, the response time is much shorter. Several other interesting trends are obtained with respect to the dependence of the transient response on the fluid, materials, and operating conditions. Steady state results are obtained at large time. The calculated velocity distributions in the screw channel are compared with experimental results in the literature for steady state flow and good agreement has been obtained. The numerical results show that not all desired operating conditions are feasible. The calculated results for transient transport agree with the few experimental observations available on this system. These results will be useful in the design, control and optimization of polymer extrusion processes.

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