Cutting
Cutting
Cutting
The work of the marker planner is subject to a number of constraints, such as:Na
ture of the fabric and the desired result in the finished garment a) Pattern ali
gnment in relation to the grain of the fabric b) Symmetry and asymmetry c) Desig
n characteristic of the finished garment 2. Requirements of quality in cutting 3
. Requirements of production planning
1.
Efficiency of the marker :The marker planner measures his success by the efficie
ncy of the marker plan created.
FORMULA: Area of patterns in the marker plan X 100% Total area of the marker pla
n
Multiple copies of the paper marker are normally needed. These copies can either
be made when the marker plan is first drawn, or the master marker can be reprod
uced as needed by a variety of methods, such as:a) Carbon duplicating b) Spirit
duplicating or hectograph carbon system c) Diazo photographic method
y After selecting the most economical marker plan devised in the time available,
the computer will provide an accurate piece count, calculate a marker plan effi
ciency percentage and total the length of the pattern peripheries. y After plann
ing the marker on the computer, the marker planner instructs the computer to plo
t the marker automatically onto paper. Granted a well-maintained plotter, this p
rovides the most accurate marker.
c) Nature of fabric packages :y Fabric packages vary in length, width, and makeup. y The choice of package to be delivered to a cutting
room relates to the characteristics of the fabric and the method of spreading em
ployed such as : Open fabric- rolled Tubular knitted fabric- rolled Folded fabric- rolled Folded
fabric- cuttled Velvet- hanging
1. Hand Shears Used when cutting only single or double plies. Flexible enough to
accommodate any pattern construction and pattern shape Time consuming leading to
high labour cost per garment
2. Straight Knife
Versatile , portable, cheaper than band knife, more accurate on curves than a ro
und knife, relatively reliable and easy to maintain Elements consist of a base p
late, usually on rollers for easy movement, an upright or standard carrying a st
raight, vertical blade with varying edge characteristics and an electric motor a
bove it, a handle for the cutter to direct the blade, and a sharpening device
3. Round knife
5. Notchers
Provides most accurate possible cutting, at high speed Made up of a table with a
cutting surface consisting of nylon bristles The carriage supporting the cuttin
g head has two synchronised servo-motors. A third servo motor positions the cutt
ing head on a beam across the width of this carriage. The cutting head contains
knife, automatic sharpner and a further servo-motor which rotates the knife to p
osition it at a tangent to the line of cut on curves
8. Die Cutting
Process involves pressing a rigid blade through the lay of the fabric The die is
a knife in the shape of a pattern periphery, including notches Provides a high
standard of accuracy of cutting but, because of the cost of dies, they are appro
priate in situations where large quantities of the same pattern shape will be cu
t
9. Laser Cutting
A laser produces a beam of light which can be focused into a very small spot (0.
25mm), producing a very high energy density Cutting takes place by vaporisation.
Charring is prevented by the use of a jet of inert gas which also removes debri
s and smoke from the cutting area If several plies are cut, the accuracy is not
perfect as it is a V cut rather than a straight line. There is also risk that th
e edges may fuse together
A very high velocity, small diameter stream of water is created by applying high
pressure water to a nozzle The high pressure jet acts as a solid tool when it e
ncounters the material to be cut, tearing the fibres on impact Here the jet of w
ater is normally caught and drained away
Uses an ultrasonically driven knife blade Disposable knife blades save sharpenin
g time and for 10-14 days Upto 10 plies can be cut and low vacuum only is needed