TECHNICAL

INFORMATION

For our clients to make the best use of the materials we provide, it is important for us to have transparency all the way. This will make you better aware and use of it to increase the efficiency of the end product and lead to a far superior experience with the product. Below are some things you must keep in mind for the better use of certain fabrics and textiles:

Twist Direction.

The direction of twist and the winding direction of the yarn determines its strength and nature. There are two kinds of twists, namely the S twist and the Z twist. The S twist yarn are those that have individual fabric twisted in a directional diagonal to the letter S. Whereas for Z twist yarn the fiber is twisted in the direction diagonal to the letter Z. The multiple twisted yarn include two different yarns with a Z twist but are combined together with an S twist. 

This ultimately determines the nature of the fabric. Ideally, stronger twists create yarn for weaving mills and the softer ones create yarn for knitting mills. The sewing thread comprises of a unique twist direction where there are three single S twisted yarns that are combined together in the Z twisted direction. This creates a very strong tear resistant fabric. Lastly, the voile is a fiber that comprises of to threads twisted in the Z direction and are combined together in the Z direction as well. 

Since the fibers are put in a Z twist twice, it causes the fabric to curl. They are effective in showcasing luminous colours and as a result were used in curtains and other decorative items. We have mentioned the most important twists seen in fabrics but there are other special twists that are made by special machines.

Yarn Numbering System.

We use a special numbering system laid out by the Tex-System:

Term

 Definition

 Basic Tex Unit [tex]

Mass of yarn in grams per 1’000 meters length.

 Decimal fraction

Mass of yarn in grams per 10’000 meters length.

 Decitex [dtex]

1 g / 10’000m = 1/10tex

Decitex is the count grading for filament and spinning yarns recognized by all international bodies in the man-made fibers  industry.

 Decimal multiple

 Mass in kilograms per 1’000 meters length.

 Kilotex [ktex]

1 kg / 1’000m = 1000 tex

Kilotex is used to state the counts of spinning tow and similar semi-finished and finished products.

Below are other number systems used for certain fabrics:

Term

Definition

 Count Denier [den]

Mass of yarn in grams for length of 9’000 meters. 

 Metric yarns number [Nm] 

Length in meters per 1 gram of mass.

 English cotton yarn number [Ne], [ECC] 

Number of 840 yards strands per 1 English pound of mass.

 Wool runs

Number of 1600 yards strands per 1 English pound of mass. 

 Wool, worsted [NeK]

Number of 560 yards strands per 1 English pound of mass.

 Wool, woolen measure [NeS]

Number of 256 yards strands per 1 English pound of mass.

 Linen Count [NeL], [Lea]

Number of 300 yards strands per 1 English pound of mass.

 Spun silk

Number of 840 yards strands per 1 English pound of mass.

Below is the a the conversion values for various Yarn Measuring Systems:

convert into →
 

known↓

 tex

 

 dtex

 

 den

 

 Nm

 

 Ne

 

 tex

10 x tex

9 x tex

1’000 / tex

591 / tex

 dtex

dtex / 10

0.9 x dtex

10’000 / dtex

5’910 / dtex

 den

den / 9

den / 0.9

9’000 / den

5314 / den

 Nm

1’000 / Nm

10’000 / Nm

9’000 / Nm

0.59 x Nm

 Ne

591 / Ne

5910 / Ne

5314 / Ne

1.69 x Ne

Yarn Testing Methods

A yarn can only be usable after we conduct certain tests on the fabric to know its durability, elongation and shrinkage. Our tests are conducted in the following conditions:

Test Room Conditions

The temperatures were prescribed by the International Bureau of Standards for Man-made Fibers:

room temperature: 20 ± 2°C

relative humidity: 65 ± 2%

*All tests are carried out in a conditioned state

Linear Density

Linear Density refers to the weight of a 10,000 meter yarn in grams. To make things simpler, instead of separating a 10,000 meter of yarn for this purpose, a yarn sample of 25 or 100 meters length taken instead and weighed on an analytical scale. Hereafter, the grams per 10,000m yarn are calculated.

Breaking Force and Elongation at Break

This test checks the point at which the fabric breaks. It measures the amount of elongation that takes place before the fabric breaks. The breaking force leads to a rupture in the thread or the yarn.

The elongation at break shows an increase in the length of the fabric produced because of excessive stretching. It is measured as a percentage of the inital length of the fiber. The test is carried out on a device used for measuring force, the dynamometer. It is used to bring about a constant and steady elongation within the fabric till it snaps. Below are the prescribed conditions of the dynamometer: 

length between clamps: 500 mm (or 250 mm) 

test velocity; if elongation at break

    • ≤ 8%:     50 mm/min (25 mm/min)
    • 8-50%:   500 mm/min (250 mm/min)
    • > 50%:   1000 mm/min (500 mm/min) 

pretension: 0.5 cN/tex

Tenacity

This is calculated from the breaking force and linear density and is expressed in centi Newton per tex [cN/tex]:

Force at Specified Elongation

This refers to the changes in the fabric caused by an external force leading to a defined extension (usually 2-5%).

Hot Air Shrinkage

Hot air shrinkage refers to the shrinkage in the fabric occurring because of its’ treatment with hot hair. There are two distinct kinds of shrinkages, namely, free shrinkage and shrinkage under pretention.

Free shrinkage refers to the change in the fiber after the influence of heat and shrinkage under pretention refers to the amount of shrinkage seen in the fiber during the influence of heat.

Hot Air Shrinkage Force

Hot air shrinkage force refers to the shrinkage force in cN that was caused by hot air treatment (180°C).
Pretension: 0.1 cN/tex.

Hot Water Shrinkage

This refers to the shrinkage in length which is caused by hot water (in 95°C). It is calculated as follows: 

  • On a standard reel, skeins of 1m circumference and approximately 5’000 dtex are prepared and measured at a pretention of 1 cN/tex lengthwise = L1 
  • The length of yarns are treated without tension for 15 minutes in hot water (95°C), dried and kept at standard conditions. 
  • The shrunk length is then determined again with 1 cN/tex pretension = L2 

Contact Us.

Do feel free to contact us to book an appointment or follow-up with any other queries. Our contact details are mentioned below. You can also send us a message and on of our professionals will happily get back to you.
  • info@stutiexports.com
  • 022 2164 2212
  • Mulund, Mumbai