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1 – 10 of 32Xiaobing Fan, Bingli Pan, Hongyu Liu, Shuang Zhao, Xiaofan Ding, Haoyu Gao, Bing Han and Hongbin Liu
This paper aims to prepare an oil-impregnated porous polytetrafluoroethylene (PTFE) composite with advanced tribological properties using citric acid as a novel pore-forming agent.
Abstract
Purpose
This paper aims to prepare an oil-impregnated porous polytetrafluoroethylene (PTFE) composite with advanced tribological properties using citric acid as a novel pore-forming agent.
Design/methodology/approach
Citric acid (CA) was used to form pores in PTFE, and then oil-impregnated PTFE composites were prepared. The pore-forming efficiency of CA was evaluated. The possible mechanism of lubrication was proposed according to the tribological properties.
Findings
The results show CA is an efficient pore-forming agent and completely removed, and the porosity of the PTFE increases with the increase of the CA content. The oil-impregnated porous PTFE exhibits an excellent tribological performance, an increased wear resistance of 77.29% was realized in comparison with neat PTFE.
Originality/value
This study enhances understanding of the lubrication mechanism of oil-impregnated porous polymers and guides for their tribological applications.
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Songhua Li, Shanhang Huang, Chao Wei, Jian Sun, Yonghua Wang and Kun Wang
This study aims to understand the influence of raceway surface topography on the temperature rise characteristics of silicon nitride (Si3N4) full ceramic ball bearing and improve…
Abstract
Purpose
This study aims to understand the influence of raceway surface topography on the temperature rise characteristics of silicon nitride (Si3N4) full ceramic ball bearing and improve its service life.
Design/methodology/approach
The arithmetic average height Sa, skewness Ssk and kurtosis Sku in the three-dimensional surface roughness parameters are used to quantitatively characterize the surface topography of the raceway after superfinishing. The bearing life testing machine is used to test the Si3N4 full ceramic ball bearing using polytetrafluoroethylene (PTFE) cage under dry friction conditions, and the self-lubricating full ceramic ball bearing heat generation model is established.
Findings
With the decrease of Sa and Ssk on the raceway surface and the increase of Sku, the average height of the raceway surface decreases, and the peaks and valleys tend to be symmetrically distributed on the average surface, and the surface texture becomes tighter. This kind of raceway surface topography is beneficial to form a thin and uniform filamentous PTFE transfer film with a wide coverage area on the raceway surface based on consuming less cage materials and improving the temperature rise characteristics of hot isostatic pressing silicon nitride full ceramic ball bearings.
Originality/value
The research results provide a theoretical basis for the reasonable selection of Si3N4 ring raceway processing technology and have important significance for improving the working characteristics and service life of Si3N4 full ceramic ball bearings under dry friction conditions.
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Kuo Yang, Yanqiu Xia, Wenhao Chen and Yi Zhang
The purpose of this study was to synthesize composite nanoparticles (TiO2@SiO2) via the chemical deposition method and investigate their efficacy as additives in…
Abstract
Purpose
The purpose of this study was to synthesize composite nanoparticles (TiO2@SiO2) via the chemical deposition method and investigate their efficacy as additives in polytetrafluoroethylene (PTFE) lubricating grease. The focus was on examining the frictional and conductive properties of the TiO2@SiO2 grease using a friction tester.
Design/methodology/approach
Composite nanoparticles (TiO2@SiO2) were synthesized using the chemical deposition method and incorporated into PTFE grease. Frictional and conductive properties were evaluated using a friction tester. Surface morphology and chemical composition of wear tracks were analyzed using scanning electron microscope and X-ray photoelectron spectroscopy, respectively.
Findings
Incorporating TiO2@SiO2 at a mass fraction of 1 Wt.% led to a significant reduction in friction coefficient and wear width. The wear depth exhibited a remarkable decrease of 260%, while the contact resistance reached its peak value. This improvement in tribological properties could be attributed to the presence of TiO2@SiO2, where TiO2 served as the core and SiO2 as the shell during the friction process. The high hardness of the SiO2 shell contributed to enhanced load-bearing capacity. In addition, the exceptional insulation properties of SiO2 demonstrated excellent electron-capturing capabilities, resulting in improved friction and insulation performance of the TiO2@SiO2 lubricating grease.
Originality/value
This study demonstrates the potential of TiO2@SiO2 composite nanoparticles as additives in lubricating greases, offering improved friction and insulation performance. The findings provide insights into the design of advanced lubricating materials with enhanced tribological properties and insulation capacity, contributing to the development of more efficient and durable lubrication systems.
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Jinming Zhen, Congcong Zhen, Min Yuan, Yingliang Liu, Li Wang, Lin Yuan, Yuhan Sun, Xinyue Zhang, Xiaoshu Yang and Haojian Huang
With the rapid development of the pipeline transportation and exploitation of mineral resources, it is urgent requirement for the high-performance polymer matrix composites with…
Abstract
Purpose
With the rapid development of the pipeline transportation and exploitation of mineral resources, it is urgent requirement for the high-performance polymer matrix composites with low friction and wear to meet the needs of solid material transportation. This paper aims to prepare high-performance ultrahigh molecular weight polyethylene (UHMWPE) matrix composites and investigate the effect of service condition on frictional behavior for composite.
Design/methodology/approach
In this study, UHMWPE matrix composites with different content of MoS2 were prepared and the tribological performance of the GCr15/composites friction pair in various sliding speeds (0.025–0.125 m/s) under dry friction conditions were studied by ball-on-disk tribology experiments.
Findings
Results show that the frictional behavior was shown to be sensitive to MoS2 concentration and sliding velocity. As the MoS2 content is 2 Wt.%, composites presented the best overall tribological performance. Besides, the friction coefficient fluctuates around 0.21 from 0.025 to 0.125 m/s sliding speed, while the wear rate increases gradually. Scanning electron microscopy images, energy-dispersive spectroscopy and Raman Spectrum analysis present that the main wear mechanisms were abrasive and fatigue wear.
Originality/value
The knowledge obtained herein will facilitate the design of UHMWPE matrix composites with promising self-lubrication performances which used in slag transport engineering field.
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The purpose of this paper is to develop a new type of embedded solid self-lubricating thrust ball bearing for conditions where grease lubrication cannot be used and to analyze its…
Abstract
Purpose
The purpose of this paper is to develop a new type of embedded solid self-lubricating thrust ball bearing for conditions where grease lubrication cannot be used and to analyze its tribological performance under different lubrication characteristics (lubrication position, width and filling amount).
Design/methodology/approach
Lubrication parameters such as position (a), width (W) and filling amount (Q) were considered. Grooves were made on the raceway with a fiber laser and solid self-lubricating materials were applied through scraping. The frictional behavior of the new bearing was analyzed using a vertical test rig and the bearing’s surface topography was examined with a noncontact profilometer to study wear mechanisms.
Findings
The new inlay thrust ball bearings exhibited excellent lubrication effects and effectively controlled the temperature rise of the bearings. When a is 0 degrees, W is 0.5 mm and Q is 16 mg, the bearing experiences the least wear, and the friction coefficient and temperature are the lowest, measuring 0.001 and 41.52 degrees, respectively. Under the same experimental conditions, compared to smooth bearings without solid lubrication, the friction coefficient decreased by 96.88% and the temperature decreased by 59.74%.
Originality/value
This study presents a self-lubricating thrust ball bearing designed for conditions where grease lubrication is not feasible. A comprehensive investigation was conducted on its surface morphology, wear mechanisms and tribological performance. This work provides valuable insights into the research of self-lubricating thrust ball bearings.
Peer review
The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-03-2024-0073/
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Abhishek Barwar, Prateek Kala and Rupinder Singh
Some studies have been reported in the past on diaphragmatic hernia (DH) surgery techniques using additive manufacturing (AM) technologies, symptoms of a hernia and post-surgery…
Abstract
Purpose
Some studies have been reported in the past on diaphragmatic hernia (DH) surgery techniques using additive manufacturing (AM) technologies, symptoms of a hernia and post-surgery complications. But hitherto little has been reported on bibliographic analysis (BA) for health monitoring of bovine post-DH surgery for long-term management. Based on BA, this study aims to explore the sensor fabrication integrated with innovative AM technologies for health monitoring assistance of bovines post-DH surgery.
Design/methodology/approach
A BA based on the data extracted through the Web of Science database was performed using bibliometric tools (R-Studio and Biblioshiny).
Findings
After going through the BA and a case study, this review provides information on various 3D-printed meshes used over the sutured site and available Internet of Things-based solutions to prevent the recurrence of DH.
Originality/value
Research gaps exist for 3D-printed conformal sensors for health monitoring of bovine post-DH surgery.
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Saloni Purandare and Chunhui Xiang
Firefighter Personal Protective Equipment (PPE) is the only barrier between the firefighter and hazardous environment. Gloves are a crucial component of the multi-component PPE…
Abstract
Purpose
Firefighter Personal Protective Equipment (PPE) is the only barrier between the firefighter and hazardous environment. Gloves are a crucial component of the multi-component PPE. Over time the gloves have reduced the intensity of hand injuries, yet further improvement in terms of material selection and glove design is required to strike the balance between protection and comfort. Focusing on the material aspect, the purpose of this study is to present literature analysis on material selection and testing for firefighter gloves.
Design/methodology/approach
The study conducted a literature analysis on material selection and characterization of firefighter PPE. The review summarizes and evaluates past work addressing the characterization of firefighter gloves in accordance with NFPA 1971 requirements and points out found research gaps to aid with foundation of future research.
Findings
The study summarizes several research works to inform readers about the material selection and characterization of firefighter gloves. Based on the analyzed literature, the study resulted in material specification sheets for firefighter gloves. The developed material specification sheets provide information in terms of crucial material properties to be incorporated for accurate functioning of firefighter gloves, testing methods to validate those material properties and materials from analyzed literature exhibiting desired properties.
Originality/value
With large research addressing firefighter PPE, only limited studies focus specifically on gloves. Thus, this study provides a literature analysis covering material selection and testing for gloves. A consolidated firefighter gloves material specification document, which does not appear to be available in the literature, will provide a foundation for the development and characterization of firefighter gloves to better serve the functions along with ensuring user comfort.
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Abhishek Kumar and Manpreet Manshahia
The aim of this study is to present an overview of sustainable practices in the development of waterproof breathable fabrics for garments. It aims to provide insights into the…
Abstract
Purpose
The aim of this study is to present an overview of sustainable practices in the development of waterproof breathable fabrics for garments. It aims to provide insights into the current state of academic research in this domain and identify and analyze major sustainable trends in the field.
Design/methodology/approach
This study conducts a thorough examination of research publications sourced from the Scopus database spanning the years 2013–2023 by employing a systematic approach. The research utilizes both descriptive analysis and content analysis to identify trends, notable journals and leading countries in sustainable waterproof breathable fabric development.
Findings
The study reveals a notable increase in studies focusing on sustainable approaches in the development of waterproof breathable fabrics for garments. Descriptive analysis highlights the most prominent journal and leading country in terms of research volume. Content analysis identifies four key trends: minimizing chemical usage, developing easily degradable materials, creating fabrics promoting health and well-being and initiatives to reduce energy consumption.
Research limitations/implications
The main limitation of this research lies in its exclusive reliance on the Scopus database.
Practical implications
The insights derived from this study offer practical guidance for prospective researchers interested in investigating sustainable approaches to developing waterproof breathable fabric for garments. The identified trends provide a foundation for aligning research endeavors with contemporary global perspectives, facilitating the integration of sustainable methodologies into the garment industry.
Originality/value
This systematic literature review contributes original insights by synthesizing current research trends and outlining evolving sustainable practices in the development of waterproof breathable fabrics. The identification of key focus areas adds a novel perspective to existing knowledge.
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Guillermo Guerrero-Vacas, Jaime Gómez-Castillo and Oscar Rodríguez-Alabanda
Polyurethane (PUR) foam parts are traditionally manufactured using metallic molds, an unsuitable approach for prototyping purposes. Thus, rapid tooling of disposable molds using…
Abstract
Purpose
Polyurethane (PUR) foam parts are traditionally manufactured using metallic molds, an unsuitable approach for prototyping purposes. Thus, rapid tooling of disposable molds using fused filament fabrication (FFF) with polylactic acid (PLA) and glycol-modified polyethylene terephthalate (PETG) is proposed as an economical, simpler and faster solution compared to traditional metallic molds or three-dimensional (3D) printing with other difficult-to-print thermoplastics, which are prone to shrinkage and delamination (acrylonitrile butadiene styrene, polypropilene-PP) or high-cost due to both material and printing equipment expenses (PEEK, polyamides or polycarbonate-PC). The purpose of this study has been to evaluate the ease of release of PUR foam on these materials in combination with release agents to facilitate the mulding/demoulding process.
Design/methodology/approach
PETG, PLA and hardenable polylactic acid (PLA 3D870) have been evaluated as mold materials in combination with aqueous and solvent-based release agents within a full design of experiments by three consecutive molding/demolding cycles.
Findings
PLA 3D870 has shown the best demoldability. A mold expressly designed to manufacture a foam cushion has been printed and the prototyping has been successfully achieved. The demolding of the part has been easier using a solvent-based release agent, meanwhile the quality has been better when using a water-based one.
Originality/value
The combination of PLA 3D870 and FFF, along with solvent-free water-based release agents, presents a compelling low-cost and eco-friendly alternative to traditional metallic molds and other 3D printing thermoplastics. This innovative approach serves as a viable option for rapid tooling in PUR foam molding.
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Shengjian Zhang, Min Li, Baoyi Li, Hansen Zhao and Feng Wang
To improve the corrosion resistance of magnesium alloys, the construction of protective coatings is necessary to extend the service life of Mg-based materials.
Abstract
Purpose
To improve the corrosion resistance of magnesium alloys, the construction of protective coatings is necessary to extend the service life of Mg-based materials.
Design/methodology/approach
SiO2 nanoparticles modified by dodecyltrimethoxysilane (DTMS) were added to the PP and a superhydrophobic Mg(OH)2/PP-60mSiO2 composite coating was fabricated on the surface of AZ31 magnesium alloy via the hydrothermal method and subsequently the immersion treatment.
Findings
Hydrophilic SiO2 nanoparticles become hydrophobic after modified by DTMS, showing a higher dispersibility in xylene. By incorporating modified SiO2 nanoparticles into the composite PP coating, the hydrophobicity of the layer was enhanced, resulting in a contact angle of 166.3° and a sliding angle of 3.4°. It also improved the water repellency and durability of the coating. Furthermore, the intermediate layer of Mg(OH)2 significantly strengthened the bond between the PP layer and the substrate. The Mg(OH)2/PP-60mSiO2 composite coating significantly enhances the corrosion resistance of the magnesium alloy by effectively blocking the infiltration of the corrosion anions during corrosion. The corrosion current density of the Mg(OH)2/PP-60mSiO2 composite coating is approximately 8.23 × 10–9 A·cm-2, which can achieve a magnitude three times lower than its substrate, making it a promising surface modification for the Mg alloy.
Originality/value
The composite coating effectively and durably enhances the corrosion resistance of magnesium alloys.
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