Presentation on theme: "Threads And Needles. Factors Affecting Characteristic Of Thread FIBRE CONTENT STRUCTURE TWIST PLY COLOR FINISHES STRENGTH SIZE THREADS."— Presentation transcript:
Threads And Needles
Factors Affecting Characteristic Of Thread FIBRE CONTENT STRUCTURE TWIST PLY COLOR FINISHES STRENGTH SIZE THREADS
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 heat Resistance to the tangling Disadvantage: Poor elasticity Poor abrasion resistance More expensive Weaker (time consuming due to thread breakage) Weakens easily by chemicals used in fabric &garment finishing But 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 Nylon Strong 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 filamentb) 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 minimum Breakage 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
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 ConstructionFiber TypeThread Finish Core Cotton wrapped polyesterSoft Polyester wrapped polyesterSoft Spun CottonSoft, Mercerized, or Glaced PolyesterSoft Air EntangledPolyesterSoft TexturedPolyesterSoft Twisted Multifilament NylonSoft PolyesterSoft or Bonded MonocordNylonBonded MonofilamentNylonSoft
THREAD LUBRICATION: To reduce amount of friction To provide protection from the needle heat Lubricant should be non-sticky, non-staining, non-soiling and shouldnt 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
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 synthetic Ticket number Needle sizes in Metric system Needle sizes in Singer system 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 seam Requires large stitch length Incisions spaced far apart Heavy decorative seams Stitches- 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.