Cutting Method & Knife

Prepared By : Mazadul Hasan sheshirID: 201000040000813th Batch (session 2009-2013)Department : Wet Processing Technology Email: mazadulhasan@yahoo.comBlog : www. Textilelab.blogspot.com (visit)

Southeast University Department Of Textile Engineering

I/A 251,252 Tejgaon Dhaka Bangladesh

Prepared By :

Total Textile Process at a Glance

Fabric Cutting To make a complete garments, cutting is necessary. It means to cut

out the garment pieces from lays of the fabric with the help of cutting templates. In garments industries fabric is cut from lay and spreading with accuracy and properly which is termed as fabric cutting.

• Object: To separate fabric parts from the spread of the lay according to the

dimension of the marker• Requirements Of Cutting: Precession of cut Clean edge Infused edge Consistency in cutting Support of the lay

Types of Cutting Method Fully Manual Hand operated scissor Manually Operated Power Knife Straight knife Band knife Round knife Die cutting Notcher Drill Computerized Methods Of Fabric Cutting Computer controlled knife cutting Cutting by Laser beam Cutting by Water jet Cutting by Plasma torch

Hand Operated Scissor

• Features: First & oldest method of fabric cutting Used for cutting one or two plies of fabric Available to cut the fabric from left to right or right to left Can be cut by scissor Needs more time & contain high cost Used in tailoring & household purpose to cut fabric

Straight Knife• Features: The elements of straight knife consists of: 1. An electric motor 2. Stand 3. A base plate usually on rollers 4. Handle 5. Knife 6. Knife Guard 7. Wheel Knife is driven by electric power Grinding wheel is present to sharp the knife during cutting Blade edge: straight edge, wave edge, saw edge, serrated edge Straight edge is mostly used Blade stroke 2.5 to 4.5 cm Can cut heavy fabric such as canvas & denim

Straight Knife• Working Principal: Two kind of powers are required to operate a Straight Knife Motor power drive the reciprocating knife Operator power drives the knife through the lay

The motor power needed is determined by Height of the lay Construction of the fabric Curvature of the line being cut Stroke of the blade

Greater power of the motor, greater blade movement to cut the fabric

Straight Knife• Advantage: Comparatively cheap & transferred easily from one place to

another place Higher lay of fabric can be cut easily Round corner can be cut more precisely then even round knife Production speed is very good & fabric can be cut from any angle

• Disadvantage: Some time deflection may occur due to the weight o the motor Knife deflection is high in risk, when lay height is too high Sometime accident may happen

Different Types Of KnifeRound Knife:

Straight Knife:

Wave knife Straight knife Notch knife

Band Knife• Features: Band knife comprises a series of three or more pulleys, powered by

electric motor Cutting knife is endless in shape & flexible Blade is usually narrower then on a straight knife This method m/c is stationary but fabric is moveable This is like saw mill cutter

Band KnifeAdvantage:

Used when a higher standard of cutting accuracy is required

Extensively used to cut very sharp corners small parts such as collars & cuff

Used more in men’s wear than ladies wearIntensively risk of accident is low

Possible to cut 90˚ angle of the fabricDisadvantage:

Work load is high as m/c is stationary & fabric is moveableNot suitable for cutting large amount of garments parts

Not possible to cut fabric directlyFabric wastage is high

Power loss is high

Round Knife• Features: Element of round knife: Base plate & Electric motor Handle for the cutter to direct the blade Rotating circular blade Blade diameter varies from 6-20 cm Blade is circular Blade is driven by electric power Circular knife is driven by 1000-3500 cm•

Round KnifeAdvantage: Suitable for single ply cutting as well as multi-

layers (say 20-30 layers)Suitable for small scale cuttingSuitable gentle curve cutting

Easy to operate Useful for cutting layer parts of a garments

Disadvantage:Not suitable for cutting very curve lines in higher no. of lays

Not suitable for higher productionPossibility of accident is high

Difficult to cut small componentNeeds skilled operator

Die Cutting

• Features: Mainly two types of die cuttings are available namely: Presses &

Clickers Main parts of all die cutting m/c are Blade, Ram Head, Die,

Motor & Operating System of Ram Die is made by metallic strip Most useful to cut sharp & small parts

Die CuttingWorking Principal:

Die is prepared with metal strip according to the shape of patternDie press generally has a cutting die just penetrates the cutting pad in order that the fibers of the lowest ply are completely separatedFor die cutting, the spreader spreads a lay to the required

placement of diesThe spread is cut into sections to allow transport to the

cutting padThe gap between two dies 2-3 mm are placed when die is

taken to cut fabric lay

Die Cutting• Advantage: Extensively used to cut sharp corners of small parts of dress

accurately Most useful to cut at any shape or any angle Comparatively less time required Best method of cutting knitted fabric

• Disadvantage: Fabric loss is high due to the need of block of fabric lay High labor cost To change the style quickly is impossible Difficult to cut large components of dress

Notcher Cutting M/CFeatures:

Special type of cutting m/c & used in special caseUsed to cut notch in the edge of some components

The invention of notcher m/c was done to make notchThe notch can be made in U-shape or V-shape

Notcher Cutting M/CAdvantage:

Special type of cutting m/c & used in special caseUseful to cut small notch to the fabric

Most useful to make consistency in notching

Disadvantage:Only used to make notch

Thermoplastic fiber can not cut by this m/cTime loss

Use of the m/c is limited

Drill Cutting M/C

Features:Needed to mark on the end of components of dresses especially for

pocket & dart settingThis m/c contains a motor, base plate, drill, & spirit level

For tightly woven fabric, making of hole by drill is permanent for longIn hypodermic drill some color is sprayed along with the hole so that it

can easy to find the marked place

Drill Cutting M/CAdvantage:

Needed to mark on the end of components of dresses especially for setting pocket & dart

Make the hole permanently for long time

Disadvantage:Only used for making hole in the fabric especially for setting pocket &

dartFor loose woven fabric it can not make the hole permanently for long

time

Computer Controlled Knife CuttingFeatures:

This method provide the most accurate possible cutting at high speedMarker is not necessary to put over the fabric lays during cutting

Cutting knife is oval shaped & very hard. Sharpness is also high & blade is made of stainless steel

Cutting knife itself moves according to the direction of computer memory

This m/c is CAM system m/c & works through CAD system

Computer Controlled Knife Cutting• Advantage:

Very fast cutting operation Very active cutting by computer controlled system Suitable for very large scale production Speed of can be controlled Intensity of accident is low No need of marker Fabric can be cut 6-8 times than manual method Less labor cost• Disadvantage: Very expensive m/c Higher maintenance cost Skilled manpower is required If correct disc is not loaded in the computer, error will

be indicated

Cutting By Laser BeamFeatures:

This method, fabric is cut by a ray of light in a very fine spot using a laser

Radius of spot of light is 0.25 mm & high powerfulWhen the ray falls on a material, it generates heat on the material &

cutting is done by vaporizationFabric is cut at a speed of 13 meter per min

Cutting head is controlled by computer

Cutting By Laser Beam

• Advantage: Very fast cutting operation Can be cut in a proper line as the cutting head is controlled by computer As the fabric is cut by ray off high so that no need of sharpening

operation • Disadvantage: Not suitable for cutting of multi-layer of fabric For thermoplastic fabric the cutting edge should be fused Very expensive cutting method

Cutting By Water Jet

Features:This system, thin jet of water is passes through a nozzle in a very

momentumPressure of water is 60,000 pounds per square inch

Water is worked as like as hard & sharp knife which can easily cut the fabric

A catcher in the bottom of fabric lays & it used with the same speed & the same direction of water jet

Cutting By Water JetAdvantage:

Higher cutting speedThere is no need of knife to cut fabric so that no need of

sharpening operationsBetter to cut hard material

Disadvantage:Not suitable for higher depth of lay of fabricCutting edge of fabric is wetted by water

Sometimes water spot should be seen in the fabricNeed of filtering & deionization of water

Need of controlling the sound of jet

Cutting By Plasma Torch

Features:This system, fabric are cut by a thin through the nozzle which is made

by Argon gasOne or more fabric plies can be cut

Most useful for cutting single ply of fabricFabrics are cut by placing in a table, the surface (85%) of which must

be place in a perforated blanked placeStill now, this system is under research

Cutting By Plasma Torch• Advantage: Automatic torch height control system Automatic oxy-fuel gas control system Automatic torch explosion system Pneumatic band clamping Standard auto-nesting package Easily networked

• Disadvantage: Synthetic fiber not cut Higher number of fabric lay is not cut Need higher skill operator Costly

Some popular garments cutting machine manufacturer

1. Yarn Manufacturing TechnologyLink : http://www.facebook.com/pages/Yarn-Manufacturing-Technology/485014954866808

2. Fabric Manufacturing TechnologyLink : http://www.facebook.com/pages/Fabric-Manufacturing-Technology/459520217425605

3. Garments Manufacturing TechnologyLink : http://www.facebook.com/pages/Garments-Manufacturing-Technology/472364799463126

3. Wet processing TechnologyLink : http://www.facebook.com/pages/Wet-Processing-Technology-Dyeing-/468645219825404

4. Fashion-Design-and-TechnologyLink : http://www.facebook.com/pages/Fashion-Design-and-Technology/587655294583875?ref=ts&fref=ts

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