Elastic Recovery

Elastic Recovery

Elasticity may be defined as that property of a body by which It tends to recover its original size and shape after deformation.

 The power of recovery from a given extension may be expressed by the elastic recovery value:

A suit made from a materials with poor elastic recovery properties would very soon exhibit baggy knees in the trousers and baggy elbows in the jacket.


 

                                                                                                                              @article by@shajib

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Yarn Hairiness and Causes of Higher Hairiness

Measurement of Hairiness

 •        Measurements of hairiness are very dependent on the experimental configuration used such as the number and type of guides the yarn passes over and also the method chosen for detecting the hairs.

•       In general hairiness of yarn is measured by

•       Shirley Hairiness Tester

•       Zweigle Hairiness Tester G565

•       Uster Tester 3

Shirley Yarn Hairiness Tester process are given below.

Shirley Yarn Hairiness Tester

•       Shirley yarn hairiness tester consists of a light beam shining on a small diameter photoreceptor opposite to it.

•       The yarn under test is run between the light and the receptor at a constant speed.

•       As a hair posses between the light and receptor the light beam is momentarily broken and an electronic circuit counts the interruption as one hair.

•       It counts the number of hairs longer than a pre-selected length (between 0 and 10 mm), usually 3 mm

shirley process

•       The instrument has two sets of yarn guides as shown. The lower set leads the yarn over a guide at a fixed distance of 3mm from the receptor.

•       The upper set leads the yarn over a movable guide which can be set at a distance of between 1 and 10mm from the receptor. 

                        * The total number of hairs in a fixed length of yarn is counted by counting for a given                    time,  the yarn running at a known speed.

related Topics

Yarn Hairiness and Causes of Higher Hairiness

 

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Yarn Hairiness and Causes of Higher Hairiness

Yarn Hairiness

• Hairiness is defined as the sum of fiber ends and loops protruding out from the main compact yarn body.

• It is the most circumstances an undesirable property, giving rise to problem in fabric production and deteriorates the fabric appearance.

• Measurement of hairiness dependent on the method chosen for detecting the hairs.

• It is not possible to represent hairiness with a single parameter because the number of hairs and the length of hairs both vary independently. 

normal view

micro view

Causes of Higher Hairiness

a)Raw Materials

-Maturity: In case of cotton 70% maturity of the fibers is needed, if less then cause hairiness. Immature and dead fibers result in hairiness.

-Micronaire (Fineness): Range of micronaire value for cotton yarn is (4.2±.2). Micronaire value of (4.2±.6) results in increased hairiness which is used in flannel like fabrics having soft fell. 

-Uniformity Ratio: normally fibers uniformity ratio is 40-50%. If it is less than hairiness results.

b) Process 

    Inadequate drafting and orientation

       Spinning Triangle

Maintenance

• Rubbery surfaces 
• Life of devices or machine parts

Related Topics:
Yarn Hairiness and Causes of Higher Hairiness 

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Moisture Regain & Moisture Content by using rapid dryer

In this experiment we will measure Moisture Regain & Moisture Content of a material by using rapid dryer. It is very important to know about the MR & MC of a material because it directly affect the end product characteristics.
  
Moisture Regain: Moisture regain is defined as the weight of water
in a material expressed as a percentage to oven dry weight.

Let, oven dry weight of the material, D
Weight of water in the material, W
Moisture regain, R = W/DX 100%
  
Moisture Content: Moisture content is the weight of water in a material
expressed as a percentage to the total weight.

Moisture content, M = = W/(D+W)X 100%
  
Rapid Dryer: It is a electrical device with motor , thermometer & container  to pass hot air & measure the temperature of the textile material in the container.
  
Objectives:

    To determine the Moisture Regain ability of a textile material.
    To know the Moisture Content ability of a textile material.
    To get a perfect testing result.

Instruments:

    Rapid dryer.
    Sample.
    Electric balance.

Rapid dryer

Working Procedure:

At first 5gm cotton fiber is taken with the help of electric balance.
Now taking the sample in the container, weight is again measured.
Placing it in the oven dryer and heated for 1 min to dy off the moisture.
Weight is again taken.
3 & 4 repeated until the last two weights are same.

Data measurement table:

Sample wt. (gm)	Sample container wt. W1 (gm)	Sample container wt. after drying W2 (gm)	Average wt. W2 (gm)	Weight of water (gm) W=W1-W2	Oven dry wt. D= 5-W (gm)
5	63.07+5 = 68.07	67.70	67.68	0.455	4.545
		67.65

Result:

Moisture Regain R = 0.455/4.545X 100%
               = 10%

Moisture Content M  = 0.455/(4.545+0.455)X 100%
                    = 9.1%


After this experiment we have a clear idea about how to measureMoisture regain & moisture content. It will help us in future.

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