Amplitude-Refers to vertical, vibratory, peak-to-peak movement produced by the convertor, modified by the booster and fine-tuned by the horn.
Booster-A device used to modify the convertor generated amplitude by either increasing or decreasing it before it gets to the horn.
Boss-A raised portion of the workpiece, usually a circular, hollow feature for pin location and insertion.
Clearance-Allowing room for the plastic to flow in the joint design.
Convertor-Converts high-frequency electrical energy into high-frequency mechanical vibratory energy.
Copolymer-A combination of two different resins joining to make one polymer.
Crystalline-Polymers with a an orderly arrangement of molecules that repeat in precise patterns. The spring-like molecules tend to absorb energy making it more difficult to transmit vibratory energy through it.
Energy director-Typically a triangular-shaped ridge molded into one of the mating plastic parts. This ridge limits initial ultrasonic contact to a very small area. The ridge melts during ultrasonics causing plastic to flow through the joint bonding the parts together.
Far field-Refers to parts having an interface more then 1/4" from the contact surface of the ultrasonic horn.
Fixture-A device used to secure the parts being ultrasonically welded.
Flash-Refers to molten plastic that seeps out of the joints.
Hermetic seal-An ultrasonically welded seal that is air and water tight under pressure.
Homopolymer-Refers to a polymer made up of just one resin.
Horn-A precisely shaped and tuned piece of material, usually aluminum or titanium, attached to the booster which transfers the ultrasonic energy to the part being welded.
Hz-Refers to the number of cycles per second. 20 kHz means 20,000 cycles per second
Inserting-Embedding metal components such as inserts into preformed holes in a thermoplastic part.
Interface-The area where two mating parts contact each other.
Jack-out-Refers to the amount of force it would take to disassemble inserts that have been ultrasonically inserted.
Joints-The point at which two thermoplastic parts connect. The four most used joints in ultrasonic assembly are Butt, Step, Shear, and Tongue and Groove.
Linear encoder-An ultrasonic welder accessory which detects the precise height location of the welder head. The welder can be programmed to weld to certain depths during staking or inserting with the use of this device.
Microprocessor-A computerized controller of an ultrasonic welder that provides precise control over weld parameters such as energy, time and pressure.
Near field-Refers to parts having and interface less then a 1/4" from the contact surface of the ultrasonic horn.
Piezoelectric crystals-Material which changes dimension when electrical energy is applied to it. The change in dimension coincides with the frequency of the alternating current which causes a vibration or conversion to mechanical energy.
Power supply-Converts standard, 50/60 Hz, alternating current to high-frequency electrical energy above 15,000 Hz. Power supplies are available in different power wattages, usually between 200 - 4,000 watts.
Resin-Chemical compounds which make up plastic polymers. These polymers are divided into the following two categories: Amorphous and Crystalline.
Spot welding-Assembling thermoplastics without preformed holes or energy directors. This method is useful for large parts and sheets of extruded or cast thermoplastics.
Staking-The process of melting and reforming a thermoplastic post to lock a dissimilar material in place mechanically.
Swagging-Capturing another component of an assembly by ultrasonically melting and reforming a ridge of plastic over the other material.
Terpolymer-A combination of three different resins which make up one polymer.
Thermoplastic-Plastic which can be remelted and reformed with the introduction of heat and pressure.
Ultrasonic welding-Ultrasonic vibration in excess of 15,000 Hz creates heat and melting of plastic at the interface of two thermoplastic parts. When the vibration stops, the molten plastic resolidifies bonding the parts together.
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