Coating and Laminating News

In the run up to the conference we will be posting regular news items. Keep up-to-date with textile coating and laminating news on the TCL2019 website.

18 February 2019

US action plan for per- and polyfluoroalkyl substances

In a move that could be significant for the technical textiles industry, the US Environmental Protection Agency (EPA) has unveiled its Per- and Polyfluoroalkyl Substances (PFAS) Action Plan

The plan identifies both short-term solutions and long-term strategies for addressing the potential hazards these chemicals pose when they are released into sources of drinking water.

As part of this plan, the EPA has begun the regulatory development process for listing perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS) as hazardous substances and will issue interim groundwater clean-up recommendations for sites contaminated with them. Both substances are by-products of the manufacture of perfluorochemicals (PFCs), which are used by the textile industry to produce durable water-repellent coatings.

Switching to PFC-free treatments is proving to be a big challenge for garment manufacturers and could be even more problematic for the manufacturers of technical textiles.

This subject will be explored in detail during the first session of the International Conference on Textile Coating and Laminating 2019 (TCL 2019), to be held in Berlin, Germany, on 14–15 March.

Contact: 

Press Office, United States Environmental Protection Agency.
Tel: +1 (202) 564-4355.

12 February 2019

Flame-retardant cellulosic fabrics without the use of additives

A polymethylmethacrylate (PMMA) coating that imparts flame retardancy (FR) to cellulosic fabrics, without the use of additives or halogenated materials, has been launched by Lubrizol Corp

The company of Wickliffe, Ohio, USA, says that the coating (Hycar NH3069) can be applied to paper, cotton, regenerated cellulose, glass and mixed-fibre media.

Media treated with Hycar NH3069 will pass: German Institute for Standardization (DIN) standard 53438 (Combustibility test) parts 2 and 3; National Fire Protection Association (NFPA) standard 701 (Standard methods of fire tests for flame propagation of textiles and films) vertical burn testing; Federal Motor Vehicle Safety Standard (MVSS) 302 (Flamability of interior materials) horizontal burn testing.

Further, Lubrizol claims that Hycar NH3069:

  • is highly durable in water. Media treated with the coating pass Technical Association of Pulp and Paper Industry (TAPPI) standard T 461 (Flame resistance of treated paper and paperboard);
  • is thermally stable during processing and imparts strength and stiffness to the substrate;
  • enables saturated paper to exhibit superior hot aging performance compared with that treated with phosphate salts and chlorinated polymers;
  • eliminates the need for mixing additives and therefore reduces the inventory needed to produce FR coatings;
  • may eliminate the need for external crosslinkers;
  • provides lower pressure drop in filtration applications compared with particulate additives added to non-FR polymers.

Hycar NH3069 can be applied using a broad range of techniques, including knife coatings (J-box), dip and squeeze (padding), foaming, gravure, screen printing and rod coating.

Contact: 

Mike Heil, Global Marketing Communications Manager, Lubrizol.
https://www.lubrizol.com

 

6 February 2019

How to add functional particles to fabrics without binders

Two UK-based partners have developed a binder-free method for adding highly functional particles to nonwoven fabrics

Functionality is added most simply to a textile at either the beginning or the end of the supply chain, according to Matthew Tipper, who was speaking during the Nonwovens for High-performance Applications symposium (held in Cannes, France, on 10–11 October 2018).

At the start of the chain, manufacturers can now choose from a wide range of raw materials, with yet more in the development pipeline. This gives them a large set of options when it comes to designing and realizing a high-performance fabric with properties that closely match the often demanding requirements of its intended end-use. At the other end, there are now plenty of easy and cheap ways, such as applying a coating, to add functionality to an otherwise finished textile.

In contrast, manufacturers are reluctant to make changes to the process of making a textile, because this is relatively difficult to do and often involves significant investment.

Dr Tipper, who is Business Director for the Leeds, UK-based Nonwovens Innovation & Research Institute (NIRI), was responding to a question from the audience following his own presentation, which described a novel method for adding functional particles to a nonwoven.

Developed in collaboration with Optimum Technology of London, UK, the patent-pending technology requires no binders or adhesives to hold the particles in the fabric, and has also shown great potential for one of the several end-uses the partners are exploring - the removal of volatile organic compounds (VOCs) from the atmosphere to improve the quality of air.

NIRI and Optimum Technology are continuing to develop this application, as well as others, and Dr Tipper will give an update to the work at TCL2019, Berlin, 14-15 March 2019. Book now to meet Dr Matthew Tipper and other industry experts at TCL2019.

 

4 February 2019

Inexpensive smart fabrics produced using metal deposition technique

A technique developed in the UK for printing metals such as silver, gold and platinum onto natural fabrics could be useful for the production of batteries, wireless devices and sensors

Current metal inks designed primarily for application on planar substrates (for example, polyethylene terephthalate foils or ceramics, for instance) and they contain polymer binders that render fabric substrates hydrophobic and brittle as they fill the pores found in such materials. By contrast, the binder-free approach developed by researchers at Imperial College London preserves the three-dimensional (3D) structure and hydrophilicity of fabrics.

To coat the fibres, the researchers first cover them in microscopic particles of a silicon precursor, and then submerge them in a solution containing metal ions. This process, called silicon ink-enabled autocatalytic metallization (SIAM), 'grows' metals throughout the fibres as the ions are deposited on the silicon particles. This approach maintains the flexibility and water absorption characteristics of fabrics while providing a metallic surface area large enough for the production of sensors and batteries.

For their proof-of-concept study, the research team dropped the silicon ink onto the fabrics by hand, but say the process could be scaled-up and performed using conventional printers.

Using the process, the researchers have fabricated silver coil antennas on paper, which can be used in near-field communication (NFC) devices such as contactless payment systems. The team also used the method to deposit silver and zinc onto paper to form a battery, and to produce a range of sensors, including a paper-based version that can detect the genetic indicators of Johne’s disease, which is fatal to grass-eating animals and associated with Crohn’s disease in humans.

The affordability of the method was cited as one of its major advantages by the researchers, who demonstrated that when using their approach, a coil antenna could cost as little as US$0.001 to manufacture, compared to $0.05 using current methods.

The team have applied for a Patent to protect their technology and are now looking for industry partners to develop it further. 

28 January 2019

Textiles for a good night’s sleep

Key market for growth

Alexium of Perth, Australia, and Greer, South Carolina, USA), now views its Alexicool PCMs for the bedding markets as the key to its growth and profitability.

Alexicool PCMs are microencapsulates that can be easily applied to many bedding components – mattress tickings, high loft materials and pillows – to provide a complete cooling system.

In December 2018, the company announced that – as a result of one of several projects with bedding manufacturer Pegasus Home Furnishings, of Elizabeth, New Jersey, USA – Alexicool had been chosen as the key ingredient in a multi-million pillow supply programme for an unnamed major North American retailer.

“We are encouraged about the new products developed in our Pegasus initiatives, and this capitalizes on strong technical and commercial efforts by both companies,” said Alexium Chief Commercial Officer (CCO) Allen Reihman. “We have worked with Pegasus to provide its extensive customer base with improved cooling functionality using the latest technical innovations. This allows Pegasus to provide comfortable solutions for bedding end-use customers. With the launch of Alexicool technology for pillows, we continue to create and commercialize a product portfolio that drives momentum and will improve profits in the months ahead.”

Alexium says that recent tests at a third-party's facility have demonstrated that, when coated on foam, Alexicool has an up to 75% greater cooling effect compared with the products of its major competitor.

Vice President of Research and Development Richard Estes adds: “Our initial product testing is very encouraging, and the positive results achieved are more dramatic than anticipated.”

During the International Conference on Textile Coating and Laminating, Berlin 14-15 March 2019, Alexium’s CEO Bob Brookins will discuss the use of PCMs for thermal management. See the full conference programme for more information.

22 January 2019

Thermal binder fibre for needlepunched nonwovens

Carpet manufacturers will now be able to make fully recyclable, latex-free needlepunched floorcoverings without compromising on performance, according to a Belgian company that has developed a polypropylene (PP) staple fibre for thermally binding nonwoven webs

Beaulieu Fibres International (BFI) of Wielsbeke launched its patented Ultrabond fibre during the Domotex exhibition, which was held in Hannover, Germany, on 11–14 January 2019. Intended as a substitute for chemical binders, such as latex, the inclusion of Ultrabond in the needlepunched web will allow manufacturers to create thermally bonded carpets from 100% PP, making it simple to recycle the whole product at the end of its life.

Compared with the use of chemical binders, Ultrabond will also offer manufacturers savings in energy and water consumption during production, as well as reducing the residual levels of volatile organic compounds (VOCs) in their carpets. In Europe, for instance, about 100 million m2 of carpet is used annually for exhibitions, a major end-use for needlepunched floorcoverings, and the substitution of the fibre for chemical binders in all of these would equate to savings in water consumption of about 20 million litres. Further, owing to the absence of water during processing, the final product does not require drying, lowering energy consumption by 93%, according to BFI, which bases its figures on a lifecycle analysis (LCA) of an exhibition carpet.

Nevertheless, the carpets demonstrate mechanical properties – such as resistance to pilling, wear, abrasion and ultraviolet (UV) radiation – on a par with those made using chemical binders.

The company’s Karena Cancilleri said: “We see textile flooring as just the beginning. Together with our customers, we look forward to exploring the potential of this unique thermal bonding fibre in other applications, such as laminated nonwovens, and as an alternative to dry powders.”

During Domotex, another part of the Wielsbeke-based Beaulieu International Group, Beaulieu Yarns introduced a range of resilient yarns (Resilya) for use in hard-wearing tufted carpets. Resilya yarns can be dyed in a wide range of colours, it told visitors to the stand.

Beaulieu Yarns also showed its Eqobalance yarns for high-value contract and automotive carpets. These polyamide 6 (PA 6) yarns are made using polymers derived using some or all raw materials based on renewable resources rather than fossil fuels, but can still be processed on existing manufacturing lines. Finally, the company showed the latest additions to its Softitude range of yarns for broadloom carpets. These PA yarns are solution-dyed, and are soft and durable.

Thermoplastic composite parts are designed to be recycled

A process for manufacturing easily recyclable composite components developed by Prodrive Composites of Milton Keynes is being refined at the University of Sheffield’s Advanced Manufacturing Research Centre (AMRC), both in the UK

Prodrive’s Primary To Tertiary (P2T) process enables the production of composite parts that can be recycled several times. The Chief Engineer at Prodrive Composites, John McQuilliam, says: “End-of-life recycling is one of the biggest debates in the composites world today. The issue affects automotive manufacturers and wider industries too, such as marine, where old fibreglass boats are often broken-up and sent to landfill. The main barrier to recycling has been the type of resin used; thermosetting resins predominate, but these cannot be readily recycled.”

Rather than a thermosetting resin, P2T employs a reactive thermoplastic resin—a plastic monomer reacts with a catalyst in the presence of reinforcing fibres to produce a cured laminate. Parts with high mechanical properties can be manufactured initially, but at the end of their useful life the reinforcement and even the resin can be recycled using chemical and thermal depolymerization techniques, supplying much of the raw material needed for the production of a secondary part, such as a body panel.

When the secondary part reaches the end of its life, it can be chopped-up and remoulded. This tertiary part can in turn be recycled several times into lower-performance parts.

As a further benefit, the P2T process does not require the use of autoclaves to produce parts,  reducing costs and the investment required to scale-up manufacture.

Partnership Lead at the AMRC Composite Centre, Hannah Tew, says that her team has been working with Prodrive on: automation of the P2T process, making it possible to produce parts in medium-to-high volumes at substantially lower costs than would otherwise be the case; looking at the recyclable nature of the materials used; increasing the technology’s attraction to other industries.

McQuilliam adds: “We have been working with the AMRC and a series of large trial panels have been produced using an innovative process that can readily be automated. These trials have demonstrated that recyclable composite panels can be produced at a rate and cost to suit many industries.”

21 December 2018

First-of-its-kind carbon fibre recycling partnership is established

Boeing and ELG Carbon Fibre are working together to recycle waste aerospace-grade carbon fibre-reinforced plastic (CFRP) so that it can be used by other companies to make products such as electronic accessories and automotive parts

The agreement between the two companies – the first formal supply deal between an aircraft original equipment manufacturer (OEM) and a carbon fibre recycler – will see around 454 t (one million pounds) of excess carbon fibre material from 11 Boeing aeroplane manufacturing sites being delivered to ELG’s facility in Coseley, UK, each year.

As the largest user of aerospace-grade CFRP, Boeing of Chicago, Illinois, USA, has been working for several years to create economically viable methods for recycling such materials. The company claims to have improved its production methods to minimize waste and to have developed a model for collecting scrap material.

ELG has developed a process called pyrolysis through which CFRP scrap – in the form of dry fibres, cured and uncured prepreg, and/or laminates – is heated to 400–650°C in the absence of oxygen, to burn off the matrix. The process leaves a tough and abrasive fluff of carbon fibre that maintains at least 90% of its tensile strength compared with virgin fibre. After several years of product development, ELG has managed to convert this material into a number of useful forms.

To prove that this method could be applied on a large scale, Boeing and ELG conducted a pilot project to recycle excess material from Boeing's Composite Wing Center in Everett, Washington, USA, where the wings for Boeing’s 777X aeroplane are made. Over the course of 18 months, the partners recycled around 680 t (1.5 million pounds) of scrap carbon fibre material, which was sold to companies in the electronics and ground transportation industries.

The partnership is particularly significant for ELG. The company estimates that it will have to triple the number of people it employs, from 39 in 2016 to 112 by the end of 2019. It will also allow the company to serve its customers better. The Managing Director of ELG, Frazer Barnes, says: "Security of supply is extremely important when considering using these materials in long-term automotive and electronic projects. This agreement gives us the ability to provide that assurance, which gives our customers the confidence to use recycled materials."

Boeing and ELG are currently considering an expansion of the agreement that would see excess carbon fibre material from three additional Boeing sites in Canada, China and Malaysia being recycled. Boeing’s ultimate goal is to reduce the amount of solid waste it sends to landfill by 20% by 2025.

According to 777 Wing Operations leader, Kevin Bartelson: “Recycling composites will eventually be as commonplace as recycling aluminium and titanium."

 

5 December 2018

Graphene-coated jute fibres for reinforcing composites

A method for coating jute fibres with graphene, which improves their mechanical properties and those of composites reinforced with them, has been developed by researchers at the University of Manchester in the UK

By coating the fibres in graphene oxide, the researchers have improved their tensile strength by 94% in comparison with untreated jute fibres. Further, the strength of the bond formed between the coated fibres and an epoxy resin matrix (the interfacial shear strength) is 245% higher than that formed with uncoated fibres.

Natural fibre-reinforced composites are attracting significant interest from a number of industries as a replacement for those reinforced with synthetic materials, such as glass fibres, which are produced using energy-intensive processes and are more expensive.

Jute is extracted from the bark of the white jute plant (Corchorus capsularis) and is completely bio-degradable and recyclable. It is the second most-produced natural fibre in the world – after cotton – and is at least 50% cheaper than flax and other similar natural fibres.

Jute fibres could be suitable replacements for fibres made from glass for the reinforcing of composites owing to their lower specific gravity (around 1.3, compared with around 2.5 for glass fibres) and their higher specific modulus (around 40 GPa, compared with around 30 GPa for glass fibres).

However, these fibres bond poorly with polymer matrices owing to the presence of a waxy cementing layer, which contains low-molecular weight fats, lignin, pectin and hemicellulose, on their surfaces. Further, they exhibit poor tensile strength.

By coating jute fibres with graphene oxide using a simple dip-coating method, the University of Manchester researchers take advantage of the oxygen-containing functional groups found within the nanomaterial’s molecular structure. These functional groups interact with an epoxy resin, forming a strong mechanical bond at the fibre–matrix interface. Further, flakes of graphene oxide possess an extremely high modulus that appears to stiffen the jute fibre and eliminates stress concentrations on the surface of the fibres during tensile loading, thus enhancing their tensile strength.

The researchers also experimented with a graphene flake-based coating , and while they found that its effect on bond strength and tensile strength was lesser than that of the graphene oxide coating, it did deliver the best result in terms of enhancing the Youngs modulus of the fibres.

Senior researcher on the project and the Director of Research for the North West Composites Centre at the University of Manchester, Professor Prasad Potluri, says: “This is an example of judicious combination of low-value, carbon-neutral commodity fibres with an extremely small volume fraction of high-value graphene in order to create a material system that could replace energy-intensive carbon and glass fibres in a number of lightweight structural applications.”

Researcher on the project and Knowledge Exchange Fellow (Graphene) at University’s National Graphene Institute, Nazmul Karim,  concludes: “The use of jute in automobile interiors by global car giants has been growing rapidly with a current demand of 100 kt a year. I believe our graphene-based jute fibres could play a very important role in meeting the growing demand of more environmentally friendly products for various industries.”

 

4 December 2018

Alternative to perfluorocarbon-based finishes for leather

A perfluorocarbon (PFC)-free, water-repellent finish for leather has been launched by HeiQ of Bad Zurzach, Switzerland, and DuPont Consumer Solutions of Wilmington, Delaware, USA

Footwear manufacturer Wolverine World Wide Leathers Inc of Rockford, Michigan, USA, is the first supplier to offer leather – its pig nubuck – treated with the finish, called HeiQ DuPont Eco-Led. Eco-led is an addition to HeiQ's Eco Dry range. 

According to research carried out by HeiQ, 49% of consumers think it is important that the water-repellent finishes used on the products they purchase are free from PFCs. Wolverine's Vice President of Sales and Marketing, Suzanne Johnson, says that this demand now extends to leather products.

Hexcel to buy ARC Technologies

Hexcel Corp of Stamford, Connecticut, is to acquire a supplier of electromagnetic interference (EMI)-shielding composites for military, aerospace and industrial applications, ARC Technologies Inc of Amesbury, Massachusetts (both in the USA)

Founded in 1988 and privately owned, ARC Technologies employs about 170 people across two locations in Amesbury. It specializes in combining absorptive filler compounds – including carbon, iron and nickel-coated graphite – with a proprietary blend of polymer resins to produce structural composites and thermoplastics. The resulting materials can absorb microwaves and provide protection from electromagnetic interference (EMI).  The company is expected to generate about US$50 million in revenue in 2018.  

Hexcel has agreed to pay US$160 million for ARC, and expects the purchase to be finalized in early 2019

Vapour coating method for charge-storing garments

Researchers at the University of Massachusetts Amherst in the USA have developed a method for embroidering charge-storing patterns that they claim can be applied to any garment

While many different electronic circuit components have been made small enough to be incorporated into wearable devices, until now the same could not be said for charge-storing devices. The lead researcher on the project, Trisha L. Andrew, says: “Batteries or other kinds of charge storage are still the limiting components for most portable, wearable, ingestible or flexible technologies. The devices tend to be some combination of too large, too heavy and not flexible.”

The method developed in Andrew’s laboratory employs stainless steel sewing threads that are coated with poly(3,4-ethylenedioxythiophene) chloride (PEDOT-Cl) using a reactive vapour deposition (RVD) process to increase their electrical conductivity.  These threads are used to embroider a pattern onto a textile substrate to form electrodes, which are then coated with a polymer gel electrolyte to make flexible microsupercapacitors (MSCs).

The process creates porous conducting films of the polymer on densely twisted yarns, the high surface area of which maximizes contact with the electrolyte ions and maintains high charge-storage capacity per unit length as compared with prior work with dyed or extruded fibres.

Andrew says: “We can embroider a charge-storing pattern onto any garment using the vapour-coated threads that our laboratory makes. This opens the door for simply sewing circuits on self-powered smart garments.”

Andrew notes that textile researchers have tended not to use vapour deposition because of technical difficulties and high costs, but more recent research has shown that the technology can be scaled-up and remain cost-effective.

She and her team are currently working with others at the University of Massachusetts Amherst Institute for Applied Life Sciences’ Personalized Health Monitoring Centre on pairing the embroidered charge-storage arrays with smart textile sensors and low-power microprocessors to make smart garments that can monitor a person’s gait and joint movements.

Interweaving layers to make durable fire-resistant textiles

A fire-resistant textile developed by Arville Textiles of Wetherby, UK, could be used to manufacture clothing for use by firefighters, military personnel and police officers

Outlined in International Patent Publication WO2018/150165, the textile is claimed to:

  • be lightweight, breathable and comfortable;
  • move moisture away from a wearer’s skin efficiently to reduce the risk of scalds;
  • meet the required standards of key flammability regulations, such as European standard EN 469 (Protective clothing for firefighters).

According to the Patent, the fire-resistant textile (100) comprises:

  • an outer woven layer (102) of meta-aramid fibres or a blend of meta-aramid and para-aramid fibres;
  • an inner woven layer (106) of para-aramid fibres;
  • an intermediate woven layer (104) in a blend of wool and cellulose fibres.

All of the layers can be made in a 2 × 2 twill resulting in an open interwoven structure that hides the stitching points of the lower layers, and provides a tight, dense construction that imparts high dimensional stability and increases durability to multiple washes, says Arville.

Preferably, the yarn count of the outer layer is around 72/2 Nm and it comprises 93% meta-aramid fibres (such as 1.4 dtex Nomex from DuPont of Wilmington, Delaware, USA), 5% para-aramid fibres and 2% antistatic fibres (such as carbon fibres).

The yarn count of the inner layer is around 100/2 Nm and it comprises 100% para-aramid fibres (such as Kevlar from DuPont) to provide the textile with strength and stability, particularly during heat exposure.

The yarn count of the intermediate layer is around 60/2 Nm and it can include shrink-resistant wool fibres with a diameter of 15.5–29.5 μm (ideally 20.8 μm)  in a blend of 55% wool/45% cellulose (such as a fire-retardant viscose fibre from Lenzing of Lenzing, Austria, with a titre of 2.2 dtex) to provide comfort and moisture management.

Warp ends from the inner layer are woven into the outer and the intermediate layers by crossing over individual picks.

The figure shows an open grid structure in which the warp (Wpint) and weft (Wtint) yarns from the intermediate layer are aligned with every other respective yarn (Wpout) and Wtout) of the outer layer; that is, there are around half the number of wool/viscose yarns relative to the yarns of the outer layer to define a grid structure that is more open than that of the outer layer.

The inner woven layer has an open grid structure of the same or similar density in terms of warp and weft spacing to that of the intermediate layer. However, the warp (Wpinn) and weft (Wtinn) yarns of the inner layer are each located between the adjacent yarns of the intermediate layer.

As shown in the figure, the weft yarns of the inner layer are located between adjacent weft yarns of the intermediate layer and are in the same plane. The warp yarns of the inner layer are aligned between the adjacent warp yarns of the intermediate layer while being predominantly in a different plane to them.

Further, the warp yarns of the inner layer occasionally interact with the weft yarns of both the intermediate and outer layers to hold the textile together.

When combined with a moisture barrier and inner liner for a firefighting garment, the fire-resistant textile has a fabric weight of around 250 g.m–2.

In 2017, Arville entered into a trade mark licencing agreement (TMLA) with DuPont for Nomex yarns.

Woven using Nomex yarns, Arville sells ComfortShell fabric that can be used to produce uniforms for firefighters that are both lightweight and comfortable.

 

Check back for more news updates. To book your place at TLC2019, the International Conference on Textile Coating and Laminating, click here.

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