Burn it.

If you have ever checked the care labels on your clothes, you can for example see that one of your sweaters contains 100% cotton or a mix of other fibers. During my sessions in the laboratory we also did burning tests on our products. Simple observations such as smell and how the products burn were able to help us figure out what fibers our products may contain. From the start, the clothes we were given were totally ribbet for labels, so we had to figure out everything ourselves. 

This is Maria's bra. While it is burning, it is also melting and dripping, and when it is done burning it sets hard. This is typical for polyester. 

Here you are able to see the residue of a pair of burned, red panties. The fabric has melted and become hard, as well as the sample above.

The pants behave differently. When I sat a sample on fire, it was rapid and bright, and you can see the afterglow. This is the behavior of cotton.

Other tests.

Together with the shrinking test we also did a lot of other tests, especially in conjunction to colour fastness. We tested the colour fastness of our products in relation to perspiration, water, washing and rubbing. While testing our products in relation to perspiration and water, we soaked our products together with a multifibre material in an acid and an alkaline perspiration solution in 30 minutes before we put every sample for a drying cupboard at 37 degrees in four hours.

While we were waiting for the perspiration test to be finished, we started the washing test. Each sample together with a multifibre material had its own small container because they were not supposed to colour each other during the wash. Together with our products and the multifibre materials we put some very small and heavy metal spheres and soap.

The last test we did on colour fastness of our products before taking out the perspiration test from the drying cupboard was the rubbing test. Would our products/Maria's clothes lose colour due to rubbing (both wet and dry)? This was to be done by a rubbing machine. 

Of course after one day with different kinds of testing, you also need results. We used the grey scales to compared the tested materials to materials that had not been tested. The grey scales are able to tell us if the colour staining and colour change are good or bad, where five on the scale is very good.

Answer.

Did Maria lie in the conversation she had with the boutique about her stockings? In our first lecture in the lab, we did a lot of tests, and one of them was shrinkage. I had to see if Maria was telling the truth or not. Before we did the test, we measured a piece of the stockings before we put it in the washing machine. We chose to wash it in the machine because that is probably the way Maria would have done it. In the washing machine we also had to put other textiles as well, because the washing process was supposed to be as realistic as possible. Because we are doing tests on to of our products, stockings and the pair of jeans, we put our sample for the jeans in the machine as well. 

Washing - 2kg

When the washing machine was finished, we put our samples in the tumble dryer to see if they could bear the hole process. The last thing to do in the process was measuring both of the samples. This is our results:

The chart shows us that the stockings shrunk 9,5% in the length which is not enough to call the boutique. She is still able to use it, because the elastane will expand. If she do not tumble dry it, she save the fibers for abrasion. In the end, the shrinkage of Maria's stockings are not a good enough reason to complain and the spot of bolognese is her own fault. She probably has to buy a new pair of stockings if she wants a clean pair.