According to John Woods, general manager of Eastman’s microfibers business, Cyphrex microfibers have been developed to satisfy a diverse set of performance needs for increasingly demanding nonwoven applications—especially those in which wetlaid nonwoven and specialty paper producers can benefit from improved strength, uniformity, and reproducibility. Customer-specific development is in progress across a variety of potential end-uses – including, but not limited to, filtration, packaging, highly-durable papers, wallcoverings, and batteries.
“Since the initial launch in 2013, we have continued to expand our portfolio of Eastman Cyphrex microfiber products. We have driven this through the pairing of continued advancements in our world-class technology and proprietary microfiber processes—a technology which enables microfibers comprising of unique combinations of sizes, shapes, and materials—with needs and insights gained from external market connect across the nonwoven and specialty paper value chains,” Woods says.
He adds that the need for innovation within the nonwovens industry drives customers to continually seek new material inputs which allow them to access differentiated performance in their products without requiring that they make significant process and/or operational changes to do so.
“Eastman Cyphrex microfibers continue to demonstrate themselves to be just such a material,” Woods continues. “As previously mentioned, our customers are typically seeking novel materials with inherent functional benefits which help them to develop differentiated nonwoven products. Often, however, those new materials can bring with them performance trade-offs. For example, a fiber which contributes significantly improved strength and durability to a nonwoven, may come at the expense of the uniformity (or even processibility) of the product. “
Because Cyphrex microfibers integrate easily into existing wet-laid processes, this can significantly broaden the design capabilities of the nonwoven producer—thereby allowing them the opportunity to develop a next generation of performance nonwoven materials.
Mark Clark, technology director, Microfibers Platform, Eastman Chemical Company, says that Eastman Cyphrex microfibers have, without question, offered nonwoven producers a novel raw material input to consider for new product development.
“New materials, particularly ones somewhat related to an old material (specifically, synthetic fibers) which has created formulation and manufacturing challenges in the past, will be assumed to bring with them at least similar such issues—if not more of them,” he says.
Through investment in both hardware (i.e. paper/nonwoven making equipment) and software (i.e. experience wetlaid nonwoven and paper scientists), Eastman has, as a microfiber supplier, built an application development competency which not only helps to clearly demonstrate the value created in-use by its unique materials but also provides its customers with access to knowledge and expertise related to how they can best utilize these microfibers in their designs and operations.
After launching the Eastman Cyphrex microfibers platform with a pair of differently-sized round microfibers, specifically Cyphrex 10001 and Cyphrex 10002, which initially targeted filtration applications, ongoing conversations with leaders in the nonwovens industry suggested a need for a synthetic fiber that could be compatible with an added value to materials with a high content of cellulose pulp – i.e. so-called specialty papers.
The outcome of those conversations and significant development efforts – both fiber-related and nonwoven-related using Eastman’s product and application development expertise – has been Cyphrex 10101. This 0.4 denier PET fiber with a unique flat cross-section actually looks quite similar to the cross-sectional shape of a cellulosic fiber.
Consequently, it is quite compatible with cellulosic materials – both in a nonwoven or paper roll goods and also, perhaps somewhat surprisingly for a synthetic fiber, in the nonwoven wet end. It is this combination of product and process functionalities which can allow the nonwoven producer to access significantly enhanced uniformity, strength, durability, and processibility in order to meet the increasingly-strenuous demands of their customers’ applications.
ExxonMobil Launches New Grades of Vistamaxx
ExxonMobil Chemical has introduced new grades of low viscosity Vistamaxx performance polymers for hygiene and assembly hot melt adhesive applications. Vistamaxx 8780 and 8380 grades expand the adhesive application options of Vistamaxx 8880 which became commercially available in 2015. These three low viscosity polymers enable the formulation of high-performance, low odor, low density hot melt adhesives used in packaging, hygiene and assembly applications.
Based on ExxonMobil’s proprietary metallocene technology, Vistamaxx polymers enable the development of a new generation of low odor, minimal color, premium hot melt adhesive formulations that offer trouble-free application.
These new polymers provide a range of properties for hot melt adhesives including low density for more adhesive mileage. They enable clean hot melt formulations with good thermal stability, while offering a broad service temperature range and the ability to tailor high consistent tack with adjustable open/set times. Hot melt adhesive formulations in which Vistamaxx polymers are used provide a broad processing window, application techniques and service temperature ranges.
“Vistamaxx polymers offer a wide range of properties that help overcome many of the shortcomings of conventional hot melt adhesive backbones,” says Gertrud Masure, global market development manager Hygiene & Adhesives, ExxonMobil Chemical. “As these polymers are made using our metallocene technology, formulators can create much cleaner and more reliable adhesives.”
Vistamaxx 8380 and 8780 are designed for hygiene applications that require low odor, minimal color adhesives. They enable thermally stable formulations with polymer loadings of 45-65%. Formulators have the flexibility to create hot melt adhesives that meet open and set time needs while also delivering higher mileage compared to adhesives based on SBC (styrene block copolymer) and metallocene polyethylene (MCN-PE). This, combined with good adhesion to low surface energy substrates, delivers added value for diaper and adult incontinence products, as less adhesive is required in the fabrication and lower adhesive use can enable premium attributes like softer touch, better fitting and less bulky products.
Vistamaxx 8380 is also well-suited for hot melt adhesives used in assembly applications, such as woodbanding, lamination and automotive. It allows thermally stable formulations with improved adhesion and heat resistance compared to APAO- and EVA-based formulations, while providing low odor and minimal color. Formulations can obtain polymer loadings of 70-90%, resulting in lower density and higher mileage as a potential source of added value for assembly adhesive consumers.
Vistamaxx 8880 is well suited for packaging applications including case and carton sealing. It enables formulations with polymer loadings as high as 90%, about double that of formulations using ethylene vinyl acetate (EVA) or MCN-PE. This leads to significantly lower density, lighter weight formulations, which can provide added value as less product is used to create a stronger bond enabling more boxes to be secured with the same amount of adhesive.
“Our low viscosity Vistamaxx polymers increase hot melt adhesive formulation flexibility in response to increasing performance needs from the adhesion industry. They provide a low odor formulation alternative, without compromising adhesive performance,” says Masure. “These polymers also help to ensure adhesive supply stability because they are from readily available feedstocks.”
Goulston Responds to Changing Needs of Nonwovens
Nonwovens producers continue to develop new products for existing applications, taking advantage of a more cost effective production scheme. One example is the replacement of rayon with polyester or polypropylene nonwoven fabrics. The performance demands of these fabrics remain the same, but the challenge is in replacing rayon with fabrics exhibiting similar hydrophilic and antistatic properties. Hydrophilic and anti-static properties can be imparted to polyester and polypropylene fabrics by way of topically applied additives that enhance or modify the fabric surface. Goulston Technologies, Inc. offers several variations of topically applied treatments that provide non-durable or semi-durable hydrophilic properties, hydrophobic properties, and antistatic properties.
Nonwovens end-uses requiring products that exhibit hydrophilic properties and are designed for single use applications usually require a non-durable hydrophilic finish system. These finishes are designed to impart good initial hydrophilic character but are easily washed off revealing the underlying hydrophobic substrate. Characteristics of these treatments include excellent emulsion quality and stability, lower surface tension values (leading to uniform coverage on the fiber surface), and static protection. This specially formulated finish chemistry can be applied as a spin finish or a topcoat finish by spray, kiss roll, or dip bath application.
Newer markets require finish chemistries that provide hydrophilic properties thru multiple insults, or are not easily removed from the surface of the fiber. Semi-durable finishes are designed to have greater affinity for the fiber surface so they do not wash off easily. Finishes that maintain semi-durable hydrophilic characteristics typically contain components with a balanced hydrophile-hydrophobe structure. As semi-durable hydrophilic performance increases, emulsion stability may decrease and make application to the substrate more difficult.
There are markets that require the nonwoven fabric to be hydrophobic. The challenge in these markets is to provide lubricity and antistatic protection required for processing without compromising the hydrophobicity of polypropylene inherent to the fiber surface. While silicones are the most commonly used hydrophobic topical treatment, other options include fluorochemical and low viscosity specialty esters for end uses where silicone may not a viable option. Whether hydrophilic or hydrophobic, many nonwovens products require static protection. Goulston Technologies, Inc. has the expertise necessary to assist customers with the proper antistat selection.
Polyvel Offers Resin Alternative
The economic value proposition of Polyvel’s CR20PX2 can replace current use of meltblown polypropylene resins with less expensive, more readily available polypropylene resins, through the addition of our specialty masterbatch directly into your meltblown system.
The cost to use the product, CR20PX2, is roughly six cents per pound. This can be compared to the price difference between a meltblown grade of polypropylene, and either spun bond or injection molding grades of polypropylene. And in addition to cost savings, the use of our product gives you the freedom to source from many polypropylene suppliers, as the list of meltblown polypropylene producers is limited, which improves your ability to avoid supply interruptions, and source from the most readily available, less expensive polypropylene grades. The NH-P01 product simply makes the fabric feel softer.
Teijin Develops Masterbatch Flame Retardant
Teijin Limited has developed a new masterbatch flame retardant that combines its phosphorus flame retardant FCX-210 with a polymer for use on fibers as well as resin. This granular type enables textile manufacturers to impart superior heat resistance to a wide range of products without the need to construct a dedicated facility or to add traditional flame retardants to raw materials in advance.
Launched in 2013, FCX-210 lends high flame retardancy to a broad range of plastics without losing any of its flame resistance or changing the original characteristics of the plastic. Additionally, only a relatively small amount is necessary. OEM production began in Taiwan in 2014, and FCX-210 has since been widely adopted for electronics and automobile parts.
Additionally, FCX-210 is a halogen-free product, making it safer for end-users and more environmentally friendly.
The new masterbatch FCX-210 will bring the same strengths to textile manufacturing, as well as the world’s highest transparency for unmatched colorability. Moreover, unlike traditional phosphorus flame retardants, FCX-210 is insoluble, that realizes easier draining process.
Teijin has begun supplying samples to expand applications for FCX-210 into interior products such as curtains, carpets and wallpapers, which require high heat resistance. Teijin expects revenue from FCX-210 to reach ¥2 billion ($21.9 million) by 2020.
Wacker Offers Softener Product
Wacker has introduced Wetsoft NE 750, an innovative hydrophilic softener for the finishing of textiles, fibers and nonwovens. Its water-free concentrate can be diluted to different concentrations easily. According to the company, the product’s main constituents are new patent pending block copolymers based on aminofunctional silicones and polyglycol. The silicone fluid segments arrange themselves in free-moving loops on the outside of the fabric and reduce friction between the fibers. This provides the fabric surface with an excellent soft feel, which remains after washing. The polyglycol segments, on the other hand, ensure that the silicone finish, which is normally water-repellent, remains permeable to water. Tests show that materials treated with Wetsoft NE 750 have a pleasant, soft and full hand feel while remaining absorbent. As a result, they quickly take up moisture from skin and hair.
The combination of softness and water absorbency is of crucial importance for high-quality textiles and nonwovens, according to the company. The hydrophilic fabric softener can also be applied to other fabrics like towels, woven textiles or knits by either exhaust or padding processes. Both cotton and blended fabrics containing polyester can be finished with the product.”
Turning hydrophobic to hydrophilic surfaces is one of the challenges in the nonwovens industry due to the use of synthetic fibers. Wetsoft NE 750 combines this advantage together with the pleasant hand feel that can only be achieved with silicone-based softeners. The product can also be used on viscose or cotton-based nonwovens-like disposables.
In modern nonwovens articles, many manufacturers are seeking multiple attributes. Wetsoft NE 750 merges hydrophilic effects with excellent softness. Moreover the unique polymer ensures stability even in fast running processes.