Stitch

 What is Stitch?

Loop or loops of one or more threads when bounds with each other, either by interlacing, interloping, intra-looping or combination of those when sewing fabric, each unit of such configuration is called stitch.

 Loops Formation Method

Interlacing:

During stitching when one loop of one thread passes over another loop of another thread is called interlacing.

Inter-looping:

When loop of one thread passes through the loop of another thread is called inter-looping.

Intra-looping:

When a loop of one thread passes through the loop of same thread during sewing is called intra-looping.

Stitch Type

Stitches are grouped in 6 classes according to British standard 3870:1991 as follows-

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 edge stitch)
6. Stitch class –600 (Covering chain stitch)

1. Stitch class –100 (Single thread chain stitch )

• Stitches are formed by intra-looping.
• One or more needle thread is used for stitch formation.
• Security of stitch is very poor.
• Temporary joining, positioning, hemming, button holing, button attaching purposes.
• Used for gathered appearance as temporary joining i.e. collar positioning, flap positioning. 

2. Stitch class –200 (Hand stitch )

• Looks like domestic hand stitch.
• It is produced from single thread.
• Needle thread is passed from one side to another side in the fabric and makes a sewn line.
• This stitch is made by special type of needle and sewing m/c.
• Very rare used in the garments manufacturing unit due to higher cost and limited length of sewing.
• Time consuming operation.

3. Stitch class –300 (Lock stitch )

• At least two groups of threads are required.
• One group of thread is called needle thread and another group of thread is called bobbin thread.
• Appearance of lock stitch is similar in both sides of the fabric.
• Security of stitches is very good.
• Abrasion resistance of lock stitch better.
• The main problem of lock stitch is the lower capacity of bobbin thread requires frequent bobbin thread changing.
• Not suitable for knit fabric sewing.
• Extensively used in sewing and fabric attachment as pocket, collar, cuff, facing etc.
• Used in top stitching, button holing, button attaching, blind stitching etc.

4. Stitch class –400 (Multi thread chain stitch )

• Stitches are formed by two or more groups of threads.
• One group is called needle thread and another is called looper thread.
• Threads are bound together by interlacing and inter-looping.
• Multi thread chain stitch is also called double locked stitch.
• Possibility of seam pucker formation is less.
• Used for long length sewing, heavy fabric sewing attaching lace, elastic etc.

5. Stitch class –500 (Over edge stitch)

• Stitches are formed by two or more groups of threads.
• At least one group of thread passes around cut end of the fabric.
• Fraying is stopped by the stitches of 500 class.
• It is also called as over lock stitch.
• At the starting and finishing ends few inches thread to be left.
• Extensively used for knit fabric sewing.
• Also used for fabric sewing of denim, jeans etc.

6. Stitch class –600 (Covering chain stitch)

• Stitches under 600 class are formed by three groups of threads.
• One group is called needle thread and other is called top cover thread and the other group is called bottom cover thread.
• Stitches under this group are very complex and may need up to 9 threads.
• Used for making knitted undergarments to attach tape, lace, elastic.
• Also used for decorative purpose.

Sub-class of different type of stitches

A. Lock stitch family: Class 300

1. Type-301: Lock Stitch
2. Type-301: Lock Stitch (Single-step zigzag)
3. Type-301: Lock Stitch (Double-step zigzag)
4. Type-301: Lock Stitch (2-needle+1bobbin thread lock stitch) (Piping seam)

B. Over edge chain stitch family: Class 500

1. Type-501: Single thread over edge
2. Type-503: 2-thread over edge
3. Type-504: 3-thread over edge
4. Type-512: 4-thread over edge
5. Type-401.503: 5-hread over edge (2-thread over edge and double chain stitch)

Merits and demerits of 301 & 304:

Stitch 301: Merits

• Seam extensibility is around 30 %.
• Seam strength is sufficient.
• Similar appearance on both sides of fabric.
• Stitches are secured.
• Abrasion resistance is better.

Demerits:

• Lower capacity bobbin thread requires frequent bobbin thread changing.
• Not suitable in knitted garments.

Stitch 304:Merits

• Zigzag type.
• It is used for lace or elastic attachment on garments.
• Extensibility comparatively high than 301.

Demerits:

• Not applicable to all attachment.