Effect of Hot Water Immersion on the Mechanical Properties of Jute and Jute Hybrid Reinforced Composites

2011 ◽  
Author(s):  
Ying Yu ◽  
Shinichiro Kawabata ◽  
Yuqiu Yang ◽  
Hiroyuki Hamada
Keyword(s):  
Mechanical Properties ◽  
Immersion Time ◽  
Bending Strength ◽  
Hybrid Composites ◽  
Water Immersion ◽  
Hot Water ◽  
Bending Test ◽  
Reinforced Composites ◽  
Moisture Contents ◽  
Hot Water Immersion

As well known, the corrosion resistance and durability of the material are always considered in the safety design of the materials. In this study, the jute fabric from recycled coffee bags was used to fabricate ecologically friendly composites. Jute fabrics with two kinds of different moisture contents were used to fabricate the natural fiber reinforced composites, and the hot water immersion properties have been evaluated. Additionally, the effects of the hybridization with glass woven fabric laminated structures were also investigated. Jute/Jute laminated composite, Jute/Jute/Glass, and Glass/Jute/Glass laminated hybrid composites had been fabricated by hand lay up method. A preliminary investigation on the effect of moisture contents of the jute fabric on the mechanical properties of the jute and jute/glass hybrid composites was discussed based on the results of 3 point bending test. Moreover, the durability of the composites in the hot water immersion was also evaluated. The effects of hot water immersion on the mechanical properties were investigated by the way of 3 point bending test. The specimens were immersed in hot water maintained at 80°C with the immersion time of 24, 120 and 240 hours. Specimens were taken out from the hot water at the same time and repeated the 3 point bending test after each immersion time and the weight changes had been measured. Results showed that the Jute/Jute composite absorbed water easily, and it could be noted that all of the natural dried composites showed comparable higher water absorbed value to the deeply dried ones. The bending strength after aging decreased remarkably. In particularly, all of the natural dried composites showed higher bending strength than the deeply dried one before aging. However, after 120 hours aging, on the contrary, almost the deeply dried composites showed comparable higher value to the natural dried ones. That could be due to the better bonding between fiber and matrix for the deeply dried composites which decreased the water absorption of the composites. Additionally, the hybrid structure is effective in protecting the composites from water absorbing especially for the Glass/Jute/Glass hybrid one.

Mechanical Property and Degradation in Hot Water of Injection Molded Glass Short Fiber/Wood Powder/Polypropylene Hybrid Composites

2013 ◽  
Author(s):  
Xujie Kong ◽  
Ying Yu ◽  
Yuqiu Yang ◽  
Jungang Li ◽  
Mengyuan Liao ◽  
...  
Keyword(s):  
Mechanical Property ◽  
Immersion Time ◽  
Hybrid Composites ◽  
Water Immersion ◽  
Natural Fibers ◽  
Hot Water ◽  
Wood Powder ◽  
Hydrothermal Aging ◽  
Injection Molded ◽  
Hot Water Immersion

As well known, natural fibers absorb water easily that will affect the mechanical property considerably and there exists a problem of incompatibility which leads the weak interfacial adhesion between the fiber and the resin matrix because of the hygroscopic nature of natural fibers. Therefore, conducting hot water immersion and tensile test is necessary to study the mechanical property and degradation. In this study, glass fiber/wood powder/pp. hybrid composites were prepared by injection molding process at a fixed reinforcement to matrix ratio of 51:49. 3 kinds of hybrid specimens with glass fiber/wood powder ratios of 51:0, 21:30, and 0:51 were fabricated. The hydrothermal aging performance was investigated during the 80°C hot water immersion experiment with a series of immersion time and the effect of hot water immersion on the mechanical properties of composites have been evaluated based on the tensile test. Results showed that both the strength and modulus of hybrid composite decrease obviously as the immersion time increase, which can be considered that the hydroscopic property of natural fiber would decrease the durability of composite in humidity environment. And the skin-core structure comes from injection molded process contributes to the better hydrothermal aging property of Glass/PP composite.

Effect of Hot Water, Immersion Time, and Length of Storage on Chilling Injury of Tomato Fruit

1997 ◽  
Vol 3 (2) ◽  
pp. 17-27 ◽  
Author(s):  
Abdul Hakim ◽  
Errki Kaukovirta ◽  
Eija Pehu ◽  
Irma Voipio
Keyword(s):  
Immersion Time ◽  
Water Immersion ◽  
Tomato Fruit ◽  
Chilling Injury ◽  
Hot Water ◽  
Hot Water Immersion

Hydrothermal Aging and Mechanical Property of Injection Molded Jute/Glass/Polypropylene Hybrid Composites

2013 ◽  
Author(s):  
Jian Wang ◽  
Putinun Uawongsuwan ◽  
Yuqiu Yang ◽  
Hiroyuki Inoya ◽  
Toshihiko Hojo ◽  
...  
Keyword(s):  
Hybrid Composites ◽  
Water Immersion ◽  
Fiber Content ◽  
Hot Water ◽  
Jute Fiber ◽  
Hydrothermal Aging ◽  
Immersion Experiment ◽  
Injection Molded ◽  
Pp Composites ◽  
Hot Water Immersion

As well known, the durability of the material is always considered in the safety design of the materials. Therefore in this study, the property of injection molded hybrid jute/glass reinforced polypropylene (PP) composites was firstly investigated after the hot water immersion experiment. The hydrothermal aging performance was investigated in the 80 °C hot water immersion experiment with a series of immersion time and different fraction of jute fiber and the effects of hot water immersion on the mechanical properties of composites have been evaluated based on the tensile test. Water absorption and weight loss of the reinforced PP composites were recorded and discussed. It is found that with the increase of jute fiber content, the tensile modulus is increased. However, the increasing of jute fiber content decreased the tensile strength of hybrid composites. For the effect of hydrothermal aging, the weight by water absorption was significantly affected by the jute fiber content. The specimens with higher jute fiber content absorbed water easier and significant materials loss by aging was also occurred. Tensile properties of hybrid composites which contain jute fiber showed the lower tensile strength than the monotonic glass/PP composite. It is considered that the hydrophilic property of jute fiber decreases the resistance of the hybrid composite in high humidity environment.

scholarly journals A comparison of heat acclimation by post-exercise hot water immersion and exercise in the heat

2021 ◽  
Author(s):  
Robert D. McIntyre ◽  
Michael J. Zurawlew ◽  
Samuel J. Oliver ◽  
Andrew T. Cox ◽  
Jessica A. Mee ◽  
...  
Keyword(s):  
Water Immersion ◽  
Heat Acclimation ◽  
Hot Water ◽  
Post Exercise ◽  
Hot Water Immersion

scholarly journals Local cooling during hot water immersion improves perceptions without inhibiting the acute interleukin-6 response

2021 ◽  
Author(s):  
R. G. Mansfield ◽  
S. P. Hoekstra ◽  
J. J. Bill ◽  
Christof A. Leicht
Keyword(s):  
Thermal Comfort ◽  
Interleukin 6 ◽  
Water Immersion ◽  
Hot Water ◽  
Upper Body ◽  
Healthy Male ◽  
Local Cooling ◽  
Blood Samples ◽  
Body Cooling ◽  
Hot Water Immersion

Abstract Purpose Passive elevation of body temperature can induce an acute inflammatory response that has been proposed to be beneficial; however, it can be perceived as uncomfortable. Here, we investigate whether local cooling of the upper body during hot water immersion can improve perception without inhibiting the interleukin-6 (IL-6) response. Methods Nine healthy male participants (age: 22 ± 1 years, body mass: 83.4 ± 9.4 kg) were immersed up to the waist for three 60-min water immersion conditions: 42 °C hot water immersion (HWI), 42 °C HWI with simultaneous upper-body cooling using a fan (FAN), and 36 °C thermoneutral water immersion (CON). Blood samples to determine IL-6 plasma concentration were collected pre- and post-water immersion; basic affect and thermal comfort were assessed throughout the intervention. Results Plasma IL-6 concentration was higher for HWI and FAN when compared with CON (P < 0.01) and did not differ between HWI and FAN (P = 0.22; pre to post, HWI: 1.0 ± 0.6 to 1.5 ± 0.7 pg·ml−1, FAN: 0.7 ± 0.5 to 1.1 ± 0.5 pg·ml−1, CON: 0.5 ± 0.2 to 0.5 ± 0.2 pg·ml−1). At the end of immersion, basic affect was lowest for HWI (HWI: − 1.8 ± 2.0, FAN: 0.2 ± 1.6, CON 1.0 ± 2.1, P < 0.02); thermal comfort for HWI was in the uncomfortable range (3.0 ± 1.0, P < 0.01 when compared with FAN and CON), whereas FAN (0.7 ± 0.7) and CON (-0.2 ± 0.7) were in the comfortable range. Conclusion Local cooling of the upper body during hot water immersion improves basic affect and thermal comfort without inhibiting the acute IL-6 response.

Hot-Water Immersion as a Potential Quarantine Treatment Against Pseudaulacaspis cockerelli (Homoptera: Diaspididae)

1993 ◽  
Vol 86 (4) ◽  
pp. 1167-1170 ◽  
Author(s):  
Arnold H. Hara ◽  
Trent Y. Hata ◽  
Benjamin K. S. Hu ◽  
Victoria L. Tenbrink
Keyword(s):  
Water Immersion ◽  
Hot Water ◽  
Hot Water Immersion

scholarly journals Lower-limb hot-water immersion acutely induces beneficial hemodynamic and cardiovascular responses in peripheral arterial disease and healthy, elderly controls

2017 ◽  
Vol 312 (3) ◽  
pp. R281-R291 ◽  
Author(s):  
Kate N. Thomas ◽  
André M. van Rij ◽  
Samuel J. E. Lucas ◽  
James D. Cotter
Keyword(s):  
Blood Pressure ◽  
Lower Limb ◽  
Water Immersion ◽  
Duplex Ultrasound ◽  
Arterial Disease ◽  
Hot Water ◽  
Healthy Elderly ◽  
Limb Perfusion ◽  
Peripheral Arterial ◽  
Hot Water Immersion

Passive heat induces beneficial perfusion profiles, provides substantive cardiovascular strain, and reduces blood pressure, thereby holding potential for healthy and cardiovascular disease populations. The aim of this study was to assess acute responses to passive heat via lower-limb, hot-water immersion in patients with peripheral arterial disease (PAD) and healthy, elderly controls. Eleven patients with PAD (age 71 ± 6 yr, 7 male, 4 female) and 10 controls (age 72 ± 7 yr, 8 male, 2 female) underwent hot-water immersion (30-min waist-level immersion in 42.1 ± 0.6°C water). Before, during, and following immersion, brachial and popliteal artery diameter, blood flow, and shear stress were assessed using duplex ultrasound. Lower-limb perfusion was measured also using venous occlusion plethysmography and near-infrared spectroscopy. During immersion, shear rate increased ( P < 0.0001) comparably between groups in the popliteal artery (controls: +183 ± 26%; PAD: +258 ± 54%) and brachial artery (controls: +117 ± 24%; PAD: +107 ± 32%). Lower-limb blood flow increased significantly in both groups, as measured from duplex ultrasound (>200%), plethysmography (>100%), and spectroscopy, while central and peripheral pulse-wave velocity decreased in both groups. Mean arterial blood pressure was reduced by 22 ± 9 mmHg (main effect P < 0.0001, interaction P = 0.60) during immersion, and remained 7 ± 7 mmHg lower 3 h afterward. In PAD, popliteal shear profiles and claudication both compared favorably with those measured immediately following symptom-limited walking. A 30-min hot-water immersion is a practical means of delivering heat therapy to PAD patients and healthy, elderly individuals to induce appreciable systemic (chronotropic and blood pressure lowering) and hemodynamic (upper and lower-limb perfusion and shear rate increases) responses.

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