A Presentation onSeam And Seam Classes
Khulna University of Engineering & Technology
Prepared by,Md. Razib Sheikh
ID. 1221025Final Year Student
Department Of Textile Engineering, KUET.
Seam• The line along which a number of layers of fabrics are joined is
called the seam. Seam can be created in sewing of fabrics or by joining of fabrics in any other alternative way(Welding, Fusing, Moulding, Adhesive).
• In other words, Seam is the combination of stitch which makes line to join two ply of fabric.
• The seam which is created by sewing of fabrics, known as stitched seam.
• Seam is used as functional purpose(e.g. strength, security etc.). Sometimes used as decorative purpose.
Seam Characteristics Seam strength: Seam strength should be equal to or a little bit
lower than the strength of the fabric in both direction. Elasticity: The elasticity of seams should be equal to or greater
than the elasticity of the fabric. Durability: The Durability of seam should be equal to duration of
the use of the garment. Security: During the wearing of the garment there should have
guarantee so the for normal reasons the will not be opened due to the opening or breaking of the thread.
Comfort: The seam of some garment( e.g. underwear, undergarment) should have comfort feel.
Some special characteristics e.g. water proof of seam should have, as for required garments.
Seam Quality ParametersThough the stitch types chosen for a seam depend on the functional or aesthetic requirements of the seam, seam quality can be measured based on the following parameters:1. Seam size:
It is measured with seam depth, seam length and seam width.2. Seam slippage strength:
It is the amount of force required to pull out a total of ¼” of the opposing sets of yarns perpendicular to the seam line.
3. Seam strength:It is the force required to break open the seam either by breaking the thread or by breaking the sewn material.
Seam classesAccording to BS 3870-1:1991, the eight seam classes are following: • Class 1 – Superimposed seam.• Class 2 – Lapped seam.• Class 3 – Bound seam.• Class 4 – Flat seam.• Class 5 – Decorative/Ornamental seam• Class 6 – Edge finishing/neatening seam.• Class 7 – Applied seam.• Class 8 – Others. Fig: Different types of seam
Class 1 – Superimposed seam• This is the most common & mostly used
seam for joining fabrics. In this seam, two plies of fabric are placed on one another perfectly & then the fabrics are sewn.
• Most commonly used.• The sewn edges of the fabrics remain in
the same side. • It has over 50 variations.• This class of seam can be sewn a variety of
m/c. e.g. Lock stitch, overlock machine.Uses:• Mostly used in inside seam like as shirts,
pants, trousers & children wears .
Fig: Class 1 – Superimposed seam
Class 2 – lapped seam• This type of seam is achieved with two or
more pieces of fabric over lapping each other.
• Two sewn ends of the fabric are in opposite direction.
• Mostly two needle chain stitch m/c is used.
• Seam under this class is very strong.• At least two line of stitching are used.Uses:• This class of seam is not mostly used for
sewing garments. This seam is used in sewing jeans pants, lunges etc.
Fig: Class 2- lapped seam
Class 3 – Bound seam• A bound seam is one piece of fabric
encompassing the raw edge of another piece of fabric. This produces a neat edge on a seam exposed to view or to wear.
• The purpose of bound seam is to finish an edge of garment.
• Some time used as decorative purpose.• The binder fabric may be different colors.• There are 18 variation of bound seam.Uses:• Used in sewing men’s underwear, pants,
sleeping suits, Neckline of a T-shirt, yoke joint in the shirt waist band.
Fig: Class 3 – Bound seam
Class 4 – Flat seam• Flat seam are constructed by
having two pieces of fabric meet precisely at their edges.
• Seam thickness is comparatively less.
• Zigzag stitch may be produced. • Edge should be cleaned before
sewing to avoid fraying.Uses:• This seam is widely used in under
garments & in knitted items.
Fig: Class 4 - flat seam
Class 5 – Decorative/Ornamental Seam• This type of seam is made by making one or
more adjacent stitch lines in one or more layer of fabric. The fabric which we used that would be folded in several times and then according to the under side of the folded part of the fabric stitch can be produced.
• This seam type consists of a minimum of one component.
• Multi needle sewing m/c is used.- • Seam under this class are produced only
for decorative purpose.Uses:• Used in pant or other dresses, Cartains, Table
cloths, Furniture wears, Decorative ladies wears etc.
Fig: Class 5 – Decorative/Ornamental Seam
Class 6 – Edge neatening seam• The seam of class-6- is called edge neatening
which is used to holds the edge of the fabric such that the yarns of the fabric can not open easily.
• All the over Lock stitch is edge neatening class seam.
• It can be made by overlock m/c.- • Extensively used.Uses:• Mostly used knitted garments and hemming. • To protect the fabric edge such that the warp
yarn of the fabric can not easily open. • Serging trouser panels, flys, facings, etc.
Fig: Class 6-Edge neatening
Class 7 – Applied Seam• This seam class involves seams that
require the addition of another component onto the edge of a piece of fabric e.g., elastic braid onto the edge of ladies briefs. This type of seam requires two components.
• They are mainly used to a decorative material to an edge of seam such as lace-elastic.
• Similar to lapped (class-2) but the joined component is extended limited on both sides from sewn line.
Uses:• Joining of lace, elastic braid to shirts of
young people, ladies briefs etc.
Joining of lace
Joining of elastic braid
Fig: Class 7 – Applied Seam
Class 8 – Others
• This seam class consists of one piece of fabric that is turned in on both edges. The edge of fabric is sewn by folding in various ways.
• It is most commonly seen in belt loops or bets for which a folder can be attached to the machine. This type of seam requires only one component.
Fig: Seam class 8
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