Patent ID: 7776171

Claim:
An arrangement for treatment of a material comprising at least two layers of material by means of an ultrasonic device comprising an ultrasonic horn arranged in conjunction with an abutment, wherein the material is positioned in a gap that is defined between the ultrasonic horn and the abutment, and the ultrasonic horn or the abutment is so arranged as to be capable of displacement to permit adjustment of the size of the gap, the arrangement further comprising: (a) a control unit for regulation of the size of the gap dependent on energy supplied to the material in the course of the treatment, (b) a detection device for determination of at least one predetermined dimension of the material, in conjunction with which the control unit is arranged for the regulation of the size of the gap dependent on at least the dimension, wherein the dimension comprises a width of at least one of the layers of material in a direction running essentially transversely to the longitudinal direction of the material, and (c) a sensor for measurement of force with which the ultrasonic device acts upon the material and the abutment, in conjunction with which the control unit is arranged for the regulation of the size of the gap dependent on the force, wherein the control unit is capable of calculating a measured value of the width, converting the measured value of the width to a correction factor, and adding the correction factor to the value which corresponds to the force during the regulation.