Page 109 - Industrial Cutting of Textile Materials

96 Industrial Cutting of Textile Materials

Fabric plies

Force

Fig. 7.16 Displacement of fabric plies in a spread.

the accumulated weight of placed fabric plies decrease their displacement but do not
entirely eliminate it. Because of these deformations, components with an incorrect
size or pattern placement may be cut. This problem is more likely in fabrics with a
slippery surface.
To minimize the displacement of fabric plies during the cutting process, the follow-
ing actions are taken:
A firm paper ply is spread under the first fabric ply (see Section 5.2.2).
●
A spread is fastened together with clamps or weighted down by heavy objects.
●
The firm paper lay beneath the spread ensures easy movement of the spread or its
cut parts along the spreading table and protects the lower fabric plies from the appear-
ance of creases and folds.
Clamps are fixed to the edges of the spread or its separated parts (see Fig. 7.17).
A variety of heavy objects are used to weigh down the fabric plies in the inside area
of the spread. During the cutting process, the location of clamps and weights are
changed, so the cutting process is not impeded.

7.4.2 The shape of the cutting device

Straight- and round-shaped blades are used in manual cutting machines (see Fig. 7.18).
The straight-knife and band-knife cutting machines have straight blades, and the
round-knife cutting machine has a circular blade. The most manoeuvrable and accu-
rate blades are those with a small cutting surface. The band knife has the narrowest
blade and therefore the highest degree of cutting precision. The round-knife blade
has the largest surface and thus the lowest degree of manoeuvrability and accuracy.

Fig. 7.17 Fabric plies fixed by clams.