Spunmelt Nonwovens Life Cycle Analysis

Thomas Broch, Senior Scientist at Fibertex Personal Care (Denmark) described the use of cradle-gate Life Cycle Analysis to determine the impact of white spunmelt nonwovens production on global warming, non-renewable energy use, and multiple impacts such as human and environmental toxicity.

The starting assumptions with regard to the boundaries chosen, transport options, and the raw material data provided by different suppliers are key and can alter the results dramatically.  Improving the waste management in the production plant also had a profound effect, reducing the Fibertex emissions from 3348 to 2907 kg CO2 equivalent between 2000 and 2011, while reducing virgin PP resin use by almost 100,000 tonnes.  Using natural gas burners for heat generation further reduced C-footprint by more than halving the kg CO2 equivalent compared with electrical heating.

Converters varied in their demands for Environmental Product Declarations, but requests for raw data for calculations further down the supply chain were becoming less common and the focus on CO2 emissions as a key figure is increasing.

Lidl: Will consumers pay for environmental benefits?

Jan Bock, Senior Management, Purchasing International of Lidl Stiftung and Co. KG (Germany) reviewed customer surveys from around the world and noted the following interesting, but sometimes conflicting conclusions regarding consumers willingness to pay more for environmental benefits:

• 81% of Chinese will pay more for energy-saving products. (Greendex 2010)
• 60% of consumers will pay a premium - on average 18% - for goods with a social or environmental benefit. (Prof. Winer, 2013)
• 50% of global consumers will pay more to companies with programs that benefit their society.  (Only 36% of consumers in the EU but 75% of those in India - Neilsen, 2013)

On the other hand…

• While 83% of global customers feel its important to improve the environment, only 22% would pay more for eco-friendly products. (Neilsen, 2011)
• Consumers have no interest in reducing climate change by paying more for low-impact products (Canada, 2004)
• 73% of consumers  don’t buy products with environmental benefits (IGD, 2008)

Mr Bock thought consumer surveys will generally overestimate the willingness to pay for sustainability.  Premiums are more likely for products with tangible benefits which directly affect the purchaser, and so marketing should be specific rather than general: global warming benefits and C-footprint are hard to sell.  They’re also more likely to pay extra for non-durable, frequently purchased items than durables, and for “egotistical” rather than “altruistic” products.  

Nevertheless, developing sustainable products does make sense because they are good for the environment and do build goodwill for your company and brands.

Viscose for Flushable Nonwovens

Sebastian Basel, the Speciality Papers Business Manager of Kelheim Fibres GmbH (Germany) provided an update on their continuing developments with short-cut viscose fibres for wet-laid nonwovens.  He noted the need for more convenience and felt this could be provided by having a single wet-wipe substrate which could be used for baby, toddler, cleaning and moisturising wipes, all of which could be disposed of into the sewerage system.

Unfortunately the flushing of non-flushable wipes has caused problems in sewage systems around the world and the requirements of these waste systems has to be respected by adherence to the lastest, 3rd edition of the INDA/EDANA Flushability Guidlines. Products which fail any one of the sequence of 7 tests for flushability and biodegradability must now be labelled as Non-Flushable.

Wet-wipes have to do the seemingly impossible, i.e. be strong in use and weak in the toilets and sewers while maintaining attractive softness, purity, absorbency and bulk.  The key to success is maintaining adequate strength in the controlled wetness of the wipe pack while achieving rapid dispersion in an excess of turbulent water in the toilet.  Mr Basel argued that wipes made from short fibres dispersed in water had a better chance of meeting these requirements than wipes made of longer fibres using carding.  Hydroentanglement bonding of these wet-laid short fibres enabled production of strong products with just the right amount of “hydro-disentanglement” potential required in flushing. Furthermore certain cross-sectional shapes achievable with the viscose process improve strength in use while simultaneously improving the dispersibility in the sewage system.  Finally, only substrates with a majority of biodegradable fibres such as viscose would meet the guidelines.

In summary, hydroentangled wet-laid nonwovens made with Kelheim’s flat-section Viloft viscose fibre provided the best bet for meeting the current flushability requirements.

Breakthrough Innovation

Dr Bryan Haynes, Director of Global Enterprise Research and Engineering, Global Nonwovens, Kimberly-Clark (USA) made the case for increasing the rate of innovation in general and in nonwovens in particular. Times were a changing, and it was not, to paraphrase Charles Darwin, the strongest that survive, it was those most responsive to change: 

• By 2022 China will be spending more on R&D than the USA. 
• R&D has to become more efficient: more profitable innovations without budget increases. 
• Breakthrough innovation is the key, and Open Innovation is the way forward. 
• Academia can contribute more and is searching for future R&D role. 
• Nonwovens technical institutes can bridge the gap between academic and industrial research. 

K-C have led product differentiation with unique features such as loop fasteners, stretch ears and breathable backsheets for diapers while reducing costs by pioneering the use of new materials such as spunbond and SMS nonwovens. New fabrics will require new raw materials, new processes and new after-treatments, but the returns make such investments worthwhile. Considering Reicofil with 300 beam installations for diapers in the last 10 years there is clearly a case for more investment in process technology.

All companies will benefit from global population growth and the ageing of the population, but to be really successful you have to expand into new “adjacent” territories and remain open to “transformational” innovation - inventing for markets that don’t yet exist. For K-C their development of spunbond housewrap was a good example of moving into adjacent territory.

What would be transformational in the nonwoven industry? With raw materials being the major source of costs and benefits, Dr Haynes thought improving the sustainability (reduce, reuse, recycle) of those materials would be the key. Basis weights of nonwovens and diaper weights could be further reduced by moving from melt-blowns to nanofibre nonwovens, and ultra-absorbents for example. However the problem of diaper waste, with 1.4 billion diapers a day being used globally, was not going to go away and the recycling of disposables or the use of biodegradable materials would be needed. Once again there appeared to be a need for “new to the world” process development and rapid progress from prototypes to commercial reality. With only 10% of R&D projects going commercial there was a need for many new programs and as a consequence many more failures. Failing faster, more cheaply and more often was the key!

Our industry must now think big, focus on open innovation and transformational technology, and minimise the costs of development by partnerships, including those with global academia and technical institutes. Large markets for nonwovens could emerge from the demand for cleaner water, air and energy.

Infra-Red Reflective Viscose

Kelheim Fibres, the world’s leading manufacturer of viscose speciality fibres, is extending its range of speciality products by a newly developed viscose fibre that reflects infrared (IR) radiation.

The human body - like any other matter with comparable temperature - releases a large part of its energy via thermal radiation. This radiation is mainly composed of infrared light. It leads to a loss of energy and therefore to a cooling of the human body. The newly developed viscose fibre with incorporated IR-reflecting particles can significantly reduce this process: Thermal radiation emanating from a body is reflected by the particles incorporated in the viscose fibre and sent back to the body, so reducing the cooling of the person.

In addition to this thermal retention function, the wearer of such a textile also benefits from the typical properties of a viscose fibre such as wearer comfort, softness and skin friendliness. This is achieved by the intrinsic quality of the treatment: in contrast to a subsequent finish with additives based on titanium oxide, the mineral IR-reflecting particles are incorporated into the fibre’s core, preserving the typical fibre properties. The effect is permanent as the additive cannot be washed out. 

First test results of the new fibres that have already been successfully manufactured on a pilot scale, show significant temperature effects in comparison to a standard viscose fibre. This opens up a multitude of possible fields of applications: Used in functional underwear, the thermal effect can increase the well-being of the wearer even at low temperatures. In functional sportswear, the new fibre can lead to improved performance and a faster regeneration of the athlete, thanks to improved blood circulation. Along with textiles, different nonwoven applications could benefit from the IR-reflecting fibre, as for example warming shoe inserts.

"Comfortable feel-good clothes and functional special clothing are just two obvious applications for our new IR fibre”, so Dr. Nina Köhne from Kelheim Fibres’ R&D team. And her colleague, Dr. Daniela Bauer, adds: “We would be happy to adapt the fibre exactly to the demands of other applications depending on our customer’s specific needs. In the past, individual development partnerships often have proven very fruitful and we are glad when our customers reach out to us with their new ideas.”

For the next step, the Bavarian fibre specialists are planning physical and physiological textile tests.

Automotive Biopolymers

José Rodilla, Senior Product Development Engineer with Faurecia - the world’s 6^th largest supplier to the auto industry with a turnover of €16 billion - described their development of “NAFI Lean”, a composite of 80%PP and 20% hemp intended to replace their P/E copolymer in cockpits, door panels, instrument panels etc.  It’s lower density and reduced thickness compared with P/E copolymer or GRP are the key benefits with reduced fuel consumption being the USP for the auto industry.

Short-cut hemp is compounded with PP to make chips for injection mouldings.  Their use provides:

  ·         25% weight savings.

  ·         20% LCA Savings (CO₂).

  ·         Processability on existing machinery with a 6% reduction in cycle time.

  ·         A step on the road to 100% bio-composites.

It is more expensive than P/E copolymer but currently perceived as the best compromise between quality and weight.  It is now used in the Peugeot 308.  3000 tonnes are produced in the EU and a further 10000 tpa planned for  Asia.

Faurecia is also developing its own 100% bio-based polymer “Biomat”,  for non-visible auto parts.  Biomat is 100% poly-butylsuccinate made from tapioca starch using monomer technology from BioAmber and polycondensation technology from Mitsubishi Chemicals.

Biodegradable Gas Barrier Films

Domenico de Angelis of Nippon Gohsei (Japan) believes their Nichigo G-Polymer™ (PVOH) makes a better gas barrier film than EVOH and in dry atmospheres it can be 50x better.  So for dry foods in controlled storage at humidities below 60% RH PVOH will outperform EVOH to an extent that downgaging  and cost saving is possible.  

PVOH gives films with glass-like transparency which biodegrade like cellulose and are therefore fully compostable.  The packaging film used PVOH as the middle layer of a sandwich with PLA as the outer layers.  There were problems with adhesion and these had been solved using a special tie resin.  The 3-layer film could also be ground and recycled as PLA; the PVOH being water soluble could be washed away. A typical construction would be 20 microns of G-Polymer inside  30micron layers of PLA each bonded to the G-Polymer with 10microns of adhesive to give an oxygen transmission rate of 0.02 ccs/square metre/day at 23C and 50%RH.

Nippon Gohsei make 70,000 tonnes/year of PVOH in Japan.  Nichigo G-Polymer™ is the world’s first amorphous PVOH and combines the strengths of regular PVOH and EVOH.

Certification of Biopolymers

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Miriam Lübbecke of DIN Certco (Germany) specialises in biopolymer certification using a scheme which is totally transparent with all details publically available on their website.  When a manufacturer applies for a certificate, DIN Certco assesses the relevant literature and decides how to test the product.  It uses appropriate independent test laboratories chosen from its list of 130 accredited and contracted testing partners, issues a report on the results,  and if appropriate, the certificate of conformance and permission to use the logo.  “Biobased” certificates cover three levels, 20-50%, 50-85% and >85% biobased according to ASTM D 6866 methods which requires a total organic carbon of >50% and a C14 content above 20%.  Testing is required every second year.

“Compostable” certificates can include 4 logos, “the seedling” for industrial compostability, and 3 “DIN-Gepruft” logos covering industrial, home composting and additive content. ASTM D6400 is among the approved tests, but only the Australian standard AS 5810 is used for home composting certification.  The tests include ultimate biodegradability, disintegration, plant toxicity, EN 13432 chemical analysis and, for home composting the ASTM E 1676 earthworm toxicity test.

“Recycled Content” is determined by DIN EN ISO 14021 and audits of the manufacturing site to determine traceability under DIN EN 15343.  A new “All-in-one” DIN Certco logo covering all 4 properties is now available.

Biocomposites from Starch, Natural Fibres and Polymers

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Leon Mentik of Roquette (France) explained how they bought maize, potatoes, wheat, tapioca and peas for processing and used the extracted starches to make bioplastics.  After cellulose, starch was the second most abundant polymer on the planet with 1.3 billion tonnes being produced annually in plants.  6% of this (80 million tonnes/year) is extracted very easily, the by-products being proteins and fibre for use as food.  Starch is highly reactive and easily grafted or alloyed with other materials to add desirable functionalities.  It can be used directly to make starch-based plastics, either as blends with other polymers or in the form of durable thermoplastic starch.  It can also be easily hydrolysed to glucose to provide the starting point for the whole range of bio-based or bacterially produced polymers.

Gaialene® is Roquette’s durable, i.e non-compostable, starch-based plastic which has been certified against ISO 14040/44 by Price Waterhouse Coopers with a carbon footprint of 0.74 kg CO₂ eq./kg resin or ~1/3^rd that of PP.  It has applications in replacing polyolefins in  films, injection moulding and foams, to produce  shopping bags (for recycling or incineration), multilayer shrink wrap, moulded paint containers, fabric coatings, mud-guards, sound insulation and packaging foams.  It is fully recyclable, GMO-free and does not compete with food crops.

Sergio Fita of Aimplas provided another comprehensive overview of the Technological Institute and its work on composites for those who joined the conference late.  He reiterated the variability issue which arises because natural fibres are inherently variable and moisture sensitive and said AIMPLAS was working to overcome this deficiency.  Examples of successes were the woven Flax/Jute battery case which used an epoxidised acrylate soybean-oil resin (ASEO); the Roadside Grit Box using wet compression moulded Flax/biobased unsaturated PET resin (thermoset); the woven flax/PLA tractor door, the Cayley project honeycombs based on FR-treated bio-resins and natural fibres and the Ecoplast project for automotive parts made by extruding PHB polymer onto flax fabrics, calendaring to impregnate and then moulding to shape.

Biopolymer Waste in Spain

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Francesc Giró of the Catalonia Waste Agency was concerned that the desertification now occurring in southern Europe needed to be corrected by adding massive amounts of organic matter to the soil, and this required more composting infrastructure.  In reality 70% of waste organic matter in the region is still land-filled or incinerated and action was needed to allow this to be collected separately and composted.  The target is to compost 50% of organic matter by 2020 and in Catalonia a tax on landfill and incineration is encouraging movement in this direction.

• ·         Door to door collection of food waste is required.
• ·         Compostable bags need to be used for this collection.
• ·         Disposable nappies were a huge problem, accounting for 2.5% of all waste.
• ·         Compostable diapers could make a large contribution to compost production, but they were currently twice the price of the petro-diapers.

Judit Janasa of TOMRA Sorting and Recycling commented on the difficulties of separating mixtures of plastics containing biopolymers but concluded that their sorting machines would soon be able to remove compostable bioplastics from the recycling stream.  They have installed 3470 sorting machines worldwide, mostly in the Iberian peninsula.  These machines use electromagnets, high intensity visible light, infra-red both transmitted and reflected, X-ray, atomic density, and laser fluorescence sensors to identify different materials.

The machines are tuned to the key wavelengths reflected or transmitted by each polymer and digital images taken at these wavelegths are analysed pixel-by-pixel so that for a bottle for example, the cap, label and body polymers are identified and recorded.  Problems arise with black polymers (no reflection), and labels made of paper prevent the underlying polymer being seen.  PLA and PET bottles which look identical can be separated easily.  The software in use can be updated for every new polymer once samples have been tested.

Asked how multilayer bottles or films would be treated, Ms Janasa said the majority polymer would take precedence.