scholarly journals Innovative Use of Sheep Wool for Obtaining Materials with Improved Sound-Absorbing Properties

Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 694 ◽  
Author(s):  
Simona Ioana Borlea (Mureşan) ◽  
Ancuţa-Elena Tiuc ◽  
Ovidiu Nemeş ◽  
Horaţiu Vermeşan ◽  
Ovidiu Vasile

In recent years, natural materials are becoming a valid alternative to traditional sound absorbers due to reduced production costs and environmental protection. This study explores alternative usage of sheep wool as a construction material with improved sound absorbing properties beyond its traditional application as a sound absorber in textile industry or using of waste wool in the textile industry as a raw material. The aim of this study was to obtain materials with improved sound-absorbing properties using sheep wool as a raw material. Seven materials were obtained by hot pressing (60 ÷ 80 °C and 0.05 ÷ 6 MPa) of wool fibers and one by cold pressing. Results showed that by simply hot pressing the wool, a different product was obtained, which could be processed and easily manipulated. The obtained materials had very good sound absorption properties, with acoustic absorption coefficient values of over 0.7 for the frequency range of 800 ÷ 3150 Hz. The results prove that sheep wool has a comparable sound absorption performance to mineral wool or recycled polyurethane foam.

2020 ◽  
Vol 12 (3) ◽  
pp. 761 ◽  
Author(s):  
Monica C.M. Parlato ◽  
Simona M.C. Porto

Greasy sheep wool is currently considered a special waste for its high bacterial load, with expensive disposal costs for sheep breeders. For this reason, wool is often burned or buried, with serious consequences for the environment. On the other hand, sheep wool is well regarded as one of the most performative insulating natural fibers due to its thermo-hygrometric and acoustic properties. In the building sector, sheep wool meets the requirements of green building components because it is an eco-friendly material, there is a surplus of it, it is annually renewable, and totally recyclable. If used instead of common insulation materials (e.g., fiberglass, rock wool, polyurethane foam, polystyrene), sheep wool offers significant benefits for sustainability such as a reduction in the production costs for new insulating materials and in environmental pollution. Mechanical and physical properties of sheep wool investigated in previous studies were assessed and discussed with the aim of providing an organized framework of possible applications of wool fibers in building components. This paper highlights in detail aspects that have not yet been investigated enough to detect new potential uses of sheep wool fibers in rural buildings and the reuse of traditional ones.


Author(s):  
Nadžida MLAĆO ◽  
Amela KATICA ◽  
Velija KATICA ◽  
Almira SOFTIĆ ◽  
Vedad ŠAKIĆ ◽  
...  

In Bosnia and Herzegovina, Montenegro, as well as in most Balkan countries, wool is a major environmental problem. After sheep shearing, farmers usually leave the wool at the shear sites, providing poorly degradable organic waste. The purchase price of such untreated wool is as low as its quality. By this research, we have tried to draw attention, from another aspect, to the quality of wool fibers of certain parts of the body, which is ultimately very important in the textile industry and in the selection of wool for further processing. The cuticle is made from cornfied cells, flakes, located on the surface of wool fibers. One of the significant roles of the cuticle is the protective. Namely, the cuticle protects the wool fibers from various external factors, whether mechanical or physic-chemical (such as ammonia evaporation in poorly maintained facilities, etc.), which can damage the fleece and thus make it less quality. We have found some differences in the flakes position and shape in the wool fibers we investigated, depending on part of the body from which they were sampled. However, by microscopic analyses of samples taken from the root of the tail, we have found that the flakes were much smaller and finer in structure than the arrangement and appearance of the cornified flakes from the rump. In this study, we have compared the appearance and arrangement of flakes of cuticle, which is very important in assessing the quality of wool and its further use as a raw material.


2021 ◽  
Vol 7 (12) ◽  
pp. 2068-2082
Author(s):  
Fatima Zohra El Wardi ◽  
Sara Ladouy ◽  
Abdelhamid Khabbazi ◽  
Khalid Ibaaz ◽  
Asmae Khaldoun

Cork is an ecological, natural, and renewable additive, an excellent thermal and acoustic insulator. All these attributes encourage its use in the building sector. Adding this additive to the Earth leads to a more lightweight composite with better thermal performance than the Earth alone. Unfortunately, the mechanical performance of this composite is degraded significantly, limiting its use in construction applications. The authors propose in this study to stabilize the clay-cork composite using natural stabilizers. A chemical stabilization was tested using local quick-lime, in addition to a physical stabilization using natural sheep-wool fibers. The primary purpose is to propose eco-friendly construction material with enhanced thermal and mechanical properties and the lowest environmental impact based on local and ecological raw materials to encourage more sustainable and low-energy constructions. First, physicochemical and mineralogical characterization of used clay was investigated. Then, an experimental investigation was conducted to identify the lime content that allows the optimal stabilization for the used clay. In this context, many different specimens of Bensmim soil stabilized with lime at six many contents 0, 10, 20, 30, 40, 50, and 70% were prepared and tested. The obtained results showed that the optimal lime content for the better stabilization of the used soil is about 30%. Next, an experimental study of thermomechanical properties was conducted on unfired clay bricks mixed with expended cork granules and stabilized by the addition of variable proportions of quick-lime 0, 10 and 30% and sheep-wool fibers 0, 1, and 2%. The mechanical performance of the specimens was investigated in terms of compressive and flexural strengths. At the same time, thermal quality was qualified through evaluating thermal conductivity using the steady-state Asymmetrical Hot Plate test method. The very encouraging experimental findings showed that using lime and sheep-wool fibers at the studied addition content resulted in lightweight composites with lower thermal conductivity and higher compressive and flexural strength than reference samples. The highest thermomechanical performances are obtained with clay-cork blocks reinforced with 30% lime content and 2% sheep-wool fibers. This block recorded values of 583 kg/m3, 0.155 W/m/K, 1.55 MPa, and 3.91 MPa, for bulk density, thermal conductivity, flexural and compressive strength respectively, compared to 765 kg/m3, 0.238 W/m/K, 0.96 MPa and 2.29 MPa for control samples. New material presents lightweight material for both improved thermal and mechanical qualities encouraging its use in building applications. Doi: 10.28991/cej-2021-03091778 Full Text: PDF


Author(s):  
María Ángela Jiménez Montañés

Resumen<br /><br />El sector al que correspondió el mayor protagonismo dentro de la industria europea moderna fue, sin lugar a dudas, el textil. Ello no representaba, en realidad, novedad alguna, pues la industria medieval se desarrolló precisamente en función primordialmente de la fabricación de tejidos. El vestido, al tiempo que una necesidad inmediata, resulta expresión visual de distinción social, aún más que la decoración de la vivienda. Por ello la industria textil creció a expensas tanto de la necesidad como del lujo. Uno de los grandes cambios que se producen en este tipo de industria durante todo el siglo XV y se consolida en el XVI se centra en las relaciones de producción, en la utilización de mano de obra campesina y la consolidación del ciclo de producción artesano rural. La mano de obra rural comienza a trabajar por su cuenta o en dependencia del empresario-productor de la ciudad. Si bien, la profunda transformación de la industria textil tendrá lugar en el siglo XVIII, con la revolución industrial.<br />La transformación de la industria textil del siglo XVI propició la expansión de una nueva figura en el ámbito mercantil, que se denomina mercader-empresario, y por tanto, del sistema doméstico de producción conocido como Verlagssystem. Este nuevo sistema implicará modificaciones de factores claves para el desarrollo de las futuras sociedades mercantiles como pueden ser: el capital, la utilización de la materia prima y su proceso de transformación, la formación de los costes de producción y comercialización, la obtención de beneficios y su distribución, la concentración del capital y la generación de rentes. En definitiva, la creación de una nueva clase social, la burguesía. Este trabajo se centra en la industria sedera de la ciudad de Toledo en el siglo XVI.<br /><br /><br />Abstract<br /><br />The textile sector, was the greater protagonist, without doubt, within the modern European industry. It did not represent, in fact, newness some, because the medieval industry was developed indeed in function fundamentally of the weave manufacture. The dress, to the time that an immediate necessity, is visual expression from social distinction, still more that the decoration of the house. For that reason, the textile industry grew as much to expenses of the necessity as of the luxury. One of the great changes that throughout take place in this type of industry, during century XV and consolidates in the XVI, is focused in the relations of production, the use of manual labor farmer and the consolidation of the cycle of production rural craftsman. The rural manual labor begins to work by itself or in dependency of the small businessman of the city. Although, the deep transformation of the textile industry will take place in century XVIII, with the industrial revolution. The transformation of the textile industry of century XVI caused the expansion of a new figure in the mercantile scope, that denominates merchant-small businessman and therefore, of the domestic system of production known like Verlagssystem. This new system will imply modifications of key factors for the development of the future mercantile societies as they can be: the capital, the use of the raw material and its process of transformation, the formation of the commercialization and production costs, the obtaining of benefits and its distribution, the concentration of the capital and the generation of you rent. Really, the creation of a new social class, the bourgeoisie. This work is focused in the silk industry of the city of Toledo in century XVI.


2015 ◽  
Vol 671 ◽  
pp. 483-489
Author(s):  
Mu Yao ◽  
Mei Yu Chen ◽  
Run Jun Sun ◽  
Zhao Huan Zhang ◽  
Cheng Kun Liu ◽  
...  

A wide variety of new wool fiber materials, such as super-fine sheep wool with the average diameter of about 11 μm, rabbit wool of long-hair rabbit, Wusuli raccoon dog wool, and vicuna wool, were developed except for sheep wool and cashmere in the wool textile industry. Tibetan antelope wool was not allowed to make a processing and trade, but it may have a development in the future. Meanwhile, other natural and chemical fibers were added as the raw materials in wool textile production because of their new functional requirements including antistativity, antibacterial, deodorant, improvement of strength and abrasion resistance, anti-electromagnetic radiation and improvement of flame retardancy. The raw materials of the wool textile industry have shown a magnificent development.


2019 ◽  
Vol 12 (1) ◽  
pp. 300 ◽  
Author(s):  
Jakob Lederer ◽  
Andreas Gassner ◽  
Florian Keringer ◽  
Ursula Mollay ◽  
Christoph Schremmer ◽  
...  

Population growth in cities leads to high raw material consumption and greenhouse gas emissions. In temperate climates were heating of buildings is among the major contributors to greenhouse gases, thermal insulation of buildings became a standard in recent years. Both population growth and greenhouse gas mitigation may thus have some influence on the quantity and composition of building material stock in cities. By using the case study of Vienna, this influence is evaluated by calculating the stock of major building materials (concrete, bricks, mortar, and plaster, steel, wood, glass, mineral wool, and polystyrene) between the years 1990 and 2015. The results show a growth of the material stock from 274 kt in the year 1990 to 345 kt in the year 2015, resulting in a total increase of 26%. During the same period, the population grew by 22%. On a material level, the increase of thermal insulation materials like polystyrene and mineral wool by factors of 6.5 and 2.5 respectively were much higher than for other materials, indicating energy efficiency and greenhouse gas mitigation in the building construction sector. The displacement of brickwork by concrete as the most important construction material, however, is rather a response to population growth as concrete buildings can be raised faster. A question for the future is to which extent this change from brickwork to high carbon-intensive concrete countervails the achievements in greenhouse gas reduction by thermal insulation.


2020 ◽  
Vol 15 ◽  
pp. 155892502093412
Author(s):  
Lihua Lyu ◽  
Changwei Li ◽  
Ying Wang ◽  
Jing Lu ◽  
Jing Guo

In order to solve the recycling problem of waste fibers, the nonwoven wall cloth was prepared with waste wool fibers and low-melting-point polyamide fibers as raw materials by combing into a net and hot-pressing method. The effect of fiber length, hot pressing temperature, mass fraction of the waste wool fibers, volume density, thickness of materials, and thickness of the rear air layer on the sound absorption properties were studied by single factor experiments. Under the optimized technological conditions, the sound absorption coefficient was above 0.91 and the noise reduction coefficient was 0.56. Then, the sound absorption mechanism was analyzed. In order to meet the fire resistance requirements of materials in the construction industry, by the orthogonal experiments, range analysis, and variance analysis, the optimal process conditions were as follows: potassium fluotitanate concentration of 8%, treatment time of 40 min, and treatment temperature of 80°C. The limit oxygen index of the nonwoven wall cloth was 32.5%. The nonwoven wall cloth had good sound absorption and flame retardant properties.


2009 ◽  
Vol 160 (7) ◽  
pp. 195-200
Author(s):  
Reto Hefti

In the mountainous canton Grisons, much visited by tourists, the forest has always had an important role to play. New challenges are now presenting themselves. The article goes more closely into two themes on the Grisons forestry agenda dominating in the next few years: the increased use of timber and climate change. With the increased demand for logs and the new sawmill in Domat/Ems new opportunities are offered to the canton for more intensive use of the raw material, wood. This depends on a reduction in production costs and a positive attitude of the population towards the greater use of wood. A series of measures from the Grisons Forestry Department should be of help here. The risk of damage to infrastructure is particularly high in a mountainous canton. The cantonal government of the Grisons has commissioned the Forestry Department to define the situation concerning the possible consequences of global warming on natural hazards and to propose measures which may be taken. The setting up of extensive measurement and information systems, the elaboration of intervention maps, the estimation of the danger potential in exposed areas outside the building zone and the maintenance of existing protective constructions through the creation of a protective constructions register, all form part of the government programme for 2009 to 2012. In the Grisons, forest owners and visitors will have to become accustomed to the fact that their forests must again produce more wood and that, on account of global warming, protective forests will become even more important than they already are today.


Author(s):  
SAFITRI NURHIDAYATI ◽  
RIZKI AMELYA SYAM

This study aims to analyze whether the difference that occurs in the cost of raw materials, direct labor, and factory overhead costs between the standard costs and the actual costs in PLTU LATI is a difference that is favorable or unfavorable. Data collection techniques with field research and library research. The analytical tool used is the analysis of the difference in raw material costs, the difference in direct labor costs and the difference in factory overhead costs. The hypothesis in this study is that the difference allegedly occurs in the cost of raw materials, direct labor costs, and factory overhead costs at PT Indo Pusaka Berau Tanjung Redeb is a favorable difference. The results showed that the difference in the cost of producing MWh electricity at PT Indo Pusaka Berau Tanjung Redeb in 2018, namely the difference in the price of raw material costs Rp. 548,029.80, - is favorable, the difference in quantity of raw materials is Rp. 957,216,602, - is (favorable) , the difference in direct labor costs Rp 2,602,642,084, - is (unfavorable), and the difference in factory overhead costs Rp 8,807,051,422, - is (favorable) This shows that the difference in the overall production cost budget is favorable or profitable. This beneficial difference shows that the company is really able to reduce production costs optimally in 2018.  


2020 ◽  
pp. 712-721
Author(s):  
Jan Maarten de Bruijn de Bruijn

The bought sugar in the processed raw material (either beet or cane) comprises a high financial value and may contribute to somewhere around 50% of the white sugar production costs. It is therefore of the utmost importance to minimize sugar losses along the process and produce as much white sugar as possible from the raw material. This paper explains the principle of technical accounting as tool to control sugar extraction and losses in beet sugar manufacture. The sugar mass balance used to calculate the overall sugar extraction yield, as well as several simple calculations proposed for estimating the different sugar losses (like e.g. extraction (diffusion) losses, infection losses, sugar losses in molasses, etc.) in the subsequent process steps will be explained in detail. Proper technical accounting is considered indispensable for continuous process control and process improvement in pursuit of best-practice operation and cost-leadership.


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