Stone Wash Enzymes

Neutral cellulase partially hydrolyses the cellulose at the denim surface, removes indigo and takes the place of pumice. Machine wear and stone residue disappear with it. Derin Kimya's stone wash family holds three products: hot, cold and blue-shade.

How does a stone wash enzyme replace pumice?

In classical stone washing, pumice abrades the denim surface mechanically and removes indigo. The result is good and the cost is heavy: the stones break up in the machine, generate dust, wear the drum and the seams, and leave stone residue in the effluent.

Neutral cellulase does the same job chemically. It partially hydrolyses the cellulose fibres at the denim surface, and with the mechanical action of the machine the loosened fibre comes away carrying indigo with it. Pumice can be dropped entirely, or kept in a small quantity to shorten the cycle.

Why neutral cellulase rather than acid cellulase?

In denim the main worry is back-staining. Indigo lifted off the surface is left free in the bath and settles on pocket lining, sewing thread and the inside of the leg. Cellulases working in the neutral range trigger less of that redeposition than acid-range ones, because the indigo dispersion is more stable at neutral pH.

The second reason is practical: holding a denim washing machine at neutral pH is easier than holding an acid window, and the trims on the garment take less punishment.

Hot type or cold type?

In denim washing the energy cost follows the cycle temperature directly. Low-temperature types shorten the heating time and reduce the shrinkage risk on made-up garments. Hot types give a more pronounced abrasion in less time, and are preferred where a high-contrast look is wanted.

Blue-shade types serve a different purpose. They affect the tone of the indigo left at the surface and leave a brighter, bluer look; they are used to pull the shade back when a wash is running yellowish or grey.

The general working window quoted in the literature for the neutral cellulase class is pH 6.0–7.5. That is a class range, not a product specification. Derin Kimya's own figures are given on each product page: pending from the client.

Where is strength loss capped?

While it abrades, cellulase also takes weight out of the fabric itself. The loss accepted in denim depends on how strong a look is wanted, but the limit shows itself at the seams: over-treated garments start to tear at the hem and the pocket mouth.

There are three control points:

1. Time. The most linear way to tune the effect: hold the dosage and step the time.
2. Drum load. An under-loaded machine works more aggressively; if the batch size changes, re-validate the recipe.
3. Deactivation. At the end of the cycle, take pH and temperature outside the enzyme's window, or the abrasion carries on through rinsing.

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