Abstract: The present invention relates to a process for producing a shaped diaphragm for electroacoustic transducers which comprises a core layer comprising poly(meth)acrylimide foam and at least one covering layer, which is characterized in that

Abstract: A process and device for the stable width wise regulation of the bulb angle in connection with the extrusion of sheets of heat-sensitive plastic (2) in an extrusion device with a calendar opening formed by two intake rollers (3,2) and a traversing measuring device (7) provided according to the calendar slot by altering positioning elements on the extrusion device. At least two traversing measurements of a parameter correlating with the bulb angle are started consecutively on the heat-sensitive plastic sheet synchronously with the positioning of one of the two calendar rollers. Like measurement conditions therefore exist and the deviation of the measured values obtained on the basis of the measurements in relation to specified expected values is used to regulate the bulb angle over its width by altering a setting element on the extrusion device.

Abstract: A process and device for the stable widthwise regulation of the bulb angle in connection with the extrusion of sheets of heat-sensitive plastic (2) in an extrusion device with a calender opening formed by two intake rollers (3, 2) and a traversing measuring device (7) provided according to the calender slot by altering positioning elements on the extrusion device. At least two traversing measurements of a parameter correlating with the bulb angle are started consecutively on the heat-sensitive plastic sheet synchronously with the positioning of one of the two calender rollers. Like measurement conditions therefore exist and the deviation of the measured values obtained on the basis of the measurements in relation to specified expected values is used to regulate the bulb angle over its width by altering a setting element on the extrusion device.

Abstract: The height of the bulge in the glazing roll gap of a supercalender in the extrusion of plates or films of a thermoplastic material smoothed on both sides may be controlled by measuring the location of the edges of the plastic sheet by means of measuring sensors and regulating the speed of the roll or the rate of extrusion of the polymer melt based on the width of the sheet so that the height of the bulge is always kept within tight tolerances.