in Vol. 5 - November Issue - Year 2004
Plastic Blast Media - and more
Wolfgang Kratschmer, Sales Manager at Flugzeug-Union S
Composite made helicopter rotorblade being stripped using DRY STRIP
Interview with Wolfgang Kratschmer, Sales Manager at Flugzeug-Union Süd GmbH (FUS), Munich, Germany
A conversation with Wolfgang Kratschmer, Sales Manager at FUS, the oldest manufacturer of thermo set plastic blast media in Europe, during which we learn, why and how this aerospace orientated trading company is producing it’s own plastic media.
(?) MFN: Who is Flugzeug-Union Süd GmbH (FUS)?
(!) W. K.: FUS was founded in 1969 as an Aircraft company. After several steps of mergers and concentration in European aeronautic industry, FUS now is part of EADS (European Aeronautic Defence and Space Company). Its main activities today are distribution of consumables, standard parts, spare parts and services linked to the production and maintenance of aircraft.
(?) MFN: How did your company become manufacturer of thermo set plastic blast media ?
(!) W. K.: In 1987, FUS together with some industrial partners found a subsidiary for the production of thermo set plastic media in Germany.
(?) MFN: Why did FUS, a trading company, start plastic media production?
(!) W. K.: FUS decided to set up its own plastic media production to enable her mother company at that time MBB (Messerschmitt – Bölkow – Blohm) to start depainting complete aircraft using the Plastic Media Blasting (PMB) process. At that time, there was no European source for thermo set plastic media and the imports from overseas did not at all fulfil the quality requirements of European aerospace industry.
In addition, there was a lot of plastic media related know-how developed by our mother company during the laboratory tests preceding the first application on real aircraft structures.
Therefore, FUS is not a typical abrasive manufacturer, but started as an aerospace company producing their own plastic media for in house use. This approach led to a strong dedication to quality aspects, to meet the demanding requirements of aerospace applications. The result was a plastic media showing top performance and thereby creating increasing demand from external users of aerospace as well as general industry, which FUS gladly satisfied.
Being part of the aerospace industry, FUS spoke the same “language” as its customers and was able to support the introduction of this new process at many major aerospace companies in Europe.
(?) MFN: Why did these companies decide to use PMB?
(!) W. K.: Well, they all encountered massive problems with chemical strippers. Modern aircraft paint became more and more resistant to all kind of chemicals so that the strippers had to be made more aggressive and also more toxic. On the other hand industrial health and safety standards became stricter. An increasing number of substances used in chemical strippers were put on the black list of banned chemicals. Briefly, health and environmental risks were no longer acceptable. This created serious technical issues and of course also cost problems occurred. In addition, the growing use of composite structures increased the need for another solution: Composites cannot be stripped chemically without being destroyed.
(?) MFN: When did the age of PMB start in Europe?
(!) W. K.: It was in October 1987, when our mother company MBB, after two years of laboratory tests, stripped a German F4 Phantom fighter aircraft using PMB. This was the first time in Europe that a complete aircraft was depainted with this new method. After further successful trials they decided to build a hangar specially designed for the use of PMB. It was officially opened in 1991 and was the first of his kind in Europe. Up to today, more than 400 aircraft have been stripped there, some of them 3 times during their life. One of the most remarkable aircraft types stripped were Russian built MIG 29, which came into service at German air force after German reunification. As far as we know, nobody else ever stripped a MIG 29 with PMB.
(?) MFN: What exactly are your products?
(!) W. K.: Today we are producing different types of DRY STRIP® thermo set plastic media: DRY STRIP® type 2, urea, the most common type for all kinds of depainting, blast cleaning and deflashing operations. DRY STRIP® type 3, melamine, a little bit harder and more aggressive, for operations where type 2 is too weak and for use in the food industry. DRY STRIP® type 5, made of acrylic resin is softer than urea and melamine, for operations on delicate substrates where surface integrity is a must, i.e. anodized skins, thin sheet metal or composite components.
To rounden our product range, we are also distributor of ENVIROStrip® wheat starch media. Where our thermo set plastic media might be too aggressive, especially on certain types of composites or other very sensitive substrates, ENVIROStrip® could be the solution. This media is based on wheat starch or corn starch and has a lower hardness and density than thermo set plastic media.
(?) MFN: Could you please explain some major aspects of your plastic media production ?
(!) W. K.: The quality requirements of plastic media spec MIL P-85891 are the baseline of our production. For several customers we are manufacturing to even stricter plastic media specifications. The production lines consist of custom made components which are the result of more than 18 years of production experience and reflect the latest state of the art solutions. Carefully selected raw material is passed through several stations, i.e. for grinding, sieving, and dust removal before the finished product is packed in bags or drums of nearly every size.
(?) MFN: What about quality control?
(!) W. K.: We are certified to EN 9120 Aerospace Quality Management System, including the standard EN-ISO 9001:2000. Our laboratory is fully equipped with all necessary tools to control consistency and properties of the plastic media at every stage of production. Self developed testing devices allow survey of all relevant parameters of raw material and finished product. This includes breakdown tests following standardized procedures using fully automated equipment. Major aircraft manufacturers audited and approved our production. We are holding approvals of German Air force and forces of other countries, and also of several OEMs, Airlines, and important maintenance companies.
(?) MFN: What are the most important Applications of your products?
(!) W. K.: Starting with the aerospace industry, where we came from, there are a lot of well established applications today: Besides chemical stripping or hand sanding, PMB is an important method for de-painting of aircraft and helicopters and their components. For parts like aircraft wheels, landing gear, brakes, engine parts etc. PMB meanwhile is the standard de-painting process. The increasing use of composite materials in aircraft also leads to increasing application there. Customers are de-painting helicopter rotor blades made of carbon fibre or they are activating carbon fibre parts prior to bonding or painting. Bond removal on metal to metal bonded parts is successfully done with PMB, sometimes by using ENVIROStrip® wheat starch. Even for space missions PMB is used to remove glue residues on bonded parts of satellite structures. This delivers significant weight reduction. And weight is everything in space.
Induced by these aerospace applications, the process found its way also into the general industry: Weight reduction is also involved when Formula 1 racing cars and other categories are stripped down with PMB to their composite surface after each race. This is done to avoid excessive weight build up caused by the fact that they are repainted like new for every race. This is a common application of ENVIROStrip® wheat starch. PMB is widely used to restore antique cars, to repair grp yachts, to clean the exterior of monuments and buildings and even to prepare archaeological findings. Cleaning of moulds in the rubber or composite industry is widely done with PMB. A very common use of PMB is de-flashing of plastic parts and electronic components in the chip industry.
(?) MFN: What else can you offer to the potential user of plastic media?
(!) W. K.: In addition to plastic media, we are able to deliver the “full package” for successful application of PMB in the aerospace industry and beyond. The package, called FUS DRY STRIPPING SYSTEM® consists of three components: plastic media, as described above, aircraft specific know-how and appropriate equipment. Our position inside EADS enables us to also deliver aircraft specific process specifications for the application of PMB and training on the aircraft for users. This gives us a unique position in the market as probably no other manufacturer of plastic media can offer such services.
We are cooperating with well-known manufacturers of blast cleaning equipment who are producing machines specially adapted to the use of plastic media. The ability to deliver all three components of successful PMB application helped us to win important projects. To give you an example, FUS was the main contractor for turn key delivery of two PMB installations for the German Airforce, including: delivery and installation of equipment, aircraft specific process specification, training on the aircraft and – of course the plastic media. Last but not least we run a test centre fully equipped with modern blast machines to find the best possible solution for our customers.