36785834-Spreading-and-Cutting-Machinary.pdf

SPREADING AND

CUTTING MACHINARY

(S.P.ME.)

By:-Aeasha

Devanu Roy ChoudhuryIshan RastogiMona Kumari

(B.F.Tech. Sem-IV)

SpreadingSpreading is the processes of superimposing lengths of fabric on a spreading table cutting table or specially designed surface in preparation for the cutting process.

A spread or Lay-up is the total amount of fabric prepared for a single marker.

Methods:-1. Spreading By Hand2. Spreading Using A Travelling Machine

Spreading By Hand

Time consuming method Require operator on each side of table But necessary for spreading some typical fabrics, like

o Checked fabricso Fabrics with crosswise stripeso Fabrics with regular repeating patternso Fabrics with a repeating design at intervals of

a garment length

Spreading Using A Travelling Machine

Spreading machines carry the piece of fabric from end to end of the spread, dispensing one ply at a time.

Components of spreading machine:-o Frame or carriageo Wheels travelling in guide rails at the edge of

the table

o A fabric supporto Guide collars to aid the correct unrolling of the

fabric.

Working:-o In the simpler version, the operator clamps the

free end of fabric in line with the end of the spread,

o Then pushes the spreader to the other end,o Cuts off the ply in line with that end,o Clamps the beginning of the next ply,o Pushes the spreader to the other end and so

on.

Cutting :-

Manual Cutting MachinesFabric Scissors

o Used to cut only single or double plies.o Appropriate for made-to-measure

garments/tailor made garments.o Can cut any fabric type & pattern shape.o Blade length- 8"-14"

Advantages:-1. Very portable2. Easily available3. Easy to handle4. Suitable for both left and right handed people5. No electricity required

Disadvantages:-1. Time consuming2. Need muscular power3. Requires a lot of skill4. Very low productivity5. Not suitable for mass production

Straight Knife

Advantages:-1. Easily available2. Cheaper3. Can be used for various types of fabrics & styles4. Knife blades are easily available & replaceable5. Have the option of changing the blade size within a

machine

Disadvantages:-1. Problem with sharp turns2. Not very safe for the operator3. It has a issue of grip on the fabric (stretchable

fabrics)

STRAIGHT KNIFE:

Blade length - 4 to 14 inches. Induction motor, HP, 220 volts. 2850 rpm. Blade holder for the blade to rest. Auto sharpening device Grinding belts.

Manual lubrication system.

Round Knife

Advantages:-o Larger surface area in contact with the fabric, so

better grip.

Disadvantages:-o Ply cutting is staggered (not uniform in all plies)o V-necks, scoop necks, steep curve cutting is almost

impossible.o Knife clearance area (KCA) required is very higho Lay height should not be more than the radius of

bladeo Costlier than straight knifeo Changing of blade is difficult

ROUND KNIFE:

Blade diameter 4 to 8 inches. 2850 rpm. Auto sharpening device Grinding stone.

Band Knife

Advantages:-1. Speed is high2. Precision cutting3. Easier to cut very small pieces of pattern4. Cutting of single layer or multiple layers can be

done easily5. Mitering of shirts, etc is done using this

Disadvantages:-1. Expensive2. Supportive infrastructure is required, which adds to

the cost3. More space is required4. Safety is a major issue5. Maintenance is difficult comparatively

BAND KNIFE:

The knife rotates on 3 blades. Works in single and 3 phase. Blade thickness 0.45mm. Blade width 10mm. Blade length 3500mm.

Maximum layer cut 12.

Die Cutting

Advantages:-1. Very high precision cutting2. Easily available3. Cost is low

Disadvantages:-1. Cannot be used for very dense fabrics2. Cannot be used for knits & leather like fabric with

woven base3. With every style & size change, a new frame is

required

Machine Specification And Details

There are 3 types of blades available:

Fine edge Medium edge Coarse edgeUsed mainly for silk, synthetic, knits and loosely woven fabrics.

Light woollen, polyester, mens suiting fabric and velvet.

Heavy weight cotton, twill, lining, tightly woven fabrics, denims, soft leather, and vinyl rubberized materials.

Blade material is generally high carbon and high speed steel.

Newer technologies are being developed for blades as well, listed below are:

o Teflon coated blade: To avoid blade heat up. o Grooved blade: Grooves on the blade provide

air for cooling, grip the fabric in a better manner.

Die Cutting Method :-

1. Cutting is done through shear hydraulic press.2. Used for non woven and leather in shoe industry.

Advantages of die cutting:

Cheaper. 100% accurate cutting. Can be used for larger patterns also. Easily available.

Disadvantages of die cutting:

Cannot be used for very dense materials. For every change in style and size a new

template has to be developed.

Fully Automatic Cutting Machines

Advantages:-1. Very high speed2. High productivity3. Cutting is done on cutting table, so the spreading

table is free for new spread of lay4. Man skill required is less

Disadvantages:-1. Cost is very-very high2. Extra infrastructure required3. Lay height is less4. Very accurate feeding of fabric needs to be done

Computerised Cutter

1. Table with a cutting surface of nylon bristles.2. Nylon bristles support the fabric lay that are

flexible enough to permit penetration & movement of the knife blade.

3. Nylon bristles also allow the passage of air through the table to create a vacuum, reducing the height of the lay & holding it in place.

4. Knife blade is supported on the top.5. The carriage supporting the cutting head has 2

synchronized servo motors which drive it on tracks on the edges of the table.

6. A sheet of air tight polyethylene covers the top of the lay which assists in creation of vacuum & allows significant compression of the lay.

7. A control cabinet houses the computer & the electrical components required to drive the cutter, its carriage & the vacuum motor.

Laser Cutter

Laser cutting works by directing the output of a high power laser, by computer, at the fabric to be cut. The material then either melts, burns, vaporizes away, or is blown away by a jet of gas, leaving an edge with a high quality surface finish.

Principle A laser produces a beam of light which can be

forced onto a very small spot (O.25mm), producing a very high energy density. The energy transfers to the material upon which it is focused, producing a rapid increase in temperature.

Cutting takes place by vaporization. Charring of the fabric is prevented by the use of a

jet of inert gas which also removes debris & smoke from the cutting area.

A laser beam does not become blunt but it does suffer with limited depth of focus.

Laser cuts with incredible speed.

Waterjet Cutter

A water jet cutter, is a machine capable of cutting fabrics using a jet of water at high velocity and pressure, or a mixture of water and an abrasive substance.

The cutter is commonly connected to a high-pressure water pump where the water is then ejected from the nozzle, cutting through the material by spraying it with the jet of high-speed water. Additives in the form of suspended grit or other abrasives, such as garnet and aluminium oxide, can assist in this process.

An important benefit of the water jet cutter is the ability to cut fabrics without interfering with the material's inherent structure as there is no "heat-affected zone" or HAZ. Minimizing the effects of heat allows fabrics to be cut without harming or changing intrinsic properties.

Water jet is considered a "green" technology. Water jets produce no hazardous waste, reducing waste disposal costs. Water jets use very little water (a half gallon to approximately one gallon per minute depending on cutting head orifice size), and the water that is used can be recycled using a closed-looped

system. Waste water usually is clean enough to filter and dispose of down a drain. The garnet abrasive is a non-toxic natural substance that can be recycled for repeated use. Garnet usually can be disposed of in a landfill. Water jets also eliminate airborne dust particles, smoke, fumes, and contaminates from cutting materials such as asbestos and fiberglass. This greatly improves the work environment and reduces problems arising from operator exposure.

Commercial water jet cutting systems are available from manufacturers all over the world, in a range of sizes, and with water pumps capable of a range of pressures.

Plasma Cutter

Plasma cutting is done using a plasma torch. In this process, an inert gas (in some units, compressed air) is blown at high speed out of a nozzle; at the same time an electrical arc is formed through that gas from the nozzle to the surface being cut, turning some of that gas to plasma. The plasma is sufficiently hot to melt the fabric being cut and moves sufficiently fast to blow molten pieces away from the cut.

The machine has small footprint, increased flexibility, optimum safety, faster operation.

Ultrasonic Cutting

The ultrasonic cutter allows its blade to vibrate ultrasonically, enabling the blade to cut a wide range of materials.