Tensile and Tensile Stress Relaxation Properties of Wool/Cotton Plied Yarns

1997 ◽  
Vol 67 (5) ◽  
pp. 378-385 ◽  
Author(s):  
Mari Inoue ◽  
Masako Niwa
Keyword(s):  
Stress Relaxation ◽  
Relative Humidity ◽  
Tensile Stress ◽  
Relaxation Rate ◽  
High Water ◽  
Absorption Properties ◽  
Relaxation Properties ◽  
Fabric Hand ◽  
High Water Absorption ◽  
Basic Objective

The basic objective of this work is to understand the effects of humidity and the ratio of wool and cotton fiber on the initial tensile and tensile stress relaxation properties of plied yarns. These low strain properties relate directly to the fabric hand, appearance, and formability of clothing. We have found that wool/cotton plied yarns have high hygroscopicity, high water absorption properties, and a low stress relaxation rate at high relative humidity. Also, we have adapted the power law to provide a relation between wool fiber content and the values of tensile resilience and stress relaxation rate. Their values are then estimated from the values of tensile resilience and stress relaxation rate of the constituent fibers and the blend composition.

scholarly journals Cellulose Nanofibrils/Xyloglucan Bio-Based Aerogels with Shape Recovery

Gels ◽  
2021 ◽  
Vol 7 (1) ◽  
pp. 5
Author(s):  
Samuel Mandin ◽  
Samuel Moreau ◽  
Malika Talantikite ◽  
Bruno Novalès ◽  
Jean-Eudes Maigret ◽  
...  
Keyword(s):  
Water Absorption ◽  
Shape Recovery ◽  
Cellulose Nanofibrils ◽  
High Water ◽  
Absorption Capacity ◽  
Absorption Properties ◽  
High Affinity ◽  
High Water Absorption ◽  
Freezing Procedure ◽  
The Impact

Bio-based aerogels containing cellulose nanofibrils (CNFs) are promising materials due to the inherent physical properties of CNF. The high affinity of cellulose to plant hemicelluloses (xyloglucan, xylan, pectin) is also an opportunity to develop biomaterials with new properties. Here, we prepared aerogels from gelled dispersions of CNFs and xyloglucan (XG) at different ratios by using a freeze-casting procedure in unidirectional (UD) and non-directional (ND) manners. As showed by rheology analysis, CNF and CNF/XG dispersions behave as true gels. We investigated the impact of the freezing procedure and the gel’s composition on the microstructure and the water absorption properties. The introduction of XG greatly affects the microstructure of the aerogel from lamellar to cellular morphology. Bio-based aerogels showed high water absorption capacity with shape recovery after compression. The relation between morphology and aerogel compositions is discussed.

Effect of Ceramsite Type on the Internal Relative Humidity of Ceramsite Concrete

2011 ◽  
Vol 94-96 ◽  
pp. 1352-1356
Author(s):  
Tao Ji ◽  
Cai Yi Chen ◽  
Yong Bo Chen ◽  
Yi Zhou Zhuang
Keyword(s):  
Relative Humidity ◽  
Water Absorption ◽  
Absorption Rate ◽  
High Water ◽  
Humidity Sensors ◽  
Ordinary Concrete ◽  
Water Absorption Rate ◽  
High Water Absorption ◽  
Different Types ◽  
Internal Relative Humidity

The internal relative humidities of concrete using different types of ceramsites with different prewetting degrees were monitored by humidity sensors. The study reveals that the internal relative humidity of concrete using low water absorption rate ceramsites declines more slowly than that of concrete using high water absorption rate ceramsites when not prewetting; the internal relative humidity of concrete using high water absorption rate ceramsites is higher than that of concrete using low water absorption rate ceramsites when their prewetting degrees (1h or 24h) are the same; the internal relative humidity of concrete using ceramsites is higher than that of ordinary concrete, whether the ceramsites are prewetted or not.

Research on Tensile Stress Relaxation Characteristics of Pinus sylvestris

2011 ◽  
Vol 704-705 ◽  
pp. 480-485
Author(s):  
Xue Qi Li ◽  
Xi Ming Wang ◽  
Jian Fang Yu
Keyword(s):  
Stress Relaxation ◽  
Moisture Content ◽  
Tensile Stress ◽  
Pinus Sylvestris ◽  
Relaxation Rate ◽  
Initial Stress ◽  
Test System ◽  
Tangential Section ◽  
Change Temperature ◽  
Relaxation Characteristics

This research aims to provide theoretical proof for the further study on the factors of stress relaxation under different conditions. In this study, use Pinus sylvestris and dynamic stress-strain test system, though change temperature and moisture to research the stress relaxation of wood. The results showed that the temperature and moisture content on the stress relaxation have a significant impact. With temperature enhancing or moisture content rising, stress dramatically relaxation and residual stress rapidly decreased. In other words, the initial stress decreased gradually and the relaxation rate was rise. It was also found that, under same conditions, compared with the tangential section of the Pinus sylvestris, the radial section has larger initial stress and smaller stress relaxation rate. Besides, the initial stress of late wood is larger than early wood but the stress relaxation rate is smaller. Key words: Pinus sylvestris, tensile stress relaxation

Study on Stress Relaxation Properties of GFRP Rebars/Bolts

2010 ◽  
Vol 168-170 ◽  
pp. 1821-1826
Author(s):  
Guo Qing Yuan ◽  
Guo Hua Dong ◽  
Jian Ma
Keyword(s):  
Stress Relaxation ◽  
Relaxation Rate ◽  
Construction Projects ◽  
Test Time ◽  
Relaxation Properties ◽  
Reinforced Plastics ◽  
Glass Fiber Reinforced ◽  
Fiber Reinforced Plastics ◽  
Superior Corrosion Resistance ◽  
Gfrp Rebars

Glass fiber reinforced plastics (GFRP) rebars / bolts are more and more being applied in construction projects with its superior corrosion resistance. To improve the economical efficiency of their application it is very significant to develop the prestressed GFRP rebars/bolts structure system. Therefore it is very valuable to probe the stress relaxation properties of GFRP rebars/bolts. With an innovation ends anchoring method for stress relaxation specimens of GFRP rebars/bolts, the stress relaxation properties has been tested in this paper. Results show that the relaxation rate of GFRP rebars/bolts increases with the initial stress increasing and with test time prolonging. It is increasing more rapidly at the beginning stage and it becomes slow after 24 hours. The relaxation law of GFRP rebars/bolts is similar to the law of CFRP and AFRP rebars/bolts. The relation between the relaxation rate and the logarithm of test time in hour follows also better linear law. The relaxation rate of GFRP rebars/bolts is bigger than CFRP ones and smaller than AFRP ones. The mechanical properties do not change obviously after 120h relaxation test.

Correlation of fatigue behavior and dynamic mechanical properties of hybrid composites of polypropylene/short glass fibers/hollow glass beads

2021 ◽  
pp. 089270572199319
Author(s):  
Gustavo B Carvalho
Keyword(s):  
Stress Relaxation ◽  
Flexural Strength ◽  
Relaxation Rate ◽  
Hybrid Composites ◽  
Fatigue Behavior ◽  
Glass Fibers ◽  
Glass Beads ◽  
Hollow Glass ◽  
Dynamic Mechanical ◽  
Short Glass

Ternary hybrid composites of Polypropylene (PP)/Short Glass Fibers (GF)/Hollow Glass Beads (HGB) were prepared using untreated and aminosilane-treated HGB, compatibilized with maleated-PP, and with varying total and relative GF/HGB contents. Static/short-term flexural strength properties data revealed, through lower flexural strength values, that the presence of untreated HGB particles induces to fiber-polymer interfacial decoupling at much higher extent than in the presence of aminosilane-treated HGB particles. This phenomenon is also evident when evaluating the data from displacement-controlled three-point bending fatigue tests. Monitored up to 106 cycles, the analyzed hybrid composites presented distinct performance relative to their fatigue stress relaxation rate: the lower the matrix-reinforcements’ interfacial adhesion, more pronounced the stress relaxation rate as a function of the number of fatigue cycles. Dynamic Mechanical Thermal Analysis (DMTA) results could successfully reveal the hybrid composites behavior at the microstructural level when they were submitted to both static flexural test and fatigue, depending on the degree of interfacial interactions between the polymer matrix of PP and the hybrid reinforcements of GF and HGB (with and without aminosilane surface treatment).

Formation of V-grooves on the (Al,Ga)N surface as means of tensile stress relaxation

2012 ◽  
Vol 353 (1) ◽  
pp. 88-94 ◽  
Author(s):  
Kai Cheng ◽  
M. Leys ◽  
S. Degroote ◽  
H. Bender ◽  
P. Favia ◽  
...  
Keyword(s):  
Stress Relaxation ◽  
Tensile Stress

Natural glycyrrhizic acid: improving stress relaxation rate and glass transition temperature simultaneously in epoxy vitrimers

2021 ◽  
Author(s):  
Jianqiao Wu ◽  
Liang Gao ◽  
Zhongkai Guo ◽  
Hao Zhang ◽  
Baoyan Zhang ◽  
...  
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Stress Relaxation ◽  
Relaxation Rate ◽  
Thermal Performance ◽  
Glycyrrhizic Acid

Epoxy vitrimers based on transesterification reactions (TERs) is a kind of recyclable thermosets which have been developed prosperously in recent years. However, the good thermal performance and the quick network...

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