Acoustic Performance of Sound Absorbing Materials Produced from Wool of Local Mountain Sheep

Katarzyna Kobiela-Mendrek, Marcin Bączek, Jan Broda, Monika Rom, Ingvild Espelien and Ingun Klepp

Abstract

Wool of mountain sheep, treated nowadays as a waste or troublesome byproduct of sheep husbandry, was used for the production of sound-absorbing materials. Felts of two different thicknesses were produced from loose fibres. Additionally, two types of yarn,ring-spun and core rug, were obtained. The yarns were used for the production of tufted fabric with cut and loop piles. During the examinations, basic parameters of the obtained materials were determined. Then, according to standard procedure with the use of impedance tube, the sound absorption coefficient was measured, and the noise reduction coefficient (NRC) was calculated. It was revealed that felt produced from coarse wool exhibits high porosity, and its sound-absorbing capacity is strongly related to the felt thickness. For thicker felt the NRC achieved0.4, which is comparable with the NRC of commercial ceiling tiles. It was shown that the crucial parameter influencing the sound absorption of the tufted fabrics was the pile height. For both types of yarns, when the height of the pile was increased from 12 to 16 mm, the NRC increased from 0.4 to 0.42. The manufactured materials made from local wool possess good absorption capacity, similar to commercial products usually made from more expensive wool types. The materials look nice and can be used for noise reduction as inner acoustic screens, panels, or carpets.

Click here to read the full article (mdpi.com).

Woolume: Potential new products from vacant wool

Anna Schytte Sigaard, Lisbeth Løvbak Berg and Ingun Grimstad Klepp

Summary

This report gives an overview of the market for alternative wool products with the perceived potential to be made using vacant wool. The work is based on a desktop study and interviews with manufacturers and distributors, focusing on products made of wool and their qualities. The report is the second deliverable from work package 2 of the WOOLUME project. The main goal of WOOLUME is to explore different ways of using wool from the Polish Mountain Sheep to achieve better utilisation of resources and value creation. Producers were identified that use wool as a material for products in the following categories: cultivation, soil improvement, insulation and personal hygiene as well as other new and alternative wool products. Findings show a range of products that take advantage of the many properties of wool, both aesthetic and technical. They also show that wool has the potential to replace synthetic materials in several applications and create truly circular products when treated in a way that preserves biodegradability. Though Merino wool dominates the wool market, several producers make use of other, local wool qualities and the interest for using the vacant wool, often discarded as a mere by-product of meat and dairy production, is growing. However, there is further potential for optimising resource utilisation in using vacant wool, in particular, non-spinnable wool with a higher fibre thickness, in products where the fineness and spinnability of merino wool are not required.

Click here to read the full report (oslomet.no).

WOOLUME: Mapping the market for acoustic and sound absorbing products made of wool

Anna Schytte Sigaard and Vilde Haugrønning

Abstract

This report is the first deliverable from work package 2 of the WOOLUME project. The main goal of WOOLUME is to
explore different ways of using wool from Polish Mountain Sheep to achieve better utilisation of resources and value
creation. The aim of the report has been to map the market for acoustic and sound absorbing products made of wool to
examine the potential to introduce coarse wool as a material. This has been done through desktop research and
interviews with a focus on the qualities of wool as a natural product. Findings show that though man-made materials
dominate the market for acoustic products due to lower prices, wool is preferred as a material due to its natural
properties as well as aesthetics. Producers using wool consider their products to be high-end, intended for people who
want very good quality products and who are willing to pay a higher price to achieve this. However, few producers use
coarse wool in these products, and many are made of pure Merino wool. Using Merino wool which is often considered
of very fine quality due to the low micron-count does not correspond with the ideal of good utilisation of resources.
Therefore, we are proposing to utilise coarse wool which today is discarded as a mere by-product to meat-production.
Merino could instead be used for products where fineness and softness are important factors such as for clothing. In
addition, we argue for the rawness and uniqueness of the look of coarse wool as positive in terms of aesthetics and as
something that adds to the position of acoustic products made of wool as high-end.

Click here to read the full report (oda.oslomet.no).

Reducing environmental impacts from garments through best practice garment use and care, using the example of a Merino wool sweater

Stephen G. Weidemann, Leo Briggs, Quan V. Nguyen, Simon J. Clarke, Kirsi Laitala and Ingun G. Klepp

Abstract

Purpose

Garment production and use generate substantial environmental impacts, and the care and use are key determinants of cradle-to-grave impacts. The present study investigated the potential to reduce environmental impacts by applying best practices for garment care combined with increased garment use. A wool sweater is used as an example because wool garments have particular attributes that favour reduced environmental impacts in the use phase.

Methods

A cradle-to-grave life cycle assessment (LCA) was used to compare six plausible best and worst-case practice scenarios for use and care of a wool sweater, relative to current practices. These focussed on options available to consumers to reduce impacts, including reduced washing frequency, use of more efficient washing machines, reduced use of machine clothing dryers, garment reuse by multiple users, and increasing number of garment wears before disposal. A sixth scenario combined all options. Worst practices took the worst plausible alternative for each option investigated. Impacts were reported per wear in Western Europe for climate change, fossil energy demand, water stress and freshwater consumption.

Results and discussion

Washing less frequently reduced impacts by between 4 and 20%, while using more efficient washing machines at capacity reduced impacts by 1 to 6%, depending on the impact category. Reduced use of machine dryer reduced impacts by < 5% across all indicators. Reusing garments by multiple users increased life span and reduced impacts by 25–28% across all indicators. Increasing wears from 109 to 400 per garment lifespan had the largest effect, decreasing impacts by 60% to 68% depending on the impact category. Best practice care, where garment use was maximised and care practices focussed on the minimum practical requirements, resulted in a ~ 75% reduction in impacts across all indicators. Unsurprisingly, worst-case scenarios increased impacts dramatically: using the garment once before disposal increased GHG impacts over 100 times.

Conclusions

Wool sweaters have potential for long life and low environmental impact in use, but there are substantial differences between the best, current and worst-case scenarios. Detailed information about garment care and lifespans is needed to understand and reduce environmental impacts. Opportunities exist for consumers to rapidly and dramatically reduce these impacts. The fashion industry can facilitate this through garment design and marketing that promotes and enables long wear life and minimal care.

Click here to read the full article (springer.com).

Environmental impacts associated with the production, use, and end-of-life of a woollen garment

S.G. Wiedemann, L. Biggs, B. Nebel, K. Bauch, K. Laitala, I.G. Klepp, P.G. Swan and K. Watson.

Abstract

Purpose

The textiles industry is a substantial contributor to environmental impacts through the production, processing, use, and end-of-life of garments. Wool is a high value, natural, and renewable fibre that is used to produce a wide range of garments, from active leisure wear to formal wear, and represents a small segment of the global fashion industry. Woollen garments are produced by long, global value chains extending from the production of ‘greasy’ wool on sheep farms, through processing to garment make-up, retail, consumer use, and end-of-life. To date, there have been limited life cycle assessment (LCA) studies on the environmental impacts of the full supply chain or use phase of garments, with the majority of wool LCA studies focusing on a segment of the supply chain. This study aimed to address this knowledge gap via a cradle-to-grave LCA of a woollen garment.

Methods

This study investigated greenhouse gas (GHG) emissions, fossil fuel energy, and water stress associated with the production, use, and end-of-life of a lightweight woollen sweater (300-g wool), together with inventory results for freshwater consumption and land occupation. Primary datasets were used for the wool production and wool processing stages, while primary datasets relating to consumer garment use were supplemented with literature data. Impacts were calculated and reported per garment wear event.

Results and discussion

Impacts per wear were 0.17 (± 0.02) kg CO2-e GHG, 0.88 (± 0.18) MJ fossil energy, and 0.96 (± 0.42) H2O-e water stress. Fossil fuel energy was dominated by wool processing, with substantial contributions of energy also arising from retail and garment care. Greenhouse gas emissions from wool production (farming) contributed the highest proportion of impacts, followed by lower contributions from processing and garment care. Contributions to water stress varied less across the supply chain, with major contributions arising from production, processing, and garment use.

Conclusions

Opportunities to improve the efficiency of production, processing, and garment care exist, which could also reduce resource use and impacts from wool. However, the number of garment wear events and length of garment lifetime was found to be the most influential factor in determining garment impacts. This indicated that consumers have the largest capacity to influence the sustainability of their woollen garments by maximising the active garment lifespan which will reduce overall impacts.

Click here to read the full article (springer.com).

KRUS final report: Enhancing local value chains in Norway

Ingun Grimstad Klepp, Tone Skårdal Tobiasson, Vilde Haugrønning, Gunnar Vittersø, Lise Grøva, Torhild Kvingedal, Ingvild Espelien & Elin Kubberød

From its initiation in 2015 to the end in 2019, KRUS had two goals: to improve the market for and the value of Norwegian wool, and survey the opportunities for local production in a move towards a goal of sustainability in the fashion sector. On a larger scale, KRUS has looked at how we can re-establish an understanding of the connection between the raw material and the finished product within the textile industry and among consumers. It is critical to understand this connection, both to ensure quality products and to reach the market potential for Norwegian wool.

To restore the understanding of “where clothes come from” is also at the heart of challenges currently facing the textile industry. The consumption and production of textiles faces major challenges and changes in the future. Today the industry is characterized by low control and little knowledge, while growth in quantity, environmental impact, as well as stress on animals and humans is high. KRUS has contributed to the debate on sustainable clothing by focusing on local value-chains and locally produced apparel.

The focus on Norwegian wool and the specific qualities of the different breeds has played an essential role for Norwegian textile tradition and dress culture, and a better understanding of this has been essential to the project. An important challenge for Norwegian wool is that it has not been marketed with any kind of label of origin. Private actors have thus entered the field and developed their own private labels for Norwegian wool. In addition, there are few products on the market containing Norwegian wool beyond hand-knitting yarn, which means that availability has been limited.

Throughout the project, we have seen a shift, especially for older sheep breeds, which have posed a special challenge. Their wool is central in keeping Norwegian handicrafts alive, but the quality on some of the wool types has been declining. For others, the challenge is that much of the wool is not taken care of, and constitutes a waste problem. Through breeding-projects, work collaboration, looking closely at labelling systems and business models, KRUS has addressed these challenges.

Click here to read the full report (oda.oslomet.no)

Use phase of apparel: A Literature review for Life Cycle Assessment with focus on wool.

Kirsi Laitala, Ingun Grimstad Klepp & Beverley Henry

Summary

This report presents a literature review of clothing use phase. The purpose is to support improved methodological development for accounting for the use phase in Life Cycle Assessment (LCA) of apparel. All relevant textile fibres are included in the review. However, the main focus is on wool. We ask whether the use of wool has different environmental impacts than clothes in other fibres. The report builds on a review of literature from the past 20 years. The review showed that clothing made from different materials are used, and reused in different ways. Wool is washed differently as it has about ten degrees lower washing temperature than the average laundry in Europe. Wool is also more likely to be either dry-cleaned or washed by hand than other textiles. Moreover, when dried, it is less likely to be tumble-dried.

When comparing the number of days between the washes of different types of clothes, we found that respondents were likely to use their woollen products about twice as long between washes compared to their equivalent cotton products. We also found that woollen products had a longer average lifespan and were more likely to be reused or recycled. There is a lot of research-based information available concerning the use and re-use of clothing, and we believe there are sufficient results available on which to base LCA studies. Furthermore, we believe that environmental tools that compare different fibres but exclude use phase provide misleading results. Including the use phase in fibre ranking benchmark tools will improve the rigour and accuracy of these tools for all fibres, compared to reporting results for fibre production only. However, we have also shown that there are several methodological, conceptual and empirical knowledge gaps in existing literature.

Click here to read the full report (researchgate.net)

Wool as an Heirloom: How Natural Fibres Can Reinvent Value in Terms of Money, Life-Span and Love

Ingun Grimstad Klepp, Tone Skårdal Tobiasson & Kirsi Laitala

Abstract

This paper addresses a main challenge for natural fibres; falling prices and increased focus on quantity versus quality. This is a challenge not only related to economic issues and profit, but is also unsustainable in an environmental perspective and in light of the challenges the textile sector and the world face. The paper uses wool as an example and in a surprising approach links the history and century-old traditions of natural fibers to an environmental thinking which supplements the traditional thinking around circular economy and LCA. Fabrics with a long life are the ones that have the lowest environmental impact (Fletcher and Tham2015; Laitala2014). Longevity or lifespan is a complex phenomenon in which both technical and social, or aesthetic aspects, are intertwined.

Click here to see the full paper in the book Advances in Science and Technology Towards Industrial Applications (springer.com)

Wool you wear it? – woollen garments in Norway and the United Kingdom

Marie Hebrok, Ingun G. Klepp & Joanne Turney

Abstract

This article was developed from the project ‘Valuing Norwegian Wool’ initiated by the Norwegian National Institute for Consumer Research to generate knowledge on how wool can contribute to sustainable textile consumption, and how value creation can be increased in the Norwegian wool industry. The article will compare consumer perceptions, attitudes, practices and knowledge concerning wool as a material and as garments in Norway and in the United Kingdom, through a case study of wardrobes owned by six middle-class families.

The aim is to generate knowledge about the diverse web of aspects that influence consumption of woollen garments. The wardrobe study as a method aims to include the materiality of garments in clothes research in a more direct way. Analysing the materiality in connection with the social and cultural aspects of clothes gives us a better understanding of the relations between materiality and practice.

Click here to read the full article (southampton.ac.uk)

Why Cotton as Linen? The Use of Wool in Beds in Norway

Ingun Grimstad Klepp, Tone Skårdal Tobiasson & Kirsi Laitala

Abstract

Cotton is the “natural” choice and the dominating material in bed linen and sleepwear in Norway as in many other European countries. Regulation of temperature and humidity are important for good sleep, but they are not cotton’s strong points. There must have been other than the functional reasons which made cotton the winner in the bedding market. This article builds on literature about bedding in Norway from the 1800s and survey questions from 1951. We ask the question: what materials have been used and why? Wool was used in all bed textiles, both closest to the body and the layers over and under, from the cheapest chopped rags to the most costly textiles. The decline was seen throughout the 1800 and 1900s, but only in the 1960s does wool become totally absent as a next to skin bed textile. The cheap imports of cotton made cottage industry and home production unprofitable and the new emphasis on cleanliness gave cotton a clear leverage.

Click here to read the full article (tandfonline.com)