Underwear

Ladies underwear

This time we worked with underwear. We choose a string in 95 % polyester and 5 % elastane. 

Fabric

Polyester is a man made fiber and we find it in the synthetic polymers category. Polyester is a very strong material, and when we did the tear test (ISO 13937-2) we were not able to break it, neither in the weft or warp direction. This is of course not only due to the polyester, but also the way it has been woven. Polyester alone is not elastic at all, and that is the reason why elastane have been added in our product. 

The panties also consist of a small part of elastane. Elastane is also a synthetic fiber, it is used to ad elasticity to the garment. It is made only from filament yarns, and is very resistant to domestic laundering, making it suitable for to use in underwear.   

The panties have a small cotton panel as well on the inside of them. We assume that is due to hygienic factors, as the cotton can stand high temperatures during wash and further on that it is easier to clean cotton than polyester. This is of course important when we deal with underwear.

Composition

The panties are put together by different types of fabrics and weaves.The front of the panties is a satin weave 4 over 1. Satin has more even surface than other weaves, because it has fewer interlacings. The shiny surface is also due to the few interlacings. The front and back is very different with this kind of weave, due to the predominance of warp on the front, and opposite on the back of the fabric. The opposite of satin weave is sateen weave, which can be seen on the backside of the fabric.

The detail with the dots is created by doing the weave opposite, so we have the sateen on the front and satin on the back.

To do this weave, you have to use a jacquard weave machine, where you can control each tread, this is necessary, when you have the detail with the dots, where you need to change the weave in a small area.

As with most panties there is a cotton panel in the bottom of the panties. This is a plain weft knit. This can be recognized by the two sides having a different appearance. One side shows only face loops (as seen on the picture), and the other side only back loops.

The back of the panties is called a raschel net, which is very common for lingerie. The lace on the panties is called a raschel lace.

There is an elastic band at the waist of the panties. It is polyester thread with a core of elastane. 

Dyeing

The dye method used to dye this material is called dispersed dyeing. This is the only method that can be used when you work with polyester material. This method makes the result water insoluble. It is applied from dispersions and diffused into the fabric at a high temperature. Materials dyed this way gain good fastness properties, which is a good quality in our case because underwear is something you wash a lot. Further on, you don’t want the colour to transfer to the clothes you are wearing over it either.

That it has a good colour fastness to washing was also confirmed by the test we did (ISO 105 C06). The test showed that it did not transmit colour to any of the other materials in the test. When performing the test we also washed it a higher temperature than the care label suggested, and this did not have an effect on the result either. The reason why we washed it at 60 degrees rather than 40 is because this is what you would normally do with underwear.