Braiding machine

A braiding machine at the Arbetets Museum (Museum of Work) in Norrköping, Sweden

A braiding machine weaves strands of yarn to form rope, reinforced hose, covered power cords, and some types of lace. Materials include Nylon, polypropylene, polyester, polypropylene/polyester blend, and others.

Maypole analogy

Braiding machines work by a circular weaving process.^[1] They were well suited to be driven by the steam engines of the industrial revolution and were common by the beginning of the 20th century being easily powered by electric motors. Common types of braiding machines work in much the same way as the process of decorating a maypole. At the start of decorating a maypole an even number of ribbons tied to the top of the pole. A group of people form a ring about the base of the pole and take a ribbon in hand. Half the people then travel clockwise and the other half counter clockwise. When the people pass one another they pass alternately to the right and to the left. This results in a downward forming braid on the pole. As the braid works its way down the pole, the ribbons become shorter and the angle of forming changes as the braid works lower on the pole. On a standard braiding machine, the supply lines are a constant angle and at a constant tension and hence the output braided product is uniform.

Process

Base of a braiding machine, with two tracks, one shaded in green and one shaded in red. Four bobbin carriers slide along each of the two tracks. The four bobbin carriers shaded in green travel around the green loop in the clockwise direction, and the four bobbin carriers shaded in red travel around the red loop in the counter-clockwise direction. As the two tracks cross over, the strands twist around each other, making a braid. In the case of this particular machine, eight strands are braided into a square braid.
The carriers are pushed by four horn-gears in the base plate. Each of the horn-gears has a gear and a horn on a common shaft. The gears intermesh with each other, with alternate gears traveling in opposite directions. Each horn has four slots for pushing a bobbin carrier. The bobbin carriers get passed along from one horn th the next as they make their way along the track.

1. Fibers are spun into yarn.
2. One or more yarns are twisted together to form a strand.
3. Strands are wound onto bobbins.
4. Bobbins are mounted on carriers.
5. Horn gears move the carriers along tracks on a braiding machine.

In a braiding machine, bobbins of thread pass one another to the left and right on pseudo-sinusoidal tracks, a peg at their bases is driven by notches in gears. These gears lie below the track plate that the thread carriers ride on, and an even number of gears must be used as there are always an even number of bobbins. The gears must be driven at multiple points on machines with two or more bobbin sets and cross-shafts are used. On a vertically oriented machine, the braided thread is taken up above the machine and height and diameter of a guide ring determines the characteristics of the braided product to some degree. On horizontal oriented machines, the braiding track plate and associated bobbins are turned through 90 degrees. This enables large stiff braided cables to be output horizontally so a tall factory building is not required. Braiding machines, although they have an apparent complex movement of bobbins, are mechanically simple and robust. Modern versions are very reliable and consequently can operate for many hours or even days without attention. This has enabled factories with hundreds of machines to be operated by just a few workers, reducing wages, and making products cheaper and/or profits higher. These modern machines have incorporated electronic controls with automated controls. Although ropes, cords and fishing line are still the core products of most braiding companies there are many other products including webbing, cable shielding and automotive products such as reinforced brake lines.

Some machines use a different system, where the motion of the thread carriers resemble a Teacup Ride.

Automatic high speed braiding machines

Automatic high speed braiding machines are normally equipped with programmable logic controller (PLC), automatic mess adjusting and motor-driven yarn feeders, so that to make the operation simple and easy. Meanwhile, compared to normal braiding machines, high speed braiding machines save cost from labour, electricity and time.

Products from braiding machines are everywhere in life, like shipbuilding, national defense industry, port operations, high pressure and magnet shielding wires and pipes, decorative ropes and belts, shoelace, elastic ropes and belts,cables etc.

There are non-traditional machines that have a grid array of thread carriers that under computer control can braid over complex shapes.

References