Technical advances in the hygiene, packaging and converting industries have led to a variety of options for the bonding, sealing and welding of nonwoven textiles, plastic packaging film and other materials. Understanding the benefits and drawbacks of each technology can help you make the right choice for your application. This article compares rotary and stationary ultrasonic with hot melt adhesive, thermal and compression welding solutions.
Each application has its own characteristics to consider when comparing these technologies. This could include ease of deployment, composition of materials being bonded, consumer preferences for the end product, production cost, process control and sustainability. Additionally, some applications must also consider FDA / USDA requirements, storage and heat tolerances of package contents, consumer preferences for re-opening a sealed package and cleanliness of the production area.
Key points of comparison shown in the table and addressed in more detail below include technical capability, quality of the bond, start up time and production speed, product damage, cost, process control, end user concerns and sustainability.
Technical Capability – Capability is impacted by composition of the materials being bonded. Ultrasonics is only applicable to certain plastics and nonwoven blends.
Quality of Bond – Excellent; providing all parameters are correct.
Start Up Time – Very short
Production Speed – Increases production line efficiency; can increase your process uptime while lowering your process waste, robust to process and web upsets such as substrate splices, elastic splices, machine stop/start events.
Product Damage – Minimal, no adhesive bleed-through, no heat damage
Cost – Ultrasonic technology carries a higher initial cost than the others, but makes up for it with savings on costly adhesive materials, complex adhesive delivery systems, labor and materials (it allows you to utilize lower cost nonwoven materials or film substrates).
Process Control – Enables customized aesthetics, Can utilize lighter weight elastic materials without compromising performance, and eliminates adhesive creep
End User Concerns – Improves product comfort and performance; maximizes elastic performance; maximizes fabric softness; eliminates the stiffening effect of adhesive; size, shape of gathers customizable
Sustainability – Lower energy cost than thermal solutions; cleaner technology than hot melt adhesive solutions.
Technical Capability – Adhesive processes offer the most substrate flexibility.
Quality of Bond – Usually very good; although there are some instances when the adhesive breaks down due to oils or temperature of the surrounding area.
Start Up Time – Process delay associated with system heat-up/cool-down cycles
Cost – Higher system energy costs; high cost of raw materials usage, storage, handling, and transportation
Process Control – Process delay to clean adhesives from process equipment due to overspray, bleed-through, etc.; spray limitations / challenges with high-speed, intermittent processes; waste issues because the lines are full of adhesive between startup and shut down events; safety concerns because of high temperature raw materials, applicators, hoses, pumps, and melters.
End User Concerns – Adhesives can cause stiffness and discomfort.
Sustainability – Adhesives are the least sustainable option listed mostly due to difficulties recycling complex chemicals.
Technical Capability – Capability is impacted by material properties but often requires a sealant layer
Quality of Bond – Usually very good; although there are some instances when it causes degradation of material outside bond zone
Start Up Time – Process delay associated with system heat-up/cool-down cycles
Production Speed – External application of heat can reduce speed capability
Product Damage – Potential product damage due to over-exposure to heat
Cost – Higher system energy costs
Process Control – Safety considerations due to high temperature equipment
End User Concerns – Degradation of material, speed capabilities
Sustainability– More sustainable option than hot melt adhesive option due to the fact that there are no raw materials added to the process.
Compression / Pressure Welding
Technical Capability – Capability impacted by material properties
Quality of Bond – Dependent on speed of process
Start Up Time – Starts immediately, but getting up to speed can take time
Production Speed – Best when operating at high speed
Product Damage – Similar to ultrasonics, no heat damage, but could have adhesive bleed through when adhesive is added to the process
Cost – lowest per code; often requires grade specific parts
Process Control – Can be a high-wear process; Waste and variability due to speed-dependent attachment strengths—at times an added adhesive system is used to overcome these limitations
End User Concerns – Grade change flexibility
Sustainability – High, unless adhesives are required to enhance low speed capabilities.
Aurizon Ultrasonics manufactures rotary ultrasonic equipment used in various industries to bond, attach, emboss and laminate thermoplastic materials. Our rotary ultrasonic systems offer a number of features and benefits over hot melt adhesive applications and thermal bonding, such as material savings, energy savings, sustainability benefits and increased process speeds.
At Pack Expo 2016, Aurizon will be introducing our Soniseal™ 40 UL series of rotary ultrasonic bonders. These systems offer maximum seal consistency and control in a high speed package and are designed specifically for flow wrapper, VFFS and HFFS machinery. In addition to an increased capacity for sealing through residual product due to the rotary action of the sonotrode, the 40 UL has the ability to achieve both continuous motion and intermittent motion sealing for maximum process flexibility.
Aurizon Ultrasonics designs and manufactures high-power rotary ultrasonic systems that are optimally designed for vertical and horizontal package sealing as well as other packaging-related applications. Our patented technology and process experience provides a solid foundation for delivering novel solutions to industrial challenges, and our spirit of innovation and dedication to technology development motivates us as we develop custom solutions.
This week, Aurizon is introducing our Adhesive Savings Calculator at Hygienix 2016 in Orlando, FL. We welcome you to stop by our tabletop display to learn more about the benefits of rotary ultrasonic bonders, including:
Personal care and hygiene products often use elastic strands secured in nonwovens to prevent leakage or improve fit. Many manufacturers secure these elastics with adhesives; however, adhesives have several drawbacks. Adhesive is expensive, the delivery systems are costly to maintain, overspray and strike-through cause machine delay and reduce elastic performance. In addition to all of the above, adhesives are not environmentally friendly.
Aurizon Ultrasonics’ Adhesive Free Elastic Entrapment solution does not require adhesive to secure the elastic strands; thus when you add this system to your process, the cost of the adhesive product is immediately eliminated. In order to estimate an accurate amount of savings over a period of time, Aurizon technical specialists have created the Adhesive Savings Calculator.
The calculator estimates “adhesive cost” savings. However, the amount saved from eliminating adhesives is only a fraction of the total savings that can be acquired when changing processes. Other benefits gained as a result of switching to ultrasonic technology includes increased operational efficiency, material cost savings and improved product comfort and performance.
Increased Operational Efficiency – By eliminating the cost of operating and maintaining the glue applicator equipment, labor and utility costs will decrease. Adhesive application processes require a significant amount of maintenance, expensive spare parts and labor to maintain. Adhesive overspray and strikethrough require the converting line to be stopped regularly for cleaning. Each delay event results in lost production time and creates a waste stream shutting down and starting up.
Material Cost Savings – Ultrasonic technology provides the option of purchasing less expensive, lighter weight nonwoven materials and elastics because there is no need to worry about adhesive bleed-through or loss of elastic performance due to the stiffening effect of adhesive.
Improved Product Comfort and Performance – Not only does eliminating glue maximize fabric softness; Aurizon’s ultrasonic entrapment technology provides extension and retraction curves close to non-attached elastic strands, maximizing performance of the elastic.
The adhesive savings calculator estimates the savings incurred by no longer purchasing glue for your elastic entrapment process. Below is a list of parameters you need to know to calculate your savings.
Adhesive Application Rate – This is the rate at which your adhesive is applied to the elastic; measured in milligrams of adhesive per meter of elastic.
Product Length – This is the length of the portion of your product that has elastic applied (in millimeters).
Number of Strands – The number of strands in the adhesive panel.
Number of Panels – The number of elastic panels per product.
Production Rate – The number of products produced per minute.
At this point the calculator will provide your total glue consumption per hour in kilograms. Once you insert the number of hours of production per day, you will have your total glue consumption per day.
Cost of Glue – The cost of glue in USD (US Dollar) per kilogram. If you need to convert your currency, Google has a simple calculator here.
Cost of Entrapment System – This cost can vary greatly. Please contact us to help you accurately define the cost of an elastic entrapment system for your application.
Days– The number of days in which to determine ROI, typically 365.
We think that removing glue from your elastic process not only results in significant savings when making hygiene products, but also helps you to produce a softer product with an improved fit. If you have any questions about using the calculator or would like to speak to us further about the Adhesive Free Elastic Entrapment solution, please contact Dan Sorensen at [email protected] or (+1) 920-750-5087.
This chart shows how many weeks horns can last before they need to be refurbished.
The technical experts at Aurizon Ultrasonics have invested many years and millions of dollars in rotary ultrasonic research and development—including advanced acoustic tool (sonotrode) modeling, fabrication and analysis. In our rotary bonders, the sonotrode (horn) delivers the ultrasonic motion radially around the disc circumference to the material being processed.
Aurizon has a tremendous variety of horns; a select few shown above.
Some of that research and development has paid off in the understanding of what can be done from a design standpoint to extend the life of the horn. We have designed the pattern placement on many of our anvils so that they evenly distribute wear across the width of the horn. We also offer bonders with independent drives that optimize the speed relationship between the horn and anvil, which can maximize the duty cycle of the horn.
How long will a horn last?
Horn life is based on the application and the materials being bonded, which can vary greatly. It is important to know what to expect in regards to the service life of the horn in a bonder so that you can determine its return on investment and create a maintenance schedule that minimizes production delay.
How will I know when the horn needs resurfacing?
Substantial wear does not always affect the performance of the horn. A horn that looks abused can still function, so rather than err on the side of resurfacing too soon, you should make sure that it actually needs to be done before going forward. Our experienced team can help you define your evaluation protocol so that you can determine when a horn needs to be resurfaced. In addition, we will work with you to develop a maintenance plan to take care of this valuable asset.
What factors influence horn wear?
The three main factors that impact horn life are metallurgy, material type and the environment in which the horn is operating.
Metallurgy—Aurizon has its titanium source material manufactured to a specific proprietary recipe. Over the years, we have developed a manufacturing process that minimizes variability in our horns. Likewise, depending on your application, we may suggest a steel horn, which has a very long lifespan in certain situations.
Material type–The materials being processed unquestionably affect the life of the horn. Not surprisingly, heavy and/or bulky materials positively influence horn life by creating a buffer between the horn and anvil that minimizes wear; resulting in longer horn life. Meanwhile, thinner material does not allow the same protection and may have the opposite effect on the life of the horn.
Operating environment—The environment in which the horn is operating can range from benign to very aggressive based on application needs, directly influencing wear life of the horn.
What is Aurizon’s process for resurfacing a horn?
Most horns can be resurfaced several times. Aurizon can provide this service for you or, if you would prefer, our technical specialists can train your people to develop the in-house capability to refurbish your horn.
Aurizon’s rotary ultrasonic bonding machines are composed of several basic components and sub-components. (Actual system components may differ depending on the application it was designed for.) Stack Assembly The stack assembly consists of a converter, drive booster and a rotary ultrasonic horn (sonotrode) along with its vibration isolation/mounting flange. All of these components […]
When the decision has been made to change an industrial process, it was likely driven by a particular factor such as:
Desire for improved economics
Improved material performance
Competitive pressure from other businesses
Reduced machine delay frequency
Reduced delay duration
Ultrasonic technology can provide multiple positive returns, such as material and energy savings, sustainability benefits and increased process speeds. However, there are several things you should think about when considering making the switch from using adhesive or heat sealing processes to using ultrasonic technology.
Why should you consider using ultrasonic technology in an established process?
Ultrasonic technology has several benefits that can affect future production including improved overall production line efficiency, less down time, lowered process waste, more effective bonding through varying thicknesses or layers and the possibility of faster process speeds.
For packaging applications, ultrasonic technology can offer a reduction in materials due to narrower seals and smaller fin sizes and the ability to seal through residual product.
In hygiene applications, ultrasonics enables the use of lighter weight materials (which are often lower cost), improved fabric performance, elimination of adhesive and adhesive delivery systems.
All applications report that their experience includes reduced machine maintenance which includes less down time and higher productivity. In addition, those who have replaced heat sealing processes experience reduced energy consumption with low wattage ultrasonic processes. This can result in a substantial savings in production costs and reduction of utility costs.
Will ultrasonic technology bond your materials?
Ultrasonic bonding is generated by molecular friction within material placed between an acoustical device (horn) and an anvil (energy guide). The horn is tuned to a specific frequency, which excites the molecules, resulting in the temperature within the material rising, flowing together and creating a bond. Ultrasonic technology works well with thermoplastic films and nonwoven materials. Each material has different physical properties, which may necessitate some experimentation before answering the question of feasibility. For that reason, Aurizon Ultrasonics has pilot facilities set up to provide initial testing that can help you determine if rotary ultrasonic technology can add value to your application.
Which ultrasonic process design is most suitable for your process?
Once you have decided that ultrasonic technology is right for your application, you will need to choose between a rotary ultrasonic system and a stationary or blade ultrasonic system. There are some applications that will have an obvious solution, but most of the time, you will have to consider both avenues to understand which route will be most beneficial. See Choosing a Rotary or Blade System for your Application for more information.
Is retrofit possible or will this change necessitate the design of a new process?
Evaluation of the suitability of your chosen process should begin with a current operating cost diagram and an estimation of the value of the existing system as is. This base value can then be compared to the estimated cost of any new process alternatives. Simulation modeling can give you an idea of future operating costs. Each process will offer its own benefits and limitations that need to be examined as well.
The appeal of designing a new process is that the new system can take into consideration all parameters that will affect the ultrasonic processing such as speed, amplitude of vibration, static contact pressure and the design can optimize these factors. This can be cost-prohibitive, in which case a retrofit may be more fitting.
The appeal of retrofitting your machine is that the existing system will remain in place and there will be less disruption in implementing the change. That being said, if there are other problematic variables in the process, they should be addressed with the change. Even with the retrofit option, the design of a new process brings with it many more decisions to be made.
While Aurizon Ultrasonics has extensive experience retrofitting machines into existing processes, because of the custom nature of each individual application, the methodology will be different with each situation. Aurizon’s technical experts can consult with you to help determine the magnitude of the effort ahead; and after purchase of a machine, support you through each stage of implementation.
What is the return on investment (ROI)?
Making the switch to ultrasonic technology will require some amount of capital investment. Both the investment amount and the ROI will vary according to your circumstances; however, our experience shows that most customers see one hundred percent ROI within 6-18 months.
The Aurizon team has conceived and developed their high-powered rotary ultrasonic technology over the course of 30 years and is vastly experienced with process development, process integration, training, service and support of ultrasonic systems in commercial production environments. We are committed to listening to you and working with you to find a viable alternative that addresses your particular challenges. Contact us to discuss your application, materials and how we can help assess the capability of our technology in relation to your requirements.
Ultrasonic technology is offering new potential across various industries including cutting, bonding, sealing, embossing, elastic entrapment and countless other custom applications. Manufacturers are employing ultrasonic technology to bond various types of materials together without using adhesives or heat sealing. Ultrasonic processes are particularly effective on nonwoven laminates and other plastic films. Making the switch to ultrasonic technology can provide increased productivity and sustainability, reduced operating costs and enable new capabilities in your industrial applications.
Once you have made the decision to apply this technology to your application, you will need to choose between a rotary ultrasonic system and a stationary or blade ultrasonic system. There are some applications that will have an obvious solution, but most of the time, you will have to consider both avenues to understand which route will be most beneficial.
Rotary ultrasonic technology can offer a number of valuable advantages to your industrial processes.
The following are some variables to consider when looking at your options for taking advantage of this leading technology.
What kind of process are you running?
Rotary systems work well in both intermittent and continuous processes while the blade systems are more suitable for intermittent systems. Rotary horns also provide higher continuous power delivery and more uniform horn amplitude. More power means faster, more consistent sealing and more uniformity delivers higher, more consistent and efficient seal performance.
Are you having mechanical problems with your current process?
Sometimes with stationary or blade systems, there is danger of component failure due to metal contact. The rotational action in rotary systems deflects the force response rather than sending a shock wave directly back into the converter, causing less vibration and greatly reducing the risk of failure. Not only does this feature allow for faster process speeds and greater consistency than stationary systems can offer, it also means less downtime, higher productivity and lower repair cost.
What kind of material are you working with?
One of the key advantages of the rotary horn is the ability to achieve very high amplitudes and operate in contact with other surfaces (patterned steel anvils) without catastrophic failure of the horn or converter—as mentioned above. This characteristic is especially valuable for the processing of extremely thin materials since the horn and anvil is able to operate in contact mode and generate the forces required for high speed bonding of lightweight materials.
Do you have varying thicknesses in the seal zone?
All types of ultrasonic technology can offer improved process speeds, the ability to seal through residual product and the ability to bond through varying thicknesses and layers. However, the rolling contact from a rotary horn enables better sealing over varying material thicknesses like seams and gussets because of the inertia possessed by the system. This can directly lead to less product failures, less waste and more effective seals.
How wide is your cross-directional bond or seal?
The orange line shows the potential width of the cross directional bond in a blade system as compared to a rotary system.
Another thought-provoking comparison of these technologies is that of potential cross-directional bond width. In a stationary or blade system, the seal width is limited by the width of the horn blade, but in a rotary system, the horn can travel across the web and is only limited by the design of the process configuration.
Would you like to test your materials?
Rotary ultrasonic technology has been custom engineered, developed and implemented on hundreds of bonding, sealing and converting applications. Aurizon Ultrasonics works with customers around the world to deliver rotary ultrasonic solutions that address your particular process. Our patented technology provides a solid foundation for delivering cutting-edge products and processes. We will strive to gain a thorough understanding of your needs and consider key parameters such as horn metallurgy, acoustic design, component fabrication and system engineering.
Contact us with your ideas or challenges and we will determine if we can develop a customized solution to meet your requirements.
Aurizon Ultrasonics is at Booth #2008 at Expo Pack in Mexico City from May 17th-20th. With more than 30 years of experience in research and manufacturing of high-power ultrasonic technology, our team is committed to partnering with our customers in a way that delivers cutting-edge products and processes. Our patented technology provides a solid foundation delivering never-before-seen impact, and our spirit of innovation and dedication to technology development will continue to guide us as we develop new solutions to meet the needs of our customers. Come talk with us!
Stop by booth #1217 at IDEA 2016 from May 3-5 and learn about Aurizon Ultrasonics’ breakthrough technology for elastic attachment with NO GLUE! Our Adhesive Free Elastic Entrapment solution is an environmentally friendly process that eliminates adhesives and allows for the use of lighter weight materials. This innovative method using rotary ultrasonic technology will change the paradigm in consumer product converting because of the many advantages it provides. See you at the show!