This document discusses the jacquard shedding mechanism used in weaving looms. It covers the scope and classification of jacquard looms, their operating principle, limitations of mechanical jacquards, and electronic jacquard machines. It also describes jacquard weaves produced using this mechanism and references used in preparing the document.

1. Department Of Textile Engineering
Jacquard shedding mechanism
Prepared by: Temesggen Feleke

2.  Introduction
 Scope of jacquard
 Classification of jacquard
 Operating principle
 Limitations of mechanical jacquard
 Electronic jacquard machine
 Jacquard weaves
 Refferences
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3. Jacquard loom is a
loom that produces
elaborate design in an
complex weave.
 It was invented by Joseph Marie
Jacquard
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4.  It can be used for a large or complex design
that are beyond the scope of tappet or dobby.
 It can produce any shape of design.
 One warp thread for each harness.
 Every thread is controlled individually.
 No heald shaft is used.
 It is possible to lift 2000-3000 yarns at any
instant.
 Most costly fabric is produced. (Costing:
Jacquard>Dobby>Tappet).
 Speed : Jacquard<Dobby and Tappet.4/26/2017 4Prepared by: Temesggen F.

5. Conventional
 English pitch(coarse
pitch)
 Mechanical
 Single/double lift
 Coarse vienna(6.82mm x
6.82 or 5.77mm x 5.11mm)
 French pitch(fine pitch)
 Mechanical/electronic
 Single/double lift
 Vincenzi/verdol
 French laccase
pitch(4mm x 4mm)
Staubli’s UNIVAL
100 jacquard
Grosse’s unished
jacquard
Pitch- the distance
between needle center.
Unconventional
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6. Jacquard machine may
be divided in to three
main parts:-
 Jacquard
head/engine:- knives,
hooks,needles,spring,c
ard cylinder and
endless pattern.
 Harnesses:-Neck-cords
,harness cords, mails
and weights(spring)
 The mechanism that
links the engine to the
weaving machine.
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7.  Fabric design is sketched and transferred on to
squared paper.
 A skilled workers translate the design in to punched
card.
 The holes in the card select threads for the pattern and
allow the hooks to path through.
 Each complete pass represents one row of the pattern.
 The cards are stitched together in a chain and feed in
to the loom.
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8. One needle and one hook for
every end in the design.
Shed formed by raising hooks
by knives
Griff rise and fall in every
pick.
Cylinder must reciprocates
and turn.
Require to form shed and
reduce the speed of loom.
Warp ends highly strained
and may cause breakage.
4/26/2017 8Prepared by: Temesggen F.

9.  One needle and two hooks for
every end in the design.
 Each needle controls two
consecutive hooks
 Pair of hooks connected to one
neck cord.
 One hook controls neck cord in
odd pick and other even pick.
 Two set of knives, 1st controls odd
hook and 2nd even hook.
 Cylinder is turned quarter
revolution every pick.
 Less tendency of harness swing
 Loom speed is higher. 4/26/2017
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Prepared by: Temesggen F.

10.  Has two set of knives.
 Two needles and two hooks for
every end in the design.
 Two card cylinder operate on
alternate picks, one carrying the
odd numbered and other carrying
even numbered cards.
 Cylinder turned quarter revolution
in every two picks because of one
cylinder handle odd picks and other
even picks.
 Is fastest than DLSC. 4/26/2017 10Prepared by: Temesggen F.

11. Modern microprocessor controlled weaving
machines can not work with mechanical
jacquards.
At speeds in excess of 700 rpm result
problem of selection and shedding control.
4/26/2017 11Prepared by: Temesggen F.

12.  Developed to overcome limitations of mechanical
jacquard.
 CAD control simplify procedures.
 Cards or patterns are changed by magnetic tape.
 Computer can scan the pattern very rapidly.
 Software program convert the warp and filling interlacing
in to a binary number form and read by computer.
 Design displayed on computer screen then the designer can
change pattern by drawing on the screen with alight sonic
pen.(Staubli CX860)
 Advantages :-
 High speed hook selection and weaving
 Elimination of cylinder needle and design card.
 Automatic pattern change by CAD system
4/26/2017 12Prepared by: Temesggen F.

13. Large figured designs that require more than 25
different arrangements of the warp yarns to complete
one repeat design—woven on a jacquard loom
• Damask
• Brocade
• Brocatelle
• Jacquard tapestry
• Wilton rugs
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14.  Hand book of weaving, Sabit Adanur, Phd.
 Hand out material, jacquard mechanism
 Internet browsing
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