**Sizing:**

Sizing is a complementary operation that is carried out on warps formed by spun yarns with insufficient tenacity or by continuous filament yarns with zero twists. In general, when sizing is necessary, the yarn is beam warped, therefore all beams corresponding to the beams are fed, as soon as warping is completed, to the sizing machine where they are assembled. Sizing consists of impregnating the yarn with particular substances which form on the yarn surface a film with the aim of improving yarn smoothness and tenacity during the subsequent weaving stage. In the article, we will discuss the sizing calculation formulas with examples.

**Sizing Calculation Formulas with Examples**

1. Weight in lbs,

….Length of warp in yds × number of ends

= …………………………………………………………..

…………………..840 × yarn count

2. Size% On warp,

…………..Weight in size

= ……………………………………. × 100

……Weight of unsized warp

3. Weight of sized warp,

……………………………………………………………………………………………………..100 + Size%

= Weight of unsized warp + weight of size or weight of unsized warp×……………………..

……………………………………………………………………………………………………………100

4. Weight of size to be put on the warp,

= Weight of unsized warp × Size% required to be put on a warp

5. Count of sized yarn,

….Number of ends in warp × length of warp in yds

= ………………………………………………………………………

…………..Weight of sized warp in-lbs × 840

Or,

………………………………………………………100

= Count of unsized yarn × ………………………………….

………………………………………100 + size% on the warp

**Example:**

The weight of sized yarn on a beam was found to be 82.5 lbs. The beam contains 1050 yds of warp, whose count before sizing was 50s cotton. If the number of ends in the warp is 3000, calculate the following:

The weight of size on the yarn.

Size% put on the yarn.

The count of sized yarn.

Solution:

(1) Weight of size on the warp,

= Weight of sized warp – the weight of the same length of unsized warp____(1)

Now,

Weight of unsized warp,

….Length of warp in yds × number of ends

= …………………………………………………………..

…………….840 × counts of unsized yarn

….1050 × 3000

= ……………………

…….840 × 50

= 75 lbs

Therefore, from (1) we have,

Weight of size on warp = 82.5 – 75 = 7.5 lbs

So, the weight of the size of the yarn is 7.5 lbs.

(2) Size% on the warp,

…………Weight in size

= ………………………………… × 100

….Weight of unsized warp

….7.5 × 100

= ………………

………75

= 10%

So, Size% put on the yarn is 10%

(3 ) Count of sized yarn,

…..Number of ends in warp × length of warp in yds

= ………………………………………………………………………..

……………..Weight of sized warp in lbs × 840

…..3000 × 1050

= …………………….

…….82.5 × 840

= 45.5 S cotton

So, the count of sized yarn is 45.5 S cotton.

Author of this Article:Mayedul IslamAssistant Chemist Ha-Meem Group, Tongi, Gazipur, Bangladesh Email: [email protected]