Ever since the inception of “blue jeans” in the 1870s as work wear for miners and cowboys, these iconic garments have evolved to become a popular item of casual wear throughout the world today. Coming in various fits to suit different tastes and fashions an important part of their appeal is the distressed look, visibly aged and worn, but still intact and functional. The process of washing improves the fastness properties of indigo-dyed denim jeans wear and in addition by altering the types of washes, various fashion looks are achieved.
In this technical bulletin we will explain how denim apparel is wet processed and highlight the parameters associated which need to be controlled in denim manufacturing and subsequent wash processes.
The “wash down” and other “post make” processes applied to denim garments are many and varied. Often the objective is to distress the garment so that it looks old and worn. This distressing gives the garments a “fashion” appeal and also softens an otherwise harsh fabric. These “post make” process can have a devastating effect on the sewing threads and therefore the seams, if care is not taken in their selection and application. After wash / post processing repair rates can be very high with harsh wash down treatments and 40% repair levels are not uncommon.
We highlight the Coats range of sewing threads that have been designed specifically to withstand the rigours of denim wet processing and which in addition can add a fashion element of their own through contrast colours and other decorative applications. For example, corespun threads such as Coats Epic and Dual Duty offer excellent all round sewing performance due to their construction and specially formulated lubrication. The high tenacity filament core provides the toughness for the majority of the most punishing applications. The cotton wrap of Dual Duty allows its colour to fade with the fabric whilst the polyester wrap of Epic retains more of its original colour.

A number of technological factors have contributed to making denim the fashion icon that it is today, including vast improvements in spinning, weaving and finishing. One of the most important parts of creating beautiful denim jeans is washing. Washing has such an important part in the denim chain because of the umpteen effects that consumers look for in their jeans.
Denim washing is an aesthetic finish that is imparted to fabric to improve the softness and comfort of the fabric. In addition, the fabric achieves a different look such as a faded or worn-out appearance. It also enhances the appeal and to provide strength. The emphasis is on comfort and softness. Fashion trends favors the broken-in look and worn/faded seams that can only be achieved through garment processing. Much of the appeal of dry denim lies in the fact that with time the fabric will fade in a manner similar to that which artificially distressed denim attempts to replicate.

Over the past few decades, different denim washing techniques have been developed and used on different materials to create a large variety of designs for trendy denim garments and jeans.
Dry denim, as opposed to washed denim, is a denim fabric that is not washed after being dyed during its production.

Much of the appeal of dry denim lies in the fact that with time the fabric will fade in a manner similar to that which artificially distressed denim attempts to replicate. With dry denim, however, such fading is affected by the body of the person who wears the jeans and the activities of their daily life. This creates what many feel to be a more natural, unique look than pre-distressed denim.
Types of Denim Washing:
Denim washing are two types. These are

1. Mechanical washes

 Stone wash
 Micro sanding
2. Chemical washes

 Denim bleaching
 Enzyme wash
 Acid wash

Author: msi.pipon