Page 160 - Industrial Cutting of Textile Materials

Automated cutting of textile materials 147

such as carpets where detailed cutting is not normally required. Decagonal blades (see
Fig. 9.7) are used to cut aramid, carbon, glass fibre textiles, felt, leather, nylon, and
polyester fabrics. Nonmotorized wheel and pizza knives cut sail cloth, polyester fab-
rics, carbon fibre, fibreglass, PVC, and other textiles. Electrically driven round knives
are used for more demanding applications, like to cut aramid fibre, glass fibre, carbon
fibre, acrylic-coated polyester, air-balloon silk, and others.

Drag knife
Drag blades are often used in a standard cutting head together with round blades (see
Section 9.3.1.1). They are used on the same hard cutting surface as round knives.
While round blades cut straight lines and simple shapes, drag knives process detailed
shapes, sharp corners, small circles, and notches. The drag knives as the main cutting
tool are used to cut tougher and more bulky materials such as PVC or composites.

Oscillating knife
Oscillating blade cutters are used to cut both hard and resistant and soft and thick ma-
terials (see Section 9.3.1.3). Because of their shape and small surface, they are good in
cutting complicated shapes and small angles. To cut different materials and different
shapes, wide range of both flat and pointed oscillating blades are used (see Fig. 9.9).
The short-stroke electrically driven oscillating knives are used to cut different textiles
and also leather. Longer-stroke electrically driven knives are used to process thick and
tough textiles and also harder leather. The pneumatically driven long-stroke knives
cut tough and dense materials that require high cutting forces and also soft but thick
materials and multilayered textiles.

9.7.2.2 Laser
Laser cutting has several important advantages in processing technical textiles (see
Section 10.10). Most traditional lasers used to cut textiles are in the 100–200 W power
range. Low-power laser (from 30 W) cutters are good to cut light textiles (e.g. very light
parachute materials and spinnaker Nylon) and small complicated shape components that
are difficult to cut with blade tools if the knife moves and drags the fabric while it is cut.
In reduced cutting speed, the low-power laser cutters can be also used to cut multi-ply
spreads and thicker materials. Besides, the lightweight fabrics are cut by laser faster than
by blade cutters, and low-power laser cutters are lower priced than the knife cutters.
More costly, high-power (200 W) cutters are appropriate to cut materials like sail-
cloth, insulation materials, nonwovens, and other synthetics. They can incorporate a
blade cutting head integral with the laser head (see Section 9.6.2).

9.7.2.3 Ultrasonic cutting
Ultrasonic cutting tool is able to cut very difficult and hard materials and also thick
fabrics, soft or loosely woven materials, or fabrics with uneven weave or variation
in thickness. In processing synthetic fabrics, ultrasonic cutters give an edge seal (see
Section 9.5).