Sanforization - What is it?

[Giles]

Sanforization is a post weave process, patented by Sanford Lockwood Cluett in 1930.  It is a method of shrinking and fixing the woven cloth in both length and width before it is made into garments and other items.

The fabric to be sanforized is moistened by water and/or steam, this lubricates the fibres and reduces the inherent friction within the fabric.  Once moist, the fabric enters the sanforization process proper.  Here, an endless rubber belt is squeezed between a pressure roll and a rubber belt cylinder, it is here that the stretching of the elastic belt surface occurs.  The more the rubber belt is squeezed, the more the surface is stretched.  This point of squeezing is known as the pressure zone, or the nip point.  The fabric is fed into the pressure zone and upon leaving it, the rubber belt recovers itself and the surface returns to its pre-squeezed (stretched) size carrying the fabric with it.  The effect of this action is a shortening of the warp yarns,  which packs the filling yarns (weft), closer together:  at this moment, shrinkage occurs.

After compaction, the fabric enters a dryer where the fibres are locked in their shrunken state as the moisture is removed from the fabric.

[scroogen]

This is a modern sanforization machine.

Here is a diagram of what's going on in that crazy machine.
(The image above and following text were lifted unscrupulously from the website http://www.sanforized.biz/e_home.htm )

Fabric (F) passes through the skyer (S) or other moistening device and is moistened by water and/or steam. This will lubricate the fibers and promote shrinkability within the fabric. Normally, a fabric must be moistened in such a way that every single thread achieves a moisture content of approximately 15%. This allows compression of the fabric with very little resistance.

When the fabric passes through the clip expander (C), we obtain the required width. The clip expander also transports the fabric to the most important part of the machine: the rubber belt unit (indicated by arrows in above figure). In the close-up of fig. 1, we see the endless rubber belt (R). By squeezing rubber belt (R) between pressure roll (P) and rubber belt cylinder (RB), we obtain an elastical stretching of the rubber belt surface. The more we squeeze the rubber belt, the more the surface is stretched. This point of squeezing is known as the pressure zone, or the nip point.

Fabric (F) is now fed into the pressure zone. When leaving the pressure zone, the rubber belt recovers itself and the surface returns to its original length carrying the fabric with it. The effect of this action is a shorting of the warp yarn which packs the filling yarns closer together. At this actual moment, shrinkage occurs.

After compaction within the rubber belt unit, the fabric enters the dryer (D). Here the fibers are locked in their shrunken state by removing the moisture from the fabric.

After the compressive shrinkage process is completed, another sample of the fabric is taken. This sample is also wash-tested. The final result of this test must meet the Sanforized Standard, in length and width before it may carry the Sanforized label.

All Sanforized Licensees are contractually obligated to follow the required test method and meet the standards set forth by The Sanforized Company.

[Giles]

I lifted mine in the main from there, but rewrote it as I needed it for the tool-tip which does not cater for diagrams….

[scroogen]

Haha I thought that maybe you had…  I thought it would be nice to see a diagram with text saying what the machine is actually doing. Just seeing the text might be a little hard to wrap your head around

[Giles]

I was looking for a photo of the Sanforization machine we use, but could not find one.  I did, however, fing a pic of the skewing machine.  Skew is sometimes intentionally introduced into denim to negate the twist is introduced into the fabric when being woven….

[Snowy]

@scroogen:

Haha I thought that maybe you had…  I thought it would be nice to see a diagram with text saying what the machine is actually doing. Just seeing the text might be a little hard to wrap your head around

Took me 20 minutes or so to get my head around the text, enjoyed the mental challenge. Appreciate the picture which helped validate it.

Funny that I've know what sanforization does for years, but until this couldn't understand how. And it's far more complicated than I assumed (I had imagined it was given a single wash or something).

The Skewing machine looks to be full of pressure/gas gauges. The scale of the machinery is crazy too!

(Aside 3rd person from the point of view of this photo, love the jacket and jeans, lol.)

[Giles]

That is Brigitte, Roger from VMC's wife.  The jeans are Edwin, the jacket is Filson….(anyone see Roger, actually trying to get into the machine?)

[Finn666]

i only have eyes for Ayumi

[Snowy]

resisting urge to hijack (Thanks Giles).

[Chris]

Who's the guy between Haraki and Ayumi?  Someone from the factory explaining how the skewing machine works?

Oh, and I enjoyed playing a quick game of "Where's Roger?"  I missed him the first time around.

[Giles]

Yep, he's the factory manager explaining how it all works….

[Sugar Mountain]

I was wondering, Why does Haraki prefer sanforization for the majority of IH denim? Selling one-wash denim would address any issues with shrinkage so I presume there are additional reasons.

[Giles]

He likes the stability that sanforization gives him.  It allows him to be be more sure of creating consistency in production.  With education (read me, going on and on and on and on about it) he is learning to embrace imperfection…..

[Chris]

From a practical standpoint, I sympathize with Haraki, but I'm glad you've been wearing him down.  Raw is much more interesting in the long run.

[RedStripe]

great post, very informative