A Presention About Double Needle Lockstitch Machine(DNLS)

2. Group Name : All Over Printing
𝐆𝐫𝐨𝐮𝐩 𝐌𝐞𝐦𝐛𝐞𝐫𝐬:
Md.Hasibur Rahman
ID:201040016
Md.Biplob Ahamed
ID:201040017
Md.Golamus Sahed
ID:201040018

3. Yeasmin Akter Munni
ID:201040019
𝐆𝐫𝐨𝐮𝐩 𝐌𝐞𝐦𝐛𝐞𝐫𝐬:
Fatema Binte Farhad
ID:201040033

4. Chapter Contents,
•LOCKSTITCH:
• PRINCIPLE OF LOCKSTITCH MACHINE
•TYPES OF LOCKSTITCH MACHINES
•Working Process of Double Needle Lockstitch
Machine:
•CHARACTERISTICS OF JUKI - LH - 3120-7
•APPLICATIONS
• Advantages

5. LOCKSTITCH:
• A lockstitch is the most common
mechanical stitch made by a sewing
machine.
• The lockstitch uses two threads, an
upper and a lower. Lockstitch is so
named because the two threads,
upper and lower, "lock" (entwine)
together in the hole in the fabric
through which they pass through.

6. PRINCIPLE OF LOCKSTITCH MACHINE :
To make one stitch, the machine lowers the threaded
needle through the cloth into the bobbin area, where a
rotating hook (or other hooking mechanism) catches the
upper thread at the point just after it goes through the
needle.
The hook mechanism carries the upper thread entirely
around the bobbin case, so that it has made one wrap of
the bobbin thread.
The take-up arm then pulls the excess
upper thread (from the bobbin area) back to
the top, forming the lockstitch. Then the
feed dogs pull the material along one stitch
length, and the cycle repeats.

7. TYPES OF LOCKSTITCH MACHINES
There are two types of lockstitch machines
based on the number of sewing needles
and bobbins present,
they are :
SNLS or Single Needle Lockstitch
Machine
DNLS or Double Needle Lockstitch
Machine

8. SINGLE NEEDLE LOCK STITCH MACHINE (SNLS)
SINGLE NEEDLE LOCK STITCH
MACHINE (SNLS) – this machine is
used when a single line of 'LOCK
STITCH' sewing is required. The
regular sewing machines are often
regarded as an end in itself rather
than as a basic sewing tool.

9. Different Parts of Single Needle Lock Stitch Sewing Machine:
Bobbin Winder
Thread wiper device Machine pulley
Lifting lever Operation panel
Hand swatch A Cotton stand
Hand swatch B Control box
Work Clamp Power indicator
Knee lifter plate USB port
Oil gauge window Pulley cover
Oil feeding Pocket The thread takes up cover
Finger guard

10. Double-Needle Lock Stitch Machine:e
Double-needle /twin/two needles is a
needle with a single shank and two
shafts, proceed stitching with the double
stitching you will get two parallel rows
on the face of the fabric and a zig-zag
stitch on the back of the fabric.

11. Working Process of Double Needle Lockstitch Machine:
• A double needle lockstitch machine
works on the same principle as the SNLS
machine while using two needles and two
bobbins thus resulting in two parallel
rows of lockstitch.
• The distance between the two stitch lines
depends upon the distance between the
two needles on the needle bar which can
be adjusted.

12. Working Process of Double Needle Lockstitch Machine:
• When the stitch forms correctly
equal amounts of bobbin and
needle thread are used. Upper and
lower threads interlock in the center
of the fabric.
• The tightness of the interlocking
stitch maybe a problem for operators
when ripping is needed.

13. CHARACTERISTICS OF JUKI - LH - 3120-7 :
• 2 - needle, Bottom - feed, Lockstitch
Machine with an automatic thread trimmer
• Low noise
• Fast speed
• Steady and enduring especially when
sewing underwear, jeans, coat's turning
and decorative parts.

14. CHARACTERISTICS OF JUKI - LH - 3120-7 :
• Synchronized feed of the needle bar
and feed dog to avoid distraction.
• Adopt inside oil line box to realize
cycling oil supply
• Double needle bar discrete design,
easy for sewing turning, acute angle
and direct stitch.

15. APPLICATIONS
• Sew box pockets on safari jackets,
light jeans and pajamas.
• Topstitch front collar edges of safari
jackets etc.
• Sew pockets on coats. Sew skirt box
pleats

16. APPLICATIONS CONT:
• Topstitch the collars of ladies 'wear
• Topstitch the cuffs of ladies' wear
• Suitable for sewing shirts, Uniforms, Jeans
and Women Underwear.
• The double needle lockstitch is the tightest
and most secure stitch which makes it a good
choice for stitching the inseam of trousers.

17. Thread trimming
mechanism with twin
bobbins
MACHINE FEATURES
Thread tension controller
equipment to produce
even stitches
Slide type presser foot
capable of preventing
loose stitches

18. MACHINE FEATURES CONT:
• It belongs to special interlock sewing machine for
heavy duty garment seaming, such as pants, jeans,
work uniform and leisure clothes.
• It is recommended for stitching overalls uniforms,
jeans and decorative sewing on bags since it features
synchronized feeding of needle bar and feed dog.
• They are applicable to the ornamental seam of
garments like jeans, skirts, overcoats and uniforms and
the edge - pressing sewing.
Compact wiper

19. Advantages of Double Needle Lockstitch Machine :
The advantages are:
Lockstitch machines are versatile and can be used for a variety of operations
Compare to all other stitch types, this class uses the least amount of thread and
produces the flattest stitch.
it is reversible
The double needle lockstitch is the tightest and most secure stitch.
It is the only stitch formation that can be backstitched if the ends need to be
secured.
It is non - ravelling.
Good hand Lies flat on the fabric

20. Conclusion:
The sewing model integrated
many excellent technique to
perform the professional sewing
skills. It is specially suitable for
handbag, suitcase, sofa, glove,
camping materials, shoes, auto
internal decoration, and leather
materials. To integrate with
bottom, needle and alternating
top feed. Suitable for medium-
weight applications.