Lithuanian and Hungarian joint venture "Bracha-Sport" was founded in 1991. In Lithuania the company produces the unique unidirectional carbon fiber ribbon, which is lightweight, hard and durable. For its properties and wide application specialists named the material "material of the future".
Initially "Bracha-Sport" joint venture produced sports
equipment, now days it exports the major portion of its
produce to many world countries. Paddles for canoes and
kayaks, oars for academic rowing, which company produces
from carbon fiber, are in great request. The best business
card for the produce is a number of the medals, representing
the winnings of the various international boat-races, achieved
with the "Bracha-Sport" oars. In 2002 rowers from different
countries with an oars made by the "Bracha-Sport" company
conquered 82 percent of the medals, and at Sydney Olympic
Games 70 percent of all medals were won.
What is special about this line? First of all, carbon
fiber is made by unique technology. The fiber could be dry
or impregnated with binders. As far as we know, this unidirectional
carbon fiber making method was never employed anywhere before.
The line is equipped with recently developed control system
Can-bus, which operates in Windows environment. Other producers
employ disc operating system DOS.
All analogical production made before has one serious problem, i.e. splits, which appears owing to the changes in diameters when the ribbon is being winded on a reel. A new line employs unique system, which permits to expand diameter of the ribbon while warping it on a reel, so all fiber filaments remain strained and even, they have no slightest split. Sufficient strain of the carbon fiber filaments makes the fabric stiffer. Up to 10 % of all filaments in fiber bundle can be split. All of them are being removed. Other producers are not able to do that so far. All fiber filaments in fabric are strictly parallel, not twisted to the right or to the left. Therefore the fabric doesn't split when winded on a reel considering increment of diameter. Very small cross shifts in reel, which are typical for other producer are avoided. When ribbon is winded on a reel of small diameter, inlying fabric are compressed, has no place to slip, getting wavy and eventually split. At the point of such microscopic split strength of the fabric decreases. That is why production of new line is winded on reel of large 400 mm diameters. That also renders certain convenience when ribbon is being reeled of.
Layers of the ribbon are separated one from another with silicon paper. The paper is not coated with silicon but impregnated, therefore the fabric itself never gets soiled with silicon and layers of ribbon don't stick when reeled up.
Talking about Unipreg, i.e. impregnated ribbon that is in general use, the main thing is that unidirectional carbon fiber is uniformly impregnated with special binders, which have different properties. Carefully all through the thickness impregnated fabric becomes homogenous, as distinct from the fabric made by other producers, where only face or back surface of the fabric is being covered with binder, sometimes leaving the surface wholly dry. Precise electronic system allows producer to regulate binder content in fabric with accuracy to within 1%. Other producers can provide precision of that characteristic only up to 3%, i.e. it ranges from 33% to 39%. Variation like that could cause a detriment to user. Precise control and operating installation allows producers to regulate weight of one square meter of the fabric within the range from 80 g/m2 to 300 g/m2. In that case the fabric of lighter weight is preferable.
That technology is different from other 5-7 carbon fiber producing technologies developed in the world. The difference is that it becomes possible to make smooth fabric of very high quality and reasonable price using 48K or 50K fiber bundle as primary product. Similar analogues are made only from 6K or 12K fiber bundles, which are considerably more expensive.
Another advantage of production made on the new line is
uniform width of the ribbon, guaranteed along the full length
of the material. If some particular item requires very precisely
measured piece of fabric, then variation of ribbon's width
between 22 and 22,5 cm would be very inconvenience for user.
Ribbon edge together with fiber filaments should be cut
in that case, and that could weaken the fabric.
The main objectives in creating this unique technology were to lower the world market price of described material and to advance its quality. That is exactly what the new line was created for: to sell produce, not technology itself. This position is going to be supported further. Today company is developing another processing line, which is going to absorb all the changes and updates made while working with the first line. The second line is developed to produce a ribbon of 50-60cm width, which is going to have significantly wider application.
Carbon fiber fabric is undoubtedly the material of the future, which has already made a revolution in many different branches of industry. This material is expected to replace all the metal in use. During the prestigious plastic exposition "Composit Jet", arranged in Paris, Unidry and Unipreg materials drew a rapt attention of car, aircraft and other branches of industry representatives.
To let you imagine vast dimensions of practical application of that material it is enough to take a look at some application examples. In space industry carbon fiber is used to produce antennas for satellites, spacecrafts' bodies and bulkheads. This material is insusceptible to ultraviolet rays. In aircraft industry carbon fiber is used to produce airplane's wings, fuselages. A munitions industry uses carbon fiber to produce various munitions items. This unique fiber is particularly usable in energy industry for constructing alternative energy equipment generators for wind and water power-stations. However, more widely and rapidly the carbon fiber is being integrated into car industry. In modern vehicles metal is replaced with carbon fiber and various carbon and other materials composites whenever it is possible: producing cars' bodies, brake disks and adhesion wheels, furnishing parts. These materials are preferred because of theirs durability, lightness, resistance to abrasion and rustproof property.
It was common knowledge that for construction industry carbon fiber would
be too expensive, but now the opposite opinion prevails.
For its special hardness the material is used to produce
bearing structures and spans for constructions and bridges.
And it certainly is very usable to produce sports equipment,
particularly paddles and oars. Unidirectional carbon fiber
Unipreg, made by "Bracha-Sport" UAB, currently are used
by different Italian, Belgium, UK, Portuguese, Hungarian,
Turkish and other countries companies. Owing to this material
those companies produced significantly better results, exceeding
those of the previous analogical production by 10-20%.
Unfortunately, this material is not widely used in Lithuania (mostly for boats' production). Its wide application would certainly allow local businessmen to improve competitive abilities of theirs' produce not only on domestic but also on the world markets.
