Ballistic vestSonobond’s SeamMaster™ High Profile Ultrasonic Bonder is regularly used for sealing the inner shell that protects the ballistic-resistant material inside the vests.  The unit’s rotary system seals, sews, and trims the nylon fabric in one quick, reliable step that uses no thread or other consumables.

Manufacturers also rely on another Sonobond unit, the SureWeld™ 20 Ultrasonic PlungeBonder™ with custom tooling, to ultrasonically bond straps within the seam of the vest’s inner shell.  This is a separate operation that does not compromise the integrity of the ultrasonically sealed inner shell.

Ultrasonic Bonding Procedure 

Sonobond machines use ultrasonic energy to reliably seam and seal synthetic materials in just one pass.  This is accomplished without stitching, heat-sealing, or adhesives. 

SureWeld 20 Ultrasonic PlungeBonderIn the case of the SureWeld™ 20 Ultrasonic PlungeBonder™, the inner shell material and the strap are placed between the unit’s customized horn and anvil.  The anvil is surrounded by a Plexiglass plate that supports the materials.  High frequency vibrations are then channeled to the materials to create a localized buildup of heat.  This seals the materials without heating the surrounding area.  The ultrasonic bonding process is fast, energy-efficient, environmentally-friendly, and produces high-quality results.  In commenting on this added capability. The new tooling for the SureWeld™ 20 is yet another example of our support for an industry that delivers important protection to police officers and military personnel.  We are very pleased that this machine can now be customized to bond straps to the front and the back sections of a ballistic vest’s inner shell.  Velcro® can then be attached to the straps and used to connect both sides of the vest. 

The SureWeld™ 20 Ultrasonic PlungeBonder™ with customized tooling can comfortably attach straps to five vests per minute.   

Versatile Machines 

Both the SeamMaster™ High Profile Ultrasonic Bonder and the SureWeld™ 20 Ultrasonic PlungeBonder™ are easy to operate with only minimal training. 

Sonobond’s SeamMaster™ High Profile Ultrasonic Bonder—the unit used to seal the inner shell of body armor—is a versatile, general-purpose machine that features a large pattern wheel and a higher clearance.  This makes it ideal for handling bulky materials, as well as for hand-guided operations.  The unit virtually eliminates fraying or unraveling of bonded edges and seams.  Also available as a modular unit, the SeamMaster™ High Profile Ultrasonic Bonder can be easily integrated into production lines.

Sonobond’s SureWeld™ 20 Ultrasonic PlungeBonder™ is a powerful machine that seals large, multiple-layer or difficult-to-bond materials with just one  pulse.  The machine consists of a rugged welding press and a heavy-duty 1000- to 1500-watt power supply.  The unit’s rigid rectangular support column eliminates deflection, even at the full 660 lb. force level.  It also has a built-in leveling feature in the base with “T” slot and toe clamps for reliable fixture holding.  This bonder permits easy changeover of the converter/booster/horn simply by loosening the bolt and opening the cover to remove or replace the component. 

Sonobond: A Leader in Ultrasonic Technology 

Sonobond is a worldwide leader in the application of ultrasonic welding and bonding technology.  Over its 60+ years of operation, Sonobond has earned an outstanding reputation for its pioneering work and quality-engineered products.  Today, the company manufactures a complete line of ultrasonic welding and bonding equipment for a wide variety of customers in the body armor, filtration, medical, apparel, automotive, appliance, electrical, HVAC, and aerospace industries.  Sonobond’s engineers and sales personnel work closely with customers to find the optimal solution for each company’s requirements.  We are committed to providing exceptional technical support and superior service before, during, and after installation. 

Additional Information 

For more information about the SeamMaster™ High Profile Ultrasonic Bonder and the SureWeld™ 20 Ultrasonic PlungeBonder™—as well as to learn  about the company’s free, no obligation Ultrasonic Bonding Viability Test—visit  Sonobond website at or call 800-323-1269. You can also contact Sonobond’s president, Janet Devine at JThis email address is being protected from spambots. You need JavaScript enabled to view it.

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