Plastics Processing with Ultrasonics, Part II

This is the second part of a two-part article that takes a look at some recent developments in the use of ultrasonics in plastics processing, where the technology can provide tantalizingly precise and cost-effective alternatives to more traditional welding, trimming and sealing techniques.

Bullet-proof technology

Sonobond Ultrasonics claims that more than 30 leading manufacturers now use its ultrasonic technology to assemble their ballistic vests.


Instead of needles, thread or glue, Sonobond’s equipment uses ultrasonic energy to create strong molecular bonds within body-armor materials, resulting in durable, perfectly sealed seams without stitch holes, glue gaps, fraying or unraveling. Sealed seams mean better protection for the bullet-proof materials contained in the vest – such as Spectra-Shield® and Kevlar® – ensuring that they are less likely to lose their life-saving effectiveness by being exposed to moisture. They also achieve compliance with the US National Institute of Justice (NIJ) wet-conditioning standards (NIJ-0101.06), which require body armor to be waterproof, even after submersion for 30 minutes.


The ultrasonic energy – directed into woven or nonwoven synthetic materials or blends with up to 40% natural fibers – results in a rapid heat build-up that causes the synthetic fibers to soften and fuse, creating the strong molecular bond.


Sonics introduces new 30 kHz Ultrasonic Welding Systems

Sonics & Materials, Inc. has introduced new 30 kHz Ultrasonic Plastics Welding Systems featuring the Model 3050 benchtop press. The 30 kHz frequency is particularly suitable for applications where both power and Class A surface cosmetics are important considerations.


At a frequency of 30 kHz, the Model 3050 Press offers front-panel pneumatic speed and pressure controls with a direct in-line air cylinder. The microprocessor-controlled power supply provides consistent reliability, with features such as digital amplitude control; ultrasonic horn/stack frequency display; good part/bad part output signal; and a 30% smaller power supply footprint.


The 3050 ultrasonic welding system is available in a 1200-watt power rating and in three weld modes (weld by digital time; digital time or constant energy; or digital time, constant energy or distance). Additional standard features include automatic frequency tuning, multiple job storage, digital force triggering, calibration pulse, ultrasonics load meter scale and upper/lower weld limit settings.


Ultrasonic welding for improved quality

Rinco Ultrasonics has extended its range of machinery with its first electrically-driven ultrasonic welding machine.


With the new Electrical Motion ultrasonic welding machine (20 kHz working frequency), Rinco Ultrasonics claims to be treading new ground, away from the traditional pneumatic drive to an electrically-driven welding machine. With this solution, the relevant parameters for the joining process can be regulated individually and very finely – from the positioning of the sonotrode and the applied welding force to the welding rate.


This is reflected above all in considerably better results in the welding, punching, cutting or sealing of molded thermoplastic parts, nonwovens or synthetic textiles.


The welding machine is equipped with a high-performance industry-type PC that can be comfortably operated via a 12-inch touchscreen. The welding process is triggered via an ergonomically designed two-hand operation.


The new Electrical Motion machine can be used for demanding joining operations in automotive manufacturing, medical technology, packaging, textiles and the domestic appliance industry.


Branson Ultrasonics demos new VFFS system

Branson Ultrasonics Corporation, a business of Emerson, demonstrated ultrasonic technology in a new Vertical, Form, Fill and Sealing (VFFS) System at Pack Expo 2015.


The ultrasonic-sealing VFFS system provides multiple advantages over heat-sealing systems, enabling the client to seal against contaminants, eliminate waste and achieve better performance and throughput. By applying ultrasonic energy, the VFFS effectively seals against all product contaminants in the seal area, making it ideal for a wide range of product packaging applications.


The VFFS can process package sizes from 2.5 inches wide by 3 inches long to 12 inches wide by 20 inches in length, with no tool size changeover required. The flexible system features Branson’s state-of–the-art balun-horn technology, which produces a continuous seal on packages up to 16 inches wide.


Employing ultrasonic thermal processes offers numerous performance, energy and sustainability benefits including: low energy consumption; narrower seals for less material consumption; elimination of warm-up time; reduced leakage; elimination of residual heating; reduced tool clean-up time; a 75% reduction in carbon footprint; and bio-plastics compatibility.






A typical bullet-proof vest, from

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