8 CLASSES SEAMAuthor- Younus Miraj

Shanto-Mariam University of Creative & Technology

UTTARA-DHAKA

INTRODUCTION

In apparel manufacturing seams are former when two or more pieces of fabric are joined by stitches. Seams have three dimensions: length, width & depth. Seam is the join between two & more plies of material. Seams are usually formed by welding, adhesives, stitching or other joining means are sometimes used. According to British Standard Seam is the application of a series of stitches or stitch types to one or several thickness of material for functional or decorative purposes. There are a number of different types of seams that have been developed over the years to do different jobs. While many seam have largely been superseded by the development of machine stitches that finish as you sew them, and by the development. it is useful to know some of the basic seams types and finishes. A lack of expensive machinery need not prevent you sewing the garments you want. Also, some of the older methods have never been bettered.  Here I am concentrating on machine sewn seams using a standard straight stitch machine.

WHAT IS SEAM?

Seam is the combination of stitch which makes line to join two ply of fabric. Seam is Used as functional purpose. Sometimes, it used as decorative purpose. When you have chosen your fabric and pattern, you need to think about the most suitable way to sew the garment together. This will depend partly on the type of fabric, partly on the use the garment will get, and partly on the finish you want.

PROPERTIES OF GOOD SEAM

There are given the below properties of good seam:

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

CLASSIFICATION OF SEAM

Seam construction– Categorized by the British Standards Institution (BS 3870 PART II: 1991, also ISO 4916:1991). The Stitched seams are divided into eight classes:

Class 1 -Plain seam & French seam (SI Seam) Class 2 -Welt seam or Lapped seam Class 3 -Bound seam Class 4 -Channel seam or flat seam Class 5 -Ornamental seam Class 6 -Edge neatening Class 7 –No title Class 8 - No title

CLASS 1 –SUPER IMPOSED SEAM

SEEM DEFINITION:

The seam of class-1 is called 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. The sewn edges of the fabrics remain in the same side. SEAM DIAGRAM:

USED:

Attaching fabrics.

Collar, Cuff sewing, Cuff topstitching.

Collar band attach sewing and top stitching

Side seam and sleeve attach with safety-sticker.

CLASS 2- LAPPED SEAM

SEEM DEFINITION:

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.

In this category of seams in which two or more plies of fabric are overlapped with the raw edges exposed (for fabrics resistant to raveling) or the seam allowance is folded under and stitched with one or more rows of stitching.

SEAM DIAGRAM:

USED: 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 3- BOUND SEAM

SEAM DEFINITION:

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.

In this category of seams in which the raw edges of the seam allowance of one ore more plies of fabric, are covered with a bias binding and stitched with one ore more rows of stitching.

SEAM DIAGRAM:

Used: 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 4: FLAT SEAM

SEAM DEFINITION:

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.

In this category of seams in which the raw edges of the fabric plies are abutted or just slightly overlapped and joined together with stitching that covers the joint. Flat seams do not contain seam allowances, reducing fabric usage but increasing thread quantity.

SEAM DIAGRAM:

Used: close fitting garments where the seam allowance may put pressure on the body, high-stretch fabrics athletic apparel, shape wear, undergarments, lingerie, thermal underwear, swimwear, sweatshirts with side panels or with raglan sleeves, eliminating bulk at seams, seaming pelts

CLASS 5: ORNAMENTAL SEAM

SEAM DEFINITION:

A seam class is used for decorative sewing on garments. Seams are produced with minimum of one piece of component, with unlimited edges on both ends.

In this category of seams that add ornamentation to one or more plies of fabric by creating straight or curved lines or a designated design.

SEAM DIAGRAM:

Used: Adding a design detail, cording, piping, tucking, welting, box or inverted pleating, decorative stitching.

CLASS 6: EDGE NEATING SEAM

SEAM DEFINITION:

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.

In this category of seam constructed with one or two plies of fabric used to finish the edge of a garment or item. There are three finishing types within the classification. First, secures a folded edge to the shell fabric by stitching, either on the face or back. Second, stitching is used at the edge or to cover the raw edges, and may or may not be folded. Third, applies a binding on a single ply of a seam allowance to finish raw edges.

SEAM DIAGRAM:

Used: To protect the fabric edge such that the warp yarns of the fabric cannot easily open.

CLASS 7: NO TITLE SEAM

SEAM DEFINITION:

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.

SEAM DIAGRAM:

Used: These are sometimes called applied seams because they are mainly used to a

decorative material to an edge of seam such as lace-elastic.

CLASS 8: NO TITLE SEAM

SEAM DEFINITION:

Only one piece of component involved in construction the seam, stitches are applied on its edges. Seams are produced with minimum of one piece of component with a limited edge on two ends.

SEAM DIAGRAM:

Used: Mainly one piece of fabric used.- This class is commonly used for waist belts and belt loops. The edge of fabric is sewn by folding in various ways.

SEWING MACHINE

After receive the garments components from cutting section, all the garments parts are joined and sewn as sequentially. Obviously all the components are sewn respects on buyer requirement. Sewing section is the most important department of a garment manufacturing industry. Sewing machines of different types are arranged as a vertical line to assemble the garments. Sequence of types of sewing machine arrangement depends on sequence of assembling operations.

POPULAR SEWING MACHINE IN GARMENTS INDUSTRY

There are discussed the below popular sewing machine in garments industry:

1. One needle lock stitch machine2. Over edge machine of stitch class 5003. Two thread double chain stitch machine for stitch class 4004. Cover stitch on interlock machine stitch class 6005. Feed of the arm hole machine6. Button hole machine7. Button sewing machine8. Bar take machine

ONE NEEDLE LOCK STITCH MACHINE

Machine Process

The oil supplied and returned system is improved already, we can adjust the front/back slant angle of feed dog freely, to reduce the crinkle possibility and the stitch error between up/down feeding material. New style lifting presser foot is very easy and reliable, can debase the malfunction rate greatly, and the operation is very convenient and agile, We can adjust the needle distance for forward and reverse stitch, based on new design, to guarantee to sew forward and reverse stitch smoothly and placidly.

Used: it is used pant, shirt, garments and all parts of apparel.

OVEREDGE MACHINE OF STITCH CLASS 500

Machine Process

The stitch types in this class are formed with one or more groups of threads, and have as a general characteristic that loops from at least one group of threads pass around the edge of the material. The loops form a narrow band of stitching along the edge of the fabric with threads intersecting at the edge and preventing. Fabric is fraying. All have high elasticity, they do not unravel easily, and trimming knife on the machine ensures a neat edge prior to sewing. These stitches are often called over edge, overcast, over lock, serge, or marrow.

Used: These stitches are best used for edge finishes and hem.

TWO THREAD DOUBLE CHAIN STITCH MACHINE OF STITCH CLASS 400

Machine Process

(Multithread chain stitch) required 1 or more needle threads that form loops as they pass through the fabric and inter. Loop with fabric and inter loop with the looped thread on the underside. Compare to the 100 class, The 400 class is more durable and used extensively on apparel. The 400 class use upper needle thread and a looped to carry the lower .The chain stitch elongates when extended.

Used: Good for setting elastic in waist bands or decorative stitching on belts and Parallel rows of stitches for lapped side seams of woven shirts and jeans.

COVER STITCH ON INTERLOCK MACHINE OF STITCH CLASS 600

Machine Process

Interlock Machine is a high speed with 3 Needles, and 5 Threads. The machine includes a New Style Dial Micro type stitch length regulator; Differential feed Adjustment and Fully Automatic Lubrication. Interlock stitch machine with cover thread for plain seaming. This versatile machine can be used for special machine by changing accessories, since cylinder bed is very small, sewing very small tubular goods, such as sleeve and neck openings. Improve base line cam structure, and move came outside, so that the base line cannot enwind cam; even if it enwind, can solve easily, increase cam anchor point in order to load and unload conveniently, more efficiency.

Used: It is used T- shirt, Trouser and so on.

FEED OF THE ARM HOLE MACHINE

Machine Process

This machine demonstrates increased feed efficiency to handle extra heavy weight 16-ply denim and Engineered with extra feeding strength for seaming the inside of jeans. The machine is best suited for lap seaming jeans, denim jackets, work uniforms, etc. constructed of heavy weight materials.

Used: Side seam and under arm. 

BUTTON HOLE MACHINE

Machine Process

A machine-made buttonhole is usually sewn with two parallel rows of machine sewing in a narrow zigzag stitch, with the ends finished in a broader zigzag stitch.

A bound buttonhole, which has its raw edges encased by pieces of fabric or trim instead of stitches.

A keyhole buttonhole is a special case of a thread-finished buttonhole that is normally machine-made due to the difficulty of achieving it by hand working. It is characterized by a round hole at the end of the slit to accommodate the button's shank without distorting the fabric.

Used: it is used making button holes. 

BUTTON SEWING MACHINE

Machine Process

1. Attach the button sewing foot, or remove the pressure foot and work with the shank only.

2. Lower the machine's feed dogs.3. Select a zigzag stitch.4. Set the stitch length to 0.5. Place your fabric and button under the machine. You should have already marked

your fabric with your buttons position.6. Lower the foot (or shank) down onto the button to hold it in place.

7. Using the hand wheel on the side of the machine, lower the needle into the left hole of the button. You may need to re-position the button a little to get the needle to clear the button hole perfectly.

8. Still using the hand wheel, raise the needle so the needle moves to the right position (the right-most edge of the zigzag stitch).

9. Lower the needle so it hovers just above the button. You're going to 'eyeball' the position of the needle as you adjust the stitch width to determine when the needle will clear the right hole of the button perfectly.

Used: Attaching button to front placket and cuff.

BAR TAKE MACHINE

Machine Process

At first this machine produces tack stitches in a small length (1-2 cm) and then sews covering stitches over and at right angles to the first stitches. The variables are the number of tacking stitches and the number of covering stitches. Typical uses are closing the ends of buttonholes, reinforcing the ends of pocket openings and the bottoms of flies and sewing on belt loops. The adjustment points of this machine are needle, pressure feed, stitch length, stitch density.

Uses of Bar Tack Sewing Machine:

1. Attaching belt loops. 2. Increasing strength in corner of pocket. 3. Closing the two corners of button hole. 4. At the end of zipper. 5. In that place where more strength is needed to support extra load.