Sunday, July 10, 2016

Twist

Twist holds yarn together.  More twist equals a more durable yarn.

Fine yarns can take more twist than thicker yarns, and thus, when plied or cabled up to the same grist are much more durable.  Thus, 1,000 ypp 5-ply is more durable than 1,000 ypp 2-ply.  Paton's 4-ply Beehive was more durable than the same grist of yarn constructed as a 2-ply.  Real 10-ply Aran yarn is much more durable than the same grist yarn spun as a 3-ply.

AA did not spin fine singles, and tended not to knit with yarns constructed with many plies.  Thus, the issue of twist and durability did not intrude into his universe.   He considered 5-ply yarn for seamen's sweaters as not worth the effort of hand spinning.  (And, he did not design wheels to produce fine singles.)

I model the durability of a yarn as proportional to the total twist in the yarn.  5-ply sport weight has plies of ~5,600 ypp ( 12 m/gram ) with twist of ~9 tpi (twist per inch) . So the plies contain at total of 45 tpi.  Finished yarn also has ~9 tpi of ply twist for a total twist in the finished yarn of about 54 tpi .  In contrast, sport weight constructed of two would be constructed of singles of about 2,200 ypp, which because low grist singles cannot tolerate high twist with out becoming stiff, would be spun more softly at ~ ~4.5 tpi, so the singles would contain 9 tpi, plus 4.5 tpi ply twist for a yarn total of  ~ 13 tpi.  Yes, I would consider an object knit from good 5-ply to be about 5 times more durable than the same object, subjected to the same use knit from 2-ply.   Thus, by knitting an a sweater of 5-py rather than 2-ply, I can save myself the time and effort of knitting 4 sweaters - that is a saving of about 400 hours of knitting over a period of ~10 years.

However, twist is expensive, and not many knitters are willing to pay extra for multi-ply, high twist yarns.  For example, sock knitters complain about their hand knit socks wearing out. They buy sock yarn from their LYS with a total of about 36 tpi in the yarn.  The sock yarn I make has ~ 100 tpi in the finished yarn. Yes, my yarn lasts longer.

If my wheel runs at something over 4,000 rpm, I am inserting twist enough twist to make about finished yarn at about a yard per minute.  (It is several processes, but it averages out.)  If it takes 500 yards of yarn for a pair of socks, then  all that spinning and plying is a good day's work.  e.g., 3, 000 yards of  11,000 ypp (25 m/gram) singles plus plying.  As 4-ply, those singles produce a yarn about the same grist as Paton's 4-ply Beehive used for gansey knitting in Gladys Thompson. At about 60 tpi for the final yarn, it tends to be even more durable than typical 5-ply sport weight.

With my DRS wheel, it is easy to spin such yarns.  With any of the commerical lace lace flyers, or high speed, hand spinning  rigs on the market that I have tried, I find it it very tedious.

The new generation of bobbins (some olive, some maple, some walnut) allows the production of true hoisery single (17 tpi, 22,000 ypp, 50 m/gr ) at only trivially more effort than the 11,000 ypp singles that I have been making. The 24 tpi of  60s ( 75 m/gr) seems like it would be a lot of work, but that new walnut bobbin will inset twist at 4,500 rpm, so I am still getting about 250 yards of single per hour.  

Drafting 250 yards per hour is not hard, so I am just sitting there, treadling along at 90 strokes per minute. Depending on the fiber prep, I do not even have to look too closely at what I am doing.  Then every couple of hours (a movie: ), I wind off a hank of single.

And high twist yarns are warmer (for the weight of wool).  If you want warm woolen fabrics, with very light weight, use multi ply yarns with very fine singles.  A yarn of a given grist spun as 2-ply will not be as warm as the same grist yarn spun as 6-ply.  And, the 6-ply will be much more durable.  For cool fabrics, worsted-spun, cabled yarns have very little "fill", and can be knit into very cool fabrics.

 For the effort that goes into knitting lace, you might as well use a durable yarn so that it can be a heirloom. The Shetland lace knitters in the Victorian era, knew what they were doing when they used 3-ply lace yarns.  They were making objects that would last.

Don't get me wrong here, I knit many objects from yarns spun with a few fat plies.  Some of those were or are excellent objects.  Many were  "weatherproof" when new.  Knit objects that I have had and worn for years are showing their age. Older objects knit from 2-py sport weight are no longer weatherproof, while the 5-ply of the same vintage are still perfectly functional.  Socks from 5-ply and 6-ply yarns have out lasted generations of socks knit from  2-ply and 3-ply yarns of the same grist.

There are many different kinds of  yarns out there and it is worth getting to know them.  As I always say, "Tools matter!" In the same way, "Yarn matters!"

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