The novel concept of long linear motors and dynamic configuration of motion paths and motion profile brings the central element of a factory – the conveyor line to the era of Industry 4.0. The factory can then become an adaptive factory which can dynamically reconfigure itself according to the production needs of the day. The world credits Henry Ford for inventing the concept of the assembly line. However, he himself gained inspiration from – of all places – a packing plant which was processing meat. With a brilliant insight, Ford visualised an assembly line by looking at the ‘disassembly line’, and the second industrial revolution was born.
The concept of conveyors is to bring the work piece to the processing station as opposed to the processor moving to work piece. Alongside of the conveyors are the processing stations, where a person or a machine repeatedly performs a single set of operations on each piece. When a conveyor becomes intelligent, it is aware of each work piece moving on it and can be programmed to deal in unique ways. Such a conveyor will be called Trak.
Challenges for manufacturing line by demands from modern consumers
F&B industries, much like CPG industries, are facing volatile demand pattern from consumers. Consumer preferences make choices for F&B, a lifestyle statement like the choice of apparels. Increased production volumes coupled with increased regulatory pressure, increased upstream awareness, etc., squeeze margins. These factors call for an adaptive factory. Success in the F&B industry is strongly determined by successful New Product Introduction (NPI). Therefore, time-to-market is an important issue. New packaging solutions like, switching from plastic to other material is a continuous challenge. Energy consumption is a serious issue; given that, machinery life is predicted 20+ years, making it is impossible to foresee all future demands. Hence, it calls for solutions that are designed for quick changes and upgrades as new demands come up.
The traditional conveying system has stood the test of time, and indeed, evolved to meet most challenges of new manufacturing. However, there are some critical aspects where it struggles specifically in dealing with individual processing of products. The line has no easy way to be aware of the product and cannot be moved in a special way through the battery of processors. One big drawback is that the conveying system in itself is not very ‘intelligent’. This is the point where one wishes for the adaptive factory.
The adaptive machine with the Trak system will support on-the- fly changeovers and allow reconfiguration with different production modules using the same base machine platform. But it will also adapt to radical and unforeseen requirements through corresponding equipment changes, such as, replacing a carton erector module with a pouch forming module. Below are features of Trak systems that can fire imagination of production engineer to enable new possibilities.
It is possible to have products moving at any pitch (any spacing). Pitch can be changed on the fly
Stop positions for each shuttle could be different and can be very accurate – less than a few tens of microns
Each shuttle and therefore, each product is accorded an individual motion profile and handling
Synchronisation with robots or CNC to machine the work piece on the fly is possible because of awareness of each work piece
It is possible to program a graceful degradation – in the sense that if a processor fails, other processors can keep working and need not bring the line to a stop. Importantly, defective work piece is not propelled through the entire line until the rejection station.
Accumulation is replaced by synchronisation via parallel processing to balance production times of dissimilar products
The lines come enhanced with IIoT capabilities, such as, analytics, process optimisation, predictive maintenance and other productivity
How does the Trak manage to deliver more?
Consider a scenario of beverage filling into bottles – if there are, say five filling nozzles, five shuttles present five bottles to the nozzles. If one nozzle fails and does not deliver, the system can quickly reconfigure to present only four bottles to the four functioning nozzles. This avoids an empty bottle travelling along until end of the line. Consider yoghurt being filled into cups; after being filled, the cups need to be moved to the next station for closure. The speed at which the cup can be moved is limited by the risk of spillage. Equally, it can also determine how much gap is left on the top of the food to prevent spillage. However, the Trak can provide a motion profile to avoid spilling, and even sloshing, without reducing speed.
If the line is used to fill bottles with different volume, the change-over from one size to another can be affected without reducing the speed of the line or having a stoppage. This is achieved because software knows which bottle is leading the sequence of new size and can quickly adjust all parameters on the fly. This will work at downstream stations, like capping or closures. The same is true for wrapping or labelling of pleasure goods, like chocolates or ice-cream. The concept of different labels etc., is very interesting; for example, for festival packaging.
Solution of new millennium – conveyor with awareness
The Trak system consists of a track with shuttles or pallets or movers mounted on it. The game-changing aspect of the Trak system is that it is intelligent. Movement and handling of each shuttle can be individually programmed. This intelligence is obtained by a novel mechanical and electromagnetic construction, and even more by intelligent motion control software. Each shuttle is uniquely identified in the system by means of a tag. The Trak is then always aware of the position and the velocity of each individual shuttle. The handling of the shuttle and the product on the shuttle can be individualised with this awareness.
Construction of a Trak system
Trak is a flexible conveyor system based on Long stator Linear Motor (LLM) technology. The LLM technology can be compared to an AC synchronous motor, with translational direct drive system. The main components are a long stator, linear motor and shuttles with permanent magnets in the form of rotors similar to conventional motors. The system comprises a motor stator in the form of an oval track and any number of shuttles. The shuttles are held in place on the track by the magnetic force alone and are propelled electromagnetically. Shuttle positions on the track are sensed with feedback encoders.
The LLM can be mounted horizontally or vertically for added flexibility without reducing bearing life. Indexing is faster and it allows the direction, acceleration, speed and position of each shuttle (moving platform, also called pallet or mover) to be individually programmed. As the motion and braking are achieved through electromagnetism, linear motors are much quieter than ordinary motors. LLM is built to carry high payload and its modularity offers design flexibility. The shuttle slides over the track with an air gap that results in no loss of energy due to friction and vibration. With fewer moving parts, maintenance is considerably reduced.
From traditional into future
Having touched upon the benefits and drawbacks of the conventional conveyor, it is clear to understand that conveyor lines are a central element of a factory producing F&B products. The new solution, the Trak system, offers many advantages for some challenging applications. Given the versatility of the system, further applications are limited only by the imagination of the designer. B&R Industrial Automation offers a series of Trak systems called ACOPOStrak and Supertrak. These systems are specially geared to work alongside with robots and CNC machines, and also with humans.