JELADO Manufacturing ~Vintage Denim~ Vol.2 "The DNA of the '501XX' woven with romance and science"
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～Part 2: From spinning yarn to making fabric～
Last time, JELADO CEO Goto cut up some deadstock 501XX fabric and sent it to a certain research institute.
This time, based on the results of that analysis, we will follow the process from spinning to finishing the fabric.
The key points of the analysis results can be summarized as follows:
[Warp thread] Count / 7 Number of twists / 1 Fiber length / 2 mm Number of threads / 6
[Weft thread] Count / 6 Number of twists / 9 Fiber length / 3 mm Number of threads / 4
*The "〇" part is not disclosed because it is the result of our own analysis.
In other words, the warp threads are made of short-fiber cotton that is relatively tightly twisted, and the weft threads are made of long-fiber cotton that is relatively loosely twisted.While this result is roughly as expected as a trend value, the point of contention this time was whether or not to pursue these figures below zero.
たとえば、「1番手」とは1ポンド（454g）の綿を840ヤード（約768m）に伸ばした際の値になるのだが、「7番手」と「7.〇番手」の差は、1ポンドの綿を「840ヤード×7」か「840番手×7.〇」の長さに伸ばす違いとなる。紡績職人曰く、正直な話7番手と7.〇番手の違いは見た目ではわからない可能性が高いという。
However, in conclusion, this time we decided to closely track the above numbers, which are below zero.
JELADO Goto says:
"In reviving the 501XX in the modern era, I think that our predecessors have already established a theory that says, 'If you make it like this, it will look like the 501XX.' However, it is also true that even if you own several 501XXs, there will be differences in the look and texture even between pieces of the same era. That's why it's important to pursue the numbers down to the decimal point and create the 'correct answer for JELADO.' It may not make sense to go that far, but I think that it is our responsibility as JELADO to pass on the 501XX to the modern era."
STEP 1: "Selecting cotton"
After completing the meeting in Tokyo, the reporting team's first visit was to a spinning factory in Sennan, Osaka Prefecture.
We asked spinners for their opinions on which cotton would be best to choose for this project, based on historical facts and the results of this analysis.
According to a spinner, "In America, there is an area called the 'Cotton Belt' where cotton can be grown, stretching from North Carolina in the east to California in the west. It is said that at the time, Levi's used a lot of cotton procured around Memphis for the warp threads. This was probably due to the fact that there was a huge cotton collection center in Memphis, Tennessee, and that large amounts of cotton harvested in neighboring states were gathered there, as well as the Gold Rush that occurred near Memphis. In other words, strictly speaking, there is no such thing as cotton that is 'produced in Memphis'; they used cotton that was 'gathered in Memphis.' Yes. And as for the weft thread, based on the results of this analysis, I think it was probably cotton harvested on the west coast. That's because cotton with such long fibers can only be harvested on the warm west coast. Now, this is just a hypothesis, but I think Levi's wanted to make denim, which is workwear, at a low cost at the time, and even if they had relied too hard on short-fiber cotton to make the weft thread, the thread would have broken during the weaving stage. So I think they had no choice but to use extra-long-fiber cotton harvested on the west coast, which is relatively expensive, for the weft thread."
Now, let's take another look at the data extracted from the deadstock 501XX pair that we used as reference this time.
The fiber length of the warp threads is 2 mm, and the fiber length of the weft threads is 3 mm.
For the warp threads, it was quickly decided to use EMOT medium-length cotton (Eastern Memphis, New Orleans, Texas), which is harvested around Memphis and is currently distributed worldwide, from the perspective of production area and specifications. While extra-long staple cotton is defined as cotton with a fiber length of 35 mm or more, for the weft threads of the sample, which had an unusually long fiber length, after lengthy discussions, it was decided to use the original species of Pima cotton from California, which is still considered "luxury" even today.
This decision, made at no cost to them, results in a soft twist being achieved during the spinning of the weft yarn, creating a soft fabric, but we will discuss this in more detail next time.
STEP 2 "Spinning"
From here, we will introduce the process of how cotton is transformed into thread.
The first step is to roll up the 1kg blocks of cotton that arrive compressed from the cotton producers with a loader, remove any debris, and suck up the surface. By lining up 200 to 20 blocks and sucking them up, the cotton is loosened and mixed at the same time to minimize individual differences. The sucked cotton passes through ducts inside the factory and is blown up by air in multiple tanks for further homogenization.
The loosened cotton is wrapped in plastic to ensure that the fibers are oriented in the same direction. Any debris that was not removed in the previous process is also removed here.
The cotton is then lightly twisted and spun into rope-like shapes called slivers, each of which is first bundled together in groups of seven to form a single strand, then in groups of eight to form a single strand, again through a process aimed at making the strands more uniform.
Finally, the sliver that has been gathered into a single thin, dense strand is further twisted and rewound to become a "thread." Incidentally, the "unevenness" of the uneven yarn that enriches the look of the finished fabric is created by intentionally giving it an irregular rotation during this rewinding process.
Once the warp and weft threads have been completed with a moderate unevenness, they are sent to a dyeing factory.
STEP 3 "Dyeing"
Once the spinning was complete and they had obtained the yarn, they headed to a dyeing factory in Hiroshima Prefecture.
There are two main reasons why JELADO asked this factory to do the dyeing. The first is that they can accurately reproduce the color of the deadstock 501XX and the specifications of the white inside, which will be described later, that are pursued in this project. The second is that they can achieve a high level of quality control with almost no deviation from lot to lot. JELADO's goal was for everyone to be able to experience the aging process of the product just like a vintage product when it was delivered to the consumer.
Now let me introduce the dyeing process.
The yarn that arrives at the factory is wound into ropes through a process called "refining," after which the oil is removed and it is immersed in an indigo dye solution. Although it is difficult to go into the details here, the important thing at this stage is the digitally controlled temperature control and the various settings of each machine. In the photo below, you can see that the yarn immersed in the solution oxidizes when exposed to air, gradually changing to indigo color. This process is repeated several times, and the yarn is dyed to a desired color that has been tested in advance. After dyeing, the warp yarn is starched to make it easier to weave and to add firmness. Incidentally, the unique scent of raw denim comes from this starch.
The important thing about the dyeing process in this project is that the rope-shaped threads are dyed while being given an exquisite tension so that they are not dyed all the way through to the core. By finishing the threads with a white center, the fabric is finished with what is commonly known as "atari".
This quality, which is the result of the overwhelming rope dyeing technique, was not available to the public during this interview as it was a trade secret, but we encourage you to experience it for yourself when the product is finished.
STEP 4 "Weaving"
After spinning and dyeing, the yarn finally moves to the weaving process.
The group was greeted by the roar of an old shuttle loom when they visited the factory in Okayama Prefecture. This factory is a rare place where Japan can proudly operate the G3 model made by Toyoda Automatic Loom Works (the predecessor company of the current Toyota Group), which is arguably the oldest shuttle loom still in operation in the world.
This factory was chosen because they wanted to use the G501 model to achieve the specification of 6 warp threads/4 weft threads, which was determined by analyzing the deadstock 3XX that served as the base for this garment.
So, what's so good about the G3?
To answer this question, we need to explain the background of the birth of type G, which can be considered the ancestor of type G3.
Sakichi Toyoda, who produced the world's first non-stop shuttle-change automatic loom, the Toyoda Type T automatic iron loom, in 1903, visited the United States and Europe in 1910 to further evolve looms. After returning to Japan, he built multiple prototypes based on the information and confidence he gained from his visits, and finally completed the non-stop shuttle-change Toyoda automatic loom, the Type G, in 1924.
The impact of the Type G on the world was immeasurable, so much so that Platt & Co., a British company that was the world's largest loom manufacturer at the time, approached Sakichi about selling the rights to manufacture and sell the Type G worldwide, excluding Japan and the United States and China, where the company had already exported to. (Incidentally, the royalties from the patent transfer are said to have helped Sakichi's eldest son, Kiichiro, fund his automobile development.) It is easy to imagine what a shock it must have been when the Type G arrived on American soil, where the utilization rate of shuttle looms was higher than in the United Kingdom, a textile powerhouse at the time. There is no doubt that it also had a significant impact on American loom manufacturers, including Draper.
Now, let's go back to the G3 model. The G3 is a direct descendant of the G model, a shuttle loom that was mainly used in the 1950s and was improved to be able to weave thicker fabrics. Yes, the reason JELADO chose the G3 model this time is because of its track record of exports to the United States, its great influence, and the era in which it was in use.
From here, we will introduce the benefits of using old-style shuttle looms, including the G3 type, in denim production.
The biggest difference between modern looms and shuttle looms is the weaving speed. One loom can weave about 1 meters of fabric per hour. And it is this slowness that creates the fluffy texture of the fabric, a characteristic of the 1XX, which enjoyed the American Golden Age.
Also, compared to the latest sluiser looms, which can weave fabric several times wider than shuttle looms at about 10 times the speed, it is important to note that shuttle looms allow for a slightly looser tension on the warp threads. In order to create a rich look when the color fades, it is necessary to loosen the tension on the warp threads, as shown in the figure below.
The speed is slow and the width of fabric that can be woven is narrow.
However, there are still some things that only shuttle looms can do.
Although manufacturing has always evolved to efficiently enrich civilization,
Even today, when technological advances are advancing dramatically, human prosperity born from inefficiency can still exist.
STEP.4 ““LAST RESORT”!?”
Using cotton with almost the same specifications as the deadstock 501XX, it is spun according to the data specifications, dyed in the same color as the real thing, and woven in a way that is as close as possible to the conditions at the time, resulting in a finished denim fabric.
This is the result of scientific analysis and the generous use of Japanese craftsmanship. The fabric itself was born in the process of reviving the 501XX, but it has now been decided that it will be made into a product on its own. Its name is "LAST RESORT"!
It is expected that "LAST RESORT" will be used not only on five-pocket jeans but also on various other items in the future. When used, a special woven label will be provided, so please look forward to it.
Next notice
Next time, we'll finally head to the sewing factory!
What will the patterns and materials be like?
stay tuned! !
<Text by Kobo Tagata, Photos by Sawada Seiji>
~3Times Romance in vintage. A deeper world.click here
JELADO original denim line Last Lesort productsclick here