1. AIRBAGS INTERNATIONAL 1 AXIS ENGINEERING AND MANUFACTURING TEACHING RESOURCE AIR BAG MANUFACTURE KS 3 & 4 – Volume 13

2. AIRBAGS INTERNATIONAL 2 AIMS  To show how computer aided manufacturing (CAM) techniques are used to produce high tech fabric for the smart airbag manufacture.  To illustrate how modern Air Looms, with electronic Jacquard Machines, facilitate high volume continuous flow weaving of intricate shapes and joints in up to triple thickness fabric.  To explain how modern state of the art smart airbags function.  To illustrate the extensive testing procedures required for the safe design and development of airbags.  To explain the relevant Health and Safety Measures essential in the modern working environment.  To highlight the priority given to environmental issues in modern manufacturing.

3. AIRBAGS INTERNATIONAL 3 Airbags International, Congleton, Cheshire manufacture the smart airbags which cars now have fitted as standard safety equipment. They are a division of Autoliv, a multi-national company, which has 80 factories in over 30 countries and employ more than 38 thousand people worldwide. They produced 14million bags in 2006! Autoliv are technological leaders in automotive safety with a massive research and development programme which ensures that they stay at the forefront of their field. They run 24 hours a day, seven days a week supplying all major vehicle manufacturers. INTRODUCTION

4. AIRBAGS INTERNATIONAL 4 WEAVING Fabric has been woven from fibre for thousands of years. Two sets of thread are arranged at right angles to each other, the weft is woven horizontally in and out of the warp, on a machine called a loom, it forms a two dimensional flexible material. Weaving.pptWeaving.ppt Material for a multitude of everyday products is made on looms, including vehicle air bags and some that are not so obvious, such as metal fence panels and cord for pneumatic vehicle tyres. Modern looms are computer controlled (CAM) and are capable of weaving at great speeds from computer aided designs (CAD). Airbags International’s weaving sheds are similar in many ways to those that occupied the big cotton and woollen mills in Lancashire and Yorkshire in the past. They are certainly very noisy! New materials and CNC techniques, however, make the weaving operation much faster and accurate.

5. AIRBAGS INTERNATIONAL 5 YARN The airbags are made from nylon yarn because of it’s strength. From which natural resource is nylon manufactured?

6. AIRBAGS INTERNATIONAL 6 JACQUARD WEAVING A French weaver, Joseph-Marie Jacquard, invented a revolutionary control device, using punched cards, in 1804, which enabled silk to be rapidly and consistently woven into intricate patterns. This machine is thought to have been a major influence on Charles Babbage who is credited with the invention of the forerunner of the modern computer, the cogwheel calculator, it was also controlled by punched cards. Babbage’s idea led to the modern computer which was initially programmed by punched cards. So the development of the computer can be traced back to a French weaver in 1804! The modern CNC Jacquard Machine enables a large variety of shapes to be woven by lifting and lowering each individual thread, as required.

7. AIRBAGS INTERNATIONAL 7 The Jacquard machine, allows weaving a design for a bag of any shape by CAD and is produced by CAM. This process has made the company world leaders in airbag manufacture. The arrow, which you can see shows the direction the fabric comes off the weaving loom, it is also used to show the direction the fabric should be loaded onto the cutting machines so it is in the correct orientation for the cutting program. DESIGNS

8. AIRBAGS INTERNATIONAL 8 Airbags International have developed advanced, computer controlled weaving techniques which allow up to 3 layers of material to be woven simultaneously; this is known as `One Piece Weave` (OPW) WeavingOPW.ppt ONE PIECE WEAVE

9. AIRBAGS INTERNATIONAL 9 The Jacquard machine is computer controlled, it has thousands of hooks which raise or lower a harness, this then carries and guides the warp threads. There are 9118 hooks on a full sized loom which can take a week to thread up! It is the sequence of raised and lowered threads which creates a pattern. This image is of a Jacquard machine and harness on a small training loom. Multi Layer weave.ppt JACQUARD HARNESS

10. AIRBAGS INTERNATIONAL 10 These CNC Jacquard Machines are positioned at the top of the looms to facilitate control of the threads. This photograph shows the top of the harness. The main drive shaft is used to create the rocking motion which lifts magnets up and down to control the harness. THE JACQUARD MACHINE

11. AIRBAGS INTERNATIONAL 11 Yarn passes through the steel apertures at the bottom of the harness. This is a close up of some of the 9118 hooks on a particular loom. Each one is attached to the Jacquard machine; they raise and drop up to three warp threads at a time, as programmed by the computer. WARP

12. AIRBAGS INTERNATIONAL 12 These weft accumulators automatically wind sufficient yarn to enable the weft to reach the other side of the warp. The yarn travels through the warp at 180 miles an hour to form the weave. An easy way to remember warp from weft, is that weft goes from left to right, or ‘weft to right’! WEFT

13. AIRBAGS INTERNATIONAL 13 This picture shows the main air nozzle firing the weft through the space formed when the harness separates the warp, this space is known as the shed. The weft is woven horizontally in and out of the warp to create the airbag material. AIR NOZZLE

14. AIRBAGS INTERNATIONAL 14 DORNIER AIR JET LOOM The Jacquard machine is used on this Dornier air jet weaving loom and allows intricate patterns to be created at very high speeds. More than one design can be created at any one time which reduces wastage. There are 50 looms in each of the 3 weaving sheds all producing airbags. The Jacquard harness.

15. AIRBAGS INTERNATIONAL 15 QUALITY CONTROL Stringent quality control checks are made during weaving. The material is woven at a rate of 10metres/hour, it is therefore very important that faults are identified quickly; as a roll can cost between £3-5,000! Quality control is critical as the airbags must work correctly whenever detonated!

16. AIRBAGS INTERNATIONAL 16 This is a special viewing machine which is used to inspect a roll of fabric when a problem has been identified. It is also used to test random samples as part of the Quality Control checks. QUALITY CONTROL

17. AIRBAGS INTERNATIONAL 17 These black lines are used for a number of Quality Control checks. One check is to ensure the dimensions of a particular feature are correct, another use is for automatic identification of datum points for the laser cutting machines and also to make automatic identification of folding points during assembly at another plant. QUALITY CONTROL

18. AIRBAGS INTERNATIONAL 18 Here is a roll of woven airbags as it comes off the loom. Once the airbags have been woven into these long rolls they are then passed to the next stage which is scouring and heat set. This photograph shows how large these looms really are! SIZE OF LOOMS

19. AIRBAGS INTERNATIONAL 19 Yarn is delivered with a coating of a chemical, called ‘size’, which facilitates the weaving process. Cleaning, or scouring, the woven material on this CNC machine removes any excess size, oil and stains from the weaving process, but it also causes the fabric to shrink. This drum contains the chemicals for the scouring. SCOUR AND STEAM CAN PROCESS

20. AIRBAGS INTERNATIONAL 20 The steam can process is a method of heat setting and drying the fabric. The heat dries the fabric as it passes over the surface of the steam filled cans and returns it to the correct dimensions. It also removes any air pockets in the weave to ensure the fabric is tight. There are 12 cans in each structure. This is a close up of the steam cans. STEAM CAN PROCESS

21. AIRBAGS INTERNATIONAL 21 COATING The silicone coating area where woven material is coated to give strength and fill any gaps in the weave to prevent gas escaping from the bag. It also helps to keep the temperature of the bag down during deployment. The bag inflates very quickly which causes energy to be discharged, this produces heat, the silicone helps to prevent the occupants of the vehicle being burnt on contact.

22. AIRBAGS INTERNATIONAL 22 This nozzle sprays the silicone gel and a blade spreads it evenly across the fabric. SPRAYING SILICONE GEL

23. AIRBAGS INTERNATIONAL 23 CUTTING – TOPSPIN Some bags are cut out on a Topspin or ‘Pizza’ cutter which is controlled from x and y coordinates, similar to a plotter or card cutter in school. It is known as a ‘pizza’ cutter because it makes circular cuts! The topspin cutter uses the edge of a disc to cut the profile and can therefore only cut broad arcs & circles. This cutter is generally used for driver and passenger airbags and are run 24 hours a day, seven days a week.

24. AIRBAGS INTERNATIONAL 24 CNC Laser cutters are generally used to cut the profiles of inflatable curtain airbags and are run 16 hours a day, seven days a week. They are able to cut much tighter and smaller arcs compared to the topspin cutters. CUTTING - LASER

25. AIRBAGS INTERNATIONAL 25 Here are a variety of airbag shapes achieved with Jacquard weaving techniques. The smart airbag system combines inputs from the severity of the crash, the seat and seat belt sensors which all react to the size of the occupant and the position of the seat. In simple terms a big person subjected to a big crash gets a bigger airbag!! DIFFERENT AIRBAGS

26. AIRBAGS INTERNATIONAL 26 INFLATION The smart airbag will inflate automatically to 45 litres but depending on the severity of the crash the extra ‘tear seam’ will be broken to allow the bag to expand to 65 litres and absorb more energy. The tear seams are woven into the fabric and will allow the airbag to inflate only where required.

27. AIRBAGS INTERNATIONAL 27 INFLATED AIR BAGS These pictures show that airbags are manufactured by two main processes: either sewn or OPW. Driver and passenger airbags can be manufactured by either process depending on the specification and target costs set by the customer.

28. AIRBAGS INTERNATIONAL 28 The main Electronic Control Unit is an imbedded computer located in the middle of the vehicle, where it is well protected. It contains a crash sensor and a microprocessor. This ‘electronic brain’ of the car's safety systems decides if and exactly when each airbag tear seam is deployed. The smart airbag reacts to impact, giving protection to the occupant of the vehicle in both low and high impact crashes. ELECTRONIC CONTROL UNIT – (ECU)

29. AIRBAGS INTERNATIONAL 29 INFLATORS Pyrotechnic inflators use a solid gas generant which is ignited on impact and produces a harmless nitrogen-based gas. This is forced through filters in the inflator and cools the gas. The gas exits the inflator and enters the airbag, deploying it and providing protection for the vehicle's occupants. Stored gas airbag inflators rely on compressed gas to deploy the airbag by using an internal pyrotechnic heating device to expand the compressed gas and so deploy the airbag. These inflators provide a cooler gas alternative to the solid pyrotechnic inflators. The inflators are manufactured at sites in France and USA.

30. AIRBAGS INTERNATIONAL 30 TESTING This is a diagram of the crash testing system. Autoliv have full scale test tracks in France, Sweden and Germany which perform tests with cars weighing up to 3.5tons at speeds up to 50mph. These test procedures comply with European Standards.

31. AIRBAGS INTERNATIONAL 31 This is a test rig which is set up in the laboratory. The results of the lab testing are then fed to the computers where the results are analysed. Volvo AdvertVolvo Advert TEST RIG

32. AIRBAGS INTERNATIONAL 32 The airbag systems are crash tested under various temperatures with and without loadings on the bag. Autoliv Europe have full scale test tracks in France, Sweden and Germany. CRASH TESTING

33. AIRBAGS INTERNATIONAL 33 Front bags inflate in 25milliseconds, side impacts deploy even faster. It takes 100 milliseconds to blink an eye which is why nobody has actually seen one go off in a real crash! DEPLOYMENT

34. AIRBAGS INTERNATIONAL 34 This is a top view of the deployed driver and passenger airbag DEPLOYMENT

35. AIRBAGS INTERNATIONAL 35 CURTAIN AIRBAGS Curtain airbags are deployed from the roof. They help to prevent injury in side-impact collisions and also in rollovers.

36. AIRBAGS INTERNATIONAL 36 Until now it has not been possible to use curtain airbags in convertibles, because they are deployed from the roof. But Autoliv have designed a triple weave curtain airbag which is mounted in the door. It is made up of a many small cells, much like a beehive, and is in three layers. This structure gives the stability and cushioning capabilities needed. CURTAIN AIRBAG

37. AIRBAGS INTERNATIONAL 37 RECYCLING All waste is separated at source and sent for recycling to specialist firms.

38. AIRBAGS INTERNATIONAL 38 The selvedge forms an important part of the woven material as it keeps the weft taut, but it is not part of the airbag so it is trimmed off, baled and recycled. SELVEDGE

39. AIRBAGS INTERNATIONAL 39 AIR CONDITIONING This is the air conditioning ducting which helps to maintain the temperature and humidity of the weaving sheds and so ensures the quality of the weave achieved is to the tolerances required.

40. AIRBAGS INTERNATIONAL 40 HEALTH AND SAFETY All employees must wear ear protectors because the noise in the weaving sheds is so great; it is impossible to hear any one speaking to you. These 2 employees are also wearing high visibility jackets because they are from an area where there are moving vehicles.

41. AIRBAGS INTERNATIONAL 41 Fork lift trucks are used to carry the rolls around the site as each one can weigh up to 835kgs. Employees must wear protective footwear and high visibility jackets in this area. This employee is checking stock with a barcode scanner. PERSONAL PROTECTIVE EQUIPMENT

42. AIRBAGS INTERNATIONAL 42 FIRE HAZARD COSHH - Control Of Substances Hazardous to Health There are employees who work in teams within the company who are responsible for Health and Safety, risk assessment and fire. Each area has its own health and safety representative. You should be able to see similar systems in school.

43. AIRBAGS INTERNATIONAL 43 ACKNOWLEDGEMENT The Axis Education team wish to acknowledge the time and help given by Airbags International, Congleton in the development of this teaching resource. Autoliv can be contacted through their website: www.autoliv.com where further information about their achievements and products may be found.www.autoliv.com We would appreciate the completion of the feedback questionnaire sheet within 12 weeks of receipt. If you would like further copies of this resource please quote: KS 3 & 4 – Volume 13 Please e-mail: axis@totalpeople.co.uk or phone 01270 848415/6 for information about Axis` activities.axis@totalpeople.co.uk