**5. The modern lace braiding machine**

The modern lace braiding machine is a direct descendent of the Barmen lace machines. The modern lace braiding machine has been continually improved; as witnessed in the numerous European, Japanese, and international patents. Some notable improvements include electromagnetic actuation of driver plates which allow electronic pattern control and computerized design to operate seamlessly without Jacquard punch paper. The electronic control eliminated the need for a mechanical Jacquard mechanism. Improvements in machine materials have increased the wear resistance and life of components. Certain mechanical features of the modern lace braiding machine protect the components and its lace product during production. For example, if the yarn breaks during production, the machine will automatically shut off as the bobbin carrier shorts an electrical switch so that the lace fabric can be saved and the broken yarn can be repaired by simply tying a knot. If this feature were not available, each time a yarn broke, the whole lace fabric would have to be discarded. A second feature is the construction of clutches out of a low-cost plastic material. If certain components fail to function perfectly, the clutch will fail before machine damage occurs. These inexpensive clutches can be replaced relatively easily and quickly. These two protective features are essential for industrial lace braiding but they limit the size and type of yarn that can be used.

Presently many of the modern machines are produced by Asian manufacturers who are in proximity to the textile manufacturing locations, although the Krenzler Company still manufactures lace braiding machines in Germany [16]. The machine evaluated in this research is manufactured in South Korea and clearly has its engineering origins from the Barmen lace machine. Considering improvements in the Barmen lace braiding machine during the last 30 years and the fact that many lace braiding machines are now manufactured outside of Germany, we refer to these machines as modern lace braiding machines. We acknowledge that the modern lace braiding machines originated from the Barmen lace machines.

**Figure 5** is an engineering rendering of the modern lace braiding machine evaluated during this research. **Figure 6** illustrates the bobbin spindle actuation assembly. Spindle cradles are used to move yarns with the driving plates. The solenoid actuates the plastic cam which in turn lifts the plastic fork and plastic clutch and engages the driver plate allowing the spur gear to rotate the spindle cradles and perform the basic cross and twist motions on the yarns. After 180 degrees of rotation, the cam pushes against the inactive solenoid and a compression spring forces the fork and clutch to the resting position while spindle cradles and bobbins remain stationary.

#### **5.1. Bobbin spindles (carriers)**

Another notable difference of the Barmen lace braiding machine is the beat-up mechanism. This mechanism is akin to the weaving machine reed used to control fabric density. The beatup mechanism is found in the center of the machine and consists of a dome with slits to allow reciprocating action of knife blades to compact the yarns following the corresponding beating motion. The blades are deployed as even and odd groups, according to the driver plate and spindle motions. These important advances over the Maypole braiding machine provide the

The driver plates are positioned as a series of overlapping circles about the machine radius. The driver plate geometry is symmetric about two orthogonal axes with concave and convex regions. For a plate to rotate adjacent plates are required to remain stationary. Adjacent concave regions precisely permit the moving convex spindle cradle to pass without interference. This motion serves as the primary mechanism for imparting motion to the spindles and ultimately the yarn. In the same way as the traditional braiding machine, two different motions

Lace machines have been employed with a variety of materials, both natural and synthetic fibers, in the production of fancy lace and other apparel products. Marenzana [15] describes the use of Rayon fiber with lace braiding machines. Surface fiber treatments, known as sizing, may improve the lace braiding process as well as resin-fiber compatibility in subsequent composite manufacture. The use of high performance fibers such as those commonly found

The modern lace braiding machine is a direct descendent of the Barmen lace machines. The modern lace braiding machine has been continually improved; as witnessed in the numerous European, Japanese, and international patents. Some notable improvements include electromagnetic actuation of driver plates which allow electronic pattern control

ability to produce complex and irregular fabric structures.

**Figure 4.** Schematic view of lace braiding machine.

64 Engineered Fabrics

in composite materials has not been reported in the literature.

**5. The modern lace braiding machine**

are required to pass a spindle.

**4.3. Known materials used**

Another important component is the bobbin spindle. Commonly referred to as carriers, they control the tension in the braiding yarn as well as allowing the release of new material during braiding. See **Figure 7** for the following operational details. The yarn is unwound from the bobbin and passed through an initial eyelet making a 90-degree bend where it continues until a second eyelet is located which also requires a 90-degree bend toward the spindle center where another 90 degree turn over a ratcheting pawl is required. The yarn now travels down the center of the spindle tube i.e. bobbin axis of revolution where a tension spring with eyelet requires a 180 degree turn. Finally, the yarn moves up the tube where a final ceramic eyelet allows the yarn to reach the fabric formation zone.

**Figure 5.** CAD drawing of modern lace braiding machine.

**6. Analysis of machine for manufacture of structural composite** 

Lace braiding technology has been demonstrated in the manufacture of intricate and decorative fabrics for more than a century. If lace braiding machines are suitable for handling large high strength yarns such as aramid and even carbon fiber prepregs, it was thought that the structures might be suitable for use as planar and 3-D space trusses. An evaluation of a modern lace braiding machine is performed on the typical execution to determine if braided composite strength-to-weight ratio could be improved by utilizing a lace braiding technology. A modern lace braiding machine incorporating a computer controllable electro-mechanical yarn interlacing system was purchased to test the proposition that it might be used to more efficiently orient and interlace yarns to create a truss-like pre-form in either a flat or cylindrical form [17]. **Figure 8** is an example of a CAD model for a proposed composite tube manu-

Lace Braiding Machines for Composite Preform Manufacture

http://dx.doi.org/10.5772/intechopen.82256

67

**Figure 9** shows the initial lace fabric preform made with a modern lace braiding machine during the evaluation and research phase of this work. The small white yarns are cotton. **Figure 10** shows a flat lace manufactured on a modern lace braiding machine made from

**Table 1** denotes a list of advantages of the modern lace and braiding machine.

**pre-forms**

**Figure 7.** Bobbin spindle (carrier).

factured with a lace braiding machine.

larger twisted yarns.

**Figure 6.** Main bobbin actuation assembly (front and rear views).

Lace Braiding Machines for Composite Preform Manufacture http://dx.doi.org/10.5772/intechopen.82256 67

**Figure 7.** Bobbin spindle (carrier).

**Figure 5.** CAD drawing of modern lace braiding machine.

66 Engineered Fabrics

**Figure 6.** Main bobbin actuation assembly (front and rear views).
