Ultrasonic Cutting and Welding Equipment Information
Ultrasonic cutting and welding equipment are often used in the manufacture of fabric goods. They are also used to join thermoplastic components and metals such as aluminum.
Ultrasonic energy is used to achieve joining, cutting, patterning, and quilting on synthetic fabrics with no more than 40% natural fabric content. Welding is accomplished by converting high-frequency electrical energy into high-frequency mechanical motion. These high frequency vibrations along with contact force, create heat by friction at the mating surfaces. The plastic material will melt and form a bond between the parts being joined. Ultrasonic cutting is achieved when the vibrating horn is pressed against a fixed anvil and the horn pushes through the fabric, sealing the edge. This method is used to punch holes, to cut preset patterns, and to cut fabric strips to preset lengths. Food processors use ultrasonic knives vibrating up and down 20,000 times per second to slice their products as they come out of ovens before packaging. The high-frequency vibration creates a nearly friction-free surface between the tool (knife) and the product; sticking and pinching issues are eliminated.
Ultrasonic cutting and welding equipment consists of five elements:
- A power supply takes line power at 50 or 60 cycles and changes it to high ultrasonic frequency at 20,000 cycles per second or even higher.
- A converter converts electricity into high frequency mechanical vibration.
- The booster transmits the vibration energy and serves to increase its amplitude.
- A horn delivers the vibration energy to the material to be worked on.
- An anvil or backup tool that supports the work material and also has channels to allow the horn to sever the material completely and seal the edge.
In operation, ultrasonic vibrations are transmitted from the horn to the material. This develops frictional heat where they contact and fuses the material at the point of contact. When a cutting edge is used on the anvil, the material is cut through and the edges are sealed at once.
There are several ways ultrasonic welding and cutting are used to replace traditional fabric assembly techniques in clothing production:
Seams—A common application is to make seams or hems in medical disposable products. These include medical garments, face masks, etc. Pattern wheels can simulate a single row, double row, or triple row of stitches.
Sleeves and Cuffs—Cylinder machines use a cylindrical arm with a rotary stitch wheel and an ultrasonic system above the wheel to effectively weld sleeves and cuffs.
Slitting/Sealing—Ultrasonic slitters cleanly cut and seal the edges of synthetic or blended fabrics. Fraying and unraveling are virtually eliminated.
Hand Cutting—A hand-held cutter is used for cutting straight lines or large radius curves by hand.
Plunge Cutting—A plunge cutter can be used to cut-to-length ribbons, strips, etc.
Plunge Sealing and Cutting—Ultrasonic plunge sealing and cutting are accomplished by single or multiple horns advancing onto the materials, which are placed on a fixed anvil.
Adhesive Bonding—Thermally activated materials are placed between two non-thermoplastic fabrics, such as cotton or wool or blends with little synthetic content. The ultrasonic vibrations cause the thermal activated adhesive to flow into the fibers of the fabric, joining them together.
Ultrasonic cutting and welding equipment are great efficiency multipliers when used in the production of synthetic clothing and other fabric products. Though woven and nonwoven fabrics are a principal application of ultrasonic cutters and welders, other plastic and metal components may lend themselves to this process. Ultrasonic food cutting provides a method to cut, slice, align, or transfer a variety of food products that simplifies production, minimizes waste, and decreases maintenance costs.
Fahad Faisal / CC BY-SA 4.0