Single Needle Lockstitch Machine: Features and Working Principles

Posted by Default on December 27, 2018 in

Introduction: 
A lockstitch is the most common mechanical stitch made by a sewing machine. The term "single needle stitching", often found on dress shirt labels, refers to lockstitch.Single needle lock stitch machine is called a plain needle sewing machine. Single needle lock stitch machine is mostly used as an industrial sewing machine. Modern single needle lockstitch has a thread trimmer which operates at the highest speed of its kind. Lockstitch machine is the most commonly used sewing machine in the apparel industry, especially in woven garments. Here in this article, about the Features of Single Needle Lock Stitch Machine with a clear understanding of single needle lock stitch sewing machine. 

Objectives:

1. To know about the working principle of Industrial lock stitch sewing machine.
2. To know about how to sew a sample fabric.

Types of Lockstitch machine: 
There are two types of lockstitch machines based on the number of sewing needles and bobbins present, they are:

1. Single Needle Lockstitch Machine.
2. Double Needle Lockstitch Machine.

Features of Single Needle Lockstitch Machine:

1. Stitch is produced by interlocking.
2. Bobbin and bobbin case are present.
3. Threads are supplied from cone.
4. It has only one needle.
5. It has different type of feed mechanism.

Working Principle of Single Needle Lockstitch Machine: 
The working principle of stitch formation of a lock stitch machine are given below:

1. At first, material feed to the needle over the throat plate.
2. Then, the needle is inserted into the material.
3. After that, as the needle moves upwards from its lowest position, the needle thread forms a loop which is caught by the point of the hook.
4. Again, the hook enlarged the needle thread loop and is guided around the bobbin thread.
5. Then, interlacing begins.
6. Finally, the take up lever tightens the stitch into the material and the material is fed forward.
7. Lock stitch is formed by the above stitching techniques of plain sewing machine.

Stitch Formation Techniques of Single Needle Lockstitch Machine: 
The steps of a stitch: The five steps of a lock stitch formation: 

Fig: Stitch formation of lockstitch machine

Step 1: 
Needle penetrates the fabric to bring top thread into bobbin area. 

Fig: Step-1

Step 2: 
The needle begins to lift and as the needle rises, top thread forms a loop for shuttle hook to catch. 

Fig: Step-2

Step 3: 
Shuttle hook carries the thread loop around and under the bobbin case. 

Fig: Step-3

Step 4: 
Loop slides off hook and bobbin case, goes around bobbin thread. 

Fig: Step-4

Step 5: 
The threads are pulled up and are set into the fabric as a lock stitch. 

Fig: Step-4

Conclusion: 
The lock stitch which is used in most modern machines is formed from a single thread by this experiment we able to know about the parts of a lock stitch sewing machine and their function clearly. 

Author of this article: 
Abeed Hasan 
Dept. of Textile Engineering, 
Khulna University of Engineering & Technology 
Email: 1521033abeed@gmail.com