JUKI MF-7900 Series, MF-7900D Series Specification

MF-7900 Series

High-speed, Cylinder-bed, Top & Bottom Coverstitch Machine

MF-7900D Series

Semi-dry-head, Cylinder-bed, Top & Bottom Coverstitch Machine

MF-7923D-U11-B56

In the case of looper thread breakage,
the looper thread twining prevention
mechanism is activated to trim the
looper thread before the thread twines
on the looper thread cam. In this way,
the looper thread twining prevention
mechanism prevents the looper
thread from twining on the looper thread cam. In addition, the looper
thread cam, which has been incorporated in the sewing machine, has
been changed so that it is mounted outside of the sewing machine. The
externally-mounted looper thread cam promises improved maintainability.

As a result of the commonality of components, commercially-available
components (presser foot, throat plate and needle clamp) are now
applicable and easily obtainable.

Seam quality is improved!!

Simplified maintenance mechanism

All of the sewing machines with
a thread trimmer are provided
with a direct-drive motor.

The direct-drive motor system has been
adopted by all of the sewing machines with
a thread trimmer. As a result, the sewing
machine starts up swiftly and promises
increased stop accuracy, thereby
demonstrating improved responsiveness.
In addition, the machine is no longer
provided with a V-belt. This means that the
adoption of the direct-drive motor is also
effective in the elimination of belt shavings. Power is directly transmitted
from the motor to the sewing machine, thereby contributing to reduced
power consumption. (This sewing machine reduces power consumption
by 27% as compared with the conventional models.)

MF7823/UT22/SC510

MF-7923/UT57/SC921/CP18

Servomotor

Direct-drive motor

Commercially-available gauge components
are applicable with no additional work.

The looper thread twining prevention mechanism has been
improved and is provided as standard for the sewing machine.

The

world's

first

27%

Power

consumption

Reduced by

Main
feed dog

Differential
feed dog

The feed locus can be adjusted externally. The
feed locus is now adjustable in terms of the
vertical direction and horizontal direction, thereby
improving responsiveness to sewing materials.

Thanks to the new feed mechanism,
many different types of sewing are achieved.

Elastic material or delicate material can be
sewn with the presser foot kept slightly raised.
This effectively helps reduce the degree of
slippage, warpage and damage of the material.

Micro-lifter mechanism

It is possible to finely adjust
the differential feed amount
to a best-suited value for the
material to be used.
The differential feed ratio is
constant even if the stitch
length is changed.

Differential-feed micro-adjustment
mechanism

It is provided with many different sewing-related mechanisms which contribute to
improved seam quality, such as the new feed mechanism, and differential-feed
micro-adjustment mechanism. In addition, the machine is provided as standard with
a looper thread twining prevention mechanism for improved maintenance.

The MF-7900 Series is a newly developed
coverstitch machine provided with lots of
mechanisms for improving the seam quality.

MF-7900

Series

High-speed, Cylinder-bed,
Top & Bottom Coverstitch Machine

MF-7900/UT

Series

Direct-drive, High-speed, Cylinder-bed,
Top & Bottom Coverstitch Machine with Needle- and Looper- Thread Trimmer

MF-7900D

Series

Semi-dry-head, Cylinder-bed,
Top & Bottom Coverstitch Machine

MF-7900D/UT

Series

Semi-dry-head, Direct-drive, Cylinder-bed,
Top & Bottom Coverstitch Machine with Needle- and Looper- Thread Trimmer

Horizontal

direction

Vertical

direction

Expand

Contract

The

world's

first

JUKI's dry-head technology
protects sewing products from being stained with oil.

With the excellent functions inherited from the MF-7900 Series, the MF-7900D is provided with a dry frame
mechanism to eliminate the cause of oil stains. Stain removing work or re-sewing work is substantially reduced
by protecting sewing products from being stained with oil, thereby improving the quality of finished products.

The frame no longer requires oiling.

Dry-head technology has materialized
a frame which does not need oiling.

Environmental consciousness

Dichlorofluoroethane (HCFC-141), which is
generally used in oil stain cleaning fluid, is included
in those chemicals which need to be reduced, as it
is a substances that can harm the ozone layer.

Since oil stains on sewing products are reduced, the quantity
of the use of stain remover generally used in sewing plants
can be reduced.

The needle bar mechanism and spreader mechanism have been applied with a
special surface treatment.
JUKI's unique special grease is used for lubrication. Grease-filled bearings have
been adopted for the crank rod. These allow the machine's frame mechanism to
demonstrate outstanding durability without being oiled.

Unlike the conventional models, the oiling mechanism inside the frame has been eliminated.
As a result, oil does not leak from the needle bar, presser bar or spreader shaft.

The semi-dry

head sewing machine

increases its sewing

speed to

5,000

sti/min

Application Seam

Model No.

Number

of

needles

Number

of

threads

Needle

gauge

(mm)

Stitch

length *

1

(mm)

Differentialfeed

ratio *

2

Presser foot

lifting amount *

3

(mm)

Max. sewing

speed

(sti/min)*

4

Binder mounting base

Various binders can be
installed by loading the
binder mounting base
supplied with the unit.

List of subclass machines

MF-7900/U11

Universal type

(basic type)

By changing over the needle bar stroke, penetrating force of
the needle as well as thread tension to fit heavy-weight
materials (fleece, blankets) can be obtained. The needle bar
stroke can be changed by adjusting the eccentric pin.
(Changing of parts is not required. Factory-set at the time of
delivery: 31mm; for sewing heavy-weight materials: 33mm)

Needle bar stroke conversion mechanism

head type sewing

machine has been

added.

A semi-dry

Universal type
(

basic type

)

U11

The machine can be used for the hemming process of the sleeves and bottoms of T-shirts and for
the covering process for sportswear and knitwear.
The front cover is trimmed to allow operators to bring their hands closer near the needle entry area,
thereby increasing work efficiency in the covering process, etc.

MF-7923-U11-B56/UT51

Polo
shirts

T-shirts knitwear sportswear

6,500

6,000

5,000

5,000

6,000

2 4

0.9~3.6

1:0.9~1:1.8

(1:0.6~1:1.1)

5 (8)

3.2,4.0,4.8

MF-7922-U11-B＊＊

3 5 5.6,6.4

MF-7923-U11-B＊＊

2 4

4.8

MF-7922-U11-B48/UT51

3 5

5.6,6.4

MF-7923-U11-B＊＊ /PL12,PL13

MF-7923-U11-B＊＊ /UT52/PL12
MF-7923-U11-B＊＊ /UT57/PL13

MF-7923-U11-B＊＊ /UT51,UT57
MF-7923-U11-B＊＊ /UT59

*1 Stitch length can be adjusted to 4.5mm at the maximum. *2 Differential ratio can be switched by adjustment.
*3 The lift of the presser foot is 5mm for the top and bottom coverstitch machine, and 8mm for the bottom coverstitch machine. *4 "sti/min" stands for "Stitches per Minute."

5,000

2 4

0.9~3.6

1:0.9~1:1.8

(1:0.6~1:1.1)

5 (8)

4.0

3 5 5.6,6.4

MF-7922D-U11-B40
MF-7923D-U11-B＊＊

MF-7923D-U11-B＊＊ /UT51,UT57
MF-7923D-U11-B＊＊ /UT59

MF-7900D/U11

Universal type

(basic type)