1. Lab Report
Course Code:-TE-3402
Course Title:-Apparel Manufacturing Engineering-I (Sessional)
Experiment No. 03
Name: Study on Straight knife & Round knife m/c.
Submitted by
Name :
ID :
Year and Semester :
Session :
Department :
Mahbubay Rabbani
175035
3/1
2018-19
Textile Engineering
Submitted to
Md. Ayub Ali
Assistant Professor
Department of TE
Dhaka University of Engineering & Technology (DUET), Gazipur
2. Introduction:-
Straight Knife Cutting Machine:-
The straight knife cutting machines are used to cut components of large lay height
& curvilinear cutting. It is the most widely used cutting machine in apparel
industry. This machine is called straight knife cutting machine because its cutter is
straight in shape. It is used for both woven & knit fabric.
Objectives:-
• To know about the different parts of the machine.
• To know about the working procedure of the machine.
Features of straight knife cutting machine:-
1. Cutting knife is straight in shape.
Blade length - 10-13 inch (10-33)
Blade width -1.5 cm,
Blade thickness - 0.5 mm,
2. Knife is driven by electric power.
3. Grinding wheel is present to sharp the knife during cutting.
4. The machines consistof base plate, electric motor, handle, knife, knife guard,
stand, roller wheel.
5. Base plate usually on roller wheel.
6. Handle for the cutter to direct the blade.
7. Blade edge: Straight edge, Weave edge, saw edge, scattered edge, but straight
edge is mostly used.
3. Advantages of Straight knife:-
1. A large number of fabric lays can be cut by the machine due to high
length of knife & r.p.m. of the motor. So, productivity is high.
2. Automatic grinding.
3. Automatically lubrication.
4. Comparatively cheap.
5. Can be moved easily by wheel.
6. Suitable for straight line & curve line.
7. Can be cut high curve line than round knife.
8. Fabric can be cut from any angle.
Disadvantages of Straight knife:-
1. Due to motor weight, can cause knife deflection time to time.
2. Skilled operator is needed.
3. Knife deflection is at high risk when lay height is too high.
4. Safety measures is must.
5. Large straight knife is difficult to move.
6. Cannot cut in 90 degree angle.
4. Round knife machine:-
Another cutting machine is round knife cutting machine. It is called round knife
because its cutter is round but slightly octagonal in shape. It is used to cut large and
medium size components with a simple shape. It is mainly used for small
production. Round knife is basically used for edge cutting while the manual laying
or spreading is taking place.
Features of round knife machine:-
1. Blade is octagonal type and has a very sharp edge.
2. Round knife is more costly than straight knife cutting
machine.
3. Round knife machine have manual grinder is used to sharp
the blade.
4. Fabric lay height can be cut using up to 40 percent of the
blade diameter of round knife.
5. Knife diameter varies from 6 to 20 cm
6. Motor rpm is 800-1600.
7. Knife is lubricated manually.
8. Three types of knife edge can be used for cutting different
objects.
9. Light weight machine ( 3 to 11 kg)
10. Most effective for cutting slippery materials.
5. Advantages:-
1. Easy to handle & operate.
2. Suitable for small scale cutting.
3. Suitable for gentle curve line cutting.
4. To cut the larger part of the garments.
Disadvantages:-
1. Very low r.p.m. & knife height.
2. Manual grinder is used.
3. Not suitable for large production.
4. Lubrication is manually done.
Materials and method:-
Fabric type:-Cotton
Straight knife cutting machine:-
Brand:-YAMATA
Model:-FY-103
Origin:-China
Motorrpm:-3000
Round knife cutting machine:-
Brand:-HONKON
Model:-HK-90
Origin:-China
7. Main parts of Straight knife cutting machine:-
1. Base plate
2. Straight knife
3. Lubricating unit
4. Handle
5. Electric motor
6. Transport handle
7. Moving handle
8. Grinder
9. Knife guard
Working principle of Straight knife machine:-
Two kind of power are required to operate a straight knife.
→ Motor power drives the reciprocating blade.
→ Operator power drives the knife through the lay.
The motor power needed is determined by
i. Height of the lay.
ii. The construction of the fabric.
iii. The curvature of the line being cut.
iv. The stroke of the blade.
The greater the powerof the motor the heavier will be the machine. The taller stand,
the thicker its cross-sectionand thegreater its width, adding resistance to the forward
movement on a curve. The greater the blade movement the faster the blade cuts the
fabric and the more rapidly and easily the operator can push the machine. Operator
effort is affected by the weight of the motor, the shape of the stand, handle height,
stroke, sharpness of blade and the effect ofthe base plate rollers onthe table surface.
9. Main parts:-
1. Motor
2. Handle
3. Power switch
4. Base plate
5. Throat plate
6. Carrier
7. Round knife
8. Knife guard
Working Procedure of Round knife machine:-
1. We have to choosepowerof the round knife cutting machine according to height
of the lay, The constructionof the fabric, The curvature of the line being cut and the
stroke of the blade.
2. Fabric lays spread on the cutting table. Then the marker is placed on the fabric,
after that a round knife cutting m/c is placed at any corner point of fabric lays.
3. Then the cutting machine being switched.
4. Until finishing the marker cutting is continued
5. The cuts of fabric depends on the movement of blade.
10. Differences between Straight knife m/c and Round knife m/c:-
S/L Substances Straight Knife Round Knife
01 Movability In this machine,
machine is movable
but fabric is fixed.
In this machine, machine
is stationary and fabric
is movable.
02 Knife
Thickness
Knife is thicker. Knife is narrower than
band knife.
03 Accident
Rate
Accident rate of this
machine is high.
Accident rate of this machine
is low.
04 Work Load Workload is less than
round knife.
Workload is higher than
straight knife.
05 Cut
Possibility
In this machine, there
has possibleto cut
fabric.
Not possible to cut directly.
06 Similar Straight knife is not like
saw cutter.
Round knife is almost like
saw cutter.
07 Cut Angle Fabric can cut at any
angle.
Possible to cut the fabric
layer in 90°.
11. Maintenance:-
1. Regular grinding of the blade
2. Lubricate the moveable wheel
3. Cleaning the moving parts
4. If grinding is not perform well then change emery paper.
Conclusion:-
After completing this experiment 2 types of manual fabric cutting machine is their
features, significance, advantages, disadvantages, working procedure are known.
How different parts of those machines are working and their maintenance is also
known. This knowledge will help in our future.
