Return On Investment by Zipper Packaging at UVA Packaging

Integration

The Newton TX is easier to integrate with other parts of a packaging and conveyor process. “The Newton TX comes with Allen-Bradley® PanelView™ Plus control screen, which means it can control all aspects of dosing and conveyor systems. The operator can therefore operate the dosing and weighing functions from the packaging machine.” Van den Hurk continues ”UVA Packaging uses various Allen-Bradley components from Rockwell Automation in the Newton TX, including a ControlLogix L61 PAC, numerous Kinetix® 6000 Servo drives, PowerFlex® frequency regulators and a touch screen. These components form an integrated solution.

Servo Drives

Important components within the Newton TX are the four Kinetix servo drives,” he explains: “These drives mean our machine’s performance is not compromised in terms of speed. We have therefore succeeded in building a very well engineered machine with a fully adjustable film belt. The machine can process Polyethylene (PE), heat-sealable film and laminated film. The spindle, around which the film is wound, is automatically unrolled in a process where the key is to control the tension of the film... the film must always be tightly wound. The film is unrolled and stored on several spindles and by varying the distances between these spindles, the film can be kept under tension at all times. This is important for both speed and quality.”

Film Belt

“The drivers carry out the primary process – making the bags,” he continues. “They also convey the film by pulling on it, allowing for maximum acceleration and deceleration. Real-time slip compensation can also be implemented. Intelligence within the controller determines the slip using the positions of the film detected by optical sensors. By making a comparison and calculation, the controller can subsequently establish if (and how much) slip has taken place. If there is slip, which can easily run into metres per second, it is corrected in real time by the servo drives. The slip also varies significantly by film type, as each has its own quality, friction and friction coefficient.

Van den Hurk continues: “After the shoulder mould, the film is shaped into the desired bag style. The machine can process two styles: pillow bag and doy-style. The zipper is added in the shoulder mould; either a push strip or ‘press to close’. There are a number of filling systems: multi-head weighers, volume-dosage systems, linear weighers and screw-dosage systems. All these types of weighing systems can be connected to our machine.”

Tilt

“Film belts can often start to unavoidably tilt throughout the movement of the belt, resulting in wasted bag production. With the aid of optical sensors, this tilt is detected and the position of the entire film belt is corrected, helping to minimise the number of bags lost. The correction of the entire film is carried out in one single process - the optical sensors send a signal to the controller, which will then engage the e-motor. We can effortlessly integrate the operation of this type system in the HMI of our machine.” says van den Hurk.

Added Functionality

“There is also an extensive list of options after the bags have gone through the buffer,” van den Hurk elaborates. “There are a variety of printing options available, for example the attaching of labels or any additional sticker to the bag if required, or a ‘banner applicator’ if needed. A banner applicator is a loose strip of film containing an advertisement. The machine can also make air-removal holes in the packaging which is done through the application of air valves or air flaps to the bag. Our machine can also make bags with screw tops, for example, on yoghurt drinks. The machine can also apply scent strips to the inside of the film or attach straws to the bags. Finally, there is an option for the application of extra corner seals or reinforced corners to the bags. These are just a few examples of the added functionality of these machines.”

Data Logging

The ControlLogix PAC can also used for storing historical process data generated by the Newton TX during operation. It can generate useful data for management to analyse such as performance, stoppage due to internal or external causes, wasted film and calculation of the Overall Equipment Effectiveness (OEE). Linking with MES or ERP is also an option. The controller has an Ethernet interface for the connection with higher automation systems.

Good Experience

Van den Hurk concludes “We opted for the solution from Rockwell Automation based on our positive past experience. The excellent support we have received in the preliminary and subsequent stages was a positive deciding factor for us. Over the years, we have built hundreds of machines with Allen-Bradley products from Rockwell Automation. An additional reason to use Rockwell Automation is that our customers prefer the Allen-Bradley brand too. The advantage of using Allen-Bradley components is the robustness and availability of the product and, of course, the service and support provided is second to none.”