Assignment 6 - Functional Wear - Raincoat

In this assignment we are looking at functional wear and more specifically at raincoats.

A raincoat is a piece of apparel that is waterproofed and would therefore, keep the body from rain, snow or other conditions when the body is exposed to water.

Desired properties for a raincoat

A rain shell like this is a lower cost alternative to a hardshell jacket. A rain shell, like a hardshell, needs to be 100% waterproof. It is easy to make a garment waterproof but what is hard, is to make the garment breathable at the same time. The material also needs to be very durable to handle conditions that rain coats are put through over a time.

Rain shells typically lose the water resistance when the coating of the fabric goes through a chemical breakup as this damages the waterproof coating.

The more wet and warmer the conditions are, the sooner the chemical breakup takes place – the fabric becomes sticky. This process happens in one to five years, or maybe later if you rarely use the jacket or if keep it at the same indoor temperature.

Other important property for a raincoat to have, is lightness. Raincoats often have to be packed in a bag and also worn outside other clothes, so the weight is critical factor.

Lastly, we would like a raincoat to be functional and comfortable – factors in consideration are the placement of pockets and other details.

Composition

The selected raincoat is made of 100% nylon (surface), and 100% PVC (backing), where the two layers are laminated. The weight of the fabric is 184 g/m2 which is a very light weight but also very good in terms of the desired lightness.

PVC (Polyvinyl Chloride)

This is a synthetic resin made by the polymerisation of vinyl chloride. It is also the third most produced kind of plastic.

PVC has become more and more used in clothing, to either create a leather-like material or sometimes simply for the effect of PVC.

PVC fabric is waterproof and water repellent so it is used in coats, skiing equipment, shoes, jackets and bag that need to be protected from water and fire (The PVC can protect the garment from fire because it is also flame resistant - Chlorine is released when you burn PVC, and chlorine atoms stop the fire).

PVC is not as breathable as sometimes wished for in a raincoat because the PVC does not allow the sweat to go through the fabric and the water stays inside the jacket.

The reason to be used in this case is mainly because the waterproofness is in focus and the low price is predominant.

Nylon

The Nylon is used for the outer layer of this raincoat. It is a synthetic fabric made from petroleum products. It has a light weight, good strength, durability and resistance to damage.

Nylon is very sensitive to heat and should be washed and dried on cool settings. Nylon does, however, dry rather fast.

Coated Nylon is a rather inexpensive and breathable alternative for raincoats. The breathability property is very needed because it is not provided by the PVC. The PVC is however the inner layer and traps the moisture inside the jacket.

When we coat the Nylon, we help keep the water out better, while still allowing breathability.

DWR coating - Durable water repellent

This is a coating which is added to fabrics to make them waterproof and breathable at the same time. It is normally used with a fabric which has some breathable properties before the coating. DWR coating wears off over time and re-treatment is recommended, as we will talk about further down.

Structure

Below we can see the of the outer layer – 100% Nylon

As it can be seen, the fabric is woven as a plain weave.

This is the simplest and tightest method of interlacing warp and weft. Each warp passed under and then over each weft. The reason the plain weave is chosen here is that it makes the fabric very tight and strong.

Tests

1. Waterproofness test

We perform this test in order to check the main property of the raincoat.

First we have tested the area around the pockets which consists of two double layers of Nylon and PVC.

The two layers handled 2700 mmwc (or higher). After the fact that there was no water coming up by the time we have reached the the minimum standard of 1200 mmwc, we have stopped the test.

Furthermore, we have tested an area with only one layer of Nylon/PVC.

We have got three water drops (1st by 800 mmwc, 2nd by 1190 and 3d by 1980 mmwc ) which made us to stop the test.

Finally we have tested a sample of PVC. Just like the second test, this one showed negative results.

We have got three water drops (1st by 315 mmwc, 2nd by 1090 mmwc and 3d by 1240 mmwc).

The overall conclusion is that the sample of one layer Nylon/PVC fails the minimum standard of good waterproofness. Therefore, the manufacturer should change the thickness of the materials or to use double layering.

2. Standard spray test / Water repellency test

We have made the water repellency test to see how the jacket reacts to water on the outer surface and see if the outer layer takes in water and stays wet.

This fabric got 50 ISO-1 - Complete wetting of whole of upper surface. Considering that the Nylon & PVC are making one single piece, there is no significant problem with the result. Having in mind the result from the previous test though, make us believe that there will be problems coming up with stronger watering.

3. Breathability test

Finally, we have performed the breathability test as the breathability is such an important property of the raincoat. As we have stated before, the rain coat can loose its DWT coating over time.

When we have started the test our sample has had a weight of 331.65 g. Over 20 hours of testing, the weight has decreased to 114.05 g. which is over 2 times the initial weight. Therefore, we can claim a very good breathability.

Waterproofness and Breathability Care Tips

Keep the jacket as clean as possible

Dirt and abrasion are very bad for the raincoat. They will wear away the DWR coating and fray the face of the fabric. This will in the end reduce the raincoats breathability because it will absorb water more easily.

Wash your jacket frequently

The oils coming naturally from the body around the hood, neck and shoulders can overtime reduce the performance of the fabrics.

Restore the DWR coating

The DWR coating is not working anymore when the fabric starts taking in water instead of shedding it. When we manually restore the DWR coating, we will increase the waterproofness and then the breathability. In order to do so, wash-in or spray-on treatments should be used.