Textile Notes related to fiber, yarn, fabric knowledge, spinning, weaving, processing, projects, knitting, Indian Traditional Textiles and denim manufacturing
Saturday, 13 February 2010
How to Stonewash Better
How to Stonewash Better
Traditionally Natural pumice stone is used in denim washing process. It has the following disadvantages:
1. Residual pumice is difficult to remove from washed fabric/garment.
2. There is always a danger of damage to the equipment by overload of tumbling stones and material.This can also clog the drains and sewer lines.
Thus enzymes like cellulase are used to achieve the desirable appearance and soft handle for the fabric.
The problem with using enzymatic treatment is that the removed indigo dye can be redposited on the white yarn of the denim fabric. this process is called back staining and it can mar the look of garment.
Industrially cellulase is used along with Pumice stone for stone washing.
The cellulase can be at ph=7, when it is called the neutrual cellulase or at a pH of 5.5, when it is called the acidic cellulase.
In general the cellulase added is for 60min at 55 deg C as a percentage of the weight of the garment. It can be 3%, 6%, 9% or 12% depending upon the appearance required.
Pumice stone is generally taken as equal in weight that of the garment.
According to a study , the best stone washing ( as measured by the lightness of the sample is achieved for treatment with Neutral cellulases with pumice stone, acid cellulases with pumice stone, neutral cellulases, acid cellulases and pumice stone, in that order.
In the same order tensile strength of the sample decreases.
However, degree of back staining increases in the order of treatment with pumice stone, acid cellulases, neutral cellulases, acid cellulases with pumice stone and neutral cellulases with pumice.
which means a balance needs to be achieved- and where the effort to increase one desirable leads to increase in another undesirable one.
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