Bleach test fabric

[2ndva]

Greetings everyone

Before the last crash there was a post that had info. about doing a bleach test on wool fabric. I thought there was a certain temperature to heat up the bleach when conducting the test. Can someone tell what the procedure is?

[Carolann Schmitt]

Re: Bleach test fabric

I use the bleach test quite frequently. I've never heated the bleach and have not seen that mentioned in other discussions about the test. I just use it at room temperature right out of the bottle. I'd be interested in learning any advantages that come with heating the bleach.

[DPSaffer]

Re: Bleach test fabric

Pardon my ignorance, but what is the purpose of a bleach test?
Kyle Wichtendahl

[Marylander in Grey]

Re: Bleach test fabric

Ladies,
I missed this one what is the intended out come of bleach testing the wool please?

[Matt Woodburn]

Re: Bleach test fabric

Gang,

It is to determine if synthetic content is in the wool sample, or if it is 100% wool. I use it at room temp right out of the bottle as well. The natural wool fibers will dissolve. Synthetic fibres, if present in the sample, will remain. Typically need to give it 24 hours on a small sample, just a few threads.

[Carolann Schmitt]

Re: Bleach test fabric

The bleach test is one way of determining if a fabric of unknown fiber content is a protein fiber - wool or silk, or a cellulose fiber - linen, cotton, pina cloth, etc.

Pour a small quantity of chlorine bleach in a glass container. I use a Pyrex measuring cup. Place a small piece of the fabric in the bleach, making sure it is covered. Watch and wait. If the fabric is silk or wool, it will dissolve. If it is a cellulose fabric, it will turn white. :) If it is a combination fiber, part of it will dissolve and part won't. If it is a combination weave, you may end up with parallel lines or graph paper. Depending on high the fibers are spun and woven, you will have results within a few minutes or a few hours.

The test works best with fresh bleach, not something that's been sitting on the laundry room shelf for several months (or years!). And it must be chlorine bleach, not an oxygenated bleach used on colored fabrics.

You can use the bleach test in combination with a burn test to further determine the fiber content. You can also examine the fibers under a microscope.

[Justin Runyon]

Re: Bleach test fabric

Just to add: You want to make sure that both warp and weft fibers are in your sample. There is no advantage to heating bleach.

[Marylander in Grey]

Re: Bleach test fabric

Folks,
Just goes to show that old dogs can learn new tricks. Thank you now I shall become the mad scientist.

[Spinster]

Re: Bleach test fabric

Warming the bleach simply serves to speed the test.

I give a cup of bleach about 45 seconds in the microwave. This can cut the testing time down to just a couple of minutes.

It can be a very 'active' reaction--use gloves and avoid breathing any steam.

Test a swatch that does not contain the selvedge edge---its not uncommon to find a few strands of man-made material in the edge of wool cloth that is not present in the the vast majority of the fabric.

[2ndva]

Re: Bleach test fabric

Greetings all

Thanks for the replies so far. The last time I did a bleach test was over a year ago and I got the idea of heating up the bleach from this forum. Unfortunately the thread must have been lost in the last crash. When I did a Google search I couldn’t find anything that mentioned heating the bleach either.

As Mrs. Lawson mentioned in her post heating the bleach seems to speed up the process. When I conducted my test I heated the bleach up and the fabric dissolved very quickly.

Oh well, I guess my question has been answered.