# Textile Calculation

## How to Find Out Sewing Time with Machine RPM

How to Find Out Sewing Time with Machine RPM
Noor Ahmed Raaz
B.Sc. in Textile Engineering (CU)
Specialized in Apparel Manufacturing
Merchandiser
A.M.C.S Textile Ltd (AEPZ)
Email: raju.uttara105@gmail.com

Introduction:
Calculation of sewing time is an important task for industrial engineers. Because it will be effective to get actual time to be taken by a sewing operator to sew a specific length of seam. From this we can get an operator production efficiency easily. If you read article with concentrately then I think you easily calculate sewing time.
 Sewing by an operator
Estimation of Sewing Time Using Machine RPM:
Machine RPM means Revolution Per Minute of that machine. By machine RPM we can get time to sew a specific length of seam with specific Stitch per Inch (SPI). Before calculating garments sewing time by using machine RPM, an industrial engineer should confirm about the below points:

• Stitch per inch (SPI) of the garments,
• Seam length in inch of the garments,
• Sewing machine RPM (Revolution per minute).
Now by using the below formula, an industrial engineer can easily calculate the required garments sewing time from machine RPM.

Machine cycle time or sewing time (in second),

Stitch per inch (SPI) x Seam length in inch x 60
= ……………………………………………………………
Sewing Machine RPM

If we see an example then concept will be clear,
Example:
If a plain stitch sewing machine RPM is 1400. How much time needed to sew a 40 inch length seam, where stitch per inch (SPI) is 8?

Solution:

Here,

Sewing machine RPM= 1400,
Seam length in inch= 50”,
Stitch per inch (SPI) = 8.

We know that,

Machine cycle time or sewing time (in second),

Stitch per inch (SPI) x Seam length in inch x 60
= ………………………………………………………
Sewing Machine RPM

8 x 50 x 60
= …………………
1400

24000
= …………
1400

= 17.14 sec

So. Sewing time of that machine is 17.14 sec.