Straight Knife Cutting Machine.docx

1. NATIONAL INSTITUTE OF FASHION TECHNOLOGY
KOLKATA
SEWN PRODUCTS MACHINERY AND EQUIPMENT (SPME)
JURY REPORT
Submitted by: -
Janvi
Vaibhav Raj

2. Straight Knife Cutting Machine
Straight knife cutting machine is used to cut components of differing size. This is the
most frequently used equipment for cutting garments in bulk. It is moved along the cut
contours, while the fabric spread remains in a fixed position. The machines are
maneuverable and capable of curvilinear cutting. Straight-knife cutting machine is the
world’s most popular and most versatile. Available in all standard electrical
configurations, with the largest variety of sizes and blade speeds in the industry. It is the
most useful cutting instrument in garment cutting. In apparel industry, more than 99%
cases this knife is used.
This machine is called straight knife cutting machine because its cutter is straight in
shape. It is used for both woven and knit fabric. In this machine different types of
straight knife are used according to the different cutting objects. This machine provides
good efficiency. The maximum height of a cut spread is 300 mm. The weight of the
machines varies between 5 and 20 kg. Heavier machines are less manoeuvrable. Small-
capacity production units may use only straight-knife machines. It is widely used in
Bangladesi garment industrry.
Features of Straight Knife Cutting machine:
1. The main parts of this machine are straight knife, electric motor, handle,
grinder, base plate, stand/ knife holder, lubricating unit, wheel etc.
2. Could be used to cut higher depth of fabric.
3. Knife height is 10 cm to 33 cm.
4. Knife stroke is 2.5 cm to 4.5 cm.
5. Motor r.p.m. is 3000 to 4000.
6. Auto grinder is used.
7. Auto lubricating unit works for this machine.
8. Different types of knife edge are used for cutting different objects. Such as,
straight edge, wave edge, sew edge and serrated edge.
9. A Handle for the cutter to direct the Knife.
10. Knife guard is attached to the front of the knife.
11. Sharp and heavy corners can be cut.
12. Maximum 70% of knife height is used for fabric lay.
13. Wheels are under the base plate to move the machine smoothly.
14. Machine weight is around 12-15 kg.
15. Knife cut the fabric very fast due to high speed of motor. That increases the
risk of fabric damage.
16. Suitable for mass trimming cotton, woolen, linen leather and chemical fiber
goods, etc.
17. Neat cutting, small-curvature radius curvilinear cutting.
18. Low noise, stable running, easy to operate and high efficiency.
19. Incorporated with an auto knife-grinding device, easier to operate.

3. Structure of Straight Knife Cutting Machine:
The straight knife cutting machine consists of a base plate, an upright stand to hold
the vertical blade, motor, a handle for moving assembly, a sharpening device and a
handle to transfer the whole assembly from one place to another.
Two kinds of power are required to operate a straight knife. Motor power drives the
reciprocating blade and operator power drives the knife through the lay. Normally
the available blade heights vary from 10 cm to 33 cm and normally available strokes
vary from 2.5 to 4.5 cm. The greater the blade movement the faster the blade cuts the
fabric and more easily the operator can move the machine.
The most important consideration is selecting a straight knife is the power required
from the operator to move the knife is the power required for the operator to move the
knife through the lay. Operator effort is affected by the weight of the motor, the shape of
the stand, handle height, stroke, sharpness of blade and the base plate movement.
The normal blade has a straight edge that varies from coarse to fine depending upon the
type of fabric being cut. Wavy edged knifes are used to reduce the heat generation and
hence can be used for cutting synthetic materials without fusing
Different Parts of Straight Knife Cutting Machine
A straight knife machine has the following main parts (See the Figure-3):
1. Upper handle,
2. Electrical cable,
3. Motor,
4. Side handle,
5. Knife sharpener,
6. Stand,
7. Presser foot,
8. Straight knife, and
9. Base plate with rollers.
difficulties. The speed of the blades can also be adjusted by having variable speed
mechanism.
The straight knife is a common means of cutting lays in conventional cutting rooms
because it is versatile, portable, chapter than a band knife and easy to maintain. Even if
a band knife is used for main cutting operation, a straight knife will be used to separate
the lay into sections for easier handling.

4. Straight knife:
The main functional part of the machine is a vertically oscillating straight knife with a
sharp blade. In more powerful machines, the knife is longer, and higher spreads can be
cut (80–300 mm). The width of the knives is between 10 and 20 mm and the thickness
from 0.40 to 0.45 mm. The thickness of the knife is directly proportional to its length.
Double-bevel knives with straight-edged blades are normally used to cut textile
materials.
The cutting blades for straight knife cutting machine comes in three grades and also in
several shapes as shown in Figure-4 for the cutting of unusual or difficult material.
Knife sharpener:
It is small band with grinder/sharpening material on it and its main function is to
sharpen the blade. It is necessary to stop the work process during the sharpening. The
frequency of sharpening depends on the material being cut and on the knife blade.
Fabric presser foot
It is a device in the machine which holds the layers of the fabric tight so that it will be
easy for cutter to cut the fabric. A presser foot is used to ensure compression of the
spread directly in front of the knife and to decrease displacement of fabric plies during
cutting. It also prevents any loosening of the plies during the return movement of the
knife. The height of the presser foot is changed according to the height of the spread.
Base plate and its rollers
A base plate with the lowest possible profile is needed to ensure the stability of the
machine. This facilitates its manoeuver ability and minimizes the risk of deforming the
material plies during the work process. Independently moving rollers are fixed under
the base plate to ensure easy movement of the machine. Wheels are under the base plate
to move the machine smoothly. Machine weight is around 12–15 kg.
Electric cable:
An electrical cable supplies the motor with electricity. During the cutting process, it
must be secured away from the surface of the cutting table to avoid the possibility of
electric shock.
Motor:
Motor rpm is 3000–4000 and its main function is to move the blade up and down and
also slightly in front direction to create a stroke on fabric. Knife cuts the fabric very fast
due to high speed of motor. That increases the risk of fabric damage.
Moving handle:
This handle is to hold the machine as well to move in predefined direction. The straight
knife is a common means of cutting lays in conventional cutting rooms because it is

5. versatile, portable, cheaper than a band knife and easy to maintain. Even if a band knife
is used for main cutting operation, a straight knife will be used to separate the lay into
sections for easier handling.
Safety devices:
A presser foot is used to compress the fabric plies and helps to protect operator’s hands
from accidental cuts. A machine may be also equipped with an autostop trigger that
switches the power off when the operator’s hand is removed from the lever. During
cutting, the operator must wear special protective gloves (Figure-5). These are made
from stainless steel chain mail and give a certain level of protection against stab wounds
or cuts that could occur when the blade moves close to the operator’s hands. The gloves
may be a universal size or of different sizes, fitting to either right or left hand and
covering the whole hand or separate fingers. Unfortunately, the protective gloves are
heavy and limit hand movement. Therefore, some operators may not use the gloves,
putting themselves at risk of serious injury.
Advantages of Straight Knife Cutting Machine:
1. A large number of fabric lays can be cut by the machine due to high length of
knife and 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 and curve line.
7. Can be cut high curve line than round knife.
8. Fabric can be cut from any angle.
Disadvantages of Straight Knife Cutting Machine:
1. High speed of the machine causes high risk of damage.
2. Faulty knife could damage fabric layer.
3. Motor weight creates knife deflection which may be creates faulty pieces.
4. Risk is high for physical damage of operator.
5. Knife required to replace.

6. Consew
Model 818-10
FEATURES
MOTOR
The motor is an originally developed motor. It assures a smooth cutting operation with
excellent cutting power and low motor temperature.
AUTOMATIC OIL LUBRICATION DEVICE
Oil can be supplied automatically from oil reservoir to the guide metals and cross head. And the
internal oil guard keeps other interior parts clean.
AUTOMATIC SHARPENING DEVICE
There is an abrasive belt sharpening device. Just press down the sharpening lever, and the
blade can be sharpened automatically to maintain the most suitable edge of the blade.
STANDARD
Thinner and flat type Standard makes the resistance of cutting material lower, and bigger blade
stroke makes cutting smoothly.
BASE PLATE
The base plate is low and the surface is smooth to make the material travel on it smoothly
before and after cutting.
OTHER
Fan-guard and Starting switch cover are equipped for safety reason.
OPTIONS
Knife Protector
Model Suffix's Options: (special order only)
"-220" 220VAC, "-3P" (Three-Phase), "-BIV" (Double Voltage)

7. Consew Model 818-10DS Cutter
FEATURES
MOTOR
"DS": Dual Speed cutters come in 6" 818-6DS / 8" 818-8DS / 10" 818-10DS sizes
MOTOR
The motor is an originally developed motor. It assures a smooth cutting operation with
excellent cutting power and low motor temperature.
AUTOMATIC OIL LUBRICATION DEVICE
Oil can be supplied automatically from oil reservoir to the guide metals and cross head. And the
internal oil guard keeps other interior parts clean.
AUTOMATIC SHARPENING DEVICE
There is an abrasive belt sharpening device. Just press down the sharpening lever, and the
blade can be sharpened automatically to maintain the most suitable edge of the blade.
STANDARD
Thinner and flat type Standard makes the resistance of cutting material lower, and bigger blade
stroke makes cutting smoothly.
BASE PLATE
The base plate is low and the surface is smooth to make the material travel on it smoothly
before and after cutting.
OTHER
Fan-guard and Starting switch cover are equipped for safety reason.
OPTIONS
Knife Protector
Model Suffix's Options: (special order only)
"-220" (220VAC), "-3P" (Three-Phase), "-BIV" (Double Voltage)

8. Consew Model 818-13
FEATURES
MOTOR
The motor is an originally developed motor. It assures a smooth cutting operation with
excellent cutting power and low motor temperature.
AUTOMATIC OIL LUBRICATION DEVICE
Oil can be supplied automatically from oil reservoir to the guide metals and cross head. And the
internal oil guard keeps other interior parts clean.
AUTOMATIC SHARPENING DEVICE
There is an abrasive belt sharpening device. Just press down the sharpening lever, and the
blade can be sharpened automatically to maintain the most suitable edge of the blade.
STANDARD
Thinner and flat type Standard makes the resistance of cutting material lower, and bigger blade
stroke makes cutting smoothly.
BASE PLATE
The base plate is low and the surface is smooth to make the material travel on it smoothly
before and after cutting.
OTHER
Fan-guard and Starting switch cover are equipped for safety reason.
OPTIONS
Knife Protector
Model Suffix's Options: (special order only)
"-2SP" (Dual-Speed), "-3P" (Three-Phase), "-BIV" (Double Voltage)

9. Consew Model 818-4
FEATURES
MOTOR
The motor is an originally developed motor. It assures a smooth cutting operation with
excellent cutting power and low motor temperature.
AUTOMATIC OIL LUBRICATION DEVICE
Oil can be supplied automatically from oil reservoir to the guide metals and cross head. And the
internal oil guard keeps other interior parts clean.
AUTOMATIC SHARPENING DEVICE
There is an abrasive belt sharpening device. Just press down the sharpening lever, and the
blade can be sharpened automatically to maintain the most suitable edge of the blade.
STANDARD
Thinner and flat type Standard makes the resistance of cutting material lower, and bigger blade
stroke makes cutting smoothly.
BASE PLATE
The base plate is low and the surface is smooth to make the material travel on it smoothly
before and after cutting.
OTHER
Fan-guard and Starting switch cover are equipped for safety reason.
OPTIONS
Knife Protector
Model Suffix's Options: (special order only)
"-2SP" (Dual-Speed), "-3P" (Three-Phase), "-BIV" (Double Voltage)

10. Consew Model 818-6DS Cutter
FEATURES
MOTOR
"DS": Dual Speed cutters come in 6" 818-6DS / 8" 818-8DS / 10" 818-10DS sizes
MOTOR
The motor is an originally developed motor. It assures a smooth cutting operation with
excellent cutting power and low motor temperature.
AUTOMATIC OIL LUBRICATION DEVICE
Oil can be supplied automatically from oil reservoir to the guide metals and cross head. And the
internal oil guard keeps other interior parts clean.
AUTOMATIC SHARPENING DEVICE
There is an abrasive belt sharpening device. Just press down the sharpening lever, and the
blade can be sharpened automatically to maintain the most suitable edge of the blade.
STANDARD
Thinner and flat type Standard makes the resistance of cutting material lower, and bigger blade
stroke makes cutting smoothly.
BASE PLATE
The base plate is low and the surface is smooth to make the material travel on it smoothly
before and after cutting.
OTHER
Fan-guard and Starting switch cover are equipped for safety reason.
OPTIONS
Knife Protector
Model Suffix's Options: (special order only)
"-220" (220VAC), "-3P" (Three-Phase), "-BIV" (Double Voltage)

11. Consew Model 818-8DS Cutter
FEATURES
MOTOR
"DS": Dual Speed cutters come in 6" 818-6DS / 8" 818-8DS / 10" 818-10DS sizes
MOTOR
The motor is an originally developed motor. It assures a smooth cutting operation with
excellent cutting power and low motor temperature.
AUTOMATIC OIL LUBRICATION DEVICE
Oil can be supplied automatically from oil reservoir to the guide metals and cross head. And the
internal oil guard keeps other interior parts clean.
AUTOMATIC SHARPENING DEVICE
There is an abrasive belt sharpening device. Just press down the sharpening lever, and the
blade can be sharpened automatically to maintain the most suitable edge of the blade.
STANDARD
Thinner and flat type Standard makes the resistance of cutting material lower, and bigger blade
stroke makes cutting smoothly.
BASE PLATE
The base plate is low and the surface is smooth to make the material travel on it smoothly
before and after cutting.
OTHER
Fan-guard and Starting switch cover are equipped for safety reason.
OPTIONS
Knife Protector
Model Suffix's Options: (special order only)
"-220" (220VAC), "-3P" (Three-Phase), "-BIV" (Double Voltage)