When we think about silk, we only really think of its use in the textile industry, but the natural protein fibre can also be a valuable contribution to science and engineering. The hairline threads are often overshadowed by synthetic man-made fibres despite the the outstanding properties silk has. Insect spun silk is stronger than steel, lightweight and flexible.
Researchers in Germany have taken inspiration from the lacewing – an insect which lays its eggs on stalks made of silk with a high tensile strength. Now the University of Bayreuth has constructed a special gene sequence which enables bacteria to produce the silk protein. They are working on ways to produce the protein in large quantities by using biotechnology. Their aim is to use the material in the future as a high-grade rigid fiber, for example, in lightweight plastics in transportation technology. It can also be used in medical technology as a biocompatible silk coating on implants.
Lacewings are insects which are already being used by farmers to combat aphids. To protect their offspring, lacewings lay their eggs on very fine but extremely resilient silk stalks. It then creates a thread which hardens in the air within a few seconds securing the egg under the leaf. In order to produce these impressive fibers, the green lacewing excretes a protein secretion onto the leaf. The threads are finer than human hair, but they are strong enough to support the weight of the egg even when the leaf is turned over.
The Fraunhofer IAP which is heading the project researches and develops polymer applications. It supports companies and partners in the customised development and optimisation of: innovative and sustainable materials, processing aids and processes. In addition to characterising polymers, the institute also produces and processes polymers in an environmental-friendly and cost-effective way on a laboratory and pilot plant scale.
A team led by Professor Thomas Scheibel from the Chair of Biomaterials at the University of Bayreuth conducted the preliminary molecular-biological work. They constructed a special gene sequence which enables bacteria to produce the silk protein. Martin Schmidt is now optimising the manufacturing process at the Fraunhofer IAP so that the silk protein can be produced inexpensively on an industrial scale. After this step it will be possible to develop the material.
“Unlike most other types of silk, the green lacewing’s egg stalk has a special structure with fascinating mechanical properties… We would like to transfer these special properties to fibres made from this silk. However, until now it has not been possible to produce this type of silk protein in sufficient quantities and purities,” explains Martin Schmidt, biotechnologist at the Fraunhofer IAP in Potsdam-Golm.
“This special property makes it interesting for medical technology and as a reinforcement fiber in lightweight engineering, for example in cars, airplanes or ships. We are pleased to be working in partnership with the Fraunhofer IAP, which is able to lend its expertise to this project in every area – from the development of the silk material to the finished fibre,“ explains Dr. Lin Römer, scientific director of AMSilk. The project is being funded by the Agency for Renewable Resources (FNR), a project management organisation of the Federal Ministry of Food and Agriculture.
For 25 years the Fraunhofer IAP has specialised in the development and characterisation of fibers and fiber-reinforced composites for lightweight engineering and in the development of biobased polymers. At the institute’s own spinning plant, technical fibers can be manufactured on an industrial scale either from a solution or a melt. “Combining biotechnology and polymer research under one roof creates ideal conditions to produce fibers made from green lacewing silk. This is an enormous advantage for the development of innovative fields of application,“ says Schmidt.
*This story first appeared on Bio-Based World News
The global apparel industry leaves a significant environmental footprint across each step in the clothing lifecycle. As consumers become aware of this reality, they are increasingly demanding products produced from sustainable resources with minimum environmental impact.
According to a recent study by Boston Consulting Group, 50 percent of Millennials believe brands “say something about who I am, my values, and where I fit in,” while a recent Nielsen study found that three out of four Millennials — a coveted audience for any apparel company — are willing to pay extra for sustainable product offerings. Fashion brands that ignore the clear preference of Millennials for sustainable products and the business opportunity this presents do so at their peril.
To address the concern of the apparel industry’s environmental footprint as well as the opportunity to build brand loyalty with Millennials and increase market share, sustainability has come to the forefront of the industry. Major fashion brand leaders are incorporating sustainability strategies into their business models and growth strategies, and reevaluating their supply chains to identify and pursue opportunities to reduce petroleum use, carbon emissions, water use and waste throughout the value chain.
As sustainability bubbles to the top of the priority list in the apparel industry, formal measurement and assessment tools have been established to help drive improved environmental and social performance. As the old adage goes, “you can’t manage what you don’t measure.”
Textile Exchange released its Preferred Fibers & Material (PFM) Benchmark program this year, following an initial trial in 2015. An astounding 89 brands and retailers from across multiple countries and product sectors have submitted entries. The PFM Benchmark provides a robust structure to help companies systematically measure, manage and integrate a preferred fiber and materials strategy into mainstream business operations. Confidential feedback to companies and a sector report will be released in September.
The Sustainable Apparel Coalition’s Higg Index is the leading suite of self-assessment tools designed to empower brands, retailers and facilities of all sizes, at every stage in their sustainability journey, to measure their environmental and social and labor impacts and identify areas for improvement. Higg delivers a holistic overview of the sustainability performance of a product or company — a big-picture perspective that is essential for progress to be made.
There are many sustainability-enabling pressure points for apparel companies to measure and manage. One such opportunity is new technology that is emerging as a solution for reducing petroleum use in the manufacturing process through the integration of bio-based chemicals and materials. Bio-based fibers are not new within the textile arena, but early materials were manufactured through a fermentation process, which made environmental improvements cost-prohibitive.
Until now the chemical industry hasn’t had a viable technology option for cost-competitively producing 100 percent bio-based “drop-in” aromatic chemicals (i.e., benzene, toluene and xylenes (BTX) – the basic chemical building blocks used to make both nylons and polyesters for apparel — due to the lack of efficient and scalable processes that utilize renewable non-food biomass feedstocks.
Today the portfolio of biosynthetic fibers embraces nylon, polyester and spandex/elastane. PET polymer producers have begun to incorporate up to 30 percent renewable content for beverage bottles, as Bio-MEG from sugar-cane ethanol becomes more widely available, but the purified terepthalic acid (PTA) has always come from petroleum sources of para-xylene. This is currently changing as second-generation bio-based materials entering the market today offer a practical and commercially viable pathway to bio-derived materials. These materials are generally comparable with and, in many cases, identical to petroleum-based products and are, by definition, renewable.
“Organic remains central to TE’s cotton work, and we are now working with the industry to support adoption of recycled and bio-based synthetics such as nylon, polyester, and spandex into company fiber and material strategies. We’ve learned a lot from our work in organic and it’s exciting to take the learnings to a wider fiber and material portfolio,” says Liesl Truscott, director of fiber and materials strategy at Textile Exchange. “We started supporting the industry on bio-synthetics in 2012 with biov8tion, and I’m pleased to say that together we are now taking this to the next level.”
“The industry today talks of bio-synthetics as new and emerging polymers and fibers, but much of today’s advancements in this area are based on the post war (1950s) research and commercial polymers. A significant opportunity exists today to improve the sustainability performance in the apparel industry through the use of renewable, bio-based materials, rather than petroleum. Finite petroleum risks market volatility and is used as the backbone of our most widely used synthetic fibers today, polyester and nylon. Renewable and bio-derived chemistry offers up promising alternatives to produce in general chemically identical materials made from non-food biomass and further innovation opportunities in the future,” explains Sophie Mather, founder and director of biov8tion.
“A shift to bio-based apparel will play a significant role in reducing fossil fuel use and resulting emissions, while providing the opportunity for integrated producers to mitigate price volatility, and benefit from the market demand consumers place on ‘greener’ products,” says David Sudolsky, president and CEO at Anellotech. “Much of the focus in the renewable space has been devoted to PET bottles, where there has been and continues to be strong progress in improving renewable content. Anellotech is developing an innovative and cost effective process technology that will enable the step from 30 percent to 100 percent and this technology will apply not only to bottles but also to polyester textiles. The time is right to join forces in a collaborative way to accelerate the transition to bio-based textiles. We are excited to be working with TE, biov8tion, and others in this space.”
TE has set up a new Bio-Synthetics Working Group, comprised of TE members and experts with an interest in the future of bio-based materials as a solution to transitioning out of non-renewables and textiles based on petroleum towards more sustainable alternatives. The multi-stakeholder group, led by Mather, will be exploring challenges and barriers to growth, sustainability benefits, and importantly how to get bio-synthetics from R&D and proof of concept to market readiness and a commercially viable alternative to virgin materials. The WG meets in Hamburg, Germany at TE’s global sustainability conference, Oct. 4-6.
*This story first appeared on Apparel Online