scholarly journals Thermo-physiological properties of woven structures in wet state

2018 ◽  
Vol 69 (04) ◽  
pp. 298-303
Author(s):  
BOUGHATTAS AMAL ◽  
BENLTOUFA SOFIEN ◽  
HES LUBOS ◽  
AZEEM MUSADDAQ ◽  
FAYALA FATEN

The utmost parameters that measure the thermo-physiological comfort of garments are thermal conductivity, thermal absorptivity and water vapor permeability. In this paper, thermo-physiological comfort was studied with different weave design and moisture content. Thermal properties and water vapor permeability in dry and wet state of all fabric samples were determined by ALAMBETA and Permetest respectively. Results showed that the weaving structure and yarn composition in weft were closely related to the thermal properties and water vapor permeability in presence of moisture. Woven fabric samples were constructed by varying the weave design and weft composition. In wet state, moisture content up to 20%, weave structures exhibited non-significant behavior for thermal properties due to air fraction. As the moisture content enhanced, woven structure made with polyester weft yarn provided cooler feeling with skin contact.

Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3090
Author(s):  
Anita Ptiček Siročić ◽  
Ana Rešček ◽  
Zvonimir Katančić ◽  
Zlata Hrnjak-Murgić

The studied samples were prepared from polyethylene (PE) polymer which was coated with modified polycaprolactone (PCL) film in order to obtain bilayer films. Thin PCL film was modified with casein/aluminum oxide compound to enhance vapor permeability as well as mechanical and thermal properties of PE/PCL films. Casein/aluminum oxide modifiers were used in order to achieve some functional properties of polymer film that can be used in various applications, e.g., reduction of water vapor permeability (WVTR) and good mechanical and thermal properties. Significant improvement was observed in mechanical properties, especially in tensile strength as well as in water vapor values. Samples prepared with aluminum oxide particles indicated significantly lower values up to 60%, and samples that were prepared with casein and 5% Al2O3 showed the lowest WVTR value.


Author(s):  
Nan Chen ◽  
Yanchun Li ◽  
Jianbo Qu ◽  
Jian-Yong Wang

The traditional thick coating on split leather does not have the ability to breathe like full grain leather.  The air and water vapor permeabilities of full grain leather are well known properties due to its fiber woven structure. Simulating the fiber morphology and weaving structure of the dermis or grain layer is very important to construct a top surface layer for split leather. In this paper, a PU (polyurethane) foam layer is put first on the split to enhance the adhesion of a second application of a superfine fibrous PU resin. This foam uses well-known waterborne polyurethane foaming technology. This dried foam has good breathability because of high porosity. A superfine fiber membrane is next put atop of the foam layer by using an electro-spun polyurethane resin. This second resin imitates collagen fibers in the network structure of the leathers’ grain layer. Thus, this resultant electrospun fiber biomimetics membrane simulated the grain layer of natural leather. SEM showed the morphology and structure of this electrospun fiber biomimetic membrane to be like that of the grain layer of natural leather. The porosity and apparent density were basically the same as the grain of leather, which were 63.65% and 583.878 kg/m3 respectively. The air and water vapor permeability of the biomimetics membrane were also as high as 2250 mL·cm-2·h-1 and 8753.02 μg·cm-2·h-1 respectively. Therefore, the biomimetics membrane largely restored the ability to breathe of split leather. Thus, this method simulates the performance and structure of full grain leather and is a novel method for industrial production


2015 ◽  
Vol 10 (2) ◽  
pp. 155892501501000 ◽  
Author(s):  
Xuechuan Wang ◽  
Xiaoqin Wang ◽  
Taotao Qiang ◽  
Longfang Ren ◽  
Peiyi Wang

Modified by the pretreated model with collagen under the crosslinking effect of glutaraldehyde, the moisture absorption of modified samples increased by 26.34% and 42.6%. The test results of SEM, AFM and DSC show that there was coating on the fibers modified with collagen, and the relative average roughness of the modified fabric decreased. Modification with collagen also affected the thermal properties of the modified sample compared with that of the non-treated sample. Modification of the base with collagen in the same way that modified the model, the result indicate that the contents of amino group on the modified base sample were 1.61 times and 8.15 times compared with that of pretreated sample and non-treated sample, water vapor permeability of collagen modified samples increased by 28.58% and 53.43% respectively.


Polymers ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 963
Author(s):  
Pornchai Rachtanapun ◽  
Warinporn Klunklin ◽  
Pensak Jantrawut ◽  
Kittisak Jantanasakulwong ◽  
Yuthana Phimolsiripol ◽  
...  

Curcumin is a phenolic compound derived from turmeric roots (Curcuma longa L.). This research studied the effects of curcumin extract on the properties of chitosan films. The film characteristics measured included mechanical properties, visual aspects, color parameters, light transmission, moisture content, water solubility, water vapor permeability, infrared spectroscopy, and antioxidant activity. The results suggest that adding curcumin to chitosan-based films increases yellowness and light barriers. Infrared spectroscopy analysis showed interactions between the phenolic compounds of the extract and the chitosan, which may have improved the mechanical properties and reduced the moisture content, water solubility, and water vapor permeability of the films. The antioxidant activity of the films increased with increasing concentrations of the curcumin extract. This study shows the potential benefits of incorporating curcumin extract into chitosan films used as active packaging.


2016 ◽  
Vol 87 (9) ◽  
pp. 1060-1070 ◽  
Author(s):  
Radostina A Angelova ◽  
Priscilla Reiners ◽  
Elena Georgieva ◽  
Hristina Plamenova Konova ◽  
Bianca Pruss ◽  
...  

This paper presents a comprehensive experimental study, conducted on a series of woven and non-woven fabric samples from different materials (cotton, polyester, and polyamide) and 14 three-layer systems of textile materials, used for production of outerwear clothing for protection from cold. Heat and mass transfer properties, related to the thermophysiological comfort of the outerwear clothing, namely conductive thermal resistance, water vapor resistance, relative water vapor permeability, air permeability, accumulative one-way transport of liquids, and overall moisture management capacity, were determined for the system of layers and the compound single layers. The transfer properties of the single layers were presented as a function of their thickness, mass per unit area, and areal porosity. The transfer properties of the system of layers were presented as a function of the thickness, mass per unit area, and bulk density of the systems. Regression analysis was applied to derive regression equations. The results obtained allowed assessment of the existence and trend of the influence, as well as evaluation of the strength of the dependences.


2020 ◽  
Vol 15 (3) ◽  
pp. 162-171
Author(s):  
Mulia W. Apriliyani ◽  
Ria Dewi Andriani ◽  
Premy Puspitawati Rahayu ◽  
Purwadi Purwadi ◽  
Abdul Manab

Edible film is potentially applied to replace non-biodegradable packaging for animal products, e.g. meat and meat products. The overall objective of this study was to observe the effect of different addition levels of modified casein hydrolysate (casein-catechin complexes) on mechanical (film thickness, water vapor permeability, tensile strength, elasticity), chemical (moisture content, water activity, and solubility) and microstructure properties of composite edible casein film. The edible films were formulated according to different combinations of modified casein hydrolysate and casein film solution (0.50:0.25, 0.50:0.50, 0.75:0.25, and 0.75:0.50) and compared with control (without addition of modified casein). No significant effects of the treatment were found on film thickness, water vapor permeability, tensile strength, elasticity, moisture content, water activity, and solubility of the composite edible film. However, the micrographs show that the amount of polymer was higher as the proportion of catechin was increased. In conclusion, the addition of catechin-added casein (modified casein) to casein edible film solution at up to 0.5% did not alter the mechanical properties, moisture content, water activity and solubility of the composite edible film.


Polymers ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2516
Author(s):  
Alex López-Córdoba

Paipa cheese is the only Colombian semi-ripened cheese with protected geographical indication. In the current work, the effect of applying starch coatings carrying carvacrol on Paipa cheeses was analyzed. Coatings were prepared based on blends of potato starch (2 g/100 g), carvacrol (0.1 g/100 g), polysorbate 80, glycerol, and water and applied to the cheese’s surface by brushing. Uncoated cheeses were also analyzed for comparison. Moreover, films were prepared and characterized in terms of their moisture content, water vapor permeability, mechanical properties, transparency, water solubility, swelling (%), and antioxidant activity. Carvacrol/starch films showed a slight decrease in their water solubility and Young’s modulus, while not significant changes were observed in water vapor permeability, moisture content, transparency, and swelling behavior, in comparison with the starch films. After application on the Paipa cheeses, the carvacrol/starch coatings enhanced the brightness of the cheeses without causing significant changes in water activity, moisture content, color attributes, and mesophilic aerobic bacteria and molds/yeasts count. Moreover, edible coatings have a significant effect on the hardness, the gumminess, the springiness, and the chewiness of the Paipa cheese. Coated cheeses were better preserved at day 60 of storage because they did not show changes in their lightness, hardness, and springiness.


Materials ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 6863
Author(s):  
Desalegn Atalie ◽  
Pavla Tesinova ◽  
Melkie Getnet Tadesse ◽  
Eyasu Ferede ◽  
Ionuț Dulgheriu ◽  
...  

Consumers expect high-performance functionality from sportswear. To meet athletic and leisure-time activity requirements, further research needs to be carried out. Sportswear layers and their specific thermal qualities, as well as the set and air layer between materials, are all important factors in sports clothing. This research aims to examine the thermal properties of sports fabrics, and how they are affected by structure parameters and maintained with different layers. Three inner and four outer layers of fabric were used to make 12 sets of sportswear in this study. Before the combination of outer and inner layers, thermal properties were measured for each individual layer. Finally, the thermal resistance, thermal conductivity, thermal absorptivity, peak heat flow density ratio, stationary heat flow density, and water vapor permeability of bi-layered sportswear were evaluated and analyzed. The findings show that sportswear made from a 60% cotton/30% polyester/10% elastane inner layer and a 100% polyester outer layer had the maximum thermal resistance of 61.16 (×103 K·m2 W−1). This performance was followed by the sample made from a 90% polyester/10% elastane inner layer and a 100% polyester outer layer, and the sample composed of a 100% elastane inner layer and a 100% polyester outer layer, which achieved a thermal resistance value of 60.41 and 59.41 (×103 K·m2 W−1), respectively. These results can be explained by the fact that thicker textiles have a higher thermal resistance. This high-thermal-resistance sportswear fabric is appropriate for the winter season. Sportswear with a 90% polyester/10% elastane inner layer had worse water vapor resistance than sportswear with a 60% cotton/30% polyester/10% elastane and a 100% elastane layer. Therefore, these sports clothes have a higher breathability and can provide the wearers with very good comfort. According to the findings, water vapor permeability of bi-layered sportswear is influenced by geometric characteristics and material properties.


Optimization of film formula-based kappa-carrageenan and polyvinyl alcohol (PVA) was studied using a two-level, two-factor Design Expert 11® by Response Surface Methodology (RSM) Central Composite Design (CCD). The aim of this study was to obtain the optimal concentration of kappa-carrageenan and polyvinyl alcohol in producing films. The influence composition ⱪ-carrageenan and polyvinyl alcohol was characterized. The results showed the effects of k-carrageenan and polyvinyl alcohol had a significant effect on the response thickness, tensile strength, burst strength, elongation, solubility, water vapor barrier, opacity, color, and moisture content. The optimized condition for production k-carrageenan and PVA was 1.21% carrageenan and 1.93% polyvinyl alcohol, which was giving film with thickness 0.044 mm, tensile strength 16.69 MPa, burst strength 167.86 kPa, elongation 81.79%, water solubility 65.04%, water vapor permeability 7.49 g/m s Pa x 10-11, opacity 2.31, ΔE 2.42, and moisture content 19.13%


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