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.


Now that you've finished reading this post, what are you going do? You should go join the Forum.

How to think in colors or Color Theory for Designers

Colors are an inseparable part for any Textile enthusiast. It is therefore, important, to understand the colors as a physical and psychological phenomena. Equally important is to understand the effect of various color patterns on an overall experience.

This site presents a  three-part series on color theory. Here the meanings behind the different color families are discussed , and some examples of how these colors are used (with a bit of analysis for each) are given.

In Part 2 there is a  talk about how hue, chroma, value, saturation, tones, tints and shades affect the way we perceive colors.

Third part discusses color pattern for designers.

The treatment of the subject is done keeping a web-designer into mind. The implications are true equally for any textile situation.

This brilliant text is written by Cameron Chapman, who is a professional Web and graphic designer with over 6 years of experience.

Now that you've finished reading this post, what are you going do? You should go join the Forum.

Chemical Identification of Silk

Please see the following link for details on chemical identification of silk.

Now that you've finished reading this post, what are you going do? You should go join the Forum.

Weighting of Silk

Weighting of Silk

Silk is sold by weight. By means of weighting the manufacturer can increase the weight of silk by 3 to 4 times. The weighting substances in the silk includes tannins such as salts or iron, tin (mostly used), chromium, sodium, magnesium and barium. Also sugar (mostly used), glucose, gelatin, glycerin and paraffins are used.

How weighting is done

Silk has great absorptive power. It can take upto 50% of tannin. Once that is applied the tannin itself can attract salts of iron and tin by another 50% without any visible indication of being changed in character. For dark colored silks, iron salts are used, for light-colored silks, tin salts are used. 

For applying weighting, the silk is first degummed. During degumming process, silk loses approximately one-fifth of the weight. This is done prior to weaving. Then it is immersed in a solution of catechu or some other substance rich in tannin. Then it is tranferred from tannin vat to iron or tin baths. After this cloth is taken out and washed in pure water. 

Effects of Weighting

Weighting causes the fabric to lose its strength as soon as the weighting is applied. Heavily weighted silk must be made into garments as soon as it is made. Spots develop in the dyes. Saltswater, perspiration and tears cause spots to be formed which seems as if the silk is eaten by acids. Sunlight also attacks weighted silk and can cause silk to fall to pieces.


How to Detected Weighting in Silk :

Weighting of silk can usually be detected by the burning test. Separate threads from the warp and the weft are set on fire with a burning match. Pure silk burns very badly and stops burning as soon as the burning match has been removed. Practically no ash is formed (less than one per cent), and the end of the fiber left unburned takes the shape of a little bulb.

Weighted fibers, when burned, leave a considerable amount of ash, and the entire thread may keep its shape after being burned. When only the filling or the warp is weighted, applying the flame to a sample of the cloth seems to consume only one set of threads, the unweighted ones, the others keeping their form because of the heavy ash content.

Now that you've finished reading this post, what are you going do? You should go join the Forum.