Stitch, seam ppt

Stitch& Seam
Prepared by,
 Haji Karim Aman
 hajikarim.aman@gmail.com
 Indus University Karachi

Stitch
Stitch:
British standard 3870, defines stitch as: One units of conformation
resulting from one or more strands or loops of thread intralooping,
Interlooping or passing into or through the fabric or material.
Inter looping : Loop of one thread passes through the loop of another thread.
Intra looping : Loop of one thread passes through the loop of same thread.
Inter Lacing: One thread passes over another thread.

Stitch
 Stitch classification is based on:
 Structure of the stitch
 Method of interlacing stitch properties.
  Stitch properties:
 Relate to aesthetics and performance
 Stitch size
 Stitch length, width, and depth.
 Thread tension
 Stitch consistency.

Stitch properties
 Stitch Length:
 Stitches per inch (spi)
 High spi
• Short stitches: High quality
• Potential problems (seam pucker or weaken fabric).
• Higher spi, the more time and thread, high cost.
 Low spi
• Long stitches: Lower quality
• Problems: Less durable, snagging, abrasion, grinthrough
• Fast, less thread, less cost.
 Example:
• men’s shirts 22 spi vs. 8 spi

Stitch properties
 Stitch Width:
 Distance between the outermost lines of stitches.
 Refers to the horizontal span covered in the formation of one stitch.
 Referred to as gauge, (inch)
• Example: over edge, zigzag, and cover stitches (1/4 inch)
 Width dimensions require multiple needles or lateral movement of
thread carriers:
 Example: needle bars, loopers, or spreaders.

Stitch properties
Stitch depth:-
Stitch depth is the distance between the upper and lower surface of stitch.
Thread tension:-
Thread tension affects stitch formation in two ways
i.The balance of force on the threads that form the stitch
ii.The degree of compression on the fabric created by the threads as a stitch
is formed.
 Stitch consistency:-
Stitch consistency is the uniformity with each stitch is formed in a row of
stitch

Classification of stitches:-
 Stitch classification is based on:
 Structure of the stitch
 Method of interlacing stitch properties.
Types of stitches:-
1. Stitch Class- 100 (Single thread chain stitch).
2. Stitch Class- 200 (Hand Stitch).
3. Stitch Class- 300 (Lock Stitch).
4. Stitch Class- 400 (Multi thread chain stitch).
5. Stitch Class- 500 (Over lock stitch).
6. Stitch Class- 600 (Covering chain stitch).

Stitch and Classification
Class 100:(Single thread chain stitch):
is chain stitch type, is formed with one or more needle threads
introduced from one side of the material only.
 chain stitch is elastic and thicker than lockstitch and can
easily be ravelled;
 particular care is required to prevent runback from the last
stitch.
 Used for temporary stitching or for Blind stitching.

Sub-Class- 101:
Uses: It is used for blasting (temporary stitching). e.g. Blazer
components joining before final sewing to cooperate sewing.
Sub-Class-103: Blind Stitch.
Feature:
One side is invisible and other side is like chain.
Use: Bottom hemming of dress pants.

Class 200:
is a hand stitch type, is formed by single thread passed from one side of
the material to the other in successive needle penetrations.
 a slow process and need huge manpower to finish bulk order.
 Used for handwork.
Sub-Classes:
 Sub-Class-202: This type of stitch is formed by hand.
 Sub-Class-209: This type of stitch is formed by “Pique Stitch
Machine’’.
Uses: Lapel of Blazer, collar of shirt, saddle stitch etc.

Saddle Stitch: A special type of stitch which is formed by Pique Stitch
Machine using Thick thread. It is used in Cowboy Jeans.
This type of stitch is formed with one
thread. It is a machine made version of
traditional hand stitching sometimes
referred to as Saddle Stitch.

Class 300:
is a lock stitch type, is formed by a needle thread or threads,
introduced from one side of the material, interlacing with an under
thread
 supplied from a bobbin on the other side.
 low bulk and thin, good strength and abrasion resistance
 Poor elasticity, non ravel
 limited sewing length, need to replace bobbin thread.
 for seams requiring stretch.
Subclass: 301, 304
Usages:
Lock stitch is extensively used for joining fabrics collar, cuff, pocket,
facing etc. Top stitching is used for button holing, attaching, blind
stitching etc.

 Sub-Class-301:
 Use: Top stitching in garments.
 Sub-Class-304:
 Uses: Elastic attaching, lace attaching etc

Class 400:
is multi thread chain stitch type, is formed with two/more groups of
threads having general characteristic of interlacing interloping of the
loops of the two groups.
 non ravel, strong, good elasticity, less likely to cause seam
pucker due to structural jamming
 good seam stretch
 does not need to wind bobbin
 lower resistance to runback and have increased bulk under
the seam
Hemming: Hem is the end of the garment and the process of making
hem is called hemming

Subclass:
401(1n+1l); Use in Jens.
406(2n+2l); Use in T-Shirt (Heming). (Flat Lock).
407(3n+1l) Use in Brief’s. (Flat Lock).
Usages:
This type of stitches is used for sewing lace, braid and elastic.
Stitch type-401 is used in jeans and trouser.

401: 1Needle + 1Looper
Uses: Inseam and out seam of jeans.
406: 2Needle + 1Looper
Uses: Sleeve and bottom hem of T-shirt.
Upper side
Bottom side

Uses: Sleeve and bottom hem of T-shirt & Polo-shirt.

Class 500:
is over lock over edge stitch type, is formed with one or more needles and/or loopier threads
with at least one thread passing round the edge of the material being sewn.
 Excellent stretchable good recovery
 Seam or edge neatening
 suitable for many types of fabric
 subject to fraying or slippage.
Subclass:
British Standard:
 503(1n+1l); Use for edging.
 504(1n+2l); Use for edging & light seaming.
 514(2n+2l); Use edging & Heavy seaming.
 American Standard: Combination Stitch
 515(401 + 503); Use for edging & sewing.
 516(401 + 504); Use for edging & sewing.
Usages: This stitch type can be used to make a decorative edge.

Sub-Classes:
Use: Only for edging.
Uses: For edging & light seaming.
Uses: For edging & heavy seaming.

Class 600:
is formed with two or more groups of threads, has for a general characteristic
that two groups of thread cover surfaces of the material.
 High elasticity, seam neatening and Flat seam stitch, Bulk,
Fast machine speed
 No need of Bobbin
 Greater thread consumption
 Covering stitches for decorative purpose, Can be used to join
two raw edges, suitable for knitted garments.
Subclass:
602; Use for decorative purpose.
605; Use for decorative purpose.
Usages:
This type of stitch is used for sewing under wear for attaching lace, braid
elasticity.

Sub-Classe-602: 2Needle + 2Looper
Use: Sleeve and bottom hem of T-shirt, Polo-shirt & decorative
purpose.
Sub-Classe-605: 3Needle + 2Looper
Uses: For decorative purpose & elastic attaching of under garments.

Seam
What is Seam?
A seam is a joint of two pieces of fabric in producing a three -dimensional
shape of a garment.
Properties of good seam are,
= Smooth fabric joints
= No Missed or Uneven stitches
= No damage to the material being sewn
= Achievement of strength, elasticity, Durability,
security and comfort
= Comfortable while garment is in use

Seam and Classification
SEAMS DESIGNATION
Each stitched seam is designed numerically by five digits:
 0.00.00 refers to the CLASS, 1-8;
 0.00.00 refers to the material configuration,
01 to 99;
 0.00.00 refers to needle penetrations, material
configurations, 01-99.

PLAIN SEAM or SUPERIMPOSED SEAM Class 1
•Formed by superimposing the edge of one piece of component over the
other, these seams are produced with a minimum of two pieces of
component.
• Each component is limited on the same end.

PLAIN SEAM or SUPERIMPOSED SEAM Class 1

Class 2 Lapped seam or welt seam
* Formed by lapping two pieces of component, they are produced with
minimum of two pieces of component.
* One component is limited on one end and the other is limited on the
other end. The limited edges of these two components are put in opposite
directions.
* Used for: main seaming of denim jackets, jeans, and overalls. Fabrics that
will not ravel, unlined garments, side seams of shirts, joining lace to another
fabric, attaching patch pockets, decorative finish

Class 2 Lapped seam or welt seam

Class 3 Bound seam
Constructed by binding the component edge with another narrow
component. The seam produced with minimum of two pieces of component.
One component is limited on one end and the other is limited on both
ends.
Used for : finishing necklines, sleeves hems, inside waistbands of trousers
and pants, finishing seams on unlined jackets and coats, adding interest as a
design or decorative detail, finishing raw edges, continuing the motif design
of lace.

Class 3 Bound seam

Class 4 Flat or channel seam
Two pieces of fabric are laid flat with their edges closing each other
without overlapping. Seams are produced with minimum of two pieces of
component.
Both components are limited on one end but they are put opposition to
each other on the same level.
* Used for: close fitting garments where the seam allowance may put
pressure on the body, high-stretch fabrics, athletic apparel, shape wear,
undergarments, thermal underwear, swimwear.

Class 4 Flat or channel seam

Class 5 Ornamental Seam
A seam class for decorative sewing on garments.
Seams are produced with minimum of one piece of component, with
unlimited edges on both ends.

* Used for: adding a design detail, cording, piping, tucking, welting,
decorative stitching

Class 5 Ornamental Seam

Class 6 Turned hem or Edge neatening
Stitching work made on the fabric edges for neatening.
Seams are produced with one piece of component. This seam has one
limited edge on one end.

Class 6 Turned hem or Edge neatening

Class 7 Edge Stitched Seam
A narrow piece is sewn to the edge of a garment part.
Seams are produced with minimum of two pieces of component. One
component is limited on one end, and the other narrow one is limited on
both ends.

Class 7 Edge Stitched Seam

Class 8 Enclosed Seam
Only one piece of component involved in construction the seam, stitches are
applied on its edge/s.
Seams are produced with minimum of one piece of component with a limited
edge on two ends.

Class 8 Enclosed Seam

Seam Problems
 SEAM PROBLEMS
• Seam Pucker
• Grinning
• Skipped Stitches
• Broken Needle Threads
• Broken Bobbin Threads
• Needle Damage on Fabric
• Seam Slippage

Seam problems
 SEAM PROBLEMS
 SEAM PUCKER
• Bad tension
• Bad feed
• Fabric-Thread instability
• Uneven shrinkage during finishing
• Thread-bloat from washing
• Structural jamming/Inherent pucker
• Tight weaving does not have enough room between yarns for thread
• Sewing caused yarns to be pushed out of place

Seam problems
Grinning
• Loose tension
• Incorrect stitch choice
• Lockstitch is the tightest stitch and will grin less than
other stitches

Seam problems
 SKIPPED STITCHES
• Bad tension
• Machine timing is off
• Bobbin hook or looper is not entering needle thread loop at
• correct time
• Incorrect needle choice
• The wrong needle can cause problems in creating the needle
• thread loop
• Damaged needle
• If the needle is bent, or is striking the throat plate, it may not
create the loop in the right place for the hook to catch

Seam problems
 NEEDLE THREAD BREAKAGE
• Tight tension
• Trapping at package base
• Snarling before tension disc
• Poor needle choice
• If eye is too small, there will be increased friction
• Excessive heat
• Poor quality thread

Seam problems
BOBBIN/LOOPER THREAD BREAKAGE
•Tight tension
•Badly wound bobbin
•Incorrect fit of bobbin case
•Trapping at package base (for loopers)
NEEDLE DAMAGE
•Incorrect needle/thread choice
•Damaged needle

Seam problems
 SEAM SLIPPAGE
• Problem is with the fabric – not the stitch
• Low yarn count, and continuous filament yarns that don’t grip each other
well are to blame
• Very minimal improvement can be achieved through increasing seam
allowance, adding top stitching, or changing to a lapped felled seam
• When possible, seams can be fused
• Best option – Change fabric

Stitch, seam ppt

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Stitch, seam ppt