Zentis: "The detection accuracy is excellent"

HEUFT foreign object inspectors are ideal for continuously monitoring product safety. The drinks sector has known this for some time now. However an increasing number of food producers are relying on the remarkable detection reliability of the particularly low-radiation X-ray devices. The best example: the Zentis confectionery producer from Aachen, Germany. The HEUFT eXaminer XA systems have been safeguarding the quality of jams and fruit spreads there for almost 18 months now - time for a recap.

Ultimate food safety has always played an important role at Zentis GmbH & Co. KG.  Zentis, one of the largest fruit processing companies in Europe, decided in favour of three HEUFT eXaminer XA devices in the middle of 2008, after intensively testing the devices of other suppliers, so that foreign objects and glass faults do not present a threat.  Beate Höppner, engineer and Production Management Assistant for jams and sweet spreads at Zentis, reported about her experiences with the full container inspection systems for paste-like products in a conversation with HEUFT:


The HEUFT eXaminer XA systems monitor product safety along three Zentis lines.  Which lines are these and where are the devices located in each case?


Beate Höppner: "The devices have been installed along the lines after the closer.  We mainly produce different brands of jams and fruit spreads there.  Up to between five and ten different container formats are run along each line."


How have the devices proved themselves in practice?


Beate Höppner: "The devices are well integrated into our production processes and function with a high operating reliability."


How do you assess the detection reliability?


Beate Höppner: "The detection accuracy of the devices is excellent.  We found small stones with a diameter of only one millimetre.  Furthermore faulty jars, e.g. with ceramic or metal inclusions, or damage are detected."


The positive results of the test runs with Zentis containers have therefore been confirmed in practice on a daily basis?


Beate Höppner: "Yes, the specifications stipulated by the HEUFT company, that is the reliable detection of glass spheres with a diameter of three millimetres and steel spheres with a diameter of one millimetre, could also be implemented during running production."


What are the advantages of the HEUFT eXaminer XA compared with the other devices tested by Zentis?


Beate Höppner: "The complete base detection which is very important for us when using jars with curved bases and which the HEUFT devices provide was the decisive factor.  Furthermore the reliable detection of faults even in the case of jar formats with alignment marks, the rejector and compressed air monitoring system, the guaranteed removal of test bottles by means of the test bottle sensor and the automatic preparation of logbook entries to ensure traceability are also of considerable importance.  Other important advantages for us are the use of pulsed X-rays which reduces the exposure to radiation as well as the minimum demands on the container flow and the software-related control of the calibration so that production standstills due to device calibration are not necessary."


To come back to the base detection:  why is covering the complete container base so decisive in the case of the foreign object inspection?


Beate Höppner: "The base detection is particularly important to us because a potential foreign object made of glass, stone or metal would with a high probability always sink to the container base in the hot-filled and therefore still liquid jam.  In addition the container bases of the jars we use are always curved and often also have alignment marks in the base area which makes the detection more difficult.  The use and the special alignment of two generators make the detection of the smallest foreign objects on the container base also possible."


How are foreign objects identified which are not on the base but which "float" above it in the jam?


Beate Höppner: "All three devices are equipped with four generators - two for the base detection and two for the sidewall detection in each case.  The second generator is optionally switched on in the case of jars with a total height as from 135 millimetres."


You mentioned that not only foreign objects but also glass faults are detected:  how important is this function to Zentis?


Beate Höppner: "It is very important to identify faulty glass containers because they are particularly susceptible to break.  This includes jars with metal or ceramic inclusions, glass bubbles or chips in the base area.  Cracks can easily form around the inclusions or glass chips can even occur in this area which can possibly detach themselves inwards into the product.  Therefore it is extremely important to remove these damaged jars in advance in order to prevent broken glass or later product contamination due to glass splinters during further production or transport."


How do you ensure that the HEUFT inspection systems really track down such risks to food safety?


Beate Höppner: "Important evidence that the operational reliability of the installation has been ensured during production are the test bottle logs mentioned earlier.  We use between four and six test containers for each format, depending on the size of the container, each prepared with glass or steel spheres.  Furthermore they are marked with a magnet which always rejects them by means of a separate monitoring software and therefore prevents them reaching the consumer.  The HEUFT eXaminer XA requests the test containers automatically after every throughput of 15,000 jars.  The test bottle log has to be repeated if it is not fulfilled - otherwise production cannot be continued.  A log is generated after the test has finished which is saved on one of our servers and can therefore be retrieved at any time."


In other words the system checks its own detection performance.  But how do you check whether the required rejection has really occurred?


Beate Höppner: "The integrated compressed air monitoring and reject verification systems ensure that containers which have not been checked or not checked correctly are rejected in any case should interference occur due to the compressed air failing or at the rejector and therefore excludes faulty products reaching the market."


What is the importance of the full container inspections as regards Zentis´ internal quality management system?


Beate Höppner: "We are about to establish the HEUFT eXaminer devices as critical control points which are decisive for the safety of a food product."


The investment has been worthwhile then?


Beate Höppner:  "The devices fulfil their purpose and are very good at dealing with their work.  We are therefore in a position to further reduce the residual risk that comes from foreign objects."

Mrs Höppner, thank you for talking to us!