Thermal-Spraying of Polymers and Polymer Blends

MRS Bulletin ◽  
2000 ◽  
Vol 25 (7) ◽  
pp. 48-53 ◽  
Author(s):  
J. A. Brogan
Keyword(s):  
Polymer Blends ◽  
Residence Time ◽  
Flame Temperature ◽  
Thermal Spraying ◽  
Polymeric Materials ◽  
Flame Spraying ◽  
Flame Spray ◽  
The Past ◽  
Lower Temperature

Thermal-spraying of polymers can be traced back to the 1940s, when polyethylene (PE) was first produced by E.I. du Pont de Nemours & Company. Early work with flame-spraying guns was unsuccessful because the equipment, designed for spraying metals, produced a flame that was both too hot and too short to melt the PE without degradation. The technology has advanced considerably in the past 20 years. Flame-spray equipment and hardware accessories have been designed by numerous companies (PFS Thermoplastics, Alamo, Eutectic + Castolin, etc.) specifically for polymeric materials. The new equipment provides either a lower flame temperature or uses special cooling shrouds to cool the center of the flame, providing a longer residence time at a lower temperature. Many plastics can now be completely melted in-flight and allow heat-sensitive components to be coated with plastic.

scholarly journals In Situ Generation of Green Hybrid Nanofibrillar Polymer-Polymer Composites—A Novel Approach to the Triple Shape Memory Polymer Formation

Polymers ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 1900
Author(s):  
Ramin Hosseinnezhad ◽  
Iurii Vozniak ◽  
Fahmi Zaïri
Keyword(s):  
Polymer Blends ◽  
Shape Memory ◽  
Shape Memory Polymer ◽  
Cellulose Nanofibers ◽  
Polymeric Materials ◽  
Novel Approach ◽  
Phase Transition Temperatures ◽  
Triple Shape Memory

The paper discusses the possibility of using in situ generated hybrid polymer-polymer nanocomposites as polymeric materials with triple shape memory, which, unlike conventional polymer blends with triple shape memory, are characterized by fully separated phase transition temperatures and strongest bonding between the polymer blends phase interfaces which are critical to the shape fixing and recovery. This was demonstrated using the three-component system polylactide/polybutylene adipateterephthalate/cellulose nanofibers (PLA/PBAT/CNFs). The role of in situ generated PBAT nanofibers and CNFs in the formation of efficient physical crosslinks at PLA-PBAT, PLA-CNF and PBAT-CNF interfaces and the effect of CNFs on the PBAT fibrillation and crystallization processes were elucidated. The in situ generated composites showed drastically higher values of strain recovery ratios, strain fixity ratios, faster recovery rate and better mechanical properties compared to the blend.

scholarly journals Mechanical and Morphological Properties of Bio-Phenolic/Epoxy Polymer Blends

Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 773
Author(s):  
Ahmad Safwan Ismail ◽  
Mohammad Jawaid ◽  
Norul Hisham Hamid ◽  
Ridwan Yahaya ◽  
Azman Hassan
Keyword(s):  
Mechanical Properties ◽  
Phase Separation ◽  
Polymer Blends ◽  
Epoxy Polymer ◽  
Flexural Modulus ◽  
Polymeric Materials ◽  
Morphological Properties ◽  
Comparison Results ◽  
Unique Material ◽  
Different Types

Polymer blends is a well-established and suitable method to produced new polymeric materials as compared to synthesis of a new polymer. The combination of two different types of polymers will produce a new and unique material, which has the attribute of both polymers. The aim of this work is to analyze mechanical and morphological properties of bio-phenolic/epoxy polymer blends to find the best formulation for future study. Bio-phenolic/epoxy polymer blends were fabricated using the hand lay-up method at different loading of bio-phenolic (5 wt%, 10 wt%, 15 wt%, 20 wt%, and 25 wt%) in the epoxy matrix whereas neat bio-phenolic and epoxy samples were also fabricated for comparison. Results indicated that mechanical properties were improved for bio-phenolic/epoxy polymer blends compared to neat epoxy and phenolic. In addition, there is no sign of phase separation in polymer blends. The highest tensile, flexural, and impact strength was shown by P-20(biophenolic-20 wt% and Epoxy-80 wt%) whereas P-25 (biophenolic-25 wt% and Epoxy-75 wt%) has the highest tensile and flexural modulus. Based on the finding, it is concluded that P-20 shows better overall mechanical properties among the polymer blends. Based on this finding, the bio-phenolic/epoxy blend with 20 wt% will be used for further study on flax-reinforced bio-phenolic/epoxy polymer blends.

Surface Wear Improvement of Al-Alloys by Amorphous Iron-Based Flame-Sprayed Coatings

2011 ◽  
Vol 690 ◽  
pp. 405-408 ◽  
Author(s):  
Joel Voyer
Keyword(s):  
Wear Resistance ◽  
Flame Spraying ◽  
Flame Spray ◽  
Phase Content ◽  
Coating Properties ◽  
Amorphous Iron ◽  
Spray Process ◽  
Spraying Parameters ◽  
Iron Based ◽  
Sprayed Coatings

Partially amorphous iron-based coatings were produced onto aluminium using a powder flame-spraying process with a commercially available feedstock powder (Nanosteel SHS-7170) obtained from the Nanosteel Company Inc.. Several coating properties such as the microstructure, porosity, phase content, micro-hardness, and wear resistance were evaluated in the as-sprayed condition. As shown by the results obtained, the powder flame iron-based coatings perform relatively well in term of wear resistance in comparison with similar coatings produced using other expensive thermal spray techniques. Furthermore, this study shows that all the coating properties (microstructure, porosity, phase content, hardness and wear performance) depend strongly on the flame spraying parameters used. Finally, this paper demonstrates clearly that the flame-spray process may be used to produce amorphous iron-based coatings having a good wear resistance, and that this process appears to be a suitable inexpensive alternative to plasma or HVOF processes based on the present results.

Use of Different Process Gases for Manufacturing Isolating Alumina Coatings by Flame Spraying with Cords

2021 ◽  
Author(s):  
M. Hauer ◽  
M. Meyer ◽  
D. Billieres ◽  
C. Bricquet ◽  
F. Gerstgrasser ◽  
...  
Keyword(s):  
Volume Resistivity ◽  
Alpha Phase ◽  
Flame Spraying ◽  
Flame Spray ◽  
Alumina Coatings ◽  
Spray Coatings ◽  
Aluminum Hydroxides ◽  
Fine Microstructure ◽  
Plasma Sprayed ◽  
Aluminum Substrates

Abstract This study assesses the quality of flame-sprayed alumina coatings produced from recently developed alumina cord using argon and compressed air as atomizing gases. Coatings of different thicknesses were deposited on aluminum substrates and then analyzed using optical microscopy, X-ray diffraction, and resistivity measurements. The coatings, particularly those sprayed with argon, had fine microstructure and higher surface and volume resistivity than flame-spray coatings made from alumina cord in the past. They were also found to have higher alpha phase content than plasma-sprayed coatings, regardless of the atomizing gas used. The effect of humidity and the possible formation of aluminum hydroxides are also addressed.

Comparison between Tribological Characteristics of Al-Cu-Fe-B Quasicrystalline and Mo Coatings

2007 ◽  
Vol 26-28 ◽  
pp. 715-718
Author(s):  
Bong Hwan Kim ◽  
Sang Mok Lee
Keyword(s):  
Mechanical Properties ◽  
Surface Energy ◽  
Bonding Strength ◽  
Tribological Behavior ◽  
Thermal Spraying ◽  
Microstructural Characterization ◽  
Flame Spraying ◽  
Energy Calculation ◽  
Air Plasma ◽  
Oxygen Fuel

Al-Cu-Fe-B quasicrystalline and Mo coatings were obtained on the mild steel and brass substrates by thermal spraying routes for the purpose of replacement of Mo coatings with quasicrystalline ones. Quasicrystalline coatings were prepared by air plasma spraying and/or HVOF (High Velocity Oxygen Fuel) techniques followed by subsequent heat treatment, and Mo coatings, wire flame spraying. For comparative studies of important properties for industrial application, mechanical properties, bonding strength, surface energy, and tribological behavior were investigated based on microstructural characterization. Basic mechanical properties such as hardness, fracture toughness, and elastic modulus of quasicrystalline coating showed comparable values with those of Mo coatings. De-bonding tests of coatings deposited onto brass substrate indicated that the bonding strength of quasicrystalline coatings obtained by HVOF techniques exhibit higher value to Mo coatings. Non-sticking property analogized from surface energy calculation and friction coefficient of quasicrystalline coatings also showed better performance during the tests. It is suggested from this investigation that the quasicrystalline coating can be effectively used as a replacement of the Mo coating, which has shown a recent steep price rise and problems of accidental existence of minor environment harmful elements such as Cr6+, Pb, Cd, and Hg.

scholarly journals Stratosphere-troposphere exchange from the Lagrangian perspective: a case study and method sensitivities

2004 ◽  
Vol 4 (3) ◽  
pp. 3249-3284 ◽  
Author(s):  
M. S. Bourqui
Keyword(s):  
Residence Time ◽  
Wave Breaking ◽  
Temporal Evolution ◽  
Baroclinic Wave ◽  
End Effects ◽  
The Past ◽  
Effective Removal ◽  
Residence Time Distributions ◽  
Temporal And Spatial

Abstract. An important part of extra-tropical stratosphere-to-troposphere transport occurs in association with baroclinic wave breaking and cut-off decay at the tropopause. In the last decade many studies have attempted to estimate stratosphere-troposphere exchange (STE) in such synoptic events with various methods, and more recently efforts have been put on inter-comparing these methods. However, large uncertainties remain on the sensitivities to methods intrinsic parameters, and on the best measure for STE with regard to end effects on chemistry. The goal of the present study is to address these two fundamental issues in the context of the application of a trajectory-based Lagrangian method, which has been applied in the past to climatological studies and has also been involved in inter-comparison studies, to a typical baroclinic wave breaking event. The analysis sheds light on (i) the fine mesoscale temporal and spatial structures that are associated with episodic, rapid inflows of stratospheric air into the troposphere; (ii) the spatial resolution of 1°×1° required to reasonably capture STE fluxes in such a wave breaking event; (iii) the effective removal of spurious exchange events using a threshold residence time; (iv) the relevance of residence time distributions for capturing the effective chemical forcing of STE; (v) the large differences in the temporal evolution and geographical distribution of STE fluxes across the 2 and the 4 potential vorticity unit iso-surface definitions of the tropopause.

scholarly journals Cryostructuring of Polymeric Systems. 50.† Cryogels and Cryotropic Gel-Formation: Terms and Definitions

Gels ◽  
2018 ◽  
Vol 4 (3) ◽  
pp. 77 ◽  
Author(s):  
Vladimir Lozinsky
Keyword(s):  
Polymeric Materials ◽  
Gel Formation ◽  
Polymeric Systems ◽  
The Past ◽  
Marked Variability ◽  
Conference Presentations

A variety of cryogenically-structured polymeric materials are of significant scientific and applied interest in various areas. However, in spite of considerable attention to these materials and intensive elaboration of their new examples, as well as the impressive growth in the number of the publications and patents on this topic over the past two decades, a marked variability of the used terminology and definitions is frequently met with in the papers, reviews, theses, patents, conference presentations, advertising materials and so forth. Therefore, the aim of this brief communication is to specify the basic terms and definitions in the particular field of macromolecular science.

End-Functionalized Polymers by Controlled/Living Radical Polymerizations: Synthesis and Applications

2021 ◽  
Author(s):  
Di Zhou ◽  
Liang-Wei Zhu ◽  
Bai-Heng Wu ◽  
Zhi-Kang Xu ◽  
Ling-Shu Wan
Keyword(s):  
Polymeric Materials ◽  
Functionalized Polymers ◽  
The Past ◽  
Living Radical Polymerizations ◽  
Radical Polymerizations

The precise design of polymers with well-defined end functionality has received great interest for synthesizing polymeric materials with advanced or distinctive properties. In the past decades, considerable attention has been...

Novel Concept for Totally Integrated Automation (TIA) Using Siemens Bus System and WinCC Online Control

2000 ◽  
Author(s):  
T. Frederking ◽  
R. Gadow
Keyword(s):  
Process Parameters ◽  
High Speed ◽  
Data Exchange ◽  
Thermal Spraying ◽  
Software Tool ◽  
Functionally Graded ◽  
Flame Spray ◽  
Total Quality ◽  
Spray Process ◽  
Bus System

Abstract Total quality management requires definite process control as well as online diagnostics, if applied in industrial surface refinement by thermal spraying. A concept for integrated online diagnostics for the high velocity oxygen fuel (HVOF) flame spray process is presented using Siemens S7-300 programmable logic controller and PC-based Siemens WinCC (Windows Control Center) visualization software. The standard functionality of the WinCC programming environment can be extended by C-scripts. The integrated database allows to protocol the relevant process parameters periodically for total quality assurance. Also particle flux imaging software tools can be implemented to adjust online process parameters and for process diagnostic purposes. The Siemens bus system hierarchy thereby provides high speed communication skills for field bus level data exchange and for supervising system components, e.g. CCD-cameras. The interconnection between S7-300 PLC, 6-axis-robot and a novel WinCC software tool enables definite automatic changes of recipes during the coating process to generate functionally graded coatings.

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