Many Kamakura Shirts denim products make use of Kaihara Denim fabric. Based in Fukuyama City, Hiroshima Prefecture, Kaihara Denim is a fabric manufacturer with a global presence.
As well as producing fabric for the Japanese market and for denim manufacturers across the world, Kaihara Denim also engage in their own projects, proudly hailing their Made in Japan credentials.
Kaiharaâ€™s story began in 1893 with the manufacture of kasuri* fabric. In 1970 they developed their own rope dyeing machine in the US and produced the first denim fabric in Japan.
Kaiharaâ€™s success stretches beyond Japan to the competitive international denim market, supplying Made in Japan denim to more than 20 countries across America, Europe and Southeast Asia.
*A traditional Japanese method which uses yarn bound with thread, woven together with pre-dyed yarn, to create patterns in the fabric.
Integrated production system
With the completion of Kaiharaâ€™s textile mill in 1991, integrated dyeing, weaving, and processing* was realized in Japan for the first time. Starting from scratch with raw cotton makes it possible to manage the entire process in-house, with the maximum quality control in place to create the perfect product.
*Heat treatment for surface finish, gluing to give texture to the textile, skew prevention to prevent twisting, shrinkage reduction and drying treatment, are a few examples.
Prototypes and Challenges
Having the process managed in-house allows variation in colors and textures through a combination of each process. Kaihara produces about one thousand prototypes a year, including both fabric used for final products and unused designs.
Kaiharaâ€™s determination in facing up to challenges, even if they donâ€™t always go smoothly, is greatly valued by denim manufacturers all over the world.
About 20,000 bales of raw cotton are stored in the warehouse â€“ enough to make 4 million pairs of jeans.
The automated spinning factory is key to consistent quality and production volume.
The dyeing process makes full use of the experience and technology built up from Kaiharaâ€™s long history of kasuri indigo dyeing.
Weaving is done on more than 300 different looms depending on the type of denim.
Color quality is checked according to the high standards set.
Visual checks of the fabric ensure even the smallest defects are caught.
Dyeing technology to ensure the most beautiful color fade
Denimâ€™s color comes from indigo dye. Indigo turns blue through oxidation after contact with the air, but the process does not produce dark colors straight away. Instead, using a rope dyeing machine, the indigo dye is repeatedly re-applied and oxidized between three to ten times to create a dark blue dye.
In rope dyeing, dozens of cotton yarns are bundled together into a rope shape and gradually dyed with indigo dye from the surface inwards.
Through careful adjustment, the center of the thread bundle is left undyed to create a white core. This creates the color fade effect in denim.
One of the unique pleasures of denim is the wearing-in process. A piece of denim clothing gives the wearer a sense of having â€œnurturedâ€ your denim, creating something unique and personal â€“ something you may still be wearing in ten yearsâ€™ time!
Rope dyeing machine currently in operation.
Cross section of yarn after rope dyeing, showing the white core that produces the color fade effect.