Perfect Japanese denim. Part I – custom jeans raw material and spinning
What makes Japanese denim so special? Why do the world’s most established brands aspire to
make custom jeans of it? Let’s take a closer look at all the stages of Japanese denim manufacture.
Raw material.
|
Only three types of cotton have commercial value. The first species is
called Gossypium hirsutum. Initially it grew in Central America and Mexica
and occupies 95% of all cotton manufacture in the USA. It is also known as
upland cotton and its fiber length is 22-24 mm. The second species is called
Gossypium barbadense and comes from south-western part of the USA. It is also
known as Pima and its fiber length is 30-70 mm. It is also distinguished by
extra solid structure, shine and smoothness. The use of such fiber gives an opportunity
to produce more soft and solid thread and fabric. Extra Long Staple is a more general name
including Pima cotton grown in the USA, Peru, Israel, as well as Egyptian cotton Giza,
Indian Suvin, Chinese Xiniang 149, Sudanese Barakat and Turkmen fine-stapled cotton.
|
|
Extra
Long Staple fiber occupies 8 % of the world’s cotton manufacture and its leading exporters are
the USA, Egypt. It is imported by Japan, Italy and Germany. Extra Long Staple grows up longer
than regular cotton and during primal processing rolling cleaning is used for it instead of
saw cleaning used for short-stapled cotton. Sometimes only one harvest a year is gathered, which
influences the quality of customized denim and the price of raw material as well. Zimbabwe
cotton didn’t undergo international classification due to Zimbabwe regime isolation. However
it is also Gossypium barbadense, cheaper compared to other countries of origin. Many Japanese
denim manufacturers use cotton from Zimbabwe. The third species of cotton Gossypium herbaceum
and arboreum grows in India and East Asia, its fiber has the length 12-25 vv and is called
short-stapled cotton.
After the cotton is gathered it comes into a cotton cleaning machine (known also as cotton gin),
where it is cleaned from seeds and separated into cotton wool and long fibers which are then
collected and sent to textile factories.
Spinning.
Thread manufacture is a complex process including opening, mixing, carding, combing, leveling
on drawing frame, roving, spinning and spooling. When rotor spinning machines are used the thread
comes with open end, it passes roving machines coming to spinning mechanism. The thread becomes
smoother, regular in thickness, but less solid compared with ring spinning. During ring spinning
also called spindle spinning roving machines pull the fiber, roll it, and the thread is formed when
the fiber passes a series of steel and rubber rolls. Ring spun denim has a more solid structure,
however, the speed and the cost of its manufacture can not be compared with rotor spinning machines.
A distinguishing feature of ringspun thread is its irregular thickness, that is why denim fabric
also appears to be slubby. Computerized open end lines enable the manufacture of Amsler Open End Yarns
also called faux ring spun, where irregularity of thickness is given by a special program. The solid
structure of ringspun thread is however not achieved.
Posted: 08.01.2010 by Stella Tornton
Bookmark and share us!
|
Getwear® is a registered trademark of Getwear LLP
|
|
