Braiding machine

The braiding machine is an apparatus are braided with the cords or strings automatically.

Principle of operation

It will be led around in a circle around the braiding rolled on spools threads. These coils are in wavy lines closer to and then further from the braiding on bobbin carriers, led the so-called clappers. The fact that threads run both clockwise or counter -clockwise, they are intertwined.

The bobbin or skein in Austria ( from the North German word doll ) wearing the coil. To compensate for the removal of the braiding bobbin previously had a lead weight, referred to as " Lot " and a spring so that the thread is always processed excited today. The bobbin thread monitoring have a cut off the braiding machine when the thread breaks. The coils can be either driven or unwound only by braking. For this they have done serrations on the drive or braking. The Barmer braiding have the coils, as seen on the picture, on top of prongs where a latch clicks into place. If the yarn is stretched as far as that the weight is pulled in the core of the coil so high, so it picks up the handle and the coil can reel off as far as the thread until the latch clicks into place again and the coil brings to a halt.

The interwoven threads are pulled away from the constant braiding with nip rollers or other deductions, and then further wound or a further production stage, for example, fed an automatic cutting.

The structure of braids is highly dependent on the number of lace. Here lies the problem of braiding machines, since the number of carriers can be changed only very limited in existing machines. Therefore, it takes a function of the products to be produced each having a different machine. So there are very few machines the clapper (eg nine clapper ) to large machines that have more than 150 clapper.

Whereas in the past the speeds limited by the quality of the yarn material, it is through the production of synthetic fibers with much greater mechanical strength rather the design of the machine itself The bobbin can be much larger by more accurate guides, leading again to shorter downtimes due spool change.

The functional principle is identical to that of the machines in the last hundred years, even with today's machines.

Braids and braids hose

Depending on whether the clapper always run in one direction or reverse at the end points, a braided tube ( string or cord ) or a flat braid yields (stranded in Austria also referred Boertel ). Usually result from the technique with an odd number of threads a strand, with an even number a string. The smallest braids are a cord of three strands, as in a braid as braid, with four threads. By supplying a soul in the braiding of down, you can braid the hose to a string to stress. In addition, tensile forces that soul, without that pulls together a braid.

Elastic cords are produced in the form that rubber threads are supplied from below in the tensioned state upwards within the wick, but not this time centered in the braiding, but in each case at the crossing points of each bobbin.

Design options of braids

In principle, the number of threads and thread thickness determines the strength of the braid. Additionally, however, are still other ways to affect the appearance of the braid possible.

A major factor is the speed of how fast deducted from a braid braiding ( pulled ) is. A slow withdrawal speed causes a dense and thicker braid, while a fast trigger speed results in a loose and easily movable mesh. Especially in elastic nettings this point to note is how soft or strict is the train of Elastic in the end.

Even with the weights in the lace-making, the density of a mesh are strongly affected. With heavier weights of each thread is stretched further, and the braid is narrower and thinner. By a particular arrangement of different weights, it is possible for example to produce a Zackenlitze, in which the strand is drawn from the respective interlacing point to the left or to the right.

If one is running in one direction and stronger threads in the opposite direction a few thin threads, you can weave example strings which have a twisted rope a similarity.

In elastic braids the look and especially the later Dehnmöglichkeit the braid is strongly dependent on the bias of the bottom straight through rubber threads.

By combining different Einflussfakturen can be produced in this way the various meshes.

Special types

Running the clapper depending on strands or braided hose usually always the same way, so -called change can similarly separate railway switches the tracks temporarily and later merge again. In this way, for example, elastic bands, with interruptions, as Knopflochgummilitzen be made ​​.

With other designs several career circles can touch only tangentially so thin connections between two strings occur at the contact points, as they represent, for example Passepoilgeflechte.

Similarly, a circle and a line Litzenkreis to be connected together, so again special braids arise such as a Kordellitze, which consists of a cord with a flat wing.

Since the braiding industry is heavily migrated in the last twenty years in total in Europe to low-wage countries, but there only a commodity is produced, the amount of such machines is only very small.

In recent years, there is again an increase of Spezialflechtmaschinen, but not in classic textile field, but in the production of fiber reinforced plastics. The machines used here were often originally designed for the textile industry and then converted to in order to process carbon, glass and aramid fibers can.

Historical

The first traces of a mechanical braiding can be found in a book by Georg Philipp Harsdörffer, which was published in 1653 in Nuremberg. According to the data of the author to the device described therein, was the drive via a hand crank, have been invented in Utrecht. Around a century later, the Englishman Thomas Walford of Manchester was granted a patent on a braiding machine for the first time in 1748. In the valley of the Wupper Johann Heinrich Bockmühl is considered the inventor of this machine, which is not true. Improvements to the braiding machine but go back to him. The industrial production of braiding machines began around 1880. Leader in this field were the manufacturer in Wuppertal- Barmen. This Börtelflechtereien, as they were often called, were in many places the beginning of industrialization. Especially in areas where water power was available as drive the water wheel, these factories arose before the electrification. Later, these drives were replaced by steam engines or traction engine.

The braiding machines were placed side by side on so-called Flechttischen. These were simple wooden frames that had a drive shaft lengthwise and powered the machines individually through bevel gears. These machines were turned ON by simply moving the machine so that the gears were engaged. From this period, the terms engagement and disengagement for turning on or off the machine. Were driven individual tables via a transmission.

This thread monitoring is remarkable because there was this automatic without a currently known sensors as in other machines. On the side of each of the clapper there is a slide which is held by the thread in the height. Tearing of the thread, the valve falls down, it pushes the guided past the trip bar is arranged laterally to the outside, which in turn causes the gears out of engagement. As a result, the machine stops, without that necessarily arises an error in the network. So it was the weak thread tension sufficient to remedy the serious machine. (see figure at right )

In weaving machines such monitoring was not possible, so that the braiding machine replaced a large portion of the products of previously known weavings. It was only in the 1970s that sparked the invention of Nadelwebstühle braiding and crochet machines which have a much higher productivity, again mostly from. Only more specialized areas of textile industry are now working with braiding.

The well-known manufacturers of these braiding settled naturally in the areas, where these Braiding prevailed. Major industrial areas, who possessed a large number of such generations, the space Wuppertal in Germany and the Waldviertel were (also known as the Bandlkramerland ) and the Vienna Basin in Austria. In Vienna itself, for example, the seventh district of Neubau was one such area. Even today, street names, such as Bandgasse or Seidengasse at this time.

Application Examples

• Elastic bands to be used in garments as Einziehgummi
• Candle wicks can be braided lines
• Snakes or Rick Rack, which are sewn on as an ornamental braid
• Shoelaces ( shoelaces ).

There are also technical braids, such as:

• So-called Einziehstrümpfe in which the contraction of the short hose braided section is used to hold a cable or hose and feed these into a conduit or cable duct, similar to a Chinese finger trap
• Braided electrical lines where the cable jacket is protected either by a braid (eg iron - lines), these replaced (so-called pendulum cord with hanging lamps with automatic retractor, and lately more and more often in headphone cables ) to a greater flexibility of the to achieve cable
• Braids for plastic reinforcement (eg, carbon, fiberglass, aramids )
• Copper, which is used as a ground connection for automotive batteries.
• Strands are used as solder wick.
• Hose braids are used for example for shower hoses, in which a rubber hose with steel wire is braided. For coaxial cables the shield is braided.
• Hoses for thermal insulation