Types of customized denim and the technologies which help it to create a worn look. Part I
Denim fabric is generally divided into three main types. Light denim is also known as chambray,
its weight is 4 to 9 ounces and it is generally used for manufacture of denim shirts. Middle denim fabric
weights 10 to 13 ounces and is used for manufacture of various denim clothes – dresses, overalls, traditional
five-pocket custom jean and others. Heavy denim weights 13,5 to 15,5 ounces and is represented by classical denim.
Denim yarn as you probably already know also has two general types. It can be ringspun or openend. Until 1970s
all denim fabric was manufactured from ringspun yarn. Afterwards denim brands tried to low the costs of jeans
manufacture by introducing openend yarn. However, genuine quality denim is still manufactured from ringspun yarn,
which gives the fabric additional durability, softness as well as characteristic rough structure. Many denim brands
mark their products with labels with this feature saying R/R, OE/OE or a mixed ringspun/openend yarn variant R/OE.
|
|
And here are some technologies with the help of which world denim brands design custom jeans with a worn look.
Here is a process of chemical post procession of ready-made jeans. First of all, denim is scoured by amylase enzymes
for 10-20 minutes. Then jeans are washed with cellulase enzymes or with enzymes and pumice stones, or just with pumice-stones
(stone-washing technology) for 30-90 minutes. After this jeans are bleached with sodium hypochlorite for 10-20 minutes.
Then they are neutralized and washed in order to get rid of chloride rests for 10 minutes. Finally, jeans are softened.
All above mentioned operations are carried out at the temperature corresponding with maximal enzymes activity and making
up 50°С -60°С. The concentration of the chemicals and pH environment are strictly observed. The main stage of post-processing
is treatment with cellulase enzymes or pumice stones.
Let us take a closer look on biochemical results of the mentioned above operations. During the first stage of
tailor-made jeans scouring sizing is removed. The warp of the denim fabric is sized so that the cloth doesn’t tear.
Each thread of the warp is treated with a special glue – amyloid or polymeric substances. Denim then gets hard and
thus has to be scoured by amylase enzymes. Such enzymes can by the way be found also in human alimentary canal as
well as in saliva, where they carry out the same function – resolve amylum. Amylum is a mixture of polysaccharides –
amylase and amylopectin. Amylase resolves glycosidic connections and long polymers are then replaced by many short
connections. This helps to dissolve amylum and it is then washed away by water.
The second operation, abrasive and biochemical treatment of denim, helps to form a beautiful worn structure of custom jeans.
Thick stitches of jeans on pockets, side stitches etc. get light and dark stripes. The main surface becomes more regular;
however, sometimes jeans are worn to such extent they tear on the knees and in other places. If denim fabric is thick and hard,
pumice stones or pumice stones with enzymes are used. Biochemical and abrasive treatment of denim with cellulase is identical
to the process of amylum dissolution. Enzymes influence first of all upper layers of denim colored with indigo dye. Under the
influence of enzymes fibers’ connections with denim surface grow weak and mechanical influence of pumice stones and washing
machines is carried out. Upper layers colored with indigo come into the solution and thus white spots appear gradually. To make
this effect more lasting special substances called dispergators are used.
Posted: 12.01.2010 by Stella Tornton
Bookmark and share us!
|
Getwear® is a registered trademark of Getwear LLP
|
|
