The German manufacturer of cup and bottle filling machines Ampack Ammann has made considerable cost savings with a new safety solution for its machines. The chosen solution, 72 Eden E Sensors and three Pluto Safety PLC’s, led to great cost savings for material, wiring, maintenance and stock keeping.
Ampack Ammann is a specialist for filling and sealing sensitive food in cups or bottles, made of plastic. Their activities are mainly focused on the industrial processing of dairy products. The company was founded in 1971 and, with its 280 employees, it is a leading manufacturer in its market place. It exports approximately 80% of its production to renowned producers of dairy products all over the world, with a share of 80% in Europe and 20% outside Europe. At the Interpack 2005 exhibition, Ampack Ammann introduced for the first time a paper bottle for aseptic products. At the moment, the company is developing a high-speed machine capable of filling 50,000 small bottles per hour.
Out of a bottle reservoir and via a bottle unscrambler, the bottles are put on the infeed conveyor. The bottle is first cut without burrs. From this moment, the bottle is already within the sterile area of the filling machine which prevents the bottle from being contaminated. Then the bottles are checked for leaks and the defective bottles are separated out. The next step is the sterilisation process where a combination of thermal (overheated steam and hot air) and chemical (hydrogen peroxide) sterilisation is used. After this the bottles are filled via a flowmeter controlled dosing valve without seals. In the sealing station, the sealing heads which individually control the temperature and pressure, weld the aluminium lids on the bottles. Finally, the bottles are taken out from the conveying system by means of grippers and lifted onto a conveyor belt.
Two years ago, Ampack Ammann decided to upgrade all their filling machines to the highest safety category 4 according to EN 954-1. The objective was to monitor both the safety and reliability of the 72 doors on the machine. The decision for the co-operation with Jokab Safety was made due to the optimum features of the Eden E Sensors for door monitoring in harsh environments.
After the initial solution based on safety relays, the enormous advantages of the Pluto Safety PLC were recognised. It replaced not only the safety relays, but it significantly simplified the wiring, the service and the maintenance, thus obtaining considerable time and cost savings. In addition, JSHD4 Three-Position devices and JSNY9 Safety Switches with locking are used.
The JSHD4 Three-Position Enabling Device is used for safely carrying out the maintenance and service work on the filling machine. If, under the threat of danger, the technician can squeeze or release the dual three-position control device in order to immediately switch the machine off.
Using the 45 mm wide Pluto Safety PLC, Ampack Ammann obtains even more flexibility and saves a great number of safety relays. Pluto is a new ”All Supervisor” safety PLC concept, which simplifies the design of safety systems and provides the highest safety level according to category 4 EN 954-1. One of the main features of the Pluto concept is that there is no Supervisor-Subordinate relationship of the control units connected to the safety bus. Every Pluto is a Supervisor unit which sees the other Pluto’s inputs and outputs and can use their information to make decisions about its own safety. This enables simple communication and easy alterations of the safety system.
The Eden E series of non-contact safety switches used at Ampack Ammann on all 72 doors and hatches of the filling machines work with dynamic signals and have a sensing distance up to 12 mm. They correspond to the highest safety category 4 and consist of two complementary parts, called Adam E and Eva E. In the closed position of a door or hatch, the two sensors are exactly face to face, where the large tolerance for distance and misalignment between Adam and Eva ensures a very easy and uncritical mounting. Moreover, tests have proven that Eden E can operate in a temperature range from -70 to +90°C.
Eden uses a dynamic input and output signal, and it has protection class IP 69K. In contrast with mechanical or magnetic switches, Eden is active all the time, and a door requires only one sensor pair. The green-red LED’s on Adam show the sensor’s status information: contact between Adam and Eve, good alignment and safety status. The sensor status is also available in one of the wires from Adam E.
Manfred Koehler (37) and Rupert Kaltenstadler (42) were responsible for the planning of the automation project. They appreciate the high technological level of the Jokab Safety products, the good technical documentation and the high competence of their personnel in service and advice. For them, the Eden E door monitoring sensors offer decisive advantages such as the possibility of evaluating the condition of each single door, as well as their high resistance to hydrogen peroxide and high temperatures. They both remember how difficult and time consuming the troubleshooting on the 72 doors was before, since these doors were formerly equipped with encapsulated reed switches. The Pluto Safety PLC makes the safety system more easily understandable, more flexible and more reliable. The approvals for Europe, the US and Asia as well as the world-wide presence and spare parts service of Jokab Safety also play an important role. (Henri Hencke EURO DOC).