Effect of Natural and Synthetic Fibers and Film and Moisture Content on Stratum Corneum Hydration in an Occlusive System

1997 ◽  
Vol 67 (8) ◽  
pp. 585-592 ◽  
Author(s):  
Bruce A. Cameron ◽  
Donna M. Brown ◽  
Merry Jo Dallas ◽  
Brenda Brandt

The effects of fabric made from natural and synthetic fibers and film on transepidermal water loss (tewl) from the stratum corneum (sc) were investigated using an occluded system. Sixteen fabrics differing in fiber type and construction were placed on the volar forearm of 35 female subjects in a dry state (standard moisture regain) and a wetted state. Each fabric was in place for 40 minutes before tewl was measured. There was no statistically significant difference in tewl measurements on a control skin site from the beginning to the end of the 75-minute test session in a controlled conditioned environment. Placement of dry fabrics on the skin did not significantly affect the hydration level of the sc, though all dry fabrics did increase the hydration level slightly. Wetted wool and cotton fabrics significantly hydrated the sc when levels were compared to either normal skin or skin covered by dry fabrics. Of the seven synthetic fiber fabrics tested in a wetted state, three (acrylic, ptfe, and spun nylon) significantly increased the sc hydration level. These three fabrics and the natural fiber fabrics had comparable wetted moisture content.

1992 ◽  
Vol 62 (11) ◽  
pp. 638-647 ◽  
Author(s):  
Kathryn L. Hatch ◽  
Nancy L. Markee ◽  
Harriet H. Prato ◽  
S. Haig Zeronian ◽  
Howard I. Maibach ◽  
...  

Fabric placed over human skin may change the stratum corneum (SC) hydration level, an important phenomenon because increases in normal levels of SC hydration pose potential health problems. The skin becomes more susceptible to abrasive damage, increases in permeability, and is more prone to microbial growth. The purpose of this study was to determine the effect of fiber type and fabric moisture content on SC hydration. Using three similarly constructed knit fabrics, six fabric type/moisture content combinations were selected for the tests. Using an occluded plastic dome, fabric samples were placed on both “normal” and “hydrated” volar forearm skin of subjects for a specified time period, then removed. Two minutes after removal, evaporative water loss and skin temperature were measured. The design of the study was a randomized complete block with all possible treatment combinations applied to each subject. Data were analyzed using analyses of variance on the linear and quadratic coefficients of best fit lines and Bonferroni t tests. For “normal” skin, SC hydration generally increased as fabric moisture content increased. The SC was significantly drier after being in contact with cotton fabric at regain than at the two moisture content levels above regain, and also under polyester fabric. For hydrated skin, the hydration state was significantly lower under the cotton fabric at regain than at 38.6% moisture content and at saturation, but was not significantly different under the polyester fabric at regain and at saturation.


Textiles ◽  
2021 ◽  
Vol 1 (1) ◽  
pp. 55-85
Author(s):  
Tufail Hassan ◽  
Hafsa Jamshaid ◽  
Rajesh Mishra ◽  
Muhammad Qamar Khan ◽  
Michal Petru ◽  
...  

Recently, very rapid growth has been observed in the innovations and use of natural-fiber-based materials and composites for acoustic applications due to their environmentally friendly nature, low cost, and good acoustic absorption capability. However, there are still challenges for researchers to improve the mechanical and acoustic properties of natural fiber composites. In contrast, synthetic fiber-based composites have good mechanical properties and can be used in a wide range of structural and automotive applications. This review aims to provide a short overview of the different factors that affect the acoustic properties of natural-fiber-based materials and composites. The various factors that influence acoustic performance are fiber type, fineness, length, orientation, density, volume fraction in the composite, thickness, level of compression, and design. The details of various factors affecting the acoustic behavior of the fiber-based composites are described. Natural-fiber-based composites exhibit relatively good sound absorption capability due to their porous structure. Surface modification by alkali treatment can enhance the sound absorption performance. These materials can be used in buildings and interiors for efficient sound insulation.


2019 ◽  
Vol 46 (12) ◽  
pp. 1081-1089 ◽  
Author(s):  
Hossein Karimzadeh ◽  
Ali Razmi ◽  
Reza Imaninasab ◽  
Afshin Esminejad

This paper evaluated mixed mode I/II fracture toughness of fiber-reinforced concrete using cracked semi-circular bend (SCB) specimens subjected to three-point bending test. Additionally, a comparison was made between the experimental results and the estimations made by different theoretical criteria. Natural and synthetic fibers at various concentrations were used in this study. After producing cracks in SCB specimens at different inclination angles to induce different mixed mode loading conditions (from pure mode I to II), the fracture toughness of SCB specimens was determined. Furthermore, the compressive, splitting tensile, and flexural strength of natural and synthetic fiber-reinforced concrete were measured after 7 and 28 days of curing. While there is an increase in the aforementioned strengths with fiber content increase, 0.3% was found to be the optimum percentage regarding fracture toughness for both fibers. Also, the comparison between the experimental and theoretical results showed that generalized maximum tangential stress criterion estimated the experimental data satisfactorily.


2015 ◽  
Vol 754-755 ◽  
pp. 235-239
Author(s):  
A. Zuliahani ◽  
H.D. Rozman ◽  
Abdul Rahman Rozyanty

The use of natural fiber as reinforcement in polymer composites has gained importance recently due to environmental concern and its abundance availability from agricultural crops and wood industry [1]. Many advantages offered by natural fibers over synthetic fibers include low density, greater deformability, low cost per unit volume, recyclability and biodegradability [2-3]. In addition, the mechanical properties of natural fibers such as flax, hemp, jute, sisal and kenaf are comparable with glass fiber in respect of strength and modulus [4]. Hence, many studies have been carried out to replace the synthetic fiber for composite preparation.


2013 ◽  
Vol 651 ◽  
pp. 486-491 ◽  
Author(s):  
Triono Agus ◽  
Wiratmaja Puja Ign ◽  
Hilman Syaeful Alam ◽  
S. Rochim

One of the natural fiber considered to replace syntetic fiber is Oil Palm Empty Fruit Bunches (OPEFB) fiber which offer advantages such as environment friendly and widely available especially in indonesia . This study investigates the characteristics of railway brake block with OPEFB fibres compare to synthetic fiber. All the test results were compared to the technical requirement of PT. Kereta Api Indonesia (PT. KAI ) and evaluated using Extension Evaluation Method (EEM) to select and get the best sample. From the evaluation results using EEM, one of non commercial sample using OPEFB fiber give a better results compare to commercial sample using synthetic fibers. So it can be concluded that OPEFB fiber as reinforcement for railway brake material could improve physical and mechanical properties of the material, environment friendly and could replace synthetic fibers.


Author(s):  
Sergio Pons Ribera ◽  
Rabah Hamzaoui ◽  
Johan Colin ◽  
Benitha Vasseur ◽  
Laetitia Bessette ◽  
...  

This work, which is part of the FIBRABETON project, aims to anti-fissuration screed formulations proposition based on natural fibers and comparing these formulations to a synthetic fiber-screed formulation. Different natural fiber (hemp, flax, miscanthus and bamboo) with contents rangingfrom 0.4% to 0.8% were tested. The spread (slump), the shrinkage and mechanical strength (flexural and compressive) studies were carried out. SEM images of natural fibers and natural fibers screed formulation were analyzed. Overall, it is found that all natural fibers screed formulations tested, have shown better behaviour than the synthetic fibers screed formulation in point of view workability, shrinkage and mechanical properties. The lowest shrinkage value is found in the case of the H5 (5 mm long hemp fibers) screed formulation. Generally speaking, the mechanical strength values (flexural and compressive) are more or less similar between natural soft fibers (hemp and flax) and rigid fibers (miscanthus and bamboo). Taking in account slump, shrinkage and mechanical behavior, the proposed good compromise in this work is the H5 screed formulation.


2001 ◽  
Vol 702 ◽  
Author(s):  
Prabhu Kandachar ◽  
Rik Brouwer

ABSTRACTAvailable as agricultural resources in many countries, natural fibers, such as flax, hemp, kenaf, exhibit mechanical properties comparable to those of synthetic fibers like glass. But they are lighter, biodegradable, and are often claimed to be less expensive. Composites with these natural fibers have the potential to be attractive alternative to synthetic fiber composites. The natural fibers, however, exhibit more scatter in their properties, are thermally less stable and are sensitive to moisture absorption. The choice of matrix to reinforce with these fibers therefore becomes critical.Currently, synthetic non-biodegradable polymers, such as polypropylene, polyester, etc., are being explored as matrix materials, for applications in sectors like automobiles and buildings. Biodegradable polymers, if made available in sufficient quantities at affordable prices, pave way for bio-composites in future. With both matrix and fibers being biodegradable, bio-composites become attractive candidates from the environment point of view.Extensive and reliable property data on natural fiber composites and/or on bio-composites, are still lacking, making product design with these materials rather tedious. Once the database is available, design & manufacture of products with natural fiber composites and biocomposites offer several opportunities and challenges.


Fibers ◽  
2020 ◽  
Vol 8 (10) ◽  
pp. 62
Author(s):  
Mike R. Bambach

Recent decades have seen substantial interest in the use of natural fibers in continuous fiber reinforced composites, such as flax, jute and hemp. Considering potential applications, it is of particular interest how natural fiber composites compare to synthetic fiber composites, such as glass and carbon, and if natural fibers can replace synthetic fibers in existing applications. Many studies have made direct comparisons between natural and synthetic fiber composites via material coupon testing; however, few studies have made such direct comparisons of full structural members. This study presents compression tests of geometrically identical structural channel sections fabricated from fiber-epoxy composites of flax, jute, hemp, glass and carbon. Glass fiber composites demonstrated superior tension material coupon properties to natural fiber composites. However, for the same fiber mass, structural compression properties of natural fiber composite channels were generally equivalent to, or in some cases superior to, glass fiber composite channels. This indicates there is substantial potential for natural fibers to replace glass fibers in structural compression members. Carbon fiber composites were far superior to all other composites, indicating little potential for replacement with natural fibers.


1993 ◽  
Vol 18 (5-6) ◽  
pp. 421-427 ◽  
Author(s):  
Nancy L. Markee ◽  
Kathryn L. Hatch ◽  
Harriet H. Prato ◽  
S.Haig Zeronian ◽  
Howard I. Maibach

Molecules ◽  
2021 ◽  
Vol 26 (2) ◽  
pp. 404
Author(s):  
Mohammed Zwawi

Increased environmental concerns and global warming have diverted focus from eco-friendly bio-composites. Naturals fibers are abundant and have low harvesting costs with adequate mechanical properties. Hazards of synthetic fibers, recycling issues, and toxic byproducts are the main driving factors in the research and development of bio-composites. Bio-composites are degradable, renewable, non-abrasive, and non-toxic, with comparable properties to those of synthetic fiber composites and used in many applications in various fields. A detailed analysis is carried out in this review paper to discuss developments in bio-composites. The review covers structure, morphology, and modifications of fiber, mechanical properties, degradable matrix materials, applications, and limitations of bio-composites. Some of the key sectors employing bio-composites are the construction, automobile, and packaging industries. Furthermore, bio-composites are used in the field of medicine and cosmetics.


Sign in / Sign up

Export Citation Format

Share Document