Washing vs. Drying...

[Jim Cissell]

Here's an interesting question...

Which factor actually shrinks denim the most - warm or hot water washing, or the dryer?

Or, is it a combination of the two?

Jim

[beatle]

Water...

The process of drying will shrink the fabric - but w/o washing them first , they would'nt shrink..

Meaning - throw a pair of dry Jeans in the dryer , the won't shrink...

[sybaritical]

^ the process of water leaving the threads tightens the weave? If so can you say the hotter you dry them the more they'll shrink ... ?

[beatle]

In a way , yes ..but there's only a certain amount of shrinkage possible...

Like - a 17 oz indigo will be able to shrink more than a 12 oz...

[theetruscan]

Pauline and I wrote those laundry instructions almost 20 years ago. I might, after 20 years of additional experience, modify that practice to include the possiblity of washing Whites in warm water if they are not terribly soiled. However, it is much, much more the dry heat of a hot dryer which will ruin the shirt than the moist heat of water.

FYI, the result of my many experiments on this subject indicate that the greatest cause of high shrinkage is not heat per se, it is temperature shock. In other words, if you wish to remove virtually all of the potential shrinkage from a garment, follow this procedure:

Turn on your dryer on the highest heat setting with a couple of dry terrycloth towels in it. Let it run while they get good and hot. Meantime, store your wet shirt in the freezer until it becomes solid. Throw the frozen shirt into the hot dryer and keep the dryer running. This is the procedure we use for our final fitting sample to insure that it is representative of shirts which have been washed 12-15 times.

Obviously, the above is about shirts, but it's from someone who knows cotton thread very well. The same thing should get maximum shrinkage from jeans. The quote is from Alexander Kabbaz at ask andy.

[Jim Cissell]

The high-heat of the dryer makes sense, but actually feezing the shirt doesn't.

Seems like that step wouldn't truly matter.

All in all, it sounds as if the hot wash/hot dryer combo approach shrinks most effectively.

Jim

[horriblyjollyjinx]

Like - a 17 oz indigo will be able to shrink more than a 12 oz...

there is no such relationship between weight and shrinkage.

Hotter water, more shrinkage. Heat from a dryer will also increase shrinkage. Tumble drying seems to help even more.

Edit: read the rest of the posts and I dont believe the freezing thing for one second.

[ang_kangkong]

The high-heat of the dryer makes sense, but actually feezing the shirt doesn't.

Seems like that step wouldn't truly matter.

All in all, it sounds as if the hot wash/hot dryer combo approach shrinks most effectively.

Jim

Don't know if it matters, but water expands when it changes to ice. Maybe that affects the weave of fabric so that it shrinks even more later when it gets into the pre-heated dryer?

Kinda strange, though. Won't be doing it anyway, we don't have a laundry at home any more.

[snugglepony]

there is no such relationship between weight and shrinkage.

Hotter water, more shrinkage. Heat from a dryer will also increase shrinkage. Tumble drying seems to help even more.

agreed - weight has very little bearing.

however, tightness of weave will have a significant effect on shrinkage; i.e. looser woven denims will shrink much more than tightly woven denims.

[Jim Cissell]

What's odd to me is the 10 wash-cycles required to totally complete the shrinking process on the LVC shrink-to-fits (see label). You'd think two or three would do it, but Levi's clearly states ten.

I wonder what the dynamic is?

Jim

[beatle]

Maybe you should take 2 pieces of denim...like a light weight denim - and a heavy weight denim....

Compare the shrinkage....

That would be surprisingly interesting...