threads and needles. factors affecting characteristic of thread fibre content structure twist ply...
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Threads And NeedlesThreads And Needles
Factors Affecting Characteristic Of Thread
FIBRE CONTENT
STRUCTURE
TWIST
PLY
COLOR
FINISHES
STRENGTH
SIZE
THREADSTHREADS
Fiber Content
Characteristics of cotton thread:
Soft
Strong and durable
Easily adjusts to changes in the fabric (such as shrinkage) since it is a natural fiber
Available in various thread weights
Easy care
Advantage of Cotton Thread:
It gives uniformity in stitch & seam appearance
Dying is easy and easily gets the color of the fabric.
Resistance to the heatResistance to the tangling
Disadvantage:
Poor elasticityPoor abrasion resistanceMore expensiveWeaker (time consuming due to thread breakage)Weakens easily by chemicals used in fabric &garment finishingBut for contrasting stitch polyester is good.
Rayon
Characteristics Of Rayon High sheen Soft, and works well in detail Relatively heat resistant Not colorfast Not as strong as polyester Less durable than polyester
Nylon
Characteristics Of NylonStrong Low melting temperature. Not heat resistant. Not colorfast. Will yellow over time. Becomes brittle through laundering
Polyester
Characteristics Of Polyester
Durable. Designed for heavy duty use
Stronger, more tensile strength than rayon
Colorfast
Retains shape
Recovers stretch
Spun poly is strong, with a matte appearance
METALLICS
Quality metallic thread has the following components:
Nylon core..
Rice paper construction.
Outer coating.
Lower end metallic threads have no outer coating.
A good metallic has an outer coating which reduces friction and acts as a protective layer.
Thread Structure
Spun yarns twisted together:-
Single yarns are twisted together to form multiply
Number of ply may be 2 to 6
Abrasion resistance varies on type of fibers
Spun polyester is one of the most popular among the least expensive threads
Large diameter cotton replaced by small diameter polyester reduces puckering
Filament threads:-
a) smooth filament b) textured filament thread c) monofilament thread
Nylon, polyester
High tensity
Used for shoes, leather garment, industrial products-tents,box cover etc
Usually polyester
Used for looper as cover stitches
Bulk of thread may increase friction
Neutral color & translucent(matches with the fabric easily)
Strong and minimumBreakage and inexpensive
The flexibility of the thread is less therefore Causes wear & tear on machine
Smoother thread are being tried to produce
CORESPUN THREAD:- Multiply construction
Polyester filament core wrapped with cotton fiber
Gains strength of polyester and sewability of cotton
Polyester is not wrapped as it is suspectable to the heat
Costlier due to more dye baths to give uniform color to the thread
AIR TANGLED THREAD: -
Is made from continuous filaments of polyester that are entangled as they pass through a high pressure air jet.
twisted, dyed, and wound on cones with lubricant.
used in everything from seaming flags to heavy denim jeans.
TWIST:
"S" direction or right twist for single strand yarn (such as spun)
"Z" direction or left twist for ply yarn (such as core and twisted multifilament)
SNLS (Single Needle Lock Stitch) machine is designed for the Z twist.
DNLS (Double Needle Lock Stitch) machine uses both S & Z twist for the balance.
S twist is better for flat stitch or cover stitch.
Correct twist balance essential for preventing kinking & snarling effect.
PLIED THREADS:-
•Made by plying the yarns together
•Plying increases the durability & performance of the thread.
Carded thread:-
When two or more plied thread are plied together & multiple plies twisted together.
Resistance of the thread to various fading forces e.G. Sunlight, washing etc.
Tests are developed by AATCC.Polyester sewing threads dyed with disperse dyes shows best color fastness.
COLOR:
Color matching Color fastness
Instruments used for the color matching:-
Spectrometer
Computer shade recipes
SPECTROMETER
FINISHES:-
Soft
Gassed
Mercerized
Glazed
Bonded
Advantages Of Finishing:-
Threads are bonded to increase ply security & smoothness.
Prevents splitting & fraying which causes breakage.
Relationship Between Thread Construction, Fiber Type, and Thread Finish
Thread Construction Fiber Type Thread Finish
CoreCotton wrapped polyester Soft
Polyester wrapped polyester Soft
SpunCotton Soft, Mercerized, or Glaced
Polyester Soft
Air Entangled Polyester Soft
Textured Polyester Soft
Twisted MultifilamentNylon Soft
Polyester Soft or Bonded
Monocord Nylon Bonded
Monofilament Nylon Soft
THREAD LUBRICATION:
To reduce amount of friction
To provide protection from the needle heat
Lubricant should be non-sticky, non-staining, non-soiling
and shouldn’t effect the thread color.
Thread size measurement
Weight
Denier.
Tex.
Conversion
Natural fibre such as cotton and silk
Length measurement
Synthetic fibres
40 weight = 225 denier = tex 25
Thread Put-ups
•Spool
•Cop
•Cones
•vicone
•Container
•Cocoons
•Prewound bobbins
SEWING MACHINE NEEDLE
Functions of the needle
To produce hole in the material
To carry the needle thread through the material and there form a loop
To pass the needle thread through the loop
PARTS OF THE NEEDLE
Shank
upper part of the needle
may be cylindrical or have a flat side.
support
larger in diameter than the rest of the needle for reason of strength
Shoulder
intermediate between shank and the blade
It is also called shaft
Blade
below the shoulder of the blade to the eye of the needle
longest part of the needle.
greatest amount of the friction .
Long Grove
provides a protective channel in which the thread is drawn through.
A Correctly shaped long groove of a depth matched to the thread diameter, offers considerable protection to the thread.
Short Groove
•It extends a little above and below the eye
•Its function is to assist in the formation of the loop in the needle thread.
Eye
It is the hole extending through the blade from the long groove on one side to the short groove on the other
The shape of the inside of the eye at the top is critical.
Scarf or Clearance cut
It is the recess across the whole face of the needle just above the eye.
Point
Best penetration
Tip
It is extreme end of the point which combines with the point in defining the penetration performance.
IF THE NEEDLE IS TOO SMALL FOR THE THREAD
• not pass freely through the eye
• not fit properly into the long groove.
•Thread will suffer from excessive abrasion. •Can lead to costly thread breakages in production.
IF THE NEEDLE IS TOO LARGE FOR THE THREAD
•There will be poor control of the loop formation which may cause slip stitches.
•It will create holes in the fabric which are too big for the stitches and give an unattractive seam appearance.
•Tends to give rise to damaged fabric along the stitch line, and in closely woven fabrics, pucker along the seam line due to fabric distortion.
Thread sizes in syntheticTicket number
Needle sizes inMetric system
Needle sizes inSinger system
8 180 24
16 140 22
30 120 19
50 110 18
75 90 14
120 80 12
180 70 10
320 60 8
Needle & Thread Sizes
Needle points
Cut point Sharp tips Used for sewing leather and plastics Modifies set of stitching and
appearance of seam Creates decorative effects
a) Narrow wedge point
Cuts at right angle to seam direction High stitched density is achieved Most frequently used
B) Narrow reverse twist point
Produces incisions at 45 degrees to seam direction`seam slithly turned left on the surface of the material Next frequently used
C) Cross Point
Incisions along line of seamRequires large stitch lengthIncisions spaced far apartHeavy decorative seamsStitches- straight appearance
Cloth point needle
• Used for sewing textile materials
Types of cloth point needle
•Set point needle
•Ball point needle
Set point needle
Slim set point
Set point
Heavy set point
Light ball point
Medium ball point
Heavy ball point
Ball point
Denim
has a very sharp, acute point with a slender eye and a strong shaft.
penetrate heavy fabrics like denim and canvas.
The slender eye holds the thread in place for proper loop formation.
prevents deflection of the needle insures accurate needle placement for stitch formation
Embroidery
Has a light point
Large eye
Special scarf to protect threads
Leather
has a wedge shaped point
good piercing strength
Curve needles
• Used for blind stitches
• Operate at high speeds
• Costly
Metallic
Have a large, elongated eye
Larger scarf
larger groove to protect fragile metallic threads during stitch formation.
Quilting
• Has a tapered point for stitching through multiple layers and across seams.
• The shape of the point minimizes damage to the quilting fabric.
Microtex
Sharper than the universal point with a more slender shaft.
Used primarily on fine woven, heirloom sewing on very fine fabrics, synthetic suede, tightly woven fabrics.
Topstitch • Used for embroidery and quilting.
• has an extra large rectangular-shaped eye which allows for smoother movement of thread.
• has a much deeper groove which works wonders with heavier threads.
• The deeper groove allows a heavier thread to lie in it, thereby reducing friction on the thread as it moves.
• most popular sizes are 90/14 or 100/16.
Hem stitch Wing Needles
• Uses: Hemstitching or heirloom embroidery on linen and batiste.
Configuration: Has fins on sides of shank to create holes as you sew.
Troubleshooting: Stitch is more effective when needle returns to same needle hole more than once. If needle pushes fabric into needle hole, put stabilizer under fabric.
Twin (double) Needle
• Uses: Topstitching, pin tucking, and decorative stitching.
Configuration: Two needles on single shaft produce two rows of stitches. Measurement between needles ranges from 1.6mm to 6mm, and needles come with universal, stretch, embroidery, denim, and Metallica points.
Troubleshooting: Be sure throat plate allows for distance between needles.
Triple Needle
• Uses: Same uses as for double needle.
Configuration: Cross bar on single shaft connects three needles to sew three stitching rows. Comes with universal point in 2.5mm and 3mm widths.
Troubleshooting: Same as for double needle.
Spring Needle• Uses: Free-motion stitching with
dropped feed dogs.
Configuration: Has wire spring above point to prevent fabrics from riding up onto needle, eliminating need for presser foot.
Troubleshooting: Before using, practice free-motion stitching with heavy regular needle, paper, and dropped feed dogs. Don't pull paper/fabric; instead gently guide it through stitching. Wear safety glasses for free-motion work, since needles often break.
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