Ultrasonic heating

Provided the ultrasonic heat is applied selectively at the interface only, it vdll cause minimum distortion and degradation of the material. Obviously in order that a good weld may be obtained, the plastic must have characteristics which make it suitable for welding. These include ... 

Rapid curing of structural epoxy adhesive by ultrasonic heating has been demonstrated successfully in recent work. The conversion of epoxy groups produced by ultrasonic curing for 50 s was almost 3 times higher than that obtained by thermal heating.51... 

Kwan, K. M., and Benatar, A., Investigation of Non-Thermal Effects Produced by Ultrasonic Heating on Curing of Two-Part Epoxy Adhesive, Society of Plastic Engineers Annual Technical... 

Convection of heat via blood depends primarily on the local blood flow in the tissue and the vascular morphology of the tissue. Thermal diffusion is determined by thermal conductivity in the steady state, and thermal diffusivity in the unsteady state. In addition to these transport parameters, we need to know the volumes and geometry of normal tissues and tumor. In general, tumor volume changes as a function of time more rapidly than normal tissue volume. In special applications, such as hyperthermia induced by electromagnetic waves or radiofrequency currents, we need electromagnetic properties of tissues—the electrical conductivity and the relative dielectric constant. In the case of ultrasonic heating, we need to specify the acoustic properties of the tissue—velocity of sound and attenuation (or absorption) coefficient. 

Hydrex DX/ Petroferm Ethoxylated polyoxypropylene, sodium xylene sulfonate, and surfactant blend in water Ultrasonic/heated (24°C-49°C), 10% in water N/A 1 cps (in use) N/A 105 (of COTicent rate) >1 (estimated)... 

Noncontact-type heating allows heat transfer by noncontacting methods to fluids such as radiative and ultrasonic heating. Infrared temperature control [4] is a noncontact heating technique, which uses the infrared excitation of a vibration band of water combined with a high-power halogen light bulb and an optical Alter (Fig. 2). 

Staking n. A term sometimes used for the process of forming a head on a protruding portion of a plastic article for the purpose of holding a surrounding part in place. Ultrasonic heating of the protrusion facilitates the staking operation. 

Other methods such as ultrasonic heating, microwaves, induction heating, or high frequency radiation and furnace heating are of no industrial importance or lead to inferior material properties [28,43-46]. The thermoplastic filament winding process is called in situ consolidation and is schematically shown in Figure 1.11. With such devices, it is possible to process tapes of different widths with winding speeds up to 30 m/min. However, better material properties are derived at speeds of between 6 and 12 m/min [30]. 

Ultrasonic heating is also applicable to hot-melt and thermosetting adhesives. In these cases, the frictional energy is generated by the substrate contacting an adhesive film be-... 

MATERIAL HIGH FREQUENCY ULTRASONIC HEAT SEALING SPIN SOLVENTS HOT GAS... 

UPVC can be machined without difficulty, but keep the surfaces being cut well cooled. It may be welded by various techniques such as ultrasonic, heated tool, hot gas, friction and solvent. UPVC can be decorated using various methods such as painting, hot foiling, vacuum metallizing, EMI shielding and silkscreening. 

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