Pet Food Packaging Machine Upgrade With SIEMENS MASTERDRIVE MC



CNC Design recently completed a project in Packaging Machine Automation. This is a full electrical upgrade of a packaging machine for an Australian manufacturer of pet food. The packaging machine is a vertical form, fill and seal machine used to package pet food into cylindrical “chubs”. The packaging film is drawn across the filling pipe, shaped into a tube and given a lengthwise seam. During this process the tube is filled with meat. At the prescribed interval the tube is clamped, crimped and cut producing an individual “chub”.

The machine has two servo axes, one for feeding the film and the other for clamping and cutting. The servo-positioning system employed is the Siemens MASTERDRIVE MC. The MASTERDRIVE MC has technology functions that ideally fit this application. Features including synchronized axes, registration mark and electronic gearbox were used to automate the machine.

The clamp axis operates at constant speed. Meat is fed from a constant volume pump with the length of the chub entered by the operator. The length is maintained by the by the film feed axis. An electronic gear box function between clamping axis and feed axis is used to produce the different chub lengths.

Each film has a repeating pattern which is required to be centralized on the chub. Part of the pattern is a registration mark. The registration marks on the film are detected by an optical sensor which is in turn used to trigger the position correction function of the MASTERDRIVE MC.

This also adjusts the position of the film axis for each chub ensuring the product is clamped at the correct position. A feature of our implementation ensures that when the machine is started the clamping axis is in registration.