Nonwoven advances in performance and sustainability

August 1st, 2017 / By: / Advanced Textiles, Markets

Teijin’s Unisel® nonwoven uses a proprietary process to achieve an ultra-fine multi-layered and stretch-expanding material that can be printed. Material and weight are both minimized, which is also good for the environment. Photo: Marie O’Mahony.
Photo: Marie O’Mahony.

The global market for nonwovens is expected to grow from a 2015 level of $2.9 billion to $8 billion by 2022, according to Stratistics Market Research Consulting, specialists in global cross-sector market research. Existing market sectors such as health, hygiene and automotive applications are expanding, and others are being added, with much of the growth driven by advances in technology and the need for more sustainable products. Exhibitors at this year’s TechTextil in Frankfurt, Germany, reflected this trend, shown in the use of specialized fibers, paired with new construction techniques for novel and more sustainable structures.

Specialized fiber

Japan’s Teijin Frontier Co. Ltd. introduced an ultrafine polyester nanofiber. The company believes that its “Nanofront” is the first 700-nanometer fiber produced using a special sea/island composite spinning technology that promises to overcome the consistent quality issues that can be associated with many mass-produced nanofibers.

The new nanofibers are incorporated into a “sea” alkaline substrate that is then dissolved to leave just the fibers, creating the maximum surface area with the lightest quantity of material and a suede-like hand. It’s used in the company’s NanoFiber air pollution mask and also in the Nano Skin Care Face Mask Sheet, which holds the cosmetic product effectively, minimizing loss of product in use.

Carbon fibers have been used to fulfill the need for high strength in industrial, automotive, sports and other applications. Many of these utilize knit, weave or composite structures. Researchers at the Institut fur Textiltechnik und Lehrstuhl fur Textilmaschinenbau (ITA), RWTH Aachen University (Aachen, Germany), have developed a fabrication process to produce semi-finished nonwovens that incorporate carbon fiber.

PolyTube is a glass fiber-reinforced plastic tube that includes layers of recycled carbon fiber (rCF) on the inside wall. The intention is to produce a GFP tube with electrical functionality using the conductivity of the rCF fibers. In this way, static charge can be discharged to realize a cost-efficient heating of the tube and detect any defects that may be within the wall of the pipe. The main source of carbon fiber textile waste comes from the liquid composite molding (LCM) process, where up to 40 percent of waste can accrue, say researchers at the Fraunhofer Institute in Germany. The savings on this process are both economic and environmental.

Novel construction

Developments in manufacturing technologies mean that we are now seeing the production of nonwovens in more refined structures. Researchers at ITA in Aachen have developed a hybrid nonwoven that allows for the individual design of a nonwoven reinforcement structure. To do this, a PA6 sheet with carbon fiber is combined with an airlaid nonwoven, resulting in a reinforced organo sheet. The nonwoven can be used to produce a 3-D reinforcement structure for use in composites. It offers good optical and haptic qualities and is suited as a functional surface material in lightweight construction. The application of heat-generating and EM shielding for transport and design is further anticipated by the developers.

One of the issues with 3-D nonwoven structures is the danger of reduced strength and stability where stitching or bonding occurs. This can be caused by compression in the case of stitching, or heat deformation where thermoplastic fibers are bonded together.

Teijin Frontier has applied its expertise in novel performance staple fibers and high-level nonwoven production to create a 3-D nonwoven called Decolay. The large surface area offers efficient filtration brought about by good collection and a low pressure loss. It offers a touch that is soft and smooth, making it ideal for sanitary goods and beauty products. Teijin has applied for patents in Japan, and the product is currently under development for mass production. It is expected to be on the market by 2018.

Teijin’s Decolay nonwoven allows for a 3-D structure that brings maximum surface cover with uniform strength throughout. Photo: Marie O’Mahony.
Sustainable approaches

Nonwovens, like all textile sectors, have been moving steadily toward more sustainable production processes. Solutions are now emerging from nonwoven textile machinery manufacturers.

One example comes from the German company Dilo Groupe, which is developing equipment that offers customer savings on raw materials and energy use—both of which are good for the environment and the balance sheet. The company produces equipment that focuses on the mechanical production of web formation and consolidation that uses low energy in comparison with non-mechanical processes. The company’s machines are capable of processing natural, bioplastic and biodegradable fibers.

The Dilo-Isomation Process offers reduced fiber consumption with an even web mass. The objective is to stabilize the quality of the material, preventing the elongation of fibers without slowing down the speed of production. Minimizing the amount of fiber in the material is achieved by reducing drafts, planar compression and the use of the doubling effect.

The common perception of nonwovens as a disposable material has not served the industry well from the point of view of sustainability. Technical Absorbents, a United Kingdom company, has developed a nonwoven fabric that is washable. The material is based on the company’s super-absorbent fiber (SAF). When this material is used as a core within protective outer materials, it can be laundered and dried with minimal loss of absorbency.

At present, this development is aimed at apparel and hygiene markets, but the company sees potential applications in many other areas worth exploring. As Technical Absorbents’ commercial director Paul Rushton explains, “Innovation is at the heart of everything we do as a company.”

The Italian corporation RadiciGroup states that it is necessary to control the entire production process in order to be fully sustainable. “Today RadiciGroup is the only European industrial group that has the capability to control the production process in its entirety, from chemicals to synthetic fibers and engineering plastics, including end-of-life recycling,” according to vice president Maurizio Radici.

Innovations include the recycling of post-consumer waste (PET bottles) with a UNI 11505-certified traceability for their r-Radyarn and r-Starlight materials. The aim of the group is to produce technical textiles that offer high-performance common resistance, durability, comfort and light weight, all with inherent sustainability to meet the criteria for the circular economy.

These are times of exploration and growth for the nonwovens industry as companies of all sizes strive to be innovative, while achieving economic and environmental efficiencies.

Marie O’Mahony is professor of Digital Futures at Ontario College of Art and Design (OCAD) University, Toronto, Ont., Canada, and a consultant to the advanced textiles industry.

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