Manufacturers of ultrasonic technologies agree—as innovation continues in the nonwovens industry, new opportunities for ultrasonics grow—especially as manufacturers continue learn more about the value of the technology.

“Ultrasonics is a clean and efficient method of joining or slitting synthetic materials,” says Guy Gil, president, Chase Machine and Engineering. “While the initial investment is much more, the long term benefits more than pay for itself.”

Ultrasonic bonding uses high frequency sound to generate localized heat through vibration and causes thermoplastic fibers to bond together. Suppliers in the industry say the technology offers several advantages.

“Ultrasonics creates a mechanical bond rather than a chemical bond created by adhesives,” says Dan Sorensen, director – Hygiene / Personal Care / Medical, Aurizon Ultrasonics. “Mechanical bonds tend to hold up better in extreme heat conditions such as may be incurred during transportation in certain geographies. Being chemical-free is also of potential benefit to the environment and end users with sensitive skin.”

Because ultrasonic bonding uses friction and pressure to bond materials directly to each other, Julia Daniel, regional technical coordinator, Emerson, says that it makes the added cost of glue and solvents, as well as the cost for added fixturing and the time for glue to “set-up,” unnecessary. “In addition, it eliminates glues and solvents as potential sources of contamination along with the need to clean and maintain glue and solvent application equipment,” she adds. “Because ultrasonics can bond over a range of frequencies and with varied levels of downforce, it also reduces the risk of damage to even the most delicate nonwoven materials and filter media.”

Following is a look at the latest innovations from some of the key suppliers of ultrasonic technology in the nonwovens industry.

Aurizon Ultrasonics
Kimberly, WI-based Aurizon Ultrasonics is a supplier of high power rotary ultrasonic systems to the packaging, hygiene and specialty converting industries.

Within the hygiene industry, Aurizon’s technology is used for adult and baby diapers/pant, surgical wrap, and medical face mask products for bonding, attachment, embossing and lamination of thermoplastic materials. The company has engineered solutions for feature attachment, core bonding, acquisition layers and backsheets.

Aurizon is also capable and willing to develop comprehensive and customized ultrasonic processing solutions that consider key parameters such as horn metallurgy, acoustic designs and geometries, component fabrication and system engineering in order to meet the processing needs of the customer.

Recently the company has introduced several new bonding solutions.

A new equipment package includes fixed blade horns over rotary anvils for material lamination and edge sealing. According to Aurizon’s Dan Sorensen, this technology reduces equipment cost by leveraging the increased width of a blade versus rotary. “For example, a 150 mm wide blade horn can be used in place of two 75 mm wide rotary horns. This solution is not a direct replacement for all rotary horn applications however, there are many applications where this is an effective solution,” he says.

Aurizon has also recently completed optimization of its elastic entrapment technology. This technology directly entraps tensioned elastic within a thermoplastic substrate, providing product advantages to producers and converters of elasticized fabrics while eliminating the direct and indirect cost of adhesives. Aurizon’s ultrasonic entrapment technology provides lower tension at elongation verses any other means of attachment, resulting in a more comfortable experience for the user.

Sorensen says Aurizon’s ultrasonic entrapment technology is very much in demand. “We are currently working with equipment manufacturers and end users in Asia, Europe and North America,” he says. “The benefits of adhesive elimination are very attractive to producers of hygiene products. The three key advantages of Aurizon’s elastic entrapment technology are savings on product cost through adhesive elimination, increased production line efficiency and Improved product comfort and performance.”

Another new introduction from Aurizon is the RS series bonder. The RS series is a rotary ultrasonic assembly mounted in a bearing housing that can be mounted in any orientation. It is available in 20, 30, and 40 kHz with bond widths of up to three inches. “The bonder is intended for machinery manufacturers and experienced end users who desire to develop their own actuation and tooling solutions,” Sorensen explains.

Chase Machine and Engineering
The latest news from Chase Machine and Engineering is the launch of the OTA, the newest product in its ultrasonic sealing family. Designed for maximum access for tough to handle, three-dimensional shaped products, the OTA—an acronym from the sewing industry meaning Off The Arm—offers end users full visibility and control of the product being welded. The extended post provides mounting features for custom folders, guides or any other device that aid in positioning the product prior to welding.

Over the years, Chase has received customer inquiries asking if there was a way to continuously weld three-dimensional shapes such as cube filters, pleated filters or the perimeter of round, cylindrical products, according to Chase’s Guy Gil. The company did not have the right solution until it developed the OTA Ultrasonic sealer. With this technology, pillows, safety and ballistic vests, face masks and medical gowns can also be welded.

Recently, Chase has also had the opportunity to integrate ultrasonics that perform both continuous and plunge welding in the same production line. “The challenge being that when ultrasonically plunge welding, the product must stop, but when joining with a continuous upstream process, the incoming web must be stored in an accumulator in order to provide enough time to plunge weld the product and index out of the way,” Gil says. “Fortunately, with Chase’s experience with web handling and tension control, we were able to design and build a system that satisfied this requirement.”

According to Gil, ultrasonics is a technology that has become more and more accepted as time passes. “Raw material suppliers understand the benefits of ultrasonics and often construct their materials with bicomponent fibers so the end user may join nonwovens with this technology, thus eliminating the need for consumables such as adhesives, needle and thread or mechanical crimping devices,” he says.

Gil is optimistic about growth for ultrasonic technology in the nonwovens industry. “Everyday there is a new opportunity in the nonwovens industry as customers design and fabricate new to the world products that require safe, clean and inexpensive means to join, laminate or emboss materials. It is truly amazing how nonwovens have become part of our everyday lives, whether it be a nurse or doctor preparing for a surgery, a painter stepping into a paint suit or even sitting down for a nice meal and draping a soft nonwoven napkin across your lap. Nonwovens have truly changed the way products are made for the better,” he says.

Emerson
Emerson, headquartered in St. Louis, MO, is a global technology and engineering company providing solutions for customers in industrial, commercial, and residential markets. Its Emerson Automation Solutions business helps process, hybrid, and discrete manufacturers maximize production, protect personnel and the environment while optimizing their energy and operating costs.

Under its Automation Solutions business Emerson offers ultrasonic equipment under the Branson brand. Branson ultrasonic products can slit, bond, seal or quilt nonwoven synthetic materials to meet a wide range of medical and non-medical application requirements. Medical applications include surgical face masks, face shields, disposable hygiene products, gowns and filter media, while non-medical uses for the technology include consumer and personal care products, baby diapers and training pants, mattress pads, seat cushions and covers, household mops and cleaning products, disposable vacuum and filter bags, and more.    

According to Emerson’s Julia Daniel, the largest source of growth recently has been in the medical industry. “Because ultrasonic technology produces strong, repeatable seams and joints, withstands sterilization processes, and eliminates the need for solvents or glues, it not only solves medical nonwoven and device manufacturing problems, but does so while reducing the risks and sources of potential contamination,” she explains.

New opportunities for ultrasonics in the nonwovens industry are everywhere, Daniel says, driven in the short term as manufacturers learn more about the value and versatility of this process, and in the longer term by changing demographics. “As the number of older citizens in the U.S. and many western countries continues to grow as a share of total population, the demand for medical, sanitary, consumer care, bedding, seating, cleaning, and filtration products will only continue to grow. So too will the need to produce these products efficiently, with maximum cleanliness and minimum risk of contamination,” she notes.

Ultrasonics offers the perfect solution to this growing need because of the equipment’s’ unique ability to handle a broad scope of nonwoven product manufacturing, including slitting, cutting, embossing, quilting and bonding.

Also, Branson ultrasonics technology can meet clean room manufacturing requirements, where required, and provide the data monitoring and storage capabilities needed to meet the highest regulatory requirements. “These and other ultrasonics capabilities will only continue to evolve and expand in the future,” Daniel says. 

One major improvement from Emerson, relevant to customer needs for continuous improvement in quality control, is its ability to monitor and record weld data in real time, even in automated lines.

Another recent advancement from the company is the availability of Fieldbus capabilities in Branson’s DCX F welding system, which allow multiple welding systems to connect to each other and communicate directly with a PLC. “With Fieldbus, the user can control not only the weld parameters for individual ultrasonic welders, but monitor the status of a multi-welder production system,” Daniel says.

Herrmann Ultrasonics
Herrmann Ultrasonics continues to see hygiene applications show a high interest in ultrasonic technology. The company’s four different global headquarters—in Karlsbad, Germany; Bartlett, IL, U.S.; Taicang, Jiangsu Province, China; and Kashiwa, Chiba Prefecture, Japan—continue to develop and test new applications like ears, elastic laminations and constructions, ADL, core, TXBS and more.

According to Steve Bellavia, director Nonwovens, Herrmann Ultrasonics has been at the forefront of pushing sustainability in the industry with its ultrasonic technology making glue free diapers possible. “We are always working with material suppliers, end users and OEMS to advance processes and technology to ensure a green future. We see a big drive to reduce the carbon footprint and make absorbent products more recyclable,” he says.

Further supporting sustainability are applications with elastic entrapment and stretch paneling, creating glue free diapers. “End users and OEM’s persist to eliminate adhesives,” says Bellavia. “They turn to ultrasonics as a solution due to the high residual costs of running adhesive production and a significant reduction in machine downtime.”
Herrmann will be spreading the ultrasonic excitement at IDEA 2019, where sustainability and the push to develop natural diapers will continue to be hot topics.

Other industries such as filter, textile and medical are turning to ultrasonics because similar advantages and benefits are realized.

Most recently, Herrmann has introduced a new control system for its Microbond systems. It allows for real time (1µs) detection of material and environmental variations, then compensates for deviations, and maintains repeatable bond quality. Parameters can be viewed and analyzed through the intuitive handheld touch display, which also allows for control of multiple actuators at the same time. “Listening to our customers’ needs and wants has led Herrmann to offer different variants of actuators for blade and rotary style systems, making new applications in limited machine space possible,” Bellavia says.

Other news from Herrmann is the expansion of its headquarters facilities, doubling the production size in Karlsbad, which will allow the company to serve the nonwovens market more efficiently. “The technical team successfully expanded our offerings for feasibility studies through the acquisition of new tooling, used for applications in the disposable goods industry,” he concludes. 

Sonobond Ultrasonics
Sonobond Ultrasonics offers a wide variety of ultrasonic rotary sewing machines, plunge welders, rotary cutters and hand cutters, in both stand-alone models and modular units that can be integrated into production lines. In addition to 500 standard pattern wheels, Sonobond can make custom tooling to achieve a customer’s specific application needs.

One new application using Sonobond technology is in the medical industry. The company’s machines work to ultrasonically assemble pouches that are used to hold medical and/or dental instruments as they go through their sterilization process, as well as to protect them while they are subsequently stored and/or transported for future use. “Our SeamMaster Ultrasonic Sewing Machines are typically used to seal the pouch edges with a strong, durable bond that can withstand the high temperatures of sterilization,” says Janet Devine, president of Sonobond.

Another new application for the company is in the industrial/cleanroom market. SeamMaster Ultrasonic Sewing Machines are also used to cut and seal the edges of special certified 99% lint free cleaning wipes, thereby eliminating any lint or particles which could cause problems with motors, sensitive devices or vehicles being prepped prior to priming or painting.

In addition to these areas, Sonobond technology is used for filters and filtration products, which is one of the company’s largest application areas. Its ultrasonic technology can bond fabrics that are 100% synthetic or blends that contain up to 40% natural fibers. HEPA, pleated, box style, heavy-duty industrial liquid and chemical filter bags, automotive air and oil filters, and vacuum bags can be assembled with Sonobond’s technology.

Medical disposables are another large application area for the company. This includes surgical gowns, caps, facemasks and booties, lint-free wound dressings, and mattress covers. “Our machines’ high-frequency vibratory waves produce the sealed edges and secure seams without stitch holes, glue gaps, fraying or unraveling, thereby meeting OSHA’s tough regulatory requirements for barrier seams,” Devine says.

Sonobond’s SeamMaster Ultrasonic Sewing Machines operate like a traditional rotary sewing machine but produce soft, smooth seams that are impervious to moisture or fluids.

One application Devine considers a growing area for ultrasonics is for the assembly of body armor. Sonobond machines satisfy National Institute of Justice (NIJ) standards requiring body armor to be waterproof, even after submersion for 30 minutes. “Bulletproof materials contained in ballistic vests lose their life-saving effectiveness when exposed to water, so it’s imperative that the seams in the outer nylon shell are perfectly fused,” she says. “Both our SeamMaster – High Profile model – and our SureWeld Plunge Bonder reduce any risk of water or moisture damage to the ballistics materials inside the shell.”

Automotive door panels and insulation “blankets” used on aircraft are two applications also increasing their use of ultrasonic assembly machinery, according to Devine.

“Ultrasonic technology is ideally suited for nonwovens,” she says. “Cutting, trimming, edge-sealing, and seaming is faster and often cheaper than sewing or gluing. So, we anticipate contributing to pretty much any new nonwoven-based product assembly.”