Suitable fabric for evening wear

We wanted to know more about silk and we found a silk tie in the second hand store. A silk tie or bow tie is essential for a classic evening dress code. 

Silk Filament

 

The silk filament consists of fibroin. Two of these fibroin fibres make one raw silk filament. The two fibroin fibres are surrounded by sericin, which is a silk gum, that holds the fibres together. It is water-soluble and can be pigmented. 

Production of silk

The silk in this tie probably is originating from the mulberry silkworm. After coming out of the egg, the caterpillar develops itself from 2 mm to a big silkworm. It feeds itself with a large quantity of mulberry leaves. After 30 days the silkworm is as large as a middle finger and begins to pupate. The silk fluid comes out of 2 glands. After 3 days the spinning is done and 3000m of silk are produced. The final cocoon has the size of a pigeon´s egg. 

14 days later the pupa transited to a moth and crawls out of the cocoon. The moth destroys the cocoon to crawl out. Therefore the pupa has to be killed to produce silk. The cocoon is placed in hot steam or hot air. After that the cocoon is put in hot water to find the end of the filaments. Then the filaments are wound up on a reel. The silk filament is really thin, therefore 7 to 10 filaments are reeled together. This silk is called net silk and is used for the finest fabrics. The net silk will be twisted together in the silk throwing machine. Spun silk is made of the longer fibres and therefore very soft and smooth. It is also called Schappe silk. The shorter fibres are spun into an irregular yarn called Bourette silk.

Materials

When we took it apart we saw that there are 4 types of fabric used in the tie. All of the fabrics in the tie have a special purpose. 

Material 1

The outside is made of 100% silk with satin weave with a pattern. The interlacings in satin weave are distributed uniform to create a very shiny fabric. There are less interlacings in a satin weave than in a plain weave. Therefore you have a predominance of warp on the surface and the fabric looks very lustrous.The fabric of the tie is usually cut on the bias.  

The fabric is yarn dyed and the yarns are twisted in a S-direction.

The fabric of the tie is usually cut on the bias. This is done, because the fabric can handle the tug. Therefore the pattern is often diagonal too. 

 















Material 2

 

The second material is a lining made of polyester. It is between the silk and the woolen lining. It is not dyed and not twisted. It is made in a loose plain weave. The lining should protect the silk from the scratchy woolen lining.

Material 3

The third material is a woolen lining which is constructed in a doubled plain weave. It is not dyed and twisted in S-direction. The lining of the tie is very important. It should be a soft and elastic fabric. Therefore in high quality ties wool is used. The lining functions as a cushion to fill up the tie and smoothen the silk fabric. With the lining it is easier to tie the tie and to keep the form.

Material 4

 
 The last material is a cotton fabric of a plain weave construction. The fabric is not dyed, but maybe bleached. The yarn is twisted in Z-direction. This layer is used to make the tie even more stable and voluminous.

Testing

Washing

The care label stated that the tie is only allowed to clean by dry cleaning. We were curious what would happen if we washed the tie. Therefore we used the A1S program, which washes on 40 degrees for 30 minutes with a detergent, but without steel balls, since silk is a very delicate fibre. There were no changes in the appearance, but the silk does not feel so soft anymore.

Tear Strength 

We also performed a tear strength test. We tested the fabric in the warp direction and in the weft direction. 

In the warp direction we put on a D load and the result was 50.49 Newton. 

In the weft direction we also put on a D load and the result was 41.26 Newton.

We also try to test the tearing strength in the diagonal direction, in which the tie is cut. But it teared in the warp direction with 46.65 Newton.

Weight

Weight is 104 gram per square meters and 3.05 ounces per square yard. 

Properties

In a tie, silk doesn’t have any functionality rather than appearance and feel. Still we will state the properties of silk as it is used in clothing to show what silk can do when it is used in garments. 

Silk can give a cooling effect when filament silk is made into fine fabrics with a small volume of enclosed air. Still, silk can be warm by creating a layer of air between the fabric and the skin, which cannot escape easily. The adsorption of water is the same for silk as it is for wool. It can absorb and hold about 1/3 of its weight of water vapour without a wet feeling. The main property of silk is the next to skin comfort. Silk is very pleasant to wear because of its fineness and softness. 

As we’ve seen, silk is very strong and has a very good tenacity. The extensibility of silk lies between 10% and 30 percent. In the tie it is not possible to stretch it, also because of the other added materials inside the tie. A very good property of silk is that the resilience is outstanding. It does almost not crease at all and wrinkles are smoothening out easily. A good property for women’s blouses is that it doesn’t built up electrostatic charge, because it always contains moisture. 

Care instruction 

The most severe laundering conditions that a fibre can tolerate are seldom those to be recommended for a given item of clothing. The care instruction says the tie can only be cleaned by dry cleaning and can be ironed on the lowest level. As we’ve seen with the washing test, the fabric loses some of its good properties when washed. Whereas a tie doesn’t need to be washed that often it is wise to follow the care instruction. 

The tie didn’t have the silk seal, which is an internationally recognized seal that stands for pure silk and good quality. The label does say it is pure silk.