April 18, 2009

Straw braid sewing: the machines


Although it is possible to sew straw braid with an ordinary free-arm sewing machine (check out this ebook by Jane Smith if you want to know more) , when sewing narrower straw it is much easier to use a machine that has been designed for the purpose (like my Corsani, above in the picture). Much of what I’ve learnt about these machines has come from reading old patents, there’s a wealth of information there.

This is what makes these straw braid sewing machines different from your household machine:

  1. They are chain stitch machines (just one thread, no bobbin)
  2. They have a special guide system for feeding the braid and holding the work in place
  3. The needle and plate are all the way to the left to make working easier
  4. They are set on a special table with a big cutout on the middle front so there is space for the hat as it grows, and for you to manouver.

Drawing from patent 218413Some of these special machines have additional special features that were designed and patented by their inventors to make the sewing of straw easier.

To start, there is a mechanism that Willcox called in his patent a “vibrator”, and that has been implemented by every manufacturer afterwards. The mechanism is used when sewing the “button” of the hat (where the hat starts with a tight spiral). When sewing this small spiral the operator of the machine is forcing the straw because the curve is very tight, without this invention the straw can get damaged as the presser foot is pushing down on the straw when the operator is pulling. and it is very difficult to keep the work flat. This “vibrator” contraption is a very clever invention that lifts the presser foot as the needle goes down, pressing down again as the feeder goes into action, thus allowing the operator to easily turn the work.

Here is the text from the patent explaining the workings of the invention.

Excerpt from patent 218413Excerpt from patent 218413

Another interesting invention is the lever that allows the tension of the thread to be easily changed to a tighter tension. This is useful because when one starts sewing the button of the hat (the center of the spiral) the stitch length shortens because of the tight angle at which one is sewing, that often causes loose loops on the underside of the work. Before this invention one had to manually change the tension, setting a tighter tension at the beginning and then stopping the work to set a looser tension as the work progresses. With this invention you can switch between a tigher and looser tension with the flick of a lever (without stopping the sewing).  Below are the drawings and explanation for this invention.

Drawing from patent 309514

Drawing from patent 298315

Excerpt from patent 298315Excerpt from patent 298315

I also wanted to mention that there are essentially two types of straw sewing machines, those that do straight stitch, and those who sew in zig-zag. From looking at the patents I know that there were machines that did a hidden stitch, but those don’t seem to have survived the test of time because the ones in use today are the visible stitch ones, machines that are more than one hundred years old and are still (amazingly) working. The zig-zag machine on the other hand (some are still available in the market) allows one to sew edge to edge and avoid wasting material.

Soon I will write some more on the subject… stay tuned.

March 28, 2009

Straw braid hats -machine sewn-

I’ve been trying to tame my straw braid sewing machine and here are the first results. I have used vintage straw braid from my personal stash.

These two hats have been created using a block that I have made myself. The block is made with Plastilina Jovi (a non hardening modelling clay similar to Play-Doh). I buy it in packs of 350 grams, and in this case I have used a long plastic  container as a base to minimize the waste of material (and give it extra stability).

Using a block is important when sewing straw as one goes back to it repeatedly, removing the hat from the machine and trying for fit, checking that the hat is adjusting to the block (and undoing rows of work when it’s too narrow or too wide).  When the hat is finished the block allows us to iron the hat and stiffen it.

My block has a serious drawback (but a design decision) and it’s that the distance between the center of the tip to the front edge is bigger than the distance to the back edge. That means that I have to add extra strips on the front (where the brim begins) to compensate for that. Adding those strips is a pain!

As for the way to wear these small hats, I did try fitting an elastic band (which is the most comfortable way to wear these small hats and hides nicely under the hair) BUT the elastic pulled the sides of the hat apart (because it’s pretty soft) and deformed it.

I used straw stiffener (before trimming) but for some reason it doesn’t stiffen the hat as much as I would want it too.

I had to think of another way of holding the hat on the head so I added a piece of elastic velvet ribbon, long ends sewn together to form a tube and then sewed the ends to the hat (being careful not to close the entry!).

That allows me to thread a metallic headband, with the advantage that I can move the hat to position it and I can change the headbands colour to adapt it to the wearers hair.

I will post some more on this subject soon. I want to share with you what I’ve worked hard to learn on my own, since (and it shouldn’t come as a surprise) there’s  nothing written on the subject on the Internet or in print and many of those who know don’t feel like sharing. As an example, I recently had the opportunity to talk to a person who makes straw braid hats (father and grandfather also did so) and when I told her that I had problems when starting the hat because it tends to curl up too soon she said “yes… yes…”, turned around and went on her merry way. Nice.

Be on the look out for more soon! All (that I know) will be revealed!

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