Herrmann T.,Herrmann Ultraschall
Kunststoffe International | Year: 2010
Walter Herrmann who is one of the pioneers of the ultrasound technology which was first employed for cleaning systems in the metal and jewelry is discussed. The ultrasonic waves that are emitted are reflected, absorbed or transmitted depends on the nature of the material that the waves are aimed at. Walter Herrmann witnessed good prospects for his generator and commenced development work on his own ultrasonic welding machine. The machine technicians could only adjust parameters on an empirical basis at the customers' but could not set the machine for permanent operation. The first machine to be serially produced with soundproofing attracted a great deal of attention at the 'K' Plastics Fair in 1980. It proved possible to reduce what, at times, were unavoidable, high reject rates in some cases, from 30% to less than 1%.
Mohr R.,Herrmann Ultraschall
Kunststoffe International | Year: 2010
Complicated joining applications involving semi-crystalline and amorphous thermoplastics can be achieved through controlled build-up of melt. Scientists from the Charité Berlin and the Kiel University Clinic, Germany, the dental company DMG, developed a special application aid named Icon clamped in a holder made of polystyrene (PS). Herrmann Ultraschall GmbH & Co KG was given the project. The challenge was to design a suitable weld joint that did not allow melt to escape laterally when welding the holder components while simultaneously clamping the film. While the amorphous holder warms readily and quickly as a result of the mechanical vibrations, the semi-crystalline film has a delayed response, which in turn protects it from degrading thermally. Graphical representation of the welding power, joining velocity and weld force permits exact statements about the quality of the joining process.
Herrmann T.,GmbH and Co. KG |
Rupp A.,Herrmann Ultraschall
Kunststoffe International | Year: 2011
A cable duct running between the inside rearview mirror and the headliner of a car needed to be produced to ensure improved stiffness, easier assembly, and minimal twisting noises. The ultrasonic welding of the two duct shells to form a stable cable duct provided a suitable solution to the problem. The cable duct was necessary as the vehicle had an extended windscreen and a shortened ceiling headliner. Sample parts were treated with ultrasonics for an extremely long time in initial fundamental tests to establish whether the LED suffered any damage. A check was also conducted to ensure that the Flexible Printed Circuit (FPC) cable was protected against damage and was not detached. It was also necessary to protect the FPC in polyethylene naphthalate (PEN) from welding to the walls of the duct during the welding process.
Herrmann A.,Herrmann Ultraschall |
Herrmann A.,Herrmann Ultrasonics Inc.
Plastics Engineering | Year: 2015
The innovative test chip from GBO Greiner Bio-One GmbH, called Genspeed is used to detect MRSA (methicillin-resistant Staphylococcus aureus) infections, one of the world's most frequently identified hospital pathogens. GBO decided on ultrasonic welding as the method for joining the two halves. Ultrasonic welding provides the fine parameterization to weld the PS microfluidic test chip in such a way that its function is assured. The upper and lower parts are joined by welding a 0.1-mm high energy director along the microfluidic structure. A reaction channel is created in which the individual test steps are performed by capillary action. A further energy director runs around the outer contour of the upper part to fix the complete film. During the course of the process optimization, the welding tool or sonotrode surface is partially milled away outside the seam geometries; this improves the focus of the ultrasonic waves, prevents coupling at the surface, and results in lower mechanical impact on the film. By zeroing the reference point, the exact point at which the weld process is to start is calculated individually for each new welding. The machine control displays the weld process as a graph.