Braiding Processes and Machines

According to the German Industrial Standard DIN 60000 (1969), braids are defined as two- or three-dimensional fabrics with even thread density and closed fabric appearance whose braiding threads cross each other in diagonal direction to the selvedges. The first braids were hand braids. At least three hair cords are necessary to braid a plait as shown in Fig. 7.1 (left). Later the production of bobbin laces became an artistic skill. 

The most important braiding methods are explained below. Further explanations can be found in Arbeitgeberkreis Gesamttextil (1981,1982,1996), Engels (1994a, 1994b), Lepperhoff (1964), Kyosev (2014), and McKenna et al (2004). 

---

To the best of this author s knowledge, 3DDfW preforms have been only produced in small demonstration samples on some manually operated devices. This author is not aware of any industrial-scale automated machines for their production. By the nature of this particular 3D weaving process, the fabric cross-sectional dimensions will be always relatively small (similar to the well-known situation with 3D braided fabrics), and the weaving speed will be always much slower than in the production of... 

The rubber hose industry is one of the two largest segments of nontire rubber fabricators. Worldwide, the hose industry had about 6 billion dollars in total sales in 2010. Automotive and industrial are two very large market areas for hose. Some hose processes, for machine-made and hand-built hose, are very labor intensive. Processes for braided and spiral hose are less labor intensive. Hoses constructed in the factory are commonly cured in autoclaves. 

In the past a limitation on this process was that it tended to be restricted to shapes which were symmetrical about an axis of rotation and from which the mandrel could be easily extracted. However, in recent years there have been major advances through the use of collapsible or expendable cores and in particular through the development of computer-controlled winding equipment. The latter has opened the door to a whole new range of products which can be filament wound - for example, space-frame structures. Braiding machines for complex shapes are shown in Fig. 4.76. 

One of the desired features of the technical plant stem is improved torsional stability and oscillation damping. As mentioned, the diagonal fiber bundles can be incorporated into the technical plant stem via a braiding machine, which was installed in-line with the pultrusion process (Figs 9.13 and 9.14). 

---