CUTTING MACHINES

SUBMITTED BY

PROTIM SAIKIA

AAMTS

CUTTING MACHINES

Cutting

Fabric cutting is the most important part of garment industry. Cutting

different parts of garment apparel very carefully according to shape of

pattern is called fabric cutting. Consistent fabric cutting is very important for

perfect garments making.

Requirement of cutting

Precision of cut- To ensure the cutting of fabric aquirtly according to the line

drown of the marker plan.

Clean edge- By avoiding the fraing out of yarn from the fabric edge. Cutting

edge must be smooth clean. Knife must be sharp for smooth or clean edge.

Consistency in cutting- All the sizing safe of the cutting parts should be same

of knife should be operated of the right angle of the fabric lay.

Methods of fabric cutting

There are mainly three methods of cutting are as follows:

1. Fully manual:

Hand operated scissor

2. Manually operated power knife:

Straight knife

Band knife

Round knife

Die cutting

Notcher

Drill

3. Computerized methods of fabric cutting:

Computer controlled knife cutting

Cutting by Laser beam

Cutting by Water jet

Cutting by Plasma torch

Hand operated scissor

Hand shears are normally used when cutting only

single or double plies. The lower blade of the shears

passes under the plies, but the subsequent distortion

of the fabric is only temporary and accurate cutting to

the line can be achieved with practice.

Advantage of hand scissor

Almost every type of cloth are cut by scissor.

Scissors are mainly used for cutting single ply fabric.

Disadvantage of hand scissor

It takes huge time for fabric cutting

It is impossible to cut the fabric lay of any height

Straight knife cutting

The most useful cutting machine in garments industry is the straight knife cutting machine.

Machine parts and their functions:

a) Blade: Cuts the fabric laterally into a spread.

b) Sharpening device: Produces degree of keenness in

the cutting edge.

c) Blade drive: Cutting blade is reciprocated vertically in

the blade housing by the blade drive. It is driven by the

motors drive.

d) Blade housing : It is anchored in the base plate.

It supports the motor, operating handle and sharpeners

e) Blade guard: It is a safety device attached indirectly

to the blade housing.

It has two functions- safety and cutting quality.

It prevents the cutter from accidentally cutting his

positioning hand on top of the spread.

f) Base plate: The foundation that supports and helps balance the cutting mechanism.

It guides the knife in relation to the table surface and elevates the spread off thecutting

table for contact with the blade.

g) Handle: It moves the cutting machine or the cutter over the lines or area to be cut.

h) Power system: It provides power to the drives for the motor drive to move blade

drive whichdrives the blade.

Advantage of straight knife

The knife is comparatively cheap & can be transferred from one place to another

easily.

Lay of higher height can be cut very easily.

Suitable for large production rate as it is convenient to cut the lay of 10 inches height.

Fabric can be cut from any angle.

Disadvantage of straight knife

Sometimes deflecting may occur due to the weight of the motor.

Chance of accident is high.

Blade deflection occurs so quality may be hampered.

Skill hand required.

The more recent development has been a travelling suspention system equipped with a

modified straight knife. These system supports the knife from above, which allows the

heavy base plate and rollers to be replaced with a small, flat plate, reducing the

possibility of distortion during cutting which can arise from the thickness of the

conventional base plate. Suspention from above also reduces the need for a heavy

gauge standard behind the knife, and the width of the blade also reduces, allowing

easier cutting of sharper curves. The drive trolley of the support arm moves

automatically along rails on the side of the table supports as the straight knife is moved

during the cutting process, allowing the best support to the knife at any part of the lay.

These servo knife system enable a much higher degree of cutting accuracy than

unsupported straight knife, with less operated unskill required. In many cases they allow

a standard of cutting to be achieved with a straight cut that is normally only achievable

by transporting roughly cut work to a band knife.

Servo assisted straight knife

Band knife

Band knife cutting machine is look

like a wood cuttermachine. Band

knife is used for precession cutting

small parts of garment. This band

knife cutting machine has lower

noise, less temperature up, high

power, less vibration and auto

sharpening device.

Cutting Blade

5" / 6" use narrow blade.

8" / 10" use wide blade.

Features of Band Knife Machine

1. This machine worked as saw mill technique.

2. Not possible to

red in bundle form to cut by this machine.

4. Blade moving vertically through a flat working table.

5. Machine remains stationary and fabric is moveable.

6. Specially used to cut small parts more accurately.

cut fabric directly from lay.

3. Block pieces of fabric requi

Round knife

Round knife is mostly use for cutting the big

parts of the garments pattern.

Advantage of round knife

Disadvantage of round knife

Not suitable for cutting very curved lines in higher

number of lays as the blade does not strike all the

piles simultaneously at the same point.

Round knife is used only for straight line & lower

number of piles.

Not suitable for higher production.

Possibility of accident is high.

Difficult to cut small components.

Round knife is widely used to separate the big parts

and separate the blocks of fabric from relatively

small height fabric lay.

Die cutting

Advantage of die cutting

Die cutting is suitable for precession cutting of small parts of a garment.

It is suitable for cutting the fabric in any angle & any shape.

Especially suitable for knitted fabric.

Disadvantage of die cutting

Die cutting method needs block of fabric lay.

More fabric wastage.

Die manufacturing cost is high

Die cutting involves pressing a rigid blade

through the lay of fabric. The die is a knife

in the shape of a pattern periphery, including

notches. One or more tie bars secure its

stability. Free standing dies generally fall into

two categories. They can be of strip steel,

manufactured by bending the strip to the

shape required and welding the joint. These cannot be sharpened and must be replaced

when worn. Alternatively, they can be heavier gauge,forged dies which can be

resharpened but which are about five times the price of strip steel. The position of the

tie bars determines the depth of cut, which is generally greater with forged dies.

Free standing dies cut the small parts of larger garments such as collars and trouser

pocketing or the parts of smaller garments such as bras. They can also be used for part

of a larger garment part., such as the neck area of a coat front. They provide a high

standard of accuracy of cutting but, because of the cost of the dies, they are only

appropriate to situations where large quantities of the same pattern shape will be cut.

Band knife cutting machine is a primary device equipment in garment and knitting etc

industries. It could accurately cut the pattern of fabrics. This machine is with special

blower decreases resistance between fabrics and table, which enables the fabrics be

moved easily and be cut precisely. And it could adjustable speed to fit different fabrics.

USES AND FEATURES

Where reference marks are needed away from

the edge of a garment part, such as for the

position of pockets, darts and similar features, a

hole is often drill through all the plies of fabric

in the lay. The drill mounting includes a motor,

a base plate with a hole to allow the drill to pass

through, and a spirit level to ensure that the

base is horizontal and hence the drill vertical.

On looser weave fabrics, where the hole may

close up, a hot drill is used, which will slightly

scorch or fuse the edge of the hole.

If It is important that no mark remains on the

Drill and Thread markers

fabric , a long thread may be passed through the lay which is then cut with scissors

between each ply, leaving a few centimeters visible on each garment panel. All drill holes

must eventually be concealed by the construction of the garment.

Advantage of drill

It has heating arrangement.

It has a system of yarn penetrating.

Disadvantage of drill

Burnt spot can come.

The fabric become penetrated.

Not suitable for loosely woven fabric

Notcher

The Hot Notcher is a multi-purpose tool used

for marking and temporarily fusing loosely

woven fabrics which can ensure precise

alignment for sewing accuracy. The spread

is held securely together and can be moved

to the cutting area without shifting. The Hot

Notcher marks a visible notch on materials

instead of a slit notch which is not easily

visible.

Computer controlled knife cutting

This methods provides the most accurate

possible cutting , at high speed, a typical computer

system has a table with a cutting surface

consisting of nylon bristles which support the

fabric lays but are flexible enough to permit

penetration and movement of the knife blade

which is supported only on the top. The bristles

also allow the passage of air through the table to

create a vaccum, reducing the height of the lay

and holding it in place. The carriage supporting the

cutting head has two synchronised servo motors

Many garment parts required that notches are cut into the edges of them to enable

allignment during sewing with other garment parts. The accuracy depends on the operator

specialised notching equipment provides greater straight notches are available. A further

machine, the hot notcher , incorporates a heating element in order that the blade may

slightly scorch the fibres adjacent to the notch in order to prevent it fraying and

disappearing. This cannot be used in thermoplastic fibres or certain unlined garments.

One fabric requiring it may be a loosely woven tweed.

It is ideal for placing notches in a lay and has a depth adjustment guide to stop you

notching too deeply.

For example when you spread synthetic fabrics the Hot Notcher is used along the lay edge, at

intervals, to seal the plies together which reduces movement and distortion.

It has a depth capacity of 200mm and selectable temperatures of 300, 400 or 500oC.

The Hot Notcher marks a visible notch on materials instead of a cutting machine slit which is

hard to see.

which drive it on tracks on the edges of the table. A third servo motor

positions the cutting head on a beam across the width of the

carriage. These two movements are co ordinated to give a knife

position at any point on the table. The cutting head contains a knife

automatic sharpener and a further servo motor which rotates the knife

to position it at a tangent to the knife with inevitably.

Laser cutting

Advantage

Very active & fast cutting by computer controlledsystem.

Suitable for very large-scale production.

Speed of cutting can be controlled.

Cutting defects are less than other.-Less labor cost.-No need of marker paper.

Disadvantage

Very expensive machine.

Higher maintenance cost.

Computerized cutting systems are achieving more widespread use as technology

costs decrease and labor costs rise. These computer-driven automated cutters utilize

vacuum technology to hold stacks of fabric in place while cutting. Cutting blades are

sharpened automatically based upon the type of fabric being cut. Gerber Garment

Technology manufactures one of the most commonly used cutting systems. This

technology has the advantage of being highly accurate and fast, but does cost

considerably more than other cutting techniques.

As a brand new processing method, laser

cutting processing depends on its precise

processing, faster, simple operation, high degree

of automation has been widly used in the leather

and textile garment industry.

Compared with the traditional cutting method,

laser cutting machine not only with low price, low

consume, moveover laser processing doesn't have

mechanical stress to the workpiece, so the

precision and cutting speed of the cutted

products' result are very well.

Laser cutting machine set of optical, mechanical, electrical as one, with processing

of accurate, fast, simple operation, high automation advantages, now in the textile and

garment, leather and other industries increasingly wide range of applications, and

promote the textile and garment related industries such as fast development.

laser cutting machine has a low price, low consumption, the other because the laser

processing on the processing of the workpiece without mechanical pressure, so the effect

of cutting out the product, precision, and cutting speed are very good. No flash, size

standard, the error is small (0.1mm), effect of soft, non-high-frequency or blunt knife

cutting sense of pressure, high efficiency, low cost, computer design graphics can be cut

out of any shape, any design, any size, lace, etc. , are compared with traditional laser

cutting machine cutting machine and hand cut a huge advantage.

Plasma Cutting Machine

Plazma cutting was originally developed

to satisfy our demand for high quality

cutting. On stainless steel ansd

alluminium. But it can also be used to

cut textile material ( ionized gas is

used )

Advantage

Very high speed cutting

Suitable for single ply cuttingDisadvantage:-

Not suitable for cutting multi layer of fabric

Not suitable for synthetic fabric

Possibility of burning

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 encounters the material to be cut,

tearing the fibres on impact. As the jet penatrates

succesive plies in a spread, the momentum

decreases and cutting ability is reduced. The jet

spread out and cut is wider and rougher at the

bottom of the spread. Here the jet of water is

Water jet cutting

Advantage

Very fast cutting operation

Not require to sharp the blade

Disadvantage

Capital costs are high

Water is to be filtered and de-ionized

normally caught and drained away. There is a danger of wet edges and water spotting.

The water used must be filtered de-ionised.Water jet cutting is most effective with harder sheet materials, including leather and

plastic. A complete computer system has been developed for leather in which hides are

inspected and blemises marked, and the hides are then scanned into the computer. A

marker plan is made in which the patterned pieces are planned into the hide, allowing for

blemishes and for the varying thicknesses that occur in leader, and the hide is then

autamatically cut, in a single layer, by water jet.

Most recently developed is a cutting system

using an ultrasonically driven knife blade .

Vibration frequencies in the 20 k hz range

produce1/20 mm movement in the blade, small

enough to remove the need for a bristle base to

the cutting table. Disposable knife blades save

sharpening time an dlast for 10-14 days. In the

systems developed so far, two cutting heads are

used, moving in different but synchronised

paths. Up to 10 plies can be cut and low

vacuum only is needed.

Ultrasonic cutting machine