Düsseldorf Oct. 6-12th. 1995, in Deutsch
The exhibitors were divided in two groups; System suppliers and Machine makers. Machine makers are increasing their distribution of this technique and the leaders are Battenfeld, Cincinnati, Krauss Maffei and Rollepaal (the last one being also a system supplier). The displayed solutions start in the medium range (e.g. diameter of 25 mm) to the large, since this range is the main market for machine makers. Only a few, for instant Weber and Theysohn, are less progressive and make their decisions case by case, in respect to buyers requests.
The machine makers have increased their activities regarding this techniques since the K '92 and display some interesting solutions. This was obvious for measurement's applications close to the die. The ones who have the most knowledge in extrusion process and mechanics, or have an equivalent partnership, are displaying good solutions.
For more details regarding the most discussed issues, look at Calibration, Mechanic and Test position, in the guide book for "Ultrasonic Testing in Pipe Extrusion".
The special ultrasonic electronic unit is purchased always from machine makers as a finished module. The basic mechanism is more or less well adapted.
Solutions with scanners and with fixed transducers were presented by all the companies mentioned. Since a complete 360 degree record is not necessary, a fixed arrangement with 6 or 8 transducers is recommended. A 4-channel technique is not so widely distributed and only for very small diameters.
Today the machine makers don't hesitate to take scanning measurements close to the die, the doupts of yesterday pessimism seem to be irrelevant. The precondition is that a good solution for handling and service is achieved. Good solutions with swivel frames, easy exchangeable guide/slide rings and easy maintenance were displayed. The well known temperature inhomogentity problem, especially with twin screw extruders, is seen by many people not to be relevant anymore.
One machine maker displayed a new solution with fixed transducers mounted very close to the sleeve's front. Due to inserting the sleeve, in pull out into the vacuum bath, transducers are located outside and so an improved handling is achieved. There is doubt whether the measured wall thicknesses are in correlation with the ready pipe wall thicknesses, this has to be proved in practice. Thus for rough centering, this idea seems to be useful. The automated centering method within ultrasonics (thermal or mechanical) was a common method.
Some common comments were: "the most important is a reliable and easy to operate system,........wondering how much is lead by politics,........automation with ultrasonic is increasing fast,........the integrated diameter measurement is today a standard."
Before leaving this field, here are a few words regarding another field of machine makers, for instant Breyer, Betol, Nokia Maillefer. They are well known for fast and small sized extrusions. Betol displayed an In-Line ultrasonic measurement equipment, the others companies are involved also in ultrasonics away from the fair. Also Swisscap, not present at the fair, has very often ultrasonic in their extrusion lines.
The System suppliers alsodisplayed "Highlights", one supplier presented an economical solution, especially for small diameters with fixed transducers. This was created by to a new electronic hardware.
The inexpensive integrated ultrasonic diameter measurement is today a standard. This was even endorsed by a supplier for laser diameter gages. Only one company presented the "ultrasonic-laser" combination. There is doubt if this will stay for the future, since only in a few cases demanding high accuracy is this necessary.
Also here some notable statements: "Not much news,......the ultrasonic calibration is also manually practicable, ...........the automatic calibration, due to high integration, will complicate the system, a difficult operation is the result,........coextrusion measurement is a difficult issue and needs more research."
Good bye and a future welcome for the K '98 exhibition.
List of exhibitors for Ultrasonic In Line Measurement:
CONPRO 08 E29
DE ROLLEPAAL MACHINEFABRIEK 12 A51
INOEX 10 A01
LASERMIKE 10 F27
MOOG-BUHL AUTOMATION 10 A59
PANAMETRICS 10 C22
WAVIN OVERSEAS 12 A51
ZUMBACH ELECTRONIC 10 A24
Exhibitors for In Line Thickness Measurements with other techniques
for instant Capacitive, Inductive, Laser, Thermos, Betha-ray.
Rolf Diederichs 16. October 1995, info@ndt.net