The Effect of Water Absorption on the Mechanical Performance of Gasket Materials

2020 ◽  
Author(s):  
Jeffery Wilson
Keyword(s):  
Water Absorption ◽  
Mechanical Performance ◽  
High Humidity ◽  
Water Exposure ◽  
Effect Of Water ◽  
Compressive Loads ◽  
External Conditions ◽  
Wide Group ◽  
And Storage ◽  
Selection Of

Abstract The selection of gasket materials for bolted flanged connections (BFCs) is largely influenced by temperature, pressure, commodity (chemical), flange geometry, and available bolt load. However, very little focus has been placed on what happens to gasket materials if they are exposed to water or high humidity before or during installation. While not all gasket materials are susceptible to the absorption of water, others are, and their performance could be critically reduced by the slightest amount of absorption. The understanding and ability to quantify the degree to which different gasket materials are affected by pre-assembly water exposure will be another tool used to determine the correct gasket for different services and external conditions, along with addressing the importance of proper gasket handling and storage environments. This paper will explore the degree to which a wide group of common industrial gasket materials absorb water and how they perform under compressive loads from a mechanical perspective. With the data collected from this testing, users will have a better understanding of which materials are susceptible to the absorption of water and to what extent it affects the mechanical performance of the gasket.

Water absorption behavior of cellulosic fibres polymer composites: A review on its effects and remedies

2020 ◽  
pp. 152808372097442
Author(s):  
Parul Sahu ◽  
MK Gupta
Keyword(s):  
Water Absorption ◽  
Polymer Composites ◽  
Environmental Conditions ◽  
Mechanical Performance ◽  
Absorption Capacity ◽  
Effect Of Water ◽  
Negative Effect ◽  
Cellulosic Fibres ◽  
Kinetics Of ◽  
Positive Effect

Recently, researchers and scientists are trying to overcome the environmental burden by using biocomposites in engineering applications as far as possible. The main source of biocomposites is cellulosic fibres which is a class of natural fibres. Instead of many advantages of cellulosic fibres, they and their polymer composites suffer from some limitations as well. The environmental conditions are one of the most important issues to degradation behavior of the cellulosic fibres polymer composites (CFPCs). Among the environmental conditions, water absorption is an important ground to degradation in the mechanical performance of the CFPCs, which resists them to be used in outdoor applications. Several studies have been presented on water absorption characteristics of cellulosic fibres and its polymer-based biocomposites. Further, the consequence of water uptake on the mechanical performance of biocomposites was also reported in many studies. In most of the cases, a negative effect of water absorption was observed, whereas in a few cases a positive effect was also seen. In the present study, mechanics and kinetics of water absorption for CFPCs are discussed. Further, a detailed literature review on water absorption of cellulosic fibres and their different types of polymer-based biocomposites has also been carried out. Furthermore, studies reported on the effect of water absorption on the mechanical properties were also systematically presented. Moreover, all the possible remedies to lower the water absorption capacity were also discussed in the present review paper.

Effect of water absorption and stacking sequences on the properties of hybrid sisal/glass fibre reinforced polyester composite

2018 ◽  
Vol 233 (10) ◽  
pp. 2045-2056 ◽  
Author(s):  
MK Gupta ◽  
Vipul Deep
Keyword(s):  
Water Absorption ◽  
Glass Fibre ◽  
Morphological Analysis ◽  
Mechanical Performance ◽  
Hybrid Composites ◽  
Static Compression ◽  
Effect Of Water ◽  
Polyester Composite ◽  
Glass Fibre Reinforced ◽  
Fibre Matrix

In this work, the effect of water absorption and stacking sequences on the mechanical properties (i.e. impact, tensile and flexural) of hybrid sisal/glass polyester composites has been studied. Each composite laminate is prepared by the hand lay-up technique followed by static compression using about 20 wt% of fibre content. Different stacking sequences are obtained by changing the position and number of glass layers keeping a total of eight plies in each composite. Water absorption behaviour is investigated by soaking the composite specimens in the distilled water until saturation and its characteristics such as sorption, diffusion and permeability coefficient are measured. The obtained results suggested that the mechanical and water resistance properties of sisal composites are considerably enhanced by the incorporation of glass fibre. There is 23%, 29% and 46% improvement in tensile strength, flexural strength and impact strength respectively in hybrid composites than that of sisal composite. However, the effect of water absorption showed a significant reduction in the mechanical performance of all the composites. Morphological analysis by scanning electron microscope has been also performed to support the statement as weakening of fibre–matrix interfacial bonding by water absorption.

Effect of water absorption on the flexural strength of a green sandwich composite

2019 ◽  
Vol 61 (4) ◽  
pp. 369-375
Author(s):  
Sivalingam Prabhakaran ◽  
Vijayan Krishnaraj ◽  
Mouleeswaran Senthilkumar ◽  
Redouane Zitoune ◽  
Krishna Shankar
Keyword(s):  
Flexural Strength ◽  
Water Absorption ◽  
Sandwich Composite ◽  
Effect Of Water

scholarly journals The Impact of Alkaloid-Producing Epichloë Endophyte on Forage Ryegrass Breeding: A New Zealand Perspective

Toxins ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 158
Author(s):  
Colin Eady
Keyword(s):  
Seed Production ◽  
Health Issues ◽  
Abiotic Stressors ◽  
Livestock Health ◽  
The Right ◽  
The Impact ◽  
The Relationship ◽  
And Storage ◽  
Selection Of ◽  
Epichloë Endophyte

For 30 years, forage ryegrass breeding has known that the germplasm may contain a maternally inherited symbiotic Epichloë endophyte. These endophytes produce a suite of secondary alkaloid compounds, dependent upon strain. Many produce ergot and other alkaloids, which are associated with both insect deterrence and livestock health issues. The levels of alkaloids and other endophyte characteristics are influenced by strain, host germplasm, and environmental conditions. Some strains in the right host germplasm can confer an advantage over biotic and abiotic stressors, thus acting as a maternally inherited desirable ‘trait’. Through seed production, these mutualistic endophytes do not transmit into 100% of the crop seed and are less vigorous than the grass seed itself. This causes stability and longevity issues for seed production and storage should the ‘trait’ be desired in the germplasm. This makes understanding the precise nature of the relationship vitally important to the plant breeder. These Epichloë endophytes cannot be ‘bred’ in the conventional sense, as they are asexual. Instead, the breeder may modulate endophyte characteristics through selection of host germplasm, a sort of breeding by proxy. This article explores, from a forage seed company perspective, the issues that endophyte characteristics and breeding them by proxy have on ryegrass breeding, and outlines the methods used to assess the ‘trait’, and the application of these through the breeding, production, and deployment processes. Finally, this article investigates opportunities for enhancing the utilisation of alkaloid-producing endophytes within pastures, with a focus on balancing alkaloid levels to further enhance pest deterrence and improving livestock outcomes.

Evaluate the durability and effect of water absorption of recycled aggregate used in pavement

2021 ◽  
Vol 42 ◽  
pp. 2561-2565
Author(s):  
Eman Abdulhasan Mohammed Al-Ghalibi ◽  
Safaa A.Mohamad
Keyword(s):  
Water Absorption ◽  
Recycled Aggregate ◽  
Effect Of Water

scholarly journals Effect of Water Ingress on the Mechanical and Chemical Properties of Polybutylene Terephthalate Reinforced with Glass Fibers

Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1261
Author(s):  
Catarina S. P. Borges ◽  
Alireza Akhavan-Safar ◽  
Eduardo A. S. Marques ◽  
Ricardo J. C. Carbas ◽  
Christoph Ueffing ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Water Absorption ◽  
Water Uptake ◽  
Significant Influence ◽  
Water Immersion ◽  
Water Diffusion ◽  
Polybutylene Terephthalate ◽  
Chemical Changes ◽  
Water Ingress ◽  
Effect Of Water

Short fiber reinforced polymers are widely used in the construction of electronic housings, where they are often exposed to harsh environmental conditions. The main purpose of this work is the in-depth study and characterization of the water uptake behavior of PBT-GF30 (polybutylene terephthalate with 30% of short glass fiber)as well as its consequent effect on the mechanical properties of the material. Further analysis was conducted to determine at which temperature range PBT-GF30 starts experiencing chemical changes. The influence of testing procedures and conditions on the evaluation of these effects was analyzed, also drawing comparisons with previous studies. The water absorption behavior was studied through gravimetric tests at 35, 70, and 130 °C. Fiber-free PBT was also studied at 35 °C for comparison purposes. The effect of water and temperature on the mechanical properties was analyzed through bulk tensile tests. The material was tested for the three temperatures in the as-supplied state (without drying or aging). Afterwards, PBT-GF30 was tested at room temperature following water immersion at the three temperatures. Chemical changes in the material were also analyzed through Fourier-transform infrared spectroscopy (FTIR). It was concluded that the water diffusion behavior is Fickian and that PBT absorbs more water than PBT-GF30 but at a slightly higher rate. However, temperature was found to have a more significant influence on the rate of water diffusion of PBT-GF30 than fiber content did. Temperature has a significant influence on the mechanical properties of the material. Humidity contributes to a slight drop in stiffness and strength, not showing a clear dependence on water uptake. This decrease in mechanical properties occurs due to the relaxation of the polymeric chain promoted by water ingress. Between 80 and 85 °C, after water immersion, the FTIR profile of the material changes, which suggests chemical changes in the PBT. The water absorption was simulated through heat transfer analogy with good results. From the developed numerical simulation, the minimum plate size to maintain the water ingress unidirectional was 30 mm, which was validated experimentally.

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