Raw material changes in nonwovens, breathable films and other substrate types used in disposable hygiene products are leading to design challenges within the industry. Because standard adhesives sometimes won’t work well with certain films or monopolymer nonwovens, designers need to look elsewhere for construction help and ultrasonics technology is coming to the rescue. Additionally, this technology offers a more eco-friendly end product as well as cost savings and flexibility.

Last year, Japanese diaper maker Unicharm announced it had incorporated ultrasonics in to the design of its latest Lifree Ultra Slim Comfort Pants.  These pants, which are part of the best-selling adult incontinence care brand “LIFREE,” feature the adoption of ultrasonic bonding technology in the waist area, allowing for easy lifting with minimal effort to provide a comfortable fit. This improvement also enhances compression rate and loading efficiency, improving delivery efficiency, thereby reducing the environmental impact. Additionally, by reducing the amount of hot melt adhesives used in the conventional bonding process, the pants become easier to recycle, contributing to the realization of a circular economy-oriented product design.

According to experts, reducing the use of adhesives and other materials in the diapers has been achieved through the use of ultrasonics technology, which can lead to significant savings in cost and production times.

“Forgoing the use of adhesives can offer a significant savings in dollars especially when it comes to wider panels where you need to use a lot of adhesives. In nonwovens, materials are changing and the use of breathable films or nonwovens made from monopolymers create issues with some heat sealing processes,” says Pat McNichols, director of applications and rotary systems, Dukane Technologies.

Dukane is working with end users and OEMS to develop the entire hygiene product without the use of adhesives, which is the goal of several of its customers in the hygiene part of our segment. Ultrasonics provide a more consistent means to do that.

“A lot of the people coming to us are having issues with their current technologies as their material changes are happening,” McNichols adds. “We are working with them to help incorporate  ultrasonics that allow them to run lines at the rates they want to and not be hindered by material changes.”

Within the nonwovens industry in general, Dukane has been working for several years on new solutions for hygiene applications and related industries. Its elastic entrapment process, which has been in development since 2015, can create elasticized panels on products like adult care items and diapers. Instead of using adhesives, the elastic is entrapped in the panels using ultraonics technology.

Another innovation is the  Optibonder, a state-of-the-art ultrasonic bonding system that offers unparalleled precision, ease of integration and sustainability for nonwoven applications. The Optibonder combines Dukane’s proprietary Active Force Control (AFC) technology with a high-performance servo actuator, enabling manufacturers with industry-leading control of frequency, amplitude, force and position.

Designed with a compact footprint, the Optibonder easily integrates into existing or new production lines, making it an ideal solution for manufacturers looking to replace outdated bonding methods. The system’s intuitive user interface, powered by Dukane’s iQLinQ software, enables seamless automation and provides complete control over parameters, including frequency, amplitude, force, and position, ensuring 6-sigma quality levels..

Dukane has also developed a new design combining technologies in a hygiene products to create a backsheeet laminate without adhesives, instead entrapping the elastics on the edge of the material. “This is what we call the backsheet laminate and we selling it into the hygiene market,” McNichols says. “It offers a big savings on adhesives and all the baggage that comes with the use of adhesives.”

McNichols adds he expects to see ultrasonics continue their expansion in the hygiene market, especially with the entrapment technology. “If you look at patents being written for elastics entrapment, everyone is trying to make that happen,” he says. “It is a very challenging application to do and we have mastered it to the point where its functioning well and customers are happy.”

“A lot of the people coming to us are having issues with their current technologies as their material changes are happening. Working with them to help them by integrating ultrasonics that allow them to run this at the rates they want to and not be hindered by material changes.”

Herrmann Ultrasonics’ Microbond CSI/RS joins nonwoven materials using ultrasonics in a more economical and efficient manner. From the first start-up, the weld process controller achieves perfect joints even at the highest product speeds. Its latest development, the Microbond CSI/RS G4, is flexible enough to react to changes and modifications in order to immediately reproduce the desired weld result. This reduces the reject rate to a minimum and consistent quality is ensured even at the highest production speeds.

According to Christoph Schillenhardt, content marketing, legal regulations within the European Union as well as consumer demand are creating a need for products made via a more eco-friendly process and with as few chemicals as possible. Ultrasonic bonding allows this in a cost efficient and flexible fashion.

“We can see up to 90 % less operational costs with ultrasonic bonding, because the technology doesn’t require adhesives,” he says. “This saves resources, space for storing the adhesives, downtime (since no adhesive modules need to be cleaned), energy consumption and transportation costs. It also offers digital quality control and a reliable process.”

Cross Seam Applications Replace Tapes and Adhesives.

MS Ultrasonics sees increased demand for ultrasonics technology in markets like pants-style diapers and incontinence products where ultrasonic sealing replaces the use of tapes and adhesives. The company continues to work on cross seam applications for baby pants and incontinence products, according to Christian Unser, head of nonwovens sales. Special features of these projects are a soft seam and speed greater than 300 meters per minute.

“As the age and number of older people increases, incontinence products will become even more important and the demand for comfort, softness and discretion is also particularly strong in this market,”  Unser says. “Meanwhile, in the baby care areas, pants-type increasing in popularity among parents, which is reflected in the sizes and quantities required. An ultrasonically sealed diaper is much softer, does not rustle, is less bulky and reduces the size of the packaging.

Beyond hygiene, areas of interest for MS Ultrasonics’ technology include wound care, packaging applications and filtration.”

With the MS sonxSYS COMBINE ultrasonic system, MS Ultraschall Technologie GmbH offers everything from a single source: ultrasonic, control technology, mechanical engineering and engraving rollers, robust mechanical engineering and high process speeds. Whether new production systems or the replacement of existing systems or outdated technologies in existing systems, the customer benefits from over 30 years of experience in the development and manufacture of high-quality and innovative ultrasonic components and machines.

Ultrasonic Welding Remains Popular in Hygiene

Ultrasonic welding for textiles is a process that uses high-frequency sound waves to bond layers of fabric without the need for adhesives or sewing, according to Sonobond Ultrasonics. This process creates strong, durable bonds, resulting in more reliable, leak-proof hygiene products like diapers, sanitary pads, and medical garments. The absence of chemicals and adhesives reduces the risk of contamination and skin irritation, improving product safety, particularly for sensitive skin, and the speed reduces production time, enabling faster manufacturing and more cost-efficient production of hygiene items. 

In essence, ultrasonic technology has streamlined manufacturing processes, boosted product performance, and elevated hygiene standards, making it a key innovation in the hygiene industry.

According to Sara Karmilowicz, business development representative, in recent years, ultrasonic technology has evolved significantly, becoming faster, more efficient, and precise, with improved control over welding parameters. Advances have enabled the integration of ultrasonic systems into smaller, more flexible designs, allowing for the production of intricate, multi-layered hygiene products like diapers and sanitary pads. The technology has also become more energy-efficient and eco-friendly, eliminating the need for adhesives and chemicals. Furthermore, its versatility in handling various materials and integration with automation has enhanced manufacturing speed, consistency, and scalability, transforming the hygiene industry by improving product quality, sustainability, and cost-effectiveness.

“In the hygiene industry, ultrasonic technology enhances product design by enabling seamless, precise bonding without the need for stitching or adhesives, resulting in cleaner, smoother products with no visible seams,” she adds. “It allows for the use of diverse materials, such as nonwoven fabrics and foams, to be integrated into a single product for improved comfort and performance. Ultrasonics also enable the creation of lightweight, thin structures that maintain strength and durability, ensuring long-lasting and comfortable wear.”

With the ability to produce intricate designs and complex patterns, ultrasonic welding contributes to advanced product features like better leak resistance and enhanced functionality.

Additionally, the eco-friendly nature of ultrasonic bonding eliminates the need for harmful chemicals, supporting more sustainable hygiene product designs.

Sonobond’s SeamMaster, which is its most popular technology for hygiene products, continues to be as  innovative as the day it was introduced to the market. We offer a range of equipment from handheld to freestanding units, and can offer integration services for fully custom production lines.