Today’s aerospace companies cutting composite materials have to be more competitive than ever, achieving this either through automation or other efficiency saving techniques. One area that, for many, still relies on outdated technology is material management, or specifically tracking the life of composite materials.

Traditional methods of tracking composite material have almost always been paper-based. Logs have to be maintained to locate complete or partly used rolls, often over multiple freezer and shopfloor locations. As the roll is cut into plies, which in turn are placed into kits ready for layup and curing, further information needs to be logged and tracked. Once the job is complete, to provide any level of fast traceability the paper records need to be logged into an MRP system (or similar), which again consumes time and is prone to error. It’s not uncommon for paperwork to be lost during its long and winding road through the manufacturing process, leaving mini black holes in the traceability trail.

There are two reasons why aerospace companies dedicate this time to manually log data:

1. The time the material is in a defrosted state has to be recorded otherwise no one would have any idea of when the material is still suitable for use or not. When the time has expired it is still possible for tests to be done to determine if the material life can be extended, i.e. it is given another period of time during which plies can be cut and laid up. This applies to all users of composite materials and not just aerospace.

2. The second reason, and the one which is vitally important to the aerospace industry, is that in the event of a problem one can provide traceability. The question is – to what level can you really provide it, and can it be improved upon, while reducing or completely removing the time consuming processes currently employed? If a part fails today many manufacturers will be able to provide traceability as to when and where that part was made, but would find it difficult or impossible to provide traceability back to individual plies or the roll/rolls that they came from.

The only way to deliver on all of the above issues is to implement a system that not only provides a method faster than pen and paper for tracking the movement of material – be it in roll, ply or kit form – but is intelligent enough to assimilate it into a format that is relevant to real world manufacturing.

Let’s examine some of the questions that many users across different areas of the business might ask of such a system:

1. I have a large delivery and need the fastest way to get these rolls processed and on the system so that they are available for manufacturing
2. I need to know where all rolls of a particular material are
3. Some material has been on the shopfloor for some time – what’s the life on it?
4. I want to make a nest using the material with the shortest life
5. I want to cut some plies from a particular material:
   • Do I have enough of this material in stock?
   • What roll should I cut it from?
   • What is the current state of the roll(s) i.e. is it in the freezer or out of the freezer?
   • If it’s still frozen how long will it be before I can cut it on the cutter?
6. There is an issue with one part. I need to know when all of the individual plies of that part were cut and which rolls they came from, and where the rolls came from

JETCAM International has recently developed a system to fulfill all these requirements. Material Life Management (MLM) not only resolves all of these problems but also provides real-time information to managers and operators such as time that a particular material has been out of the freezer, material stock levels, material left on each roll, material location and expiry date, etc. The possibility for error is virtually eliminated as once input, the information is carried through the system electronically, and is being constantly updated to reflect the real remaining life of the material. It is also environmentally friendly as it drastically reduces paper usage.

Entering information is much faster than existing manual methods due to minimal human interaction requirement and use of simplified input methods such as touch screens, barcode readers, or RFID tags. Material is booked in and out of storage within seconds, providing full life traceability from roll to ply to finished part.

MLM utilises JETCAM’s Application Server, a relational and highly customisable database structure which has several modules spanning all areas of composite manufacturing. One such module is the Shop Floor Module, which is used by the cutter operator and allows him to correctly select and place materials onto the cutting table. The system handles split rolls on a single or on any number of nest layers. It automatically calculates the most efficient overlap for the operator when the nest is split i.e. uses more than one roll. Multiple Layers are supported and any layer can be split any number of times. This allows users to easily use “end of roll” cut-offs (remnants) for other nests if those cut-offs are of a useable size.

MLM can be used in conjunction with any other Application Server modules to deliver an overall manufacturing management solution.

How does it work on a daily basis?
The first benefit is the removal of all related paperwork. All inputs would be done by swiping barcodes or automatic reading of the RFID tags. For example, when the roll of material is received in the company a unique barcode or RFID tag is generated that follows the roll/material through all the processes. The roll is then ‘booked in’ by scanning the barcode or reading the RFID tag and its location (ie. ’freezer’ or ‘shopfloor’ etc.) is selected from a drop-down menu. At this point the clock starts ticking and the system automatically and constantly tracks the roll’s life in and out of freezer. The real-time status of this roll can be seen by management using live reporting modules, and by production controllers and NC programmers on the shop floor who are scheduling the cutting of nests on CNC cutters. Warnings can be issued when a particular material or a kit of plies is nearing the end of it’s life.

When the roll is required at the cutter it is taken out of the freezer and scanned again, selecting ‘Out of Freezer’ as a new status. There is no guesswork required to decide when it is ready for cutting as the system keeps track of the defrosting time and a colour coded bar will inform the cutter operator or scheduler that the defrosting is complete. Should any cut, kitted, and bagged plies need to go back in the freezer for use at some time in the future, the same process will apply. Again the bag of kitted plies will have a barcode or an RFID tag attached and the system will automatically keep track of its ‘life’.

Taking it further – ply identification
Another logical extension of this is the use of the knowledge of which ply belongs to which kit to provide the cutter operator with the necessary information to quickly unload the plies from the cutter table in the correct order for kitting and for layup.  This is done with the help of a Laser Identification system which guides the operator through the picking and kitting process.

Summary
Many companies are losing tens or even hundreds of thousands of Euros per year due to wasted material caused by outdated and inefficient tracking mechanisms. They may not even be aware of the true value of this waste. More worryingly, their current systems deny them the very traceability levels that they aim to achieve. By replacing these methods with new technologies companies not only have the opportunity to comply to traceability requirements of the highest levels, but also make considerable savings which often pay for the system in a matter of months.

About the Author/Company:
Martin Bailey is the Marketing Manager for JETCAM International, and is also the author of several marketing and technology sector books. JETCAM Expert is used in over 7000 locations worldwide and supports virtually all punching and cutting/profiling CNC machines in the sheet metal, aerospace/automotive and other industries.

For more information visit www.jetcam.com.