Title:

              To develop a fabric 100% cotton with high crease recovery angle and minimum tear strength.

1         Abstract:

                           Maximum crease recovery angle and tear resistance is observed by varying concentration of softener. Tear strength and crease recovery angle are compared. Resin is applied on the fabric by padding machine. Then, it is dried and cured on stenter at 120 C and 170 C respectively. Pick up percentage and add-on are calculated by formulas.

2         Introduction:

                                 Resins are also known as wrinkle free, crease free and easy care finish. Wrinkles are produced when the hydrogen bonding break in amorphous chains. When the fabric is dried it has hydrogen bonding in their chains. When we  wet the fabric water enter the chains  swell the fibers and brake the hydrogen bonding and make new hydrogen bonding itself. After that fabric dry the water evaporates shrink the chains and form hydrogen bonding on other point not the same point and wrinkling produced. Resin results when a number of simple molecular of low molecular weight become jointed together and to end to form much longer molecules which may be linear or linear molecules cross-linked.

 Resin Finishing is the process of bringing out a special property of crease recovery to Cotton. Resin finishing is a process in which resin cross link inside the amorphous region, block the free hydroxyl groups, prevent the H-bond formation and thus improve resin finishing. It may be applied on the surface of the material to form a coating or it may be applied to the amorphous region of the material to impart a crease resisting property. Resin finishing often known by various fancy terminologies is an important process of textile processing [1]. Resin finishing quite often called Wash & wear finish, Anti crease finish and Crease resistant finish.

The resin  that is use in this experiment is  Fixapret F Eco and chemically it is compound Dimethylol Dihydroxy Ethylene Urea (DMDHEU).This is almost free formaldehyde product and Condensol FM catalyst use that is magnesium chloride .MgCl2 is used as a catalyst  it is week acid so it not damage the cellulose.    

                                          
                                             MgCl2 + 2HOH -----> Mg (OH)2 + 2HCl

Softeners are surfactant that imparts softness on the fabric. A substance added to another substance to increase its softness, pliability, or plasticity. There are many types of softeners. We classified it on the basis of chemistry of softness imparting groups and on the basis of ionicity. On the basis of softening imparting groups there are two categories of softeners.

 By apply the softeners the inter yarns and inter fibers lubrication increase of the fabric and co efficient friction also less .due to these movement of chains easily and we feel softness. The second reason of softening is pilling effect.

Silicon based softener are generally polysiloxane derivatives of low molecular weight. They are insoluble in water, and therefore must be applied on fabrics after dissolution in organic solvents, or in the form of disperse products. They feature quite good fastness to washing. They create a lubricating and moderately waterproof film on the surface and give fabrics.

 

In this experiment we achieve maximum crease recovery angle and minimum loss of tear strength.

 

 

3         Material and method:

 

 Material:

·         Bleached Cotton Fabric

·         Fixapret F-ECO

·         MgCl2

·         Micro emulsions of silicon softener

·         Water

·         Weight balance

·         Padder machine

·         Stenter machine

 

Recipe:

·         500 ml water

·         Fixapret F-ECO(90 g/l)

·         MgCl2 30% of concentration

·         Silicon softener (5 g/l,10 g/l,15 g/l)

 

Method:

First 500 mL water was taken in the beaker. Then Fixapret F-ECO was added in the water according to the concentration along with MgCl2. Then softener was added according to the concentration. After that the solution was poured in the trough of padder machine. Then the bleached cotton fabric was padded after passing through the trough. A small piece of fabric was cut before padding to check add on and pick up percentage. The sample was then passed through the Stenter for drying at 120 degrees for 3 min & for curing at 170 degrees for 45 seconds.

·         The pick-up %age can be checked by using formula:

Pick-up = [(weight of wet fabric ˗ weight of dry fabric)/weight of dry fabric] × 100

                 Pick up % = 71.35 % 

4         Characterization:

 

Crease recovery angle:

  ASTM D1295 is used to perform the test [2]. The specimen is cut by template and carefully creased by folding in half. The crease is imparted on fabric by placing it between two glass plates and adding to 500gm weight on it. After 1 min the weight is removed and the creased fabric is clamped on the instrument. Then it is allowed to recover from the crease. The recovery time may vary to suit particular creases. Usually it is 1 min.When crease recovers the dial of the instrument is rotated to keep the free edge of the specimen in line with the knife edge. The recovery angle is read from the engraved scale.

Tear strength tester:

              Tear strength was checked by Elmendorf’s Tear strength tester [3]. All three fabric samples were snipped in the warp and weft directions with the dimensions of the 4”*2.5”. The cut pieces were placed in the clamps of the tester one by one. A small cut was made with the help of blade on the tester. By pendulum move of instrument tearing is done. The readings were taken from the tester for all samples one by one.

5         Result and discussion:

5.1        Crease recovery angle:

                                                      In this experiment we take four different samples. A sample is controlled that is untreated sample. Sample 1 is treated with 5 g/l concentration of softener. Sample 2 treated with 10 g/l and sample 3 with 15 g/l concentration of softener. We can see that with increasing the concentration of softener decrease the crease recovery angle. 


we can see that control sample has highest crease recovery angle because it not applied softener. As gradually increase the concentration of softener as in sample1 and 2 sample 1 high crease recovery  angle because less concentration applied then sample 2 that is 10 g/l applied softener. Sample 3 has less crease recovery angle then control and 1 sample. By applying the softener lubrication among the fibers and yarns due to fabric become more  pliable.

1.1        Tear strength:

 

According to the theory tear strength increase by apply softener. Tear strength increase due to slippage or mobility of yarns and fibers. When we tear the fabric yarns slip and accumulate and resist the force that  tear the fabric. As we see that fig 2 sample A  has no softener ,affect its tear strength also less. Sample 1 has (5g/l) high tear strength then control sample .As gradually increase the softener concentration increase the tear softener. As we see that sample 3 (15g/l) has highly concentration then others and has greater tear strength then others


1           Conclusion:

                            It is concluded that the concentration of softener at 15 g/l achieve optimize results. At this concentration we get optimum crease recovery angle and minimum loss of tear strength. It was also conclude that with increase in concentration of softener there was decrease in crease recovery angle and tensile strength, while with increase in concentration of softener there was increase in tear strength.